samples: bpf: refactor xdp_sample_pkts_kern with BTF-defined map #11
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
|
Master branch: 95cec14 patch https://patchwork.ozlabs.org/project/netdev/patch/20200905154137.24800-1-danieltimlee@gmail.com/ applied successfully |
|
Master branch: f9bec5d patch https://patchwork.ozlabs.org/project/netdev/patch/20200905154137.24800-1-danieltimlee@gmail.com/ applied successfully |
they moved to libbbpf, but some of the samples were missing. Instead of using the previous BPF MAP definition, this commit refactors xdp_sample_pkts_kern MAP definition with the new BTF-defined MAP format. Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com> --- samples/bpf/xdp_sample_pkts_kern.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-)
|
Master branch: bc0b5a0 patch https://patchwork.ozlabs.org/project/netdev/patch/20200905154137.24800-1-danieltimlee@gmail.com/ applied successfully |
|
At least one diff in series https://patchwork.ozlabs.org/project/netdev/list/?series=199711 expired. Closing PR. |
kernel-patches-bot
pushed a commit
that referenced
this pull request
Sep 16, 2020
…s metrics" test Linux 5.9 introduced perf test case "Parse and process metrics" and on s390 this test case always dumps core: [root@t35lp67 perf]# ./perf test -vvvv -F 67 67: Parse and process metrics : --- start --- metric expr inst_retired.any / cpu_clk_unhalted.thread for IPC parsing metric: inst_retired.any / cpu_clk_unhalted.thread Segmentation fault (core dumped) [root@t35lp67 perf]# I debugged this core dump and gdb shows this call chain: (gdb) where #0 0x000003ffabc3192a in __strnlen_c_1 () from /lib64/libc.so.6 #1 0x000003ffabc293de in strcasestr () from /lib64/libc.so.6 #2 0x0000000001102ba2 in match_metric(list=0x1e6ea20 "inst_retired.any", n=<optimized out>) at util/metricgroup.c:368 #3 find_metric (map=<optimized out>, map=<optimized out>, metric=0x1e6ea20 "inst_retired.any") at util/metricgroup.c:765 #4 __resolve_metric (ids=0x0, map=<optimized out>, metric_list=0x0, metric_no_group=<optimized out>, m=<optimized out>) at util/metricgroup.c:844 #5 resolve_metric (ids=0x0, map=0x0, metric_list=0x0, metric_no_group=<optimized out>) at util/metricgroup.c:881 #6 metricgroup__add_metric (metric=<optimized out>, metric_no_group=metric_no_group@entry=false, events=<optimized out>, events@entry=0x3ffd84fb878, metric_list=0x0, metric_list@entry=0x3ffd84fb868, map=0x0) at util/metricgroup.c:943 #7 0x00000000011034ae in metricgroup__add_metric_list (map=0x13f9828 <map>, metric_list=0x3ffd84fb868, events=0x3ffd84fb878, metric_no_group=<optimized out>, list=<optimized out>) at util/metricgroup.c:988 #8 parse_groups (perf_evlist=perf_evlist@entry=0x1e70260, str=str@entry=0x12f34b2 "IPC", metric_no_group=<optimized out>, metric_no_merge=<optimized out>, fake_pmu=fake_pmu@entry=0x1462f18 <perf_pmu.fake>, metric_events=0x3ffd84fba58, map=0x1) at util/metricgroup.c:1040 #9 0x0000000001103eb2 in metricgroup__parse_groups_test( evlist=evlist@entry=0x1e70260, map=map@entry=0x13f9828 <map>, str=str@entry=0x12f34b2 "IPC", metric_no_group=metric_no_group@entry=false, metric_no_merge=metric_no_merge@entry=false, metric_events=0x3ffd84fba58) at util/metricgroup.c:1082 #10 0x00000000010c84d8 in __compute_metric (ratio2=0x0, name2=0x0, ratio1=<synthetic pointer>, name1=0x12f34b2 "IPC", vals=0x3ffd84fbad8, name=0x12f34b2 "IPC") at tests/parse-metric.c:159 #11 compute_metric (ratio=<synthetic pointer>, vals=0x3ffd84fbad8, name=0x12f34b2 "IPC") at tests/parse-metric.c:189 #12 test_ipc () at tests/parse-metric.c:208 ..... ..... omitted many more lines This test case was added with commit 218ca91 ("perf tests: Add parse metric test for frontend metric"). When I compile with make DEBUG=y it works fine and I do not get a core dump. It turned out that the above listed function call chain worked on a struct pmu_event array which requires a trailing element with zeroes which was missing. The marco map_for_each_event() loops over that array tests for members metric_expr/metric_name/metric_group being non-NULL. Adding this element fixes the issue. Output after: [root@t35lp46 perf]# ./perf test 67 67: Parse and process metrics : Ok [root@t35lp46 perf]# Committer notes: As Ian remarks, this is not s390 specific: <quote Ian> This also shows up with address sanitizer on all architectures (perhaps change the patch title) and perhaps add a "Fixes: <commit>" tag. ================================================================= ==4718==ERROR: AddressSanitizer: global-buffer-overflow on address 0x55c93b4d59e8 at pc 0x55c93a1541e2 bp 0x7ffd24327c60 sp 0x7ffd24327c58 READ of size 8 at 0x55c93b4d59e8 thread T0 #0 0x55c93a1541e1 in find_metric tools/perf/util/metricgroup.c:764:2 #1 0x55c93a153e6c in __resolve_metric tools/perf/util/metricgroup.c:844:9 #2 0x55c93a152f18 in resolve_metric tools/perf/util/metricgroup.c:881:9 #3 0x55c93a1528db in metricgroup__add_metric tools/perf/util/metricgroup.c:943:9 #4 0x55c93a151996 in metricgroup__add_metric_list tools/perf/util/metricgroup.c:988:9 #5 0x55c93a1511b9 in parse_groups tools/perf/util/metricgroup.c:1040:8 #6 0x55c93a1513e1 in metricgroup__parse_groups_test tools/perf/util/metricgroup.c:1082:9 #7 0x55c93a0108ae in __compute_metric tools/perf/tests/parse-metric.c:159:8 #8 0x55c93a010744 in compute_metric tools/perf/tests/parse-metric.c:189:9 #9 0x55c93a00f5ee in test_ipc tools/perf/tests/parse-metric.c:208:2 #10 0x55c93a00f1e8 in test__parse_metric tools/perf/tests/parse-metric.c:345:2 #11 0x55c939fd7202 in run_test tools/perf/tests/builtin-test.c:410:9 #12 0x55c939fd6736 in test_and_print tools/perf/tests/builtin-test.c:440:9 #13 0x55c939fd58c3 in __cmd_test tools/perf/tests/builtin-test.c:661:4 #14 0x55c939fd4e02 in cmd_test tools/perf/tests/builtin-test.c:807:9 #15 0x55c939e4763d in run_builtin tools/perf/perf.c:313:11 #16 0x55c939e46475 in handle_internal_command tools/perf/perf.c:365:8 #17 0x55c939e4737e in run_argv tools/perf/perf.c:409:2 #18 0x55c939e45f7e in main tools/perf/perf.c:539:3 0x55c93b4d59e8 is located 0 bytes to the right of global variable 'pme_test' defined in 'tools/perf/tests/parse-metric.c:17:25' (0x55c93b4d54a0) of size 1352 SUMMARY: AddressSanitizer: global-buffer-overflow tools/perf/util/metricgroup.c:764:2 in find_metric Shadow bytes around the buggy address: 0x0ab9a7692ae0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x0ab9a7692af0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x0ab9a7692b00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x0ab9a7692b10: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x0ab9a7692b20: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 =>0x0ab9a7692b30: 00 00 00 00 00 00 00 00 00 00 00 00 00[f9]f9 f9 0x0ab9a7692b40: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 0x0ab9a7692b50: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 0x0ab9a7692b60: f9 f9 f9 f9 f9 f9 f9 f9 00 00 00 00 00 00 00 00 0x0ab9a7692b70: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x0ab9a7692b80: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 Shadow byte legend (one shadow byte represents 8 application bytes): Addressable: 00 Partially addressable: 01 02 03 04 05 06 07 Heap left redzone: fa Freed heap region: fd Stack left redzone: f1 Stack mid redzone: f2 Stack right redzone: f3 Stack after return: f5 Stack use after scope: f8 Global redzone: f9 Global init order: f6 Poisoned by user: f7 Container overflow: fc Array cookie: ac Intra object redzone: bb ASan internal: fe Left alloca redzone: ca Right alloca redzone: cb Shadow gap: cc </quote> I'm also adding the missing "Fixes" tag and setting just .name to NULL, as doing it that way is more compact (the compiler will zero out everything else) and the table iterators look for .name being NULL as the sentinel marking the end of the table. Fixes: 0a507af ("perf tests: Add parse metric test for ipc metric") Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Reviewed-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Acked-by: Ian Rogers <irogers@google.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Link: http://lore.kernel.org/lkml/20200825071211.16959-1-tmricht@linux.ibm.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
kernel-patches-bot
pushed a commit
that referenced
this pull request
Sep 24, 2020
The aliases were never released causing the following leaks:
Indirect leak of 1224 byte(s) in 9 object(s) allocated from:
#0 0x7feefb830628 in malloc (/lib/x86_64-linux-gnu/libasan.so.5+0x107628)
#1 0x56332c8f1b62 in __perf_pmu__new_alias util/pmu.c:322
#2 0x56332c8f401f in pmu_add_cpu_aliases_map util/pmu.c:778
#3 0x56332c792ce9 in __test__pmu_event_aliases tests/pmu-events.c:295
#4 0x56332c792ce9 in test_aliases tests/pmu-events.c:367
#5 0x56332c76a09b in run_test tests/builtin-test.c:410
#6 0x56332c76a09b in test_and_print tests/builtin-test.c:440
#7 0x56332c76ce69 in __cmd_test tests/builtin-test.c:695
#8 0x56332c76ce69 in cmd_test tests/builtin-test.c:807
#9 0x56332c7d2214 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:312
#10 0x56332c6701a8 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:364
#11 0x56332c6701a8 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:408
#12 0x56332c6701a8 in main /home/namhyung/project/linux/tools/perf/perf.c:538
#13 0x7feefb359cc9 in __libc_start_main ../csu/libc-start.c:308
Fixes: 956a783 ("perf test: Test pmu-events aliases")
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Reviewed-by: John Garry <john.garry@huawei.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20200915031819.386559-11-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
kernel-patches-bot
pushed a commit
that referenced
this pull request
Sep 24, 2020
The evsel->unit borrows a pointer of pmu event or alias instead of
owns a string. But tool event (duration_time) passes a result of
strdup() caused a leak.
It was found by ASAN during metric test:
Direct leak of 210 byte(s) in 70 object(s) allocated from:
#0 0x7fe366fca0b5 in strdup (/lib/x86_64-linux-gnu/libasan.so.5+0x920b5)
#1 0x559fbbcc6ea3 in add_event_tool util/parse-events.c:414
#2 0x559fbbcc6ea3 in parse_events_add_tool util/parse-events.c:1414
#3 0x559fbbd8474d in parse_events_parse util/parse-events.y:439
#4 0x559fbbcc95da in parse_events__scanner util/parse-events.c:2096
#5 0x559fbbcc95da in __parse_events util/parse-events.c:2141
#6 0x559fbbc28555 in check_parse_id tests/pmu-events.c:406
#7 0x559fbbc28555 in check_parse_id tests/pmu-events.c:393
#8 0x559fbbc28555 in check_parse_cpu tests/pmu-events.c:415
#9 0x559fbbc28555 in test_parsing tests/pmu-events.c:498
#10 0x559fbbc0109b in run_test tests/builtin-test.c:410
#11 0x559fbbc0109b in test_and_print tests/builtin-test.c:440
#12 0x559fbbc03e69 in __cmd_test tests/builtin-test.c:695
#13 0x559fbbc03e69 in cmd_test tests/builtin-test.c:807
#14 0x559fbbc691f4 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:312
#15 0x559fbbb071a8 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:364
#16 0x559fbbb071a8 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:408
#17 0x559fbbb071a8 in main /home/namhyung/project/linux/tools/perf/perf.c:538
#18 0x7fe366b68cc9 in __libc_start_main ../csu/libc-start.c:308
Fixes: f0fbb11 ("perf stat: Implement duration_time as a proper event")
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20200915031819.386559-6-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
kernel-patches-bot
pushed a commit
that referenced
this pull request
Sep 24, 2020
The test_generic_metric() missed to release entries in the pctx. Asan
reported following leak (and more):
Direct leak of 128 byte(s) in 1 object(s) allocated from:
#0 0x7f4c9396980e in calloc (/lib/x86_64-linux-gnu/libasan.so.5+0x10780e)
#1 0x55f7e748cc14 in hashmap_grow (/home/namhyung/project/linux/tools/perf/perf+0x90cc14)
#2 0x55f7e748d497 in hashmap__insert (/home/namhyung/project/linux/tools/perf/perf+0x90d497)
#3 0x55f7e7341667 in hashmap__set /home/namhyung/project/linux/tools/perf/util/hashmap.h:111
#4 0x55f7e7341667 in expr__add_ref util/expr.c:120
#5 0x55f7e7292436 in prepare_metric util/stat-shadow.c:783
#6 0x55f7e729556d in test_generic_metric util/stat-shadow.c:858
#7 0x55f7e712390b in compute_single tests/parse-metric.c:128
#8 0x55f7e712390b in __compute_metric tests/parse-metric.c:180
#9 0x55f7e712446d in compute_metric tests/parse-metric.c:196
#10 0x55f7e712446d in test_dcache_l2 tests/parse-metric.c:295
#11 0x55f7e712446d in test__parse_metric tests/parse-metric.c:355
#12 0x55f7e70be09b in run_test tests/builtin-test.c:410
#13 0x55f7e70be09b in test_and_print tests/builtin-test.c:440
#14 0x55f7e70c101a in __cmd_test tests/builtin-test.c:661
#15 0x55f7e70c101a in cmd_test tests/builtin-test.c:807
#16 0x55f7e7126214 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:312
#17 0x55f7e6fc41a8 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:364
#18 0x55f7e6fc41a8 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:408
#19 0x55f7e6fc41a8 in main /home/namhyung/project/linux/tools/perf/perf.c:538
#20 0x7f4c93492cc9 in __libc_start_main ../csu/libc-start.c:308
Fixes: 6d432c4 ("perf tools: Add test_generic_metric function")
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20200915031819.386559-8-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
kernel-patches-bot
pushed a commit
that referenced
this pull request
Sep 24, 2020
The metricgroup__add_metric() can find multiple match for a metric group
and it's possible to fail. Also it can fail in the middle like in
resolve_metric() even for single metric.
In those cases, the intermediate list and ids will be leaked like:
Direct leak of 3 byte(s) in 1 object(s) allocated from:
#0 0x7f4c938f40b5 in strdup (/lib/x86_64-linux-gnu/libasan.so.5+0x920b5)
#1 0x55f7e71c1bef in __add_metric util/metricgroup.c:683
#2 0x55f7e71c31d0 in add_metric util/metricgroup.c:906
#3 0x55f7e71c3844 in metricgroup__add_metric util/metricgroup.c:940
#4 0x55f7e71c488d in metricgroup__add_metric_list util/metricgroup.c:993
#5 0x55f7e71c488d in parse_groups util/metricgroup.c:1045
#6 0x55f7e71c60a4 in metricgroup__parse_groups_test util/metricgroup.c:1087
#7 0x55f7e71235ae in __compute_metric tests/parse-metric.c:164
#8 0x55f7e7124650 in compute_metric tests/parse-metric.c:196
#9 0x55f7e7124650 in test_recursion_fail tests/parse-metric.c:318
#10 0x55f7e7124650 in test__parse_metric tests/parse-metric.c:356
#11 0x55f7e70be09b in run_test tests/builtin-test.c:410
#12 0x55f7e70be09b in test_and_print tests/builtin-test.c:440
#13 0x55f7e70c101a in __cmd_test tests/builtin-test.c:661
#14 0x55f7e70c101a in cmd_test tests/builtin-test.c:807
#15 0x55f7e7126214 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:312
#16 0x55f7e6fc41a8 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:364
#17 0x55f7e6fc41a8 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:408
#18 0x55f7e6fc41a8 in main /home/namhyung/project/linux/tools/perf/perf.c:538
#19 0x7f4c93492cc9 in __libc_start_main ../csu/libc-start.c:308
Fixes: 83de0b7 ("perf metric: Collect referenced metrics in struct metric_ref_node")
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20200915031819.386559-9-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
kernel-patches-bot
pushed a commit
that referenced
this pull request
Sep 24, 2020
The following leaks were detected by ASAN:
Indirect leak of 360 byte(s) in 9 object(s) allocated from:
#0 0x7fecc305180e in calloc (/lib/x86_64-linux-gnu/libasan.so.5+0x10780e)
#1 0x560578f6dce5 in perf_pmu__new_format util/pmu.c:1333
#2 0x560578f752fc in perf_pmu_parse util/pmu.y:59
#3 0x560578f6a8b7 in perf_pmu__format_parse util/pmu.c:73
#4 0x560578e07045 in test__pmu tests/pmu.c:155
#5 0x560578de109b in run_test tests/builtin-test.c:410
#6 0x560578de109b in test_and_print tests/builtin-test.c:440
#7 0x560578de401a in __cmd_test tests/builtin-test.c:661
#8 0x560578de401a in cmd_test tests/builtin-test.c:807
#9 0x560578e49354 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:312
#10 0x560578ce71a8 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:364
#11 0x560578ce71a8 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:408
#12 0x560578ce71a8 in main /home/namhyung/project/linux/tools/perf/perf.c:538
#13 0x7fecc2b7acc9 in __libc_start_main ../csu/libc-start.c:308
Fixes: cff7f95 ("perf tests: Move pmu tests into separate object")
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20200915031819.386559-12-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
kernel-patches-bot
pushed a commit
that referenced
this pull request
Sep 24, 2020
Ido Schimmel says: ==================== mlxsw: Refactor headroom management Petr says: On Spectrum, port buffers, also called port headroom, is where packets are stored while they are parsed and the forwarding decision is being made. For lossless traffic flows, in case shared buffer admission is not allowed, headroom is also where to put the extra traffic received before the sent PAUSE takes effect. Another aspect of the port headroom is the so called internal buffer, which is used for egress mirroring. Linux supports two DCB interfaces related to the headroom: dcbnl_setbuffer for configuration, and dcbnl_getbuffer for inspection. In order to make it possible to implement these interfaces, it is first necessary to clean up headroom handling, which is currently strewn in several places in the driver. The end goal is an architecture whereby it is possible to take a copy of the current configuration, adjust parameters, and then hand the proposed configuration over to the system to implement it. When everything works, the proposed configuration is accepted and saved. First, this centralizes the reconfiguration handling to one function, which takes care of coordinating buffer size changes and priority map changes to avoid introducing drops. Second, the fact that the configuration is all in one place makes it easy to keep a backup and handle error path rollbacks, which were previously hard to understand. Patch #1 introduces struct mlxsw_sp_hdroom, which will keep port headroom configuration. Patch #2 unifies handling of delay provision between PFC and PAUSE. From now on, delay is to be measured in bytes of extra space, and will not include MTU. PFC handler sets the delay directly from the parameter it gets through the DCB interface. For PAUSE, MLXSW_SP_PAUSE_DELAY is converted to have the same meaning. In patches #3-#5, MTU, lossiness and priorities are gradually moved over to struct mlxsw_sp_hdroom. In patches #6-#11, handling of buffer resizing and priority maps is moved from spectrum.c and spectrum_dcb.c to spectrum_buffers.c. The API is gradually adapted so that struct mlxsw_sp_hdroom becomes the main interface through which the various clients express how the headroom should be configured. Patch #12 is a small cleanup that the previous transformation made possible. In patch #13, the port init code becomes a boring client of the headroom code, instead of rolling its own thing. Patches #14 and #15 move handling of internal mirroring buffer to the new headroom code as well. Previously, this code was in the SPAN module. This patchset converts the SPAN module to another boring client of the headroom code. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
kernel-patches-bot
pushed a commit
that referenced
this pull request
Nov 6, 2020
Andrii Nakryiko says: ==================== This patch set adds support for generating and deduplicating split BTF. This is an enhancement to the BTF, which allows to designate one BTF as the "base BTF" (e.g., vmlinux BTF), and one or more other BTFs as "split BTF" (e.g., kernel module BTF), which are building upon and extending base BTF with extra types and strings. Once loaded, split BTF appears as a single unified BTF superset of base BTF, with continuous and transparent numbering scheme. This allows all the existing users of BTF to work correctly and stay agnostic to the base/split BTFs composition. The only difference is in how to instantiate split BTF: it requires base BTF to be alread instantiated and passed to btf__new_xxx_split() or btf__parse_xxx_split() "constructors" explicitly. This split approach is necessary if we are to have a reasonably-sized kernel module BTFs. By deduping each kernel module's BTF individually, resulting module BTFs contain copies of a lot of kernel types that are already present in vmlinux BTF. Even those single copies result in a big BTF size bloat. On my kernel configuration with 700 modules built, non-split BTF approach results in 115MBs of BTFs across all modules. With split BTF deduplication approach, total size is down to 5.2MBs total, which is on part with vmlinux BTF (at around 4MBs). This seems reasonable and practical. As to why we'd need kernel module BTFs, that should be pretty obvious to anyone using BPF at this point, as it allows all the BTF-powered features to be used with kernel modules: tp_btf, fentry/fexit/fmod_ret, lsm, bpf_iter, etc. This patch set is a pre-requisite to adding split BTF support to pahole, which is a prerequisite to integrating split BTF into the Linux kernel build setup to generate BTF for kernel modules. The latter will come as a follow-up patch series once this series makes it to the libbpf and pahole makes use of it. Patch #4 introduces necessary basic support for split BTF into libbpf APIs. Patch #8 implements minimal changes to BTF dedup algorithm to allow deduplicating split BTFs. Patch #11 adds extra -B flag to bpftool to allow to specify the path to base BTF for cases when one wants to dump or inspect split BTF. All the rest are refactorings, clean ups, bug fixes and selftests. v1->v2: - addressed Song's feedback. ==================== Signed-off-by: Alexei Starovoitov <ast@kernel.org>
kernel-patches-bot
pushed a commit
that referenced
this pull request
Nov 16, 2020
Ido Schimmel says: ==================== nexthop: Add support for nexthop objects offload This patch set adds support for nexthop objects offload with a dummy implementation over netdevsim. mlxsw support will be added later. The general idea is very similar to route offload in that notifications are sent whenever nexthop objects are changed. A listener can veto the change and the error will be communicated to user space with extack. To keep listeners as simple as possible, they not only receive notifications for the nexthop object that is changed, but also for all the other objects affected by this change. For example, when a single nexthop is replaced, a replace notification is sent for the single nexthop, but also for all the nexthop groups this nexthop is member in. This relieves listeners from the need to track such dependencies. To simplify things further for listeners, the notification info does not contain the raw nexthop data structures (e.g., 'struct nexthop'), but less complex data structures into which the raw data structures are parsed into. Tested with a new selftest over netdevsim and with fib_nexthops.sh: Tests passed: 164 Tests failed: 0 Patch set overview: Patches #1-#4 introduce the aforementioned data structures and convert existing listeners (i.e., the VXLAN driver) to use them. Patches #5-#6 add a new RTNH_F_TRAP flag and the ability to set it and RTNH_F_OFFLOAD on nexthops. This flag is used by netdevsim for testing purposes and will also be used by mlxsw. These flags are consistent with the existing RTM_F_OFFLOAD and RTM_F_TRAP flags. Patches #7-#14 gradually add the new nexthop notifications. Patches #15-#18 add a dummy implementation for nexthop offload over netdevsim and a selftest to exercise both good and bad flows. Changes since RFC [1]: Patch #1: s/is_encap/has_encap/ Patch #3: Add a blank line in __nh_notifier_single_info_init() Patch #5: Reword commit message Patch #6: s/nexthop_hw_flags_set/nexthop_set_hw_flags/ Patch #7: Reword commit message Patch #11: Allocate extack on the stack Follow-up patch sets: selftests: forwarding: Add nexthop objects tests mlxsw: Preparations for nexthop objects support - part 1/2 mlxsw: Preparations for nexthop objects support - part 2/2 mlxsw: Add support for nexthop objects mlxsw: Add support for blackhole nexthops mlxsw: Update adjacency index more efficiently [1] https://lore.kernel.org/netdev/20200908091037.2709823-1-idosch@idosch.org/ ==================== Link: https://lore.kernel.org/r/20201104133040.1125369-1-idosch@idosch.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
kernel-patches-bot
pushed a commit
that referenced
this pull request
Nov 20, 2020
This fix is for a failure that occurred in the DWARF unwind perf test.
Stack unwinders may probe memory when looking for frames.
Memory sanitizer will poison and track uninitialized memory on the
stack, and on the heap if the value is copied to the heap.
This can lead to false memory sanitizer failures for the use of an
uninitialized value.
Avoid this problem by removing the poison on the copied stack.
The full msan failure with track origins looks like:
==2168==WARNING: MemorySanitizer: use-of-uninitialized-value
#0 0x559ceb10755b in handle_cfi elfutils/libdwfl/frame_unwind.c:648:8
#1 0x559ceb105448 in __libdwfl_frame_unwind elfutils/libdwfl/frame_unwind.c:741:4
#2 0x559ceb0ece90 in dwfl_thread_getframes elfutils/libdwfl/dwfl_frame.c:435:7
#3 0x559ceb0ec6b7 in get_one_thread_frames_cb elfutils/libdwfl/dwfl_frame.c:379:10
#4 0x559ceb0ec6b7 in get_one_thread_cb elfutils/libdwfl/dwfl_frame.c:308:17
#5 0x559ceb0ec6b7 in dwfl_getthreads elfutils/libdwfl/dwfl_frame.c:283:17
#6 0x559ceb0ec6b7 in getthread elfutils/libdwfl/dwfl_frame.c:354:14
#7 0x559ceb0ec6b7 in dwfl_getthread_frames elfutils/libdwfl/dwfl_frame.c:388:10
#8 0x559ceaff6ae6 in unwind__get_entries tools/perf/util/unwind-libdw.c:236:8
#9 0x559ceabc9dbc in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:111:8
#10 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26
#11 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0)
#12 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2
#13 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9
#14 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9
#15 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8
#16 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9
#17 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9
#18 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4
#19 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9
#20 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11
#21 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8
#22 0x559cea95fbce in run_argv tools/perf/perf.c:409:2
#23 0x559cea95fbce in main tools/perf/perf.c:539:3
Uninitialized value was stored to memory at
#0 0x559ceb106acf in __libdwfl_frame_reg_set elfutils/libdwfl/frame_unwind.c:77:22
#1 0x559ceb106acf in handle_cfi elfutils/libdwfl/frame_unwind.c:627:13
#2 0x559ceb105448 in __libdwfl_frame_unwind elfutils/libdwfl/frame_unwind.c:741:4
#3 0x559ceb0ece90 in dwfl_thread_getframes elfutils/libdwfl/dwfl_frame.c:435:7
#4 0x559ceb0ec6b7 in get_one_thread_frames_cb elfutils/libdwfl/dwfl_frame.c:379:10
#5 0x559ceb0ec6b7 in get_one_thread_cb elfutils/libdwfl/dwfl_frame.c:308:17
#6 0x559ceb0ec6b7 in dwfl_getthreads elfutils/libdwfl/dwfl_frame.c:283:17
#7 0x559ceb0ec6b7 in getthread elfutils/libdwfl/dwfl_frame.c:354:14
#8 0x559ceb0ec6b7 in dwfl_getthread_frames elfutils/libdwfl/dwfl_frame.c:388:10
#9 0x559ceaff6ae6 in unwind__get_entries tools/perf/util/unwind-libdw.c:236:8
#10 0x559ceabc9dbc in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:111:8
#11 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26
#12 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0)
#13 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2
#14 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9
#15 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9
#16 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8
#17 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9
#18 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9
#19 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4
#20 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9
#21 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11
#22 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8
#23 0x559cea95fbce in run_argv tools/perf/perf.c:409:2
#24 0x559cea95fbce in main tools/perf/perf.c:539:3
Uninitialized value was stored to memory at
#0 0x559ceb106a54 in handle_cfi elfutils/libdwfl/frame_unwind.c:613:9
#1 0x559ceb105448 in __libdwfl_frame_unwind elfutils/libdwfl/frame_unwind.c:741:4
#2 0x559ceb0ece90 in dwfl_thread_getframes elfutils/libdwfl/dwfl_frame.c:435:7
#3 0x559ceb0ec6b7 in get_one_thread_frames_cb elfutils/libdwfl/dwfl_frame.c:379:10
#4 0x559ceb0ec6b7 in get_one_thread_cb elfutils/libdwfl/dwfl_frame.c:308:17
#5 0x559ceb0ec6b7 in dwfl_getthreads elfutils/libdwfl/dwfl_frame.c:283:17
#6 0x559ceb0ec6b7 in getthread elfutils/libdwfl/dwfl_frame.c:354:14
#7 0x559ceb0ec6b7 in dwfl_getthread_frames elfutils/libdwfl/dwfl_frame.c:388:10
#8 0x559ceaff6ae6 in unwind__get_entries tools/perf/util/unwind-libdw.c:236:8
#9 0x559ceabc9dbc in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:111:8
#10 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26
#11 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0)
#12 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2
#13 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9
#14 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9
#15 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8
#16 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9
#17 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9
#18 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4
#19 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9
#20 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11
#21 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8
#22 0x559cea95fbce in run_argv tools/perf/perf.c:409:2
#23 0x559cea95fbce in main tools/perf/perf.c:539:3
Uninitialized value was stored to memory at
#0 0x559ceaff8800 in memory_read tools/perf/util/unwind-libdw.c:156:10
#1 0x559ceb10f053 in expr_eval elfutils/libdwfl/frame_unwind.c:501:13
#2 0x559ceb1060cc in handle_cfi elfutils/libdwfl/frame_unwind.c:603:18
#3 0x559ceb105448 in __libdwfl_frame_unwind elfutils/libdwfl/frame_unwind.c:741:4
#4 0x559ceb0ece90 in dwfl_thread_getframes elfutils/libdwfl/dwfl_frame.c:435:7
#5 0x559ceb0ec6b7 in get_one_thread_frames_cb elfutils/libdwfl/dwfl_frame.c:379:10
#6 0x559ceb0ec6b7 in get_one_thread_cb elfutils/libdwfl/dwfl_frame.c:308:17
#7 0x559ceb0ec6b7 in dwfl_getthreads elfutils/libdwfl/dwfl_frame.c:283:17
#8 0x559ceb0ec6b7 in getthread elfutils/libdwfl/dwfl_frame.c:354:14
#9 0x559ceb0ec6b7 in dwfl_getthread_frames elfutils/libdwfl/dwfl_frame.c:388:10
#10 0x559ceaff6ae6 in unwind__get_entries tools/perf/util/unwind-libdw.c:236:8
#11 0x559ceabc9dbc in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:111:8
#12 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26
#13 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0)
#14 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2
#15 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9
#16 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9
#17 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8
#18 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9
#19 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9
#20 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4
#21 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9
#22 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11
#23 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8
#24 0x559cea95fbce in run_argv tools/perf/perf.c:409:2
#25 0x559cea95fbce in main tools/perf/perf.c:539:3
Uninitialized value was stored to memory at
#0 0x559cea9027d9 in __msan_memcpy llvm/llvm-project/compiler-rt/lib/msan/msan_interceptors.cpp:1558:3
#1 0x559cea9d2185 in sample_ustack tools/perf/arch/x86/tests/dwarf-unwind.c:41:2
#2 0x559cea9d202c in test__arch_unwind_sample tools/perf/arch/x86/tests/dwarf-unwind.c:72:9
#3 0x559ceabc9cbd in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:106:6
#4 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26
#5 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0)
#6 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2
#7 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9
#8 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9
#9 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8
#10 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9
#11 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9
#12 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4
#13 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9
#14 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11
#15 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8
#16 0x559cea95fbce in run_argv tools/perf/perf.c:409:2
#17 0x559cea95fbce in main tools/perf/perf.c:539:3
Uninitialized value was created by an allocation of 'bf' in the stack frame of function 'perf_event__synthesize_mmap_events'
#0 0x559ceafc5f60 in perf_event__synthesize_mmap_events tools/perf/util/synthetic-events.c:445
SUMMARY: MemorySanitizer: use-of-uninitialized-value elfutils/libdwfl/frame_unwind.c:648:8 in handle_cfi
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: clang-built-linux@googlegroups.com
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sandeep Dasgupta <sdasgup@google.com>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20201113182053.754625-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
kernel-patches-bot
pushed a commit
that referenced
this pull request
Dec 4, 2020
Currently 'while (q->queued > 0)' loop was removed from mt76u_stop_tx() code. This causes crash on device removal as we try to cleanup empty queue: [ 96.495571] kernel BUG at include/linux/skbuff.h:2297! [ 96.498983] invalid opcode: 0000 [#1] SMP PTI [ 96.501162] CPU: 3 PID: 27 Comm: kworker/3:0 Not tainted 5.10.0-rc5+ #11 [ 96.502754] Hardware name: LENOVO 20DGS08H00/20DGS08H00, BIOS J5ET48WW (1.19 ) 08/27/2015 [ 96.504378] Workqueue: usb_hub_wq hub_event [ 96.505983] RIP: 0010:skb_pull+0x2d/0x30 [ 96.507576] Code: 00 00 8b 47 70 39 c6 77 1e 29 f0 89 47 70 3b 47 74 72 17 48 8b 87 c8 00 00 00 89 f6 48 01 f0 48 89 87 c8 00 00 00 c3 31 c0 c3 <0f> 0b 90 0f 1f 44 00 00 53 48 89 fb 48 8b bf c8 00 00 00 8b 43 70 [ 96.509296] RSP: 0018:ffffb11b801639b8 EFLAGS: 00010287 [ 96.511038] RAX: 000000001c6939ed RBX: ffffb11b801639f8 RCX: 0000000000000000 [ 96.512964] RDX: ffffb11b801639f8 RSI: 0000000000000018 RDI: ffff90c64e4fb800 [ 96.514710] RBP: ffff90c654551ee0 R08: ffff90c652bce7a8 R09: ffffb11b80163728 [ 96.516450] R10: 0000000000000001 R11: 0000000000000001 R12: ffff90c64e4fb800 [ 96.519749] R13: 0000000000000010 R14: 0000000000000020 R15: ffff90c64e352ce8 [ 96.523455] FS: 0000000000000000(0000) GS:ffff90c96eec0000(0000) knlGS:0000000000000000 [ 96.527171] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 96.530900] CR2: 0000242556f18288 CR3: 0000000146a10002 CR4: 00000000003706e0 [ 96.534678] Call Trace: [ 96.538418] mt76x02u_tx_complete_skb+0x1f/0x50 [mt76x02_usb] [ 96.542231] mt76_queue_tx_complete+0x23/0x50 [mt76] [ 96.546028] mt76u_stop_tx.cold+0x71/0xa2 [mt76_usb] [ 96.549797] mt76x0u_stop+0x2f/0x90 [mt76x0u] [ 96.553638] drv_stop+0x33/0xd0 [mac80211] [ 96.557449] ieee80211_do_stop+0x558/0x860 [mac80211] [ 96.561262] ? dev_deactivate_many+0x298/0x2d0 [ 96.565101] ieee80211_stop+0x16/0x20 [mac80211] Fix that by adding while loop again. We need loop, not just single check, to clean all pending entries. Additionally move mt76_worker_disable/enable after !mt76_has_tx_pending() as we want to tx_worker to run to process tx queues, while we wait for exactly that. I was a bit worried about accessing q->queued without lock, but mt76_worker_disable() -> kthread_park() should assure this value will be seen updated on other cpus. Fixes: fe5b5ab ("mt76: unify queue tx cleanup code") Signed-off-by: Stanislaw Gruszka <stf_xl@wp.pl> Acked-by: Felix Fietkau <nbd@nbd.name> Signed-off-by: Kalle Valo <kvalo@codeaurora.org> Link: https://lore.kernel.org/r/20201126125520.72912-1-stf_xl@wp.pl
kernel-patches-bot
pushed a commit
that referenced
this pull request
Dec 15, 2020
Ido Schimmel says:
====================
mlxsw: Add support for Q-in-VNI
This patch set adds support for Q-in-VNI over Spectrum-{2,3} ASICs.
Q-in-VNI is like regular VxLAN encapsulation with the sole difference
that overlay packets can contain a VLAN tag. In Linux, this is achieved
by adding the VxLAN device to a 802.1ad bridge instead of a 802.1q
bridge.
From mlxsw perspective, Q-in-VNI support entails two main changes:
1. An outer VLAN tag should always be pushed to the overlay packet
during decapsulation
2. The EtherType used during decapsulation should be 802.1ad (0x88a8)
instead of the default 802.1q (0x8100)
Patch set overview:
Patches #1-#3 add required device registers and fields
Patch #4 performs small refactoring to allow code re-use
Patches #5-#7 make the EtherType used during decapsulation a property of
the tunnel port (i.e., VxLAN). This leads to the driver vetoing
configurations in which VxLAN devices are member in both 802.1ad and
802.1q/802.1d bridges. Will be handled in the future by determining the
overlay EtherType on the egress port instead
Patch #8 adds support for Q-in-VNI for Spectrum-2 and newer ASICs
Patches #9-#10 veto Q-in-VNI for Spectrum-1 ASICs due to some hardware
limitations. Can be worked around, but decided not to support it for now
Patch #11 adjusts mlxsw to stop vetoing addition of VXLAN devices to
802.1ad bridges
Patch #12 adds a generic forwarding test that can be used with both veth
pairs and physical ports with a loopback
Patch #13 adds a test to make sure mlxsw vetoes unsupported Q-in-VNI
configurations
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
kernel-patches-bot
pushed a commit
that referenced
this pull request
Dec 15, 2020
Ido Schimmel says:
====================
mlxsw: Introduce initial XM router support
This patch set implements initial eXtended Mezzanine (XM) router
support.
The XM is an external device connected to the Spectrum-{2,3} ASICs using
dedicated Ethernet ports. Its purpose is to increase the number of
routes that can be offloaded to hardware. This is achieved by having the
ASIC act as a cache that refers cache misses to the XM where the FIB is
stored and LPM lookup is performed.
Future patch sets will add more sophisticated cache flushing and
selftests that utilize cache counters on the ASIC, which we plan to
expose via devlink-metric [1].
Patch set overview:
Patches #1-#2 add registers to insert/remove routes to/from the XM and
to enable/disable it. Patch #3 utilizes these registers in order to
implement XM-specific router low-level operations.
Patches #4-#5 query from firmware the availability of the XM and the
local ports that are used to connect the ASIC to the XM, so that netdevs
will not be created for them.
Patches #6-#8 initialize the XM by configuring its cache parameters.
Patch #9-#10 implement cache management, so that LPM lookup will be
correctly cached in the ASIC.
Patches #11-#13 implement cache flushing, so that routes
insertions/removals to/from the XM will flush the affected entries in
the cache.
Patch #14 configures the ASIC to allocate half of its memory for the
cache, so that room will be left for other entries (e.g., FDBs,
neighbours).
Patch #15 starts using the XM for IPv4 route offload, when available.
[1] https://lore.kernel.org/netdev/20200817125059.193242-1-idosch@idosch.org/
====================
Link: https://lore.kernel.org/r/20201214113041.2789043-1-idosch@idosch.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
kernel-patches-bot
pushed a commit
that referenced
this pull request
Mar 10, 2021
Calling btrfs_qgroup_reserve_meta_prealloc from btrfs_delayed_inode_reserve_metadata can result in flushing delalloc while holding a transaction and delayed node locks. This is deadlock prone. In the past multiple commits: * ae5e070 ("btrfs: qgroup: don't try to wait flushing if we're already holding a transaction") * 6f23277 ("btrfs: qgroup: don't commit transaction when we already hold the handle") Tried to solve various aspects of this but this was always a whack-a-mole game. Unfortunately those 2 fixes don't solve a deadlock scenario involving btrfs_delayed_node::mutex. Namely, one thread can call btrfs_dirty_inode as a result of reading a file and modifying its atime: PID: 6963 TASK: ffff8c7f3f94c000 CPU: 2 COMMAND: "test" #0 __schedule at ffffffffa529e07d #1 schedule at ffffffffa529e4ff #2 schedule_timeout at ffffffffa52a1bdd #3 wait_for_completion at ffffffffa529eeea <-- sleeps with delayed node mutex held #4 start_delalloc_inodes at ffffffffc0380db5 #5 btrfs_start_delalloc_snapshot at ffffffffc0393836 #6 try_flush_qgroup at ffffffffc03f04b2 #7 __btrfs_qgroup_reserve_meta at ffffffffc03f5bb6 <-- tries to reserve space and starts delalloc inodes. #8 btrfs_delayed_update_inode at ffffffffc03e31aa <-- acquires delayed node mutex #9 btrfs_update_inode at ffffffffc0385ba8 #10 btrfs_dirty_inode at ffffffffc038627b <-- TRANSACTIION OPENED #11 touch_atime at ffffffffa4cf0000 #12 generic_file_read_iter at ffffffffa4c1f123 #13 new_sync_read at ffffffffa4ccdc8a #14 vfs_read at ffffffffa4cd0849 #15 ksys_read at ffffffffa4cd0bd1 #16 do_syscall_64 at ffffffffa4a052eb #17 entry_SYSCALL_64_after_hwframe at ffffffffa540008c This will cause an asynchronous work to flush the delalloc inodes to happen which can try to acquire the same delayed_node mutex: PID: 455 TASK: ffff8c8085fa4000 CPU: 5 COMMAND: "kworker/u16:30" #0 __schedule at ffffffffa529e07d #1 schedule at ffffffffa529e4ff #2 schedule_preempt_disabled at ffffffffa529e80a #3 __mutex_lock at ffffffffa529fdcb <-- goes to sleep, never wakes up. #4 btrfs_delayed_update_inode at ffffffffc03e3143 <-- tries to acquire the mutex #5 btrfs_update_inode at ffffffffc0385ba8 <-- this is the same inode that pid 6963 is holding #6 cow_file_range_inline.constprop.78 at ffffffffc0386be7 #7 cow_file_range at ffffffffc03879c1 #8 btrfs_run_delalloc_range at ffffffffc038894c #9 writepage_delalloc at ffffffffc03a3c8f #10 __extent_writepage at ffffffffc03a4c01 #11 extent_write_cache_pages at ffffffffc03a500b #12 extent_writepages at ffffffffc03a6de2 #13 do_writepages at ffffffffa4c277eb #14 __filemap_fdatawrite_range at ffffffffa4c1e5bb #15 btrfs_run_delalloc_work at ffffffffc0380987 <-- starts running delayed nodes #16 normal_work_helper at ffffffffc03b706c #17 process_one_work at ffffffffa4aba4e4 #18 worker_thread at ffffffffa4aba6fd #19 kthread at ffffffffa4ac0a3d #20 ret_from_fork at ffffffffa54001ff To fully address those cases the complete fix is to never issue any flushing while holding the transaction or the delayed node lock. This patch achieves it by calling qgroup_reserve_meta directly which will either succeed without flushing or will fail and return -EDQUOT. In the latter case that return value is going to be propagated to btrfs_dirty_inode which will fallback to start a new transaction. That's fine as the majority of time we expect the inode will have BTRFS_DELAYED_NODE_INODE_DIRTY flag set which will result in directly copying the in-memory state. Fixes: c53e965 ("btrfs: qgroup: try to flush qgroup space when we get -EDQUOT") CC: stable@vger.kernel.org # 5.10+ Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
kernel-patches-bot
pushed a commit
that referenced
this pull request
Mar 10, 2021
The evlist has the maps with its own refcounts so we don't need to set
the pointers to NULL. Otherwise following error was reported by Asan.
# perf test -v 4
4: Read samples using the mmap interface :
--- start ---
test child forked, pid 139782
mmap size 528384B
=================================================================
==139782==ERROR: LeakSanitizer: detected memory leaks
Direct leak of 40 byte(s) in 1 object(s) allocated from:
#0 0x7f1f76daee8f in __interceptor_malloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:145
#1 0x564ba21a0fea in cpu_map__trim_new /home/namhyung/project/linux/tools/lib/perf/cpumap.c:79
#2 0x564ba21a1a0f in perf_cpu_map__read /home/namhyung/project/linux/tools/lib/perf/cpumap.c:149
#3 0x564ba21a21cf in cpu_map__read_all_cpu_map /home/namhyung/project/linux/tools/lib/perf/cpumap.c:166
#4 0x564ba21a21cf in perf_cpu_map__new /home/namhyung/project/linux/tools/lib/perf/cpumap.c:181
#5 0x564ba1e48298 in test__basic_mmap tests/mmap-basic.c:55
#6 0x564ba1e278fb in run_test tests/builtin-test.c:428
#7 0x564ba1e278fb in test_and_print tests/builtin-test.c:458
#8 0x564ba1e29a53 in __cmd_test tests/builtin-test.c:679
#9 0x564ba1e29a53 in cmd_test tests/builtin-test.c:825
#10 0x564ba1e95cb4 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313
#11 0x564ba1d1fa88 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365
#12 0x564ba1d1fa88 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409
#13 0x564ba1d1fa88 in main /home/namhyung/project/linux/tools/perf/perf.c:539
#14 0x7f1f768e4d09 in __libc_start_main ../csu/libc-start.c:308
...
test child finished with 1
---- end ----
Read samples using the mmap interface: FAILED!
failed to open shell test directory: /home/namhyung/libexec/perf-core/tests/shell
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Link: https://lore.kernel.org/r/20210301140409.184570-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
kernel-patches-daemon-bpf bot
pushed a commit
that referenced
this pull request
Jan 9, 2025
During the update procedure, when overwrite element in a pre-allocated
htab, the freeing of old_element is protected by the bucket lock. The
reason why the bucket lock is necessary is that the old_element has
already been stashed in htab->extra_elems after alloc_htab_elem()
returns. If freeing the old_element after the bucket lock is unlocked,
the stashed element may be reused by concurrent update procedure and the
freeing of old_element will run concurrently with the reuse of the
old_element. However, the invocation of check_and_free_fields() may
acquire a spin-lock which violates the lockdep rule because its caller
has already held a raw-spin-lock (bucket lock). The following warning
will be reported when such race happens:
BUG: scheduling while atomic: test_progs/676/0x00000003
3 locks held by test_progs/676:
#0: ffffffff864b0240 (rcu_read_lock_trace){....}-{0:0}, at: bpf_prog_test_run_syscall+0x2c0/0x830
#1: ffff88810e961188 (&htab->lockdep_key){....}-{2:2}, at: htab_map_update_elem+0x306/0x1500
#2: ffff8881f4eac1b8 (&base->softirq_expiry_lock){....}-{2:2}, at: hrtimer_cancel_wait_running+0xe9/0x1b0
Modules linked in: bpf_testmod(O)
Preemption disabled at:
[<ffffffff817837a3>] htab_map_update_elem+0x293/0x1500
CPU: 0 UID: 0 PID: 676 Comm: test_progs Tainted: G ... 6.12.0+ #11
Tainted: [W]=WARN, [O]=OOT_MODULE
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)...
Call Trace:
<TASK>
dump_stack_lvl+0x57/0x70
dump_stack+0x10/0x20
__schedule_bug+0x120/0x170
__schedule+0x300c/0x4800
schedule_rtlock+0x37/0x60
rtlock_slowlock_locked+0x6d9/0x54c0
rt_spin_lock+0x168/0x230
hrtimer_cancel_wait_running+0xe9/0x1b0
hrtimer_cancel+0x24/0x30
bpf_timer_delete_work+0x1d/0x40
bpf_timer_cancel_and_free+0x5e/0x80
bpf_obj_free_fields+0x262/0x4a0
check_and_free_fields+0x1d0/0x280
htab_map_update_elem+0x7fc/0x1500
bpf_prog_9f90bc20768e0cb9_overwrite_cb+0x3f/0x43
bpf_prog_ea601c4649694dbd_overwrite_timer+0x5d/0x7e
bpf_prog_test_run_syscall+0x322/0x830
__sys_bpf+0x135d/0x3ca0
__x64_sys_bpf+0x75/0xb0
x64_sys_call+0x1b5/0xa10
do_syscall_64+0x3b/0xc0
entry_SYSCALL_64_after_hwframe+0x4b/0x53
...
</TASK>
It seems feasible to break the reuse and refill of per-cpu extra_elems
into two independent parts: reuse the per-cpu extra_elems with bucket
lock being held and refill the old_element as per-cpu extra_elems after
the bucket lock is unlocked. However, it will make the concurrent
overwrite procedures on the same CPU return unexpected -E2BIG error when
the map is full.
Therefore, the patch fixes the lock problem by breaking the cancelling
of bpf_timer into two steps:
1) use hrtimer_try_to_cancel() and check its return value
2) if the timer is running, use hrtimer_cancel() through a kworker to
cancel it again
Considering that the current implementation of hrtimer_cancel() will try
to spin on current CPU or acquire a being held softirq_expiry_lock
when the current timer is running, these steps above are reasonable.
However, it also has downside. When the timer is running, the cancelling
of the timer is delayed when releasing the last map uref. The delay is
also fixable (e.g., break the cancelling of bpf timer into two parts:
one part in locked scope, another one in unlocked scope), so it can be
revised later if necessary.
It is a bit hard to decide the right fix tag. One reason is that the
problem depends on PREEMPT_RT which is enabled in v6.12. Considering the
softirq_expiry_lock lock exists since v5.4 and bpf_timer is introduced
in v5.15, the bpf_timer commit is used in the fixes tag and an extra
depends-on tag is added to state the dependency on PREEMPT_RT.
Fixes: b00628b ("bpf: Introduce bpf timers.")
Depends-on: v6.12 with PREEMPT_RT enabled
Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Closes: https://lore.kernel.org/bpf/20241106084527.4gPrMnHt@linutronix.de
Signed-off-by: Hou Tao <houtao1@huawei.com>
kernel-patches-daemon-bpf bot
pushed a commit
that referenced
this pull request
Jan 10, 2025
During the update procedure, when overwrite element in a pre-allocated
htab, the freeing of old_element is protected by the bucket lock. The
reason why the bucket lock is necessary is that the old_element has
already been stashed in htab->extra_elems after alloc_htab_elem()
returns. If freeing the old_element after the bucket lock is unlocked,
the stashed element may be reused by concurrent update procedure and the
freeing of old_element will run concurrently with the reuse of the
old_element. However, the invocation of check_and_free_fields() may
acquire a spin-lock which violates the lockdep rule because its caller
has already held a raw-spin-lock (bucket lock). The following warning
will be reported when such race happens:
BUG: scheduling while atomic: test_progs/676/0x00000003
3 locks held by test_progs/676:
#0: ffffffff864b0240 (rcu_read_lock_trace){....}-{0:0}, at: bpf_prog_test_run_syscall+0x2c0/0x830
#1: ffff88810e961188 (&htab->lockdep_key){....}-{2:2}, at: htab_map_update_elem+0x306/0x1500
#2: ffff8881f4eac1b8 (&base->softirq_expiry_lock){....}-{2:2}, at: hrtimer_cancel_wait_running+0xe9/0x1b0
Modules linked in: bpf_testmod(O)
Preemption disabled at:
[<ffffffff817837a3>] htab_map_update_elem+0x293/0x1500
CPU: 0 UID: 0 PID: 676 Comm: test_progs Tainted: G ... 6.12.0+ #11
Tainted: [W]=WARN, [O]=OOT_MODULE
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)...
Call Trace:
<TASK>
dump_stack_lvl+0x57/0x70
dump_stack+0x10/0x20
__schedule_bug+0x120/0x170
__schedule+0x300c/0x4800
schedule_rtlock+0x37/0x60
rtlock_slowlock_locked+0x6d9/0x54c0
rt_spin_lock+0x168/0x230
hrtimer_cancel_wait_running+0xe9/0x1b0
hrtimer_cancel+0x24/0x30
bpf_timer_delete_work+0x1d/0x40
bpf_timer_cancel_and_free+0x5e/0x80
bpf_obj_free_fields+0x262/0x4a0
check_and_free_fields+0x1d0/0x280
htab_map_update_elem+0x7fc/0x1500
bpf_prog_9f90bc20768e0cb9_overwrite_cb+0x3f/0x43
bpf_prog_ea601c4649694dbd_overwrite_timer+0x5d/0x7e
bpf_prog_test_run_syscall+0x322/0x830
__sys_bpf+0x135d/0x3ca0
__x64_sys_bpf+0x75/0xb0
x64_sys_call+0x1b5/0xa10
do_syscall_64+0x3b/0xc0
entry_SYSCALL_64_after_hwframe+0x4b/0x53
...
</TASK>
It seems feasible to break the reuse and refill of per-cpu extra_elems
into two independent parts: reuse the per-cpu extra_elems with bucket
lock being held and refill the old_element as per-cpu extra_elems after
the bucket lock is unlocked. However, it will make the concurrent
overwrite procedures on the same CPU return unexpected -E2BIG error when
the map is full.
Therefore, the patch fixes the lock problem by breaking the cancelling
of bpf_timer into two steps:
1) use hrtimer_try_to_cancel() and check its return value
2) if the timer is running, use hrtimer_cancel() through a kworker to
cancel it again
Considering that the current implementation of hrtimer_cancel() will try
to spin on current CPU or acquire a being held softirq_expiry_lock
when the current timer is running, these steps above are reasonable.
However, it also has downside. When the timer is running, the cancelling
of the timer is delayed when releasing the last map uref. The delay is
also fixable (e.g., break the cancelling of bpf timer into two parts:
one part in locked scope, another one in unlocked scope), so it can be
revised later if necessary.
It is a bit hard to decide the right fix tag. One reason is that the
problem depends on PREEMPT_RT which is enabled in v6.12. Considering the
softirq_expiry_lock lock exists since v5.4 and bpf_timer is introduced
in v5.15, the bpf_timer commit is used in the fixes tag and an extra
depends-on tag is added to state the dependency on PREEMPT_RT.
Fixes: b00628b ("bpf: Introduce bpf timers.")
Depends-on: v6.12 with PREEMPT_RT enabled
Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Closes: https://lore.kernel.org/bpf/20241106084527.4gPrMnHt@linutronix.de
Signed-off-by: Hou Tao <houtao1@huawei.com>
kernel-patches-daemon-bpf bot
pushed a commit
that referenced
this pull request
Jan 10, 2025
During the update procedure, when overwrite element in a pre-allocated
htab, the freeing of old_element is protected by the bucket lock. The
reason why the bucket lock is necessary is that the old_element has
already been stashed in htab->extra_elems after alloc_htab_elem()
returns. If freeing the old_element after the bucket lock is unlocked,
the stashed element may be reused by concurrent update procedure and the
freeing of old_element will run concurrently with the reuse of the
old_element. However, the invocation of check_and_free_fields() may
acquire a spin-lock which violates the lockdep rule because its caller
has already held a raw-spin-lock (bucket lock). The following warning
will be reported when such race happens:
BUG: scheduling while atomic: test_progs/676/0x00000003
3 locks held by test_progs/676:
#0: ffffffff864b0240 (rcu_read_lock_trace){....}-{0:0}, at: bpf_prog_test_run_syscall+0x2c0/0x830
#1: ffff88810e961188 (&htab->lockdep_key){....}-{2:2}, at: htab_map_update_elem+0x306/0x1500
#2: ffff8881f4eac1b8 (&base->softirq_expiry_lock){....}-{2:2}, at: hrtimer_cancel_wait_running+0xe9/0x1b0
Modules linked in: bpf_testmod(O)
Preemption disabled at:
[<ffffffff817837a3>] htab_map_update_elem+0x293/0x1500
CPU: 0 UID: 0 PID: 676 Comm: test_progs Tainted: G ... 6.12.0+ #11
Tainted: [W]=WARN, [O]=OOT_MODULE
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)...
Call Trace:
<TASK>
dump_stack_lvl+0x57/0x70
dump_stack+0x10/0x20
__schedule_bug+0x120/0x170
__schedule+0x300c/0x4800
schedule_rtlock+0x37/0x60
rtlock_slowlock_locked+0x6d9/0x54c0
rt_spin_lock+0x168/0x230
hrtimer_cancel_wait_running+0xe9/0x1b0
hrtimer_cancel+0x24/0x30
bpf_timer_delete_work+0x1d/0x40
bpf_timer_cancel_and_free+0x5e/0x80
bpf_obj_free_fields+0x262/0x4a0
check_and_free_fields+0x1d0/0x280
htab_map_update_elem+0x7fc/0x1500
bpf_prog_9f90bc20768e0cb9_overwrite_cb+0x3f/0x43
bpf_prog_ea601c4649694dbd_overwrite_timer+0x5d/0x7e
bpf_prog_test_run_syscall+0x322/0x830
__sys_bpf+0x135d/0x3ca0
__x64_sys_bpf+0x75/0xb0
x64_sys_call+0x1b5/0xa10
do_syscall_64+0x3b/0xc0
entry_SYSCALL_64_after_hwframe+0x4b/0x53
...
</TASK>
It seems feasible to break the reuse and refill of per-cpu extra_elems
into two independent parts: reuse the per-cpu extra_elems with bucket
lock being held and refill the old_element as per-cpu extra_elems after
the bucket lock is unlocked. However, it will make the concurrent
overwrite procedures on the same CPU return unexpected -E2BIG error when
the map is full.
Therefore, the patch fixes the lock problem by breaking the cancelling
of bpf_timer into two steps:
1) use hrtimer_try_to_cancel() and check its return value
2) if the timer is running, use hrtimer_cancel() through a kworker to
cancel it again
Considering that the current implementation of hrtimer_cancel() will try
to spin on current CPU or acquire a being held softirq_expiry_lock
when the current timer is running, these steps above are reasonable.
However, it also has downside. When the timer is running, the cancelling
of the timer is delayed when releasing the last map uref. The delay is
also fixable (e.g., break the cancelling of bpf timer into two parts:
one part in locked scope, another one in unlocked scope), so it can be
revised later if necessary.
It is a bit hard to decide the right fix tag. One reason is that the
problem depends on PREEMPT_RT which is enabled in v6.12. Considering the
softirq_expiry_lock lock exists since v5.4 and bpf_timer is introduced
in v5.15, the bpf_timer commit is used in the fixes tag and an extra
depends-on tag is added to state the dependency on PREEMPT_RT.
Fixes: b00628b ("bpf: Introduce bpf timers.")
Depends-on: v6.12 with PREEMPT_RT enabled
Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Closes: https://lore.kernel.org/bpf/20241106084527.4gPrMnHt@linutronix.de
Signed-off-by: Hou Tao <houtao1@huawei.com>
kernel-patches-daemon-bpf bot
pushed a commit
that referenced
this pull request
Jan 10, 2025
During the update procedure, when overwrite element in a pre-allocated
htab, the freeing of old_element is protected by the bucket lock. The
reason why the bucket lock is necessary is that the old_element has
already been stashed in htab->extra_elems after alloc_htab_elem()
returns. If freeing the old_element after the bucket lock is unlocked,
the stashed element may be reused by concurrent update procedure and the
freeing of old_element will run concurrently with the reuse of the
old_element. However, the invocation of check_and_free_fields() may
acquire a spin-lock which violates the lockdep rule because its caller
has already held a raw-spin-lock (bucket lock). The following warning
will be reported when such race happens:
BUG: scheduling while atomic: test_progs/676/0x00000003
3 locks held by test_progs/676:
#0: ffffffff864b0240 (rcu_read_lock_trace){....}-{0:0}, at: bpf_prog_test_run_syscall+0x2c0/0x830
#1: ffff88810e961188 (&htab->lockdep_key){....}-{2:2}, at: htab_map_update_elem+0x306/0x1500
#2: ffff8881f4eac1b8 (&base->softirq_expiry_lock){....}-{2:2}, at: hrtimer_cancel_wait_running+0xe9/0x1b0
Modules linked in: bpf_testmod(O)
Preemption disabled at:
[<ffffffff817837a3>] htab_map_update_elem+0x293/0x1500
CPU: 0 UID: 0 PID: 676 Comm: test_progs Tainted: G ... 6.12.0+ #11
Tainted: [W]=WARN, [O]=OOT_MODULE
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)...
Call Trace:
<TASK>
dump_stack_lvl+0x57/0x70
dump_stack+0x10/0x20
__schedule_bug+0x120/0x170
__schedule+0x300c/0x4800
schedule_rtlock+0x37/0x60
rtlock_slowlock_locked+0x6d9/0x54c0
rt_spin_lock+0x168/0x230
hrtimer_cancel_wait_running+0xe9/0x1b0
hrtimer_cancel+0x24/0x30
bpf_timer_delete_work+0x1d/0x40
bpf_timer_cancel_and_free+0x5e/0x80
bpf_obj_free_fields+0x262/0x4a0
check_and_free_fields+0x1d0/0x280
htab_map_update_elem+0x7fc/0x1500
bpf_prog_9f90bc20768e0cb9_overwrite_cb+0x3f/0x43
bpf_prog_ea601c4649694dbd_overwrite_timer+0x5d/0x7e
bpf_prog_test_run_syscall+0x322/0x830
__sys_bpf+0x135d/0x3ca0
__x64_sys_bpf+0x75/0xb0
x64_sys_call+0x1b5/0xa10
do_syscall_64+0x3b/0xc0
entry_SYSCALL_64_after_hwframe+0x4b/0x53
...
</TASK>
It seems feasible to break the reuse and refill of per-cpu extra_elems
into two independent parts: reuse the per-cpu extra_elems with bucket
lock being held and refill the old_element as per-cpu extra_elems after
the bucket lock is unlocked. However, it will make the concurrent
overwrite procedures on the same CPU return unexpected -E2BIG error when
the map is full.
Therefore, the patch fixes the lock problem by breaking the cancelling
of bpf_timer into two steps:
1) use hrtimer_try_to_cancel() and check its return value
2) if the timer is running, use hrtimer_cancel() through a kworker to
cancel it again
Considering that the current implementation of hrtimer_cancel() will try
to spin on current CPU or acquire a being held softirq_expiry_lock
when the current timer is running, these steps above are reasonable.
However, it also has downside. When the timer is running, the cancelling
of the timer is delayed when releasing the last map uref. The delay is
also fixable (e.g., break the cancelling of bpf timer into two parts:
one part in locked scope, another one in unlocked scope), so it can be
revised later if necessary.
It is a bit hard to decide the right fix tag. One reason is that the
problem depends on PREEMPT_RT which is enabled in v6.12. Considering the
softirq_expiry_lock lock exists since v5.4 and bpf_timer is introduced
in v5.15, the bpf_timer commit is used in the fixes tag and an extra
depends-on tag is added to state the dependency on PREEMPT_RT.
Fixes: b00628b ("bpf: Introduce bpf timers.")
Depends-on: v6.12 with PREEMPT_RT enabled
Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Closes: https://lore.kernel.org/bpf/20241106084527.4gPrMnHt@linutronix.de
Signed-off-by: Hou Tao <houtao1@huawei.com>
kernel-patches-daemon-bpf bot
pushed a commit
that referenced
this pull request
Jan 10, 2025
During the update procedure, when overwrite element in a pre-allocated
htab, the freeing of old_element is protected by the bucket lock. The
reason why the bucket lock is necessary is that the old_element has
already been stashed in htab->extra_elems after alloc_htab_elem()
returns. If freeing the old_element after the bucket lock is unlocked,
the stashed element may be reused by concurrent update procedure and the
freeing of old_element will run concurrently with the reuse of the
old_element. However, the invocation of check_and_free_fields() may
acquire a spin-lock which violates the lockdep rule because its caller
has already held a raw-spin-lock (bucket lock). The following warning
will be reported when such race happens:
BUG: scheduling while atomic: test_progs/676/0x00000003
3 locks held by test_progs/676:
#0: ffffffff864b0240 (rcu_read_lock_trace){....}-{0:0}, at: bpf_prog_test_run_syscall+0x2c0/0x830
#1: ffff88810e961188 (&htab->lockdep_key){....}-{2:2}, at: htab_map_update_elem+0x306/0x1500
#2: ffff8881f4eac1b8 (&base->softirq_expiry_lock){....}-{2:2}, at: hrtimer_cancel_wait_running+0xe9/0x1b0
Modules linked in: bpf_testmod(O)
Preemption disabled at:
[<ffffffff817837a3>] htab_map_update_elem+0x293/0x1500
CPU: 0 UID: 0 PID: 676 Comm: test_progs Tainted: G ... 6.12.0+ #11
Tainted: [W]=WARN, [O]=OOT_MODULE
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)...
Call Trace:
<TASK>
dump_stack_lvl+0x57/0x70
dump_stack+0x10/0x20
__schedule_bug+0x120/0x170
__schedule+0x300c/0x4800
schedule_rtlock+0x37/0x60
rtlock_slowlock_locked+0x6d9/0x54c0
rt_spin_lock+0x168/0x230
hrtimer_cancel_wait_running+0xe9/0x1b0
hrtimer_cancel+0x24/0x30
bpf_timer_delete_work+0x1d/0x40
bpf_timer_cancel_and_free+0x5e/0x80
bpf_obj_free_fields+0x262/0x4a0
check_and_free_fields+0x1d0/0x280
htab_map_update_elem+0x7fc/0x1500
bpf_prog_9f90bc20768e0cb9_overwrite_cb+0x3f/0x43
bpf_prog_ea601c4649694dbd_overwrite_timer+0x5d/0x7e
bpf_prog_test_run_syscall+0x322/0x830
__sys_bpf+0x135d/0x3ca0
__x64_sys_bpf+0x75/0xb0
x64_sys_call+0x1b5/0xa10
do_syscall_64+0x3b/0xc0
entry_SYSCALL_64_after_hwframe+0x4b/0x53
...
</TASK>
It seems feasible to break the reuse and refill of per-cpu extra_elems
into two independent parts: reuse the per-cpu extra_elems with bucket
lock being held and refill the old_element as per-cpu extra_elems after
the bucket lock is unlocked. However, it will make the concurrent
overwrite procedures on the same CPU return unexpected -E2BIG error when
the map is full.
Therefore, the patch fixes the lock problem by breaking the cancelling
of bpf_timer into two steps:
1) use hrtimer_try_to_cancel() and check its return value
2) if the timer is running, use hrtimer_cancel() through a kworker to
cancel it again
Considering that the current implementation of hrtimer_cancel() will try
to spin on current CPU or acquire a being held softirq_expiry_lock
when the current timer is running, these steps above are reasonable.
However, it also has downside. When the timer is running, the cancelling
of the timer is delayed when releasing the last map uref. The delay is
also fixable (e.g., break the cancelling of bpf timer into two parts:
one part in locked scope, another one in unlocked scope), so it can be
revised later if necessary.
It is a bit hard to decide the right fix tag. One reason is that the
problem depends on PREEMPT_RT which is enabled in v6.12. Considering the
softirq_expiry_lock lock exists since v5.4 and bpf_timer is introduced
in v5.15, the bpf_timer commit is used in the fixes tag and an extra
depends-on tag is added to state the dependency on PREEMPT_RT.
Fixes: b00628b ("bpf: Introduce bpf timers.")
Depends-on: v6.12 with PREEMPT_RT enabled
Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Closes: https://lore.kernel.org/bpf/20241106084527.4gPrMnHt@linutronix.de
Signed-off-by: Hou Tao <houtao1@huawei.com>
kernel-patches-daemon-bpf bot
pushed a commit
that referenced
this pull request
Jan 11, 2025
During the update procedure, when overwrite element in a pre-allocated
htab, the freeing of old_element is protected by the bucket lock. The
reason why the bucket lock is necessary is that the old_element has
already been stashed in htab->extra_elems after alloc_htab_elem()
returns. If freeing the old_element after the bucket lock is unlocked,
the stashed element may be reused by concurrent update procedure and the
freeing of old_element will run concurrently with the reuse of the
old_element. However, the invocation of check_and_free_fields() may
acquire a spin-lock which violates the lockdep rule because its caller
has already held a raw-spin-lock (bucket lock). The following warning
will be reported when such race happens:
BUG: scheduling while atomic: test_progs/676/0x00000003
3 locks held by test_progs/676:
#0: ffffffff864b0240 (rcu_read_lock_trace){....}-{0:0}, at: bpf_prog_test_run_syscall+0x2c0/0x830
#1: ffff88810e961188 (&htab->lockdep_key){....}-{2:2}, at: htab_map_update_elem+0x306/0x1500
#2: ffff8881f4eac1b8 (&base->softirq_expiry_lock){....}-{2:2}, at: hrtimer_cancel_wait_running+0xe9/0x1b0
Modules linked in: bpf_testmod(O)
Preemption disabled at:
[<ffffffff817837a3>] htab_map_update_elem+0x293/0x1500
CPU: 0 UID: 0 PID: 676 Comm: test_progs Tainted: G ... 6.12.0+ #11
Tainted: [W]=WARN, [O]=OOT_MODULE
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)...
Call Trace:
<TASK>
dump_stack_lvl+0x57/0x70
dump_stack+0x10/0x20
__schedule_bug+0x120/0x170
__schedule+0x300c/0x4800
schedule_rtlock+0x37/0x60
rtlock_slowlock_locked+0x6d9/0x54c0
rt_spin_lock+0x168/0x230
hrtimer_cancel_wait_running+0xe9/0x1b0
hrtimer_cancel+0x24/0x30
bpf_timer_delete_work+0x1d/0x40
bpf_timer_cancel_and_free+0x5e/0x80
bpf_obj_free_fields+0x262/0x4a0
check_and_free_fields+0x1d0/0x280
htab_map_update_elem+0x7fc/0x1500
bpf_prog_9f90bc20768e0cb9_overwrite_cb+0x3f/0x43
bpf_prog_ea601c4649694dbd_overwrite_timer+0x5d/0x7e
bpf_prog_test_run_syscall+0x322/0x830
__sys_bpf+0x135d/0x3ca0
__x64_sys_bpf+0x75/0xb0
x64_sys_call+0x1b5/0xa10
do_syscall_64+0x3b/0xc0
entry_SYSCALL_64_after_hwframe+0x4b/0x53
...
</TASK>
It seems feasible to break the reuse and refill of per-cpu extra_elems
into two independent parts: reuse the per-cpu extra_elems with bucket
lock being held and refill the old_element as per-cpu extra_elems after
the bucket lock is unlocked. However, it will make the concurrent
overwrite procedures on the same CPU return unexpected -E2BIG error when
the map is full.
Therefore, the patch fixes the lock problem by breaking the cancelling
of bpf_timer into two steps:
1) use hrtimer_try_to_cancel() and check its return value
2) if the timer is running, use hrtimer_cancel() through a kworker to
cancel it again
Considering that the current implementation of hrtimer_cancel() will try
to spin on current CPU or acquire a being held softirq_expiry_lock
when the current timer is running, these steps above are reasonable.
However, it also has downside. When the timer is running, the cancelling
of the timer is delayed when releasing the last map uref. The delay is
also fixable (e.g., break the cancelling of bpf timer into two parts:
one part in locked scope, another one in unlocked scope), so it can be
revised later if necessary.
It is a bit hard to decide the right fix tag. One reason is that the
problem depends on PREEMPT_RT which is enabled in v6.12. Considering the
softirq_expiry_lock lock exists since v5.4 and bpf_timer is introduced
in v5.15, the bpf_timer commit is used in the fixes tag and an extra
depends-on tag is added to state the dependency on PREEMPT_RT.
Fixes: b00628b ("bpf: Introduce bpf timers.")
Depends-on: v6.12 with PREEMPT_RT enabled
Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Closes: https://lore.kernel.org/bpf/20241106084527.4gPrMnHt@linutronix.de
Signed-off-by: Hou Tao <houtao1@huawei.com>
kernel-patches-daemon-bpf bot
pushed a commit
that referenced
this pull request
Jan 13, 2025
During the update procedure, when overwrite element in a pre-allocated
htab, the freeing of old_element is protected by the bucket lock. The
reason why the bucket lock is necessary is that the old_element has
already been stashed in htab->extra_elems after alloc_htab_elem()
returns. If freeing the old_element after the bucket lock is unlocked,
the stashed element may be reused by concurrent update procedure and the
freeing of old_element will run concurrently with the reuse of the
old_element. However, the invocation of check_and_free_fields() may
acquire a spin-lock which violates the lockdep rule because its caller
has already held a raw-spin-lock (bucket lock). The following warning
will be reported when such race happens:
BUG: scheduling while atomic: test_progs/676/0x00000003
3 locks held by test_progs/676:
#0: ffffffff864b0240 (rcu_read_lock_trace){....}-{0:0}, at: bpf_prog_test_run_syscall+0x2c0/0x830
#1: ffff88810e961188 (&htab->lockdep_key){....}-{2:2}, at: htab_map_update_elem+0x306/0x1500
#2: ffff8881f4eac1b8 (&base->softirq_expiry_lock){....}-{2:2}, at: hrtimer_cancel_wait_running+0xe9/0x1b0
Modules linked in: bpf_testmod(O)
Preemption disabled at:
[<ffffffff817837a3>] htab_map_update_elem+0x293/0x1500
CPU: 0 UID: 0 PID: 676 Comm: test_progs Tainted: G ... 6.12.0+ #11
Tainted: [W]=WARN, [O]=OOT_MODULE
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)...
Call Trace:
<TASK>
dump_stack_lvl+0x57/0x70
dump_stack+0x10/0x20
__schedule_bug+0x120/0x170
__schedule+0x300c/0x4800
schedule_rtlock+0x37/0x60
rtlock_slowlock_locked+0x6d9/0x54c0
rt_spin_lock+0x168/0x230
hrtimer_cancel_wait_running+0xe9/0x1b0
hrtimer_cancel+0x24/0x30
bpf_timer_delete_work+0x1d/0x40
bpf_timer_cancel_and_free+0x5e/0x80
bpf_obj_free_fields+0x262/0x4a0
check_and_free_fields+0x1d0/0x280
htab_map_update_elem+0x7fc/0x1500
bpf_prog_9f90bc20768e0cb9_overwrite_cb+0x3f/0x43
bpf_prog_ea601c4649694dbd_overwrite_timer+0x5d/0x7e
bpf_prog_test_run_syscall+0x322/0x830
__sys_bpf+0x135d/0x3ca0
__x64_sys_bpf+0x75/0xb0
x64_sys_call+0x1b5/0xa10
do_syscall_64+0x3b/0xc0
entry_SYSCALL_64_after_hwframe+0x4b/0x53
...
</TASK>
It seems feasible to break the reuse and refill of per-cpu extra_elems
into two independent parts: reuse the per-cpu extra_elems with bucket
lock being held and refill the old_element as per-cpu extra_elems after
the bucket lock is unlocked. However, it will make the concurrent
overwrite procedures on the same CPU return unexpected -E2BIG error when
the map is full.
Therefore, the patch fixes the lock problem by breaking the cancelling
of bpf_timer into two steps:
1) use hrtimer_try_to_cancel() and check its return value
2) if the timer is running, use hrtimer_cancel() through a kworker to
cancel it again
Considering that the current implementation of hrtimer_cancel() will try
to spin on current CPU or acquire a being held softirq_expiry_lock
when the current timer is running, these steps above are reasonable.
However, it also has downside. When the timer is running, the cancelling
of the timer is delayed when releasing the last map uref. The delay is
also fixable (e.g., break the cancelling of bpf timer into two parts:
one part in locked scope, another one in unlocked scope), so it can be
revised later if necessary.
It is a bit hard to decide the right fix tag. One reason is that the
problem depends on PREEMPT_RT which is enabled in v6.12. Considering the
softirq_expiry_lock lock exists since v5.4 and bpf_timer is introduced
in v5.15, the bpf_timer commit is used in the fixes tag and an extra
depends-on tag is added to state the dependency on PREEMPT_RT.
Fixes: b00628b ("bpf: Introduce bpf timers.")
Depends-on: v6.12 with PREEMPT_RT enabled
Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Closes: https://lore.kernel.org/bpf/20241106084527.4gPrMnHt@linutronix.de
Signed-off-by: Hou Tao <houtao1@huawei.com>
kernel-patches-daemon-bpf bot
pushed a commit
that referenced
this pull request
Jan 14, 2025
Under PREEMPT_RT, it is not safe to use GPF_ATOMIC kmalloc when
preemption or irq is disabled. The following warning is reported when
running test_progs under PREEMPT_RT:
BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48
in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 675, name: test_progs
preempt_count: 1, expected: 0
RCU nest depth: 0, expected: 0
2 locks held by test_progs/675:
#0: ffffffff864b0240 (rcu_read_lock_trace){....}-{0:0}, at: bpf_prog_test_run_syscall+0x2c0/0x830
#1: ffff8881f4ec40c8 ((&c->lock)){....}-{2:2}, at: ___slab_alloc+0xbc/0x1280
Preemption disabled at:
[<ffffffff8175ae2b>] __bpf_async_init+0xbb/0xb10
CPU: 1 UID: 0 PID: 675 Comm: test_progs Tainted: G O 6.12.0+ #11
Tainted: [O]=OOT_MODULE
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) ...
Call Trace:
<TASK>
dump_stack_lvl+0x57/0x70
dump_stack+0x10/0x20
__might_resched+0x337/0x4d0
rt_spin_lock+0xd4/0x230
___slab_alloc+0xbc/0x1280
__slab_alloc.isra.0+0x5d/0xa0
__kmalloc_node_noprof+0xf7/0x4f0
bpf_map_kmalloc_node+0xf5/0x6b0
__bpf_async_init+0x20e/0xb10
bpf_timer_init+0x30/0x40
bpf_prog_c7e2dc9ff3d5ba62_start_cb+0x55/0x85
bpf_prog_4eb421be69ae82fa_start_timer+0x5d/0x7e
bpf_prog_test_run_syscall+0x322/0x830
__sys_bpf+0x135d/0x3ca0
__x64_sys_bpf+0x75/0xb0
x64_sys_call+0x1b5/0xa10
do_syscall_64+0x3b/0xc0
entry_SYSCALL_64_after_hwframe+0x4b/0x53
Fix the problem by using bpf_global_ma to allocate bpf_async_cb when
PREEMPT_RT is enabled. The reason for still using kmalloc for
no-PREEMPT_RT case is that bpf_global_ma doesn't support accouting the
allocated memory to specific memcg. Also doing the memory allocation
before invoking __bpf_spin_lock_irqsave() to reduce the possibility of
-ENOMEM for bpf_global_ma.
Signed-off-by: Hou Tao <houtao1@huawei.com>
kernel-patches-daemon-bpf bot
pushed a commit
that referenced
this pull request
Jan 14, 2025
During the update procedure, when overwrite element in a pre-allocated
htab, the freeing of old_element is protected by the bucket lock. The
reason why the bucket lock is necessary is that the old_element has
already been stashed in htab->extra_elems after alloc_htab_elem()
returns. If freeing the old_element after the bucket lock is unlocked,
the stashed element may be reused by concurrent update procedure and the
freeing of old_element will run concurrently with the reuse of the
old_element. However, the invocation of check_and_free_fields() may
acquire a spin-lock which violates the lockdep rule because its caller
has already held a raw-spin-lock (bucket lock). The following warning
will be reported when such race happens:
BUG: scheduling while atomic: test_progs/676/0x00000003
3 locks held by test_progs/676:
#0: ffffffff864b0240 (rcu_read_lock_trace){....}-{0:0}, at: bpf_prog_test_run_syscall+0x2c0/0x830
#1: ffff88810e961188 (&htab->lockdep_key){....}-{2:2}, at: htab_map_update_elem+0x306/0x1500
#2: ffff8881f4eac1b8 (&base->softirq_expiry_lock){....}-{2:2}, at: hrtimer_cancel_wait_running+0xe9/0x1b0
Modules linked in: bpf_testmod(O)
Preemption disabled at:
[<ffffffff817837a3>] htab_map_update_elem+0x293/0x1500
CPU: 0 UID: 0 PID: 676 Comm: test_progs Tainted: G ... 6.12.0+ #11
Tainted: [W]=WARN, [O]=OOT_MODULE
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)...
Call Trace:
<TASK>
dump_stack_lvl+0x57/0x70
dump_stack+0x10/0x20
__schedule_bug+0x120/0x170
__schedule+0x300c/0x4800
schedule_rtlock+0x37/0x60
rtlock_slowlock_locked+0x6d9/0x54c0
rt_spin_lock+0x168/0x230
hrtimer_cancel_wait_running+0xe9/0x1b0
hrtimer_cancel+0x24/0x30
bpf_timer_delete_work+0x1d/0x40
bpf_timer_cancel_and_free+0x5e/0x80
bpf_obj_free_fields+0x262/0x4a0
check_and_free_fields+0x1d0/0x280
htab_map_update_elem+0x7fc/0x1500
bpf_prog_9f90bc20768e0cb9_overwrite_cb+0x3f/0x43
bpf_prog_ea601c4649694dbd_overwrite_timer+0x5d/0x7e
bpf_prog_test_run_syscall+0x322/0x830
__sys_bpf+0x135d/0x3ca0
__x64_sys_bpf+0x75/0xb0
x64_sys_call+0x1b5/0xa10
do_syscall_64+0x3b/0xc0
entry_SYSCALL_64_after_hwframe+0x4b/0x53
...
</TASK>
It seems feasible to break the reuse and refill of per-cpu extra_elems
into two independent parts: reuse the per-cpu extra_elems with bucket
lock being held and refill the old_element as per-cpu extra_elems after
the bucket lock is unlocked. However, it will make the concurrent
overwrite procedures on the same CPU return unexpected -E2BIG error when
the map is full.
Therefore, the patch fixes the lock problem by breaking the cancelling
of bpf_timer into two steps:
1) use hrtimer_try_to_cancel() and check its return value
2) if the timer is running, use hrtimer_cancel() through a kworker to
cancel it again
Considering that the current implementation of hrtimer_cancel() will try
to spin on current CPU or acquire a being held softirq_expiry_lock
when the current timer is running, these steps above are reasonable.
However, it also has downside. When the timer is running, the cancelling
of the timer is delayed when releasing the last map uref. The delay is
also fixable (e.g., break the cancelling of bpf timer into two parts:
one part in locked scope, another one in unlocked scope), so it can be
revised later if necessary.
It is a bit hard to decide the right fix tag. One reason is that the
problem depends on PREEMPT_RT which is enabled in v6.12. Considering the
softirq_expiry_lock lock exists since v5.4 and bpf_timer is introduced
in v5.15, the bpf_timer commit is used in the fixes tag and an extra
depends-on tag is added to state the dependency on PREEMPT_RT.
Fixes: b00628b ("bpf: Introduce bpf timers.")
Depends-on: v6.12 with PREEMPT_RT enabled
Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Closes: https://lore.kernel.org/bpf/20241106084527.4gPrMnHt@linutronix.de
Signed-off-by: Hou Tao <houtao1@huawei.com>
kernel-patches-daemon-bpf bot
pushed a commit
that referenced
this pull request
Jan 14, 2025
Under PREEMPT_RT, it is not safe to use GPF_ATOMIC kmalloc when
preemption or irq is disabled. The following warning is reported when
running test_progs under PREEMPT_RT:
BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48
in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 675, name: test_progs
preempt_count: 1, expected: 0
RCU nest depth: 0, expected: 0
2 locks held by test_progs/675:
#0: ffffffff864b0240 (rcu_read_lock_trace){....}-{0:0}, at: bpf_prog_test_run_syscall+0x2c0/0x830
#1: ffff8881f4ec40c8 ((&c->lock)){....}-{2:2}, at: ___slab_alloc+0xbc/0x1280
Preemption disabled at:
[<ffffffff8175ae2b>] __bpf_async_init+0xbb/0xb10
CPU: 1 UID: 0 PID: 675 Comm: test_progs Tainted: G O 6.12.0+ #11
Tainted: [O]=OOT_MODULE
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) ...
Call Trace:
<TASK>
dump_stack_lvl+0x57/0x70
dump_stack+0x10/0x20
__might_resched+0x337/0x4d0
rt_spin_lock+0xd4/0x230
___slab_alloc+0xbc/0x1280
__slab_alloc.isra.0+0x5d/0xa0
__kmalloc_node_noprof+0xf7/0x4f0
bpf_map_kmalloc_node+0xf5/0x6b0
__bpf_async_init+0x20e/0xb10
bpf_timer_init+0x30/0x40
bpf_prog_c7e2dc9ff3d5ba62_start_cb+0x55/0x85
bpf_prog_4eb421be69ae82fa_start_timer+0x5d/0x7e
bpf_prog_test_run_syscall+0x322/0x830
__sys_bpf+0x135d/0x3ca0
__x64_sys_bpf+0x75/0xb0
x64_sys_call+0x1b5/0xa10
do_syscall_64+0x3b/0xc0
entry_SYSCALL_64_after_hwframe+0x4b/0x53
Fix the problem by using bpf_global_ma to allocate bpf_async_cb when
PREEMPT_RT is enabled. The reason for still using kmalloc for
no-PREEMPT_RT case is that bpf_global_ma doesn't support accouting the
allocated memory to specific memcg. Also doing the memory allocation
before invoking __bpf_spin_lock_irqsave() to reduce the possibility of
-ENOMEM for bpf_global_ma.
Signed-off-by: Hou Tao <houtao1@huawei.com>
kernel-patches-daemon-bpf bot
pushed a commit
that referenced
this pull request
Jan 15, 2025
Under PREEMPT_RT, it is not safe to use GPF_ATOMIC kmalloc when
preemption or irq is disabled. The following warning is reported when
running test_progs under PREEMPT_RT:
BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48
in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 675, name: test_progs
preempt_count: 1, expected: 0
RCU nest depth: 0, expected: 0
2 locks held by test_progs/675:
#0: ffffffff864b0240 (rcu_read_lock_trace){....}-{0:0}, at: bpf_prog_test_run_syscall+0x2c0/0x830
#1: ffff8881f4ec40c8 ((&c->lock)){....}-{2:2}, at: ___slab_alloc+0xbc/0x1280
Preemption disabled at:
[<ffffffff8175ae2b>] __bpf_async_init+0xbb/0xb10
CPU: 1 UID: 0 PID: 675 Comm: test_progs Tainted: G O 6.12.0+ #11
Tainted: [O]=OOT_MODULE
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) ...
Call Trace:
<TASK>
dump_stack_lvl+0x57/0x70
dump_stack+0x10/0x20
__might_resched+0x337/0x4d0
rt_spin_lock+0xd4/0x230
___slab_alloc+0xbc/0x1280
__slab_alloc.isra.0+0x5d/0xa0
__kmalloc_node_noprof+0xf7/0x4f0
bpf_map_kmalloc_node+0xf5/0x6b0
__bpf_async_init+0x20e/0xb10
bpf_timer_init+0x30/0x40
bpf_prog_c7e2dc9ff3d5ba62_start_cb+0x55/0x85
bpf_prog_4eb421be69ae82fa_start_timer+0x5d/0x7e
bpf_prog_test_run_syscall+0x322/0x830
__sys_bpf+0x135d/0x3ca0
__x64_sys_bpf+0x75/0xb0
x64_sys_call+0x1b5/0xa10
do_syscall_64+0x3b/0xc0
entry_SYSCALL_64_after_hwframe+0x4b/0x53
Fix the problem by using bpf_global_ma to allocate bpf_async_cb when
PREEMPT_RT is enabled. The reason for still using kmalloc for
no-PREEMPT_RT case is that bpf_global_ma doesn't support accouting the
allocated memory to specific memcg. Also doing the memory allocation
before invoking __bpf_spin_lock_irqsave() to reduce the possibility of
-ENOMEM for bpf_global_ma.
Signed-off-by: Hou Tao <houtao1@huawei.com>
kernel-patches-daemon-bpf bot
pushed a commit
that referenced
this pull request
Jan 15, 2025
Under PREEMPT_RT, it is not safe to use GPF_ATOMIC kmalloc when
preemption or irq is disabled. The following warning is reported when
running test_progs under PREEMPT_RT:
BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48
in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 675, name: test_progs
preempt_count: 1, expected: 0
RCU nest depth: 0, expected: 0
2 locks held by test_progs/675:
#0: ffffffff864b0240 (rcu_read_lock_trace){....}-{0:0}, at: bpf_prog_test_run_syscall+0x2c0/0x830
#1: ffff8881f4ec40c8 ((&c->lock)){....}-{2:2}, at: ___slab_alloc+0xbc/0x1280
Preemption disabled at:
[<ffffffff8175ae2b>] __bpf_async_init+0xbb/0xb10
CPU: 1 UID: 0 PID: 675 Comm: test_progs Tainted: G O 6.12.0+ #11
Tainted: [O]=OOT_MODULE
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) ...
Call Trace:
<TASK>
dump_stack_lvl+0x57/0x70
dump_stack+0x10/0x20
__might_resched+0x337/0x4d0
rt_spin_lock+0xd4/0x230
___slab_alloc+0xbc/0x1280
__slab_alloc.isra.0+0x5d/0xa0
__kmalloc_node_noprof+0xf7/0x4f0
bpf_map_kmalloc_node+0xf5/0x6b0
__bpf_async_init+0x20e/0xb10
bpf_timer_init+0x30/0x40
bpf_prog_c7e2dc9ff3d5ba62_start_cb+0x55/0x85
bpf_prog_4eb421be69ae82fa_start_timer+0x5d/0x7e
bpf_prog_test_run_syscall+0x322/0x830
__sys_bpf+0x135d/0x3ca0
__x64_sys_bpf+0x75/0xb0
x64_sys_call+0x1b5/0xa10
do_syscall_64+0x3b/0xc0
entry_SYSCALL_64_after_hwframe+0x4b/0x53
Fix the problem by using bpf_global_ma to allocate bpf_async_cb when
PREEMPT_RT is enabled. The reason for still using kmalloc for
no-PREEMPT_RT case is that bpf_global_ma doesn't support accouting the
allocated memory to specific memcg. Also doing the memory allocation
before invoking __bpf_spin_lock_irqsave() to reduce the possibility of
-ENOMEM for bpf_global_ma.
Signed-off-by: Hou Tao <houtao1@huawei.com>
kernel-patches-daemon-bpf bot
pushed a commit
that referenced
this pull request
Jan 16, 2025
Under PREEMPT_RT, it is not safe to use GPF_ATOMIC kmalloc when
preemption or irq is disabled. The following warning is reported when
running test_progs under PREEMPT_RT:
BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48
in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 675, name: test_progs
preempt_count: 1, expected: 0
RCU nest depth: 0, expected: 0
2 locks held by test_progs/675:
#0: ffffffff864b0240 (rcu_read_lock_trace){....}-{0:0}, at: bpf_prog_test_run_syscall+0x2c0/0x830
#1: ffff8881f4ec40c8 ((&c->lock)){....}-{2:2}, at: ___slab_alloc+0xbc/0x1280
Preemption disabled at:
[<ffffffff8175ae2b>] __bpf_async_init+0xbb/0xb10
CPU: 1 UID: 0 PID: 675 Comm: test_progs Tainted: G O 6.12.0+ #11
Tainted: [O]=OOT_MODULE
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) ...
Call Trace:
<TASK>
dump_stack_lvl+0x57/0x70
dump_stack+0x10/0x20
__might_resched+0x337/0x4d0
rt_spin_lock+0xd4/0x230
___slab_alloc+0xbc/0x1280
__slab_alloc.isra.0+0x5d/0xa0
__kmalloc_node_noprof+0xf7/0x4f0
bpf_map_kmalloc_node+0xf5/0x6b0
__bpf_async_init+0x20e/0xb10
bpf_timer_init+0x30/0x40
bpf_prog_c7e2dc9ff3d5ba62_start_cb+0x55/0x85
bpf_prog_4eb421be69ae82fa_start_timer+0x5d/0x7e
bpf_prog_test_run_syscall+0x322/0x830
__sys_bpf+0x135d/0x3ca0
__x64_sys_bpf+0x75/0xb0
x64_sys_call+0x1b5/0xa10
do_syscall_64+0x3b/0xc0
entry_SYSCALL_64_after_hwframe+0x4b/0x53
Fix the problem by using bpf_global_ma to allocate bpf_async_cb when
PREEMPT_RT is enabled. The reason for still using kmalloc for
no-PREEMPT_RT case is that bpf_global_ma doesn't support accouting the
allocated memory to specific memcg. Also doing the memory allocation
before invoking __bpf_spin_lock_irqsave() to reduce the possibility of
-ENOMEM for bpf_global_ma.
Signed-off-by: Hou Tao <houtao1@huawei.com>
kernel-patches-daemon-bpf bot
pushed a commit
that referenced
this pull request
Jan 16, 2025
Under PREEMPT_RT, it is not safe to use GPF_ATOMIC kmalloc when
preemption or irq is disabled. The following warning is reported when
running test_progs under PREEMPT_RT:
BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48
in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 675, name: test_progs
preempt_count: 1, expected: 0
RCU nest depth: 0, expected: 0
2 locks held by test_progs/675:
#0: ffffffff864b0240 (rcu_read_lock_trace){....}-{0:0}, at: bpf_prog_test_run_syscall+0x2c0/0x830
#1: ffff8881f4ec40c8 ((&c->lock)){....}-{2:2}, at: ___slab_alloc+0xbc/0x1280
Preemption disabled at:
[<ffffffff8175ae2b>] __bpf_async_init+0xbb/0xb10
CPU: 1 UID: 0 PID: 675 Comm: test_progs Tainted: G O 6.12.0+ #11
Tainted: [O]=OOT_MODULE
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) ...
Call Trace:
<TASK>
dump_stack_lvl+0x57/0x70
dump_stack+0x10/0x20
__might_resched+0x337/0x4d0
rt_spin_lock+0xd4/0x230
___slab_alloc+0xbc/0x1280
__slab_alloc.isra.0+0x5d/0xa0
__kmalloc_node_noprof+0xf7/0x4f0
bpf_map_kmalloc_node+0xf5/0x6b0
__bpf_async_init+0x20e/0xb10
bpf_timer_init+0x30/0x40
bpf_prog_c7e2dc9ff3d5ba62_start_cb+0x55/0x85
bpf_prog_4eb421be69ae82fa_start_timer+0x5d/0x7e
bpf_prog_test_run_syscall+0x322/0x830
__sys_bpf+0x135d/0x3ca0
__x64_sys_bpf+0x75/0xb0
x64_sys_call+0x1b5/0xa10
do_syscall_64+0x3b/0xc0
entry_SYSCALL_64_after_hwframe+0x4b/0x53
Fix the problem by using bpf_global_ma to allocate bpf_async_cb when
PREEMPT_RT is enabled. The reason for still using kmalloc for
no-PREEMPT_RT case is that bpf_global_ma doesn't support accouting the
allocated memory to specific memcg. Also doing the memory allocation
before invoking __bpf_spin_lock_irqsave() to reduce the possibility of
-ENOMEM for bpf_global_ma.
Signed-off-by: Hou Tao <houtao1@huawei.com>
kernel-patches-daemon-bpf bot
pushed a commit
that referenced
this pull request
Jan 16, 2025
Under PREEMPT_RT, it is not safe to use GPF_ATOMIC kmalloc when
preemption or irq is disabled. The following warning is reported when
running test_progs under PREEMPT_RT:
BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48
in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 675, name: test_progs
preempt_count: 1, expected: 0
RCU nest depth: 0, expected: 0
2 locks held by test_progs/675:
#0: ffffffff864b0240 (rcu_read_lock_trace){....}-{0:0}, at: bpf_prog_test_run_syscall+0x2c0/0x830
#1: ffff8881f4ec40c8 ((&c->lock)){....}-{2:2}, at: ___slab_alloc+0xbc/0x1280
Preemption disabled at:
[<ffffffff8175ae2b>] __bpf_async_init+0xbb/0xb10
CPU: 1 UID: 0 PID: 675 Comm: test_progs Tainted: G O 6.12.0+ #11
Tainted: [O]=OOT_MODULE
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) ...
Call Trace:
<TASK>
dump_stack_lvl+0x57/0x70
dump_stack+0x10/0x20
__might_resched+0x337/0x4d0
rt_spin_lock+0xd4/0x230
___slab_alloc+0xbc/0x1280
__slab_alloc.isra.0+0x5d/0xa0
__kmalloc_node_noprof+0xf7/0x4f0
bpf_map_kmalloc_node+0xf5/0x6b0
__bpf_async_init+0x20e/0xb10
bpf_timer_init+0x30/0x40
bpf_prog_c7e2dc9ff3d5ba62_start_cb+0x55/0x85
bpf_prog_4eb421be69ae82fa_start_timer+0x5d/0x7e
bpf_prog_test_run_syscall+0x322/0x830
__sys_bpf+0x135d/0x3ca0
__x64_sys_bpf+0x75/0xb0
x64_sys_call+0x1b5/0xa10
do_syscall_64+0x3b/0xc0
entry_SYSCALL_64_after_hwframe+0x4b/0x53
Fix the problem by using bpf_global_ma to allocate bpf_async_cb when
PREEMPT_RT is enabled. The reason for still using kmalloc for
no-PREEMPT_RT case is that bpf_global_ma doesn't support accouting the
allocated memory to specific memcg. Also doing the memory allocation
before invoking __bpf_spin_lock_irqsave() to reduce the possibility of
-ENOMEM for bpf_global_ma.
Signed-off-by: Hou Tao <houtao1@huawei.com>
kernel-patches-daemon-bpf bot
pushed a commit
that referenced
this pull request
Jan 16, 2025
Under PREEMPT_RT, it is not safe to use GPF_ATOMIC kmalloc when
preemption or irq is disabled. The following warning is reported when
running test_progs under PREEMPT_RT:
BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48
in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 675, name: test_progs
preempt_count: 1, expected: 0
RCU nest depth: 0, expected: 0
2 locks held by test_progs/675:
#0: ffffffff864b0240 (rcu_read_lock_trace){....}-{0:0}, at: bpf_prog_test_run_syscall+0x2c0/0x830
#1: ffff8881f4ec40c8 ((&c->lock)){....}-{2:2}, at: ___slab_alloc+0xbc/0x1280
Preemption disabled at:
[<ffffffff8175ae2b>] __bpf_async_init+0xbb/0xb10
CPU: 1 UID: 0 PID: 675 Comm: test_progs Tainted: G O 6.12.0+ #11
Tainted: [O]=OOT_MODULE
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) ...
Call Trace:
<TASK>
dump_stack_lvl+0x57/0x70
dump_stack+0x10/0x20
__might_resched+0x337/0x4d0
rt_spin_lock+0xd4/0x230
___slab_alloc+0xbc/0x1280
__slab_alloc.isra.0+0x5d/0xa0
__kmalloc_node_noprof+0xf7/0x4f0
bpf_map_kmalloc_node+0xf5/0x6b0
__bpf_async_init+0x20e/0xb10
bpf_timer_init+0x30/0x40
bpf_prog_c7e2dc9ff3d5ba62_start_cb+0x55/0x85
bpf_prog_4eb421be69ae82fa_start_timer+0x5d/0x7e
bpf_prog_test_run_syscall+0x322/0x830
__sys_bpf+0x135d/0x3ca0
__x64_sys_bpf+0x75/0xb0
x64_sys_call+0x1b5/0xa10
do_syscall_64+0x3b/0xc0
entry_SYSCALL_64_after_hwframe+0x4b/0x53
Fix the problem by using bpf_global_ma to allocate bpf_async_cb when
PREEMPT_RT is enabled. The reason for still using kmalloc for
no-PREEMPT_RT case is that bpf_global_ma doesn't support accouting the
allocated memory to specific memcg. Also doing the memory allocation
before invoking __bpf_spin_lock_irqsave() to reduce the possibility of
-ENOMEM for bpf_global_ma.
Signed-off-by: Hou Tao <houtao1@huawei.com>
kernel-patches-daemon-bpf bot
pushed a commit
that referenced
this pull request
Jan 17, 2025
Under PREEMPT_RT, it is not safe to use GPF_ATOMIC kmalloc when
preemption or irq is disabled. The following warning is reported when
running test_progs under PREEMPT_RT:
BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48
in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 675, name: test_progs
preempt_count: 1, expected: 0
RCU nest depth: 0, expected: 0
2 locks held by test_progs/675:
#0: ffffffff864b0240 (rcu_read_lock_trace){....}-{0:0}, at: bpf_prog_test_run_syscall+0x2c0/0x830
#1: ffff8881f4ec40c8 ((&c->lock)){....}-{2:2}, at: ___slab_alloc+0xbc/0x1280
Preemption disabled at:
[<ffffffff8175ae2b>] __bpf_async_init+0xbb/0xb10
CPU: 1 UID: 0 PID: 675 Comm: test_progs Tainted: G O 6.12.0+ #11
Tainted: [O]=OOT_MODULE
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) ...
Call Trace:
<TASK>
dump_stack_lvl+0x57/0x70
dump_stack+0x10/0x20
__might_resched+0x337/0x4d0
rt_spin_lock+0xd4/0x230
___slab_alloc+0xbc/0x1280
__slab_alloc.isra.0+0x5d/0xa0
__kmalloc_node_noprof+0xf7/0x4f0
bpf_map_kmalloc_node+0xf5/0x6b0
__bpf_async_init+0x20e/0xb10
bpf_timer_init+0x30/0x40
bpf_prog_c7e2dc9ff3d5ba62_start_cb+0x55/0x85
bpf_prog_4eb421be69ae82fa_start_timer+0x5d/0x7e
bpf_prog_test_run_syscall+0x322/0x830
__sys_bpf+0x135d/0x3ca0
__x64_sys_bpf+0x75/0xb0
x64_sys_call+0x1b5/0xa10
do_syscall_64+0x3b/0xc0
entry_SYSCALL_64_after_hwframe+0x4b/0x53
Fix the problem by using bpf_global_ma to allocate bpf_async_cb when
PREEMPT_RT is enabled. The reason for still using kmalloc for
no-PREEMPT_RT case is that bpf_global_ma doesn't support accouting the
allocated memory to specific memcg. Also doing the memory allocation
before invoking __bpf_spin_lock_irqsave() to reduce the possibility of
-ENOMEM for bpf_global_ma.
Signed-off-by: Hou Tao <houtao1@huawei.com>
kernel-patches-daemon-bpf bot
pushed a commit
that referenced
this pull request
Jan 17, 2025
Under PREEMPT_RT, it is not safe to use GPF_ATOMIC kmalloc when
preemption or irq is disabled. The following warning is reported when
running test_progs under PREEMPT_RT:
BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48
in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 675, name: test_progs
preempt_count: 1, expected: 0
RCU nest depth: 0, expected: 0
2 locks held by test_progs/675:
#0: ffffffff864b0240 (rcu_read_lock_trace){....}-{0:0}, at: bpf_prog_test_run_syscall+0x2c0/0x830
#1: ffff8881f4ec40c8 ((&c->lock)){....}-{2:2}, at: ___slab_alloc+0xbc/0x1280
Preemption disabled at:
[<ffffffff8175ae2b>] __bpf_async_init+0xbb/0xb10
CPU: 1 UID: 0 PID: 675 Comm: test_progs Tainted: G O 6.12.0+ #11
Tainted: [O]=OOT_MODULE
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) ...
Call Trace:
<TASK>
dump_stack_lvl+0x57/0x70
dump_stack+0x10/0x20
__might_resched+0x337/0x4d0
rt_spin_lock+0xd4/0x230
___slab_alloc+0xbc/0x1280
__slab_alloc.isra.0+0x5d/0xa0
__kmalloc_node_noprof+0xf7/0x4f0
bpf_map_kmalloc_node+0xf5/0x6b0
__bpf_async_init+0x20e/0xb10
bpf_timer_init+0x30/0x40
bpf_prog_c7e2dc9ff3d5ba62_start_cb+0x55/0x85
bpf_prog_4eb421be69ae82fa_start_timer+0x5d/0x7e
bpf_prog_test_run_syscall+0x322/0x830
__sys_bpf+0x135d/0x3ca0
__x64_sys_bpf+0x75/0xb0
x64_sys_call+0x1b5/0xa10
do_syscall_64+0x3b/0xc0
entry_SYSCALL_64_after_hwframe+0x4b/0x53
Fix the problem by using bpf_global_ma to allocate bpf_async_cb when
PREEMPT_RT is enabled. The reason for still using kmalloc for
no-PREEMPT_RT case is that bpf_global_ma doesn't support accouting the
allocated memory to specific memcg. Also doing the memory allocation
before invoking __bpf_spin_lock_irqsave() to reduce the possibility of
-ENOMEM for bpf_global_ma.
Signed-off-by: Hou Tao <houtao1@huawei.com>
kernel-patches-daemon-bpf bot
pushed a commit
that referenced
this pull request
Jan 17, 2025
During the update procedure, when overwrite element in a pre-allocated
htab, the freeing of old_element is protected by the bucket lock. The
reason why the bucket lock is necessary is that the old_element has
already been stashed in htab->extra_elems after alloc_htab_elem()
returns. If freeing the old_element after the bucket lock is unlocked,
the stashed element may be reused by concurrent update procedure and the
freeing of old_element will run concurrently with the reuse of the
old_element. However, the invocation of check_and_free_fields() may
acquire a spin-lock which violates the lockdep rule because its caller
has already held a raw-spin-lock (bucket lock). The following warning
will be reported when such race happens:
BUG: scheduling while atomic: test_progs/676/0x00000003
3 locks held by test_progs/676:
#0: ffffffff864b0240 (rcu_read_lock_trace){....}-{0:0}, at: bpf_prog_test_run_syscall+0x2c0/0x830
#1: ffff88810e961188 (&htab->lockdep_key){....}-{2:2}, at: htab_map_update_elem+0x306/0x1500
#2: ffff8881f4eac1b8 (&base->softirq_expiry_lock){....}-{2:2}, at: hrtimer_cancel_wait_running+0xe9/0x1b0
Modules linked in: bpf_testmod(O)
Preemption disabled at:
[<ffffffff817837a3>] htab_map_update_elem+0x293/0x1500
CPU: 0 UID: 0 PID: 676 Comm: test_progs Tainted: G ... 6.12.0+ #11
Tainted: [W]=WARN, [O]=OOT_MODULE
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)...
Call Trace:
<TASK>
dump_stack_lvl+0x57/0x70
dump_stack+0x10/0x20
__schedule_bug+0x120/0x170
__schedule+0x300c/0x4800
schedule_rtlock+0x37/0x60
rtlock_slowlock_locked+0x6d9/0x54c0
rt_spin_lock+0x168/0x230
hrtimer_cancel_wait_running+0xe9/0x1b0
hrtimer_cancel+0x24/0x30
bpf_timer_delete_work+0x1d/0x40
bpf_timer_cancel_and_free+0x5e/0x80
bpf_obj_free_fields+0x262/0x4a0
check_and_free_fields+0x1d0/0x280
htab_map_update_elem+0x7fc/0x1500
bpf_prog_9f90bc20768e0cb9_overwrite_cb+0x3f/0x43
bpf_prog_ea601c4649694dbd_overwrite_timer+0x5d/0x7e
bpf_prog_test_run_syscall+0x322/0x830
__sys_bpf+0x135d/0x3ca0
__x64_sys_bpf+0x75/0xb0
x64_sys_call+0x1b5/0xa10
do_syscall_64+0x3b/0xc0
entry_SYSCALL_64_after_hwframe+0x4b/0x53
...
</TASK>
It seems feasible to break the reuse and refill of per-cpu extra_elems
into two independent parts: reuse the per-cpu extra_elems with bucket
lock being held and refill the old_element as per-cpu extra_elems after
the bucket lock is unlocked. However, it will make the concurrent
overwrite procedures on the same CPU return unexpected -E2BIG error when
the map is full.
Therefore, the patch fixes the lock problem by breaking the cancelling
of bpf_timer into two steps for PREEMPT_RT:
1) use hrtimer_try_to_cancel() and check its return value
2) if the timer is running, use hrtimer_cancel() through a kworker to
cancel it again
Considering that the current implementation of hrtimer_cancel() will try
to acquire a being held softirq_expiry_lock when the current timer is
running, these steps above are reasonable. However, it also has
downside. When the timer is running, the cancelling of the timer is
delayed when releasing the last map uref. The delay is also fixable
(e.g., break the cancelling of bpf timer into two parts: one part in
locked scope, another one in unlocked scope), it can be revised later if
necessary.
It is a bit hard to decide the right fix tag. One reason is that the
problem depends on PREEMPT_RT which is enabled in v6.12. Considering the
softirq_expiry_lock lock exists since v5.4 and bpf_timer is introduced
in v5.15, the bpf_timer commit is used in the fixes tag and an extra
depends-on tag is added to state the dependency on PREEMPT_RT.
Fixes: b00628b ("bpf: Introduce bpf timers.")
Depends-on: v6.12+ with PREEMPT_RT enabled
Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Closes: https://lore.kernel.org/bpf/20241106084527.4gPrMnHt@linutronix.de
Signed-off-by: Hou Tao <houtao1@huawei.com>
kernel-patches-daemon-bpf bot
pushed a commit
that referenced
this pull request
Jan 17, 2025
During the update procedure, when overwrite element in a pre-allocated
htab, the freeing of old_element is protected by the bucket lock. The
reason why the bucket lock is necessary is that the old_element has
already been stashed in htab->extra_elems after alloc_htab_elem()
returns. If freeing the old_element after the bucket lock is unlocked,
the stashed element may be reused by concurrent update procedure and the
freeing of old_element will run concurrently with the reuse of the
old_element. However, the invocation of check_and_free_fields() may
acquire a spin-lock which violates the lockdep rule because its caller
has already held a raw-spin-lock (bucket lock). The following warning
will be reported when such race happens:
BUG: scheduling while atomic: test_progs/676/0x00000003
3 locks held by test_progs/676:
#0: ffffffff864b0240 (rcu_read_lock_trace){....}-{0:0}, at: bpf_prog_test_run_syscall+0x2c0/0x830
#1: ffff88810e961188 (&htab->lockdep_key){....}-{2:2}, at: htab_map_update_elem+0x306/0x1500
#2: ffff8881f4eac1b8 (&base->softirq_expiry_lock){....}-{2:2}, at: hrtimer_cancel_wait_running+0xe9/0x1b0
Modules linked in: bpf_testmod(O)
Preemption disabled at:
[<ffffffff817837a3>] htab_map_update_elem+0x293/0x1500
CPU: 0 UID: 0 PID: 676 Comm: test_progs Tainted: G ... 6.12.0+ #11
Tainted: [W]=WARN, [O]=OOT_MODULE
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)...
Call Trace:
<TASK>
dump_stack_lvl+0x57/0x70
dump_stack+0x10/0x20
__schedule_bug+0x120/0x170
__schedule+0x300c/0x4800
schedule_rtlock+0x37/0x60
rtlock_slowlock_locked+0x6d9/0x54c0
rt_spin_lock+0x168/0x230
hrtimer_cancel_wait_running+0xe9/0x1b0
hrtimer_cancel+0x24/0x30
bpf_timer_delete_work+0x1d/0x40
bpf_timer_cancel_and_free+0x5e/0x80
bpf_obj_free_fields+0x262/0x4a0
check_and_free_fields+0x1d0/0x280
htab_map_update_elem+0x7fc/0x1500
bpf_prog_9f90bc20768e0cb9_overwrite_cb+0x3f/0x43
bpf_prog_ea601c4649694dbd_overwrite_timer+0x5d/0x7e
bpf_prog_test_run_syscall+0x322/0x830
__sys_bpf+0x135d/0x3ca0
__x64_sys_bpf+0x75/0xb0
x64_sys_call+0x1b5/0xa10
do_syscall_64+0x3b/0xc0
entry_SYSCALL_64_after_hwframe+0x4b/0x53
...
</TASK>
It seems feasible to break the reuse and refill of per-cpu extra_elems
into two independent parts: reuse the per-cpu extra_elems with bucket
lock being held and refill the old_element as per-cpu extra_elems after
the bucket lock is unlocked. However, it will make the concurrent
overwrite procedures on the same CPU return unexpected -E2BIG error when
the map is full.
Therefore, the patch fixes the lock problem by breaking the cancelling
of bpf_timer into two steps for PREEMPT_RT:
1) use hrtimer_try_to_cancel() and check its return value
2) if the timer is running, use hrtimer_cancel() through a kworker to
cancel it again
Considering that the current implementation of hrtimer_cancel() will try
to acquire a being held softirq_expiry_lock when the current timer is
running, these steps above are reasonable. However, it also has
downside. When the timer is running, the cancelling of the timer is
delayed when releasing the last map uref. The delay is also fixable
(e.g., break the cancelling of bpf timer into two parts: one part in
locked scope, another one in unlocked scope), it can be revised later if
necessary.
It is a bit hard to decide the right fix tag. One reason is that the
problem depends on PREEMPT_RT which is enabled in v6.12. Considering the
softirq_expiry_lock lock exists since v5.4 and bpf_timer is introduced
in v5.15, the bpf_timer commit is used in the fixes tag and an extra
depends-on tag is added to state the dependency on PREEMPT_RT.
Fixes: b00628b ("bpf: Introduce bpf timers.")
Depends-on: v6.12+ with PREEMPT_RT enabled
Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Closes: https://lore.kernel.org/bpf/20241106084527.4gPrMnHt@linutronix.de
Signed-off-by: Hou Tao <houtao1@huawei.com>
kernel-patches-daemon-bpf bot
pushed a commit
that referenced
this pull request
Jan 17, 2025
During the update procedure, when overwrite element in a pre-allocated
htab, the freeing of old_element is protected by the bucket lock. The
reason why the bucket lock is necessary is that the old_element has
already been stashed in htab->extra_elems after alloc_htab_elem()
returns. If freeing the old_element after the bucket lock is unlocked,
the stashed element may be reused by concurrent update procedure and the
freeing of old_element will run concurrently with the reuse of the
old_element. However, the invocation of check_and_free_fields() may
acquire a spin-lock which violates the lockdep rule because its caller
has already held a raw-spin-lock (bucket lock). The following warning
will be reported when such race happens:
BUG: scheduling while atomic: test_progs/676/0x00000003
3 locks held by test_progs/676:
#0: ffffffff864b0240 (rcu_read_lock_trace){....}-{0:0}, at: bpf_prog_test_run_syscall+0x2c0/0x830
#1: ffff88810e961188 (&htab->lockdep_key){....}-{2:2}, at: htab_map_update_elem+0x306/0x1500
#2: ffff8881f4eac1b8 (&base->softirq_expiry_lock){....}-{2:2}, at: hrtimer_cancel_wait_running+0xe9/0x1b0
Modules linked in: bpf_testmod(O)
Preemption disabled at:
[<ffffffff817837a3>] htab_map_update_elem+0x293/0x1500
CPU: 0 UID: 0 PID: 676 Comm: test_progs Tainted: G ... 6.12.0+ #11
Tainted: [W]=WARN, [O]=OOT_MODULE
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)...
Call Trace:
<TASK>
dump_stack_lvl+0x57/0x70
dump_stack+0x10/0x20
__schedule_bug+0x120/0x170
__schedule+0x300c/0x4800
schedule_rtlock+0x37/0x60
rtlock_slowlock_locked+0x6d9/0x54c0
rt_spin_lock+0x168/0x230
hrtimer_cancel_wait_running+0xe9/0x1b0
hrtimer_cancel+0x24/0x30
bpf_timer_delete_work+0x1d/0x40
bpf_timer_cancel_and_free+0x5e/0x80
bpf_obj_free_fields+0x262/0x4a0
check_and_free_fields+0x1d0/0x280
htab_map_update_elem+0x7fc/0x1500
bpf_prog_9f90bc20768e0cb9_overwrite_cb+0x3f/0x43
bpf_prog_ea601c4649694dbd_overwrite_timer+0x5d/0x7e
bpf_prog_test_run_syscall+0x322/0x830
__sys_bpf+0x135d/0x3ca0
__x64_sys_bpf+0x75/0xb0
x64_sys_call+0x1b5/0xa10
do_syscall_64+0x3b/0xc0
entry_SYSCALL_64_after_hwframe+0x4b/0x53
...
</TASK>
It seems feasible to break the reuse and refill of per-cpu extra_elems
into two independent parts: reuse the per-cpu extra_elems with bucket
lock being held and refill the old_element as per-cpu extra_elems after
the bucket lock is unlocked. However, it will make the concurrent
overwrite procedures on the same CPU return unexpected -E2BIG error when
the map is full.
Therefore, the patch fixes the lock problem by breaking the cancelling
of bpf_timer into two steps for PREEMPT_RT:
1) use hrtimer_try_to_cancel() and check its return value
2) if the timer is running, use hrtimer_cancel() through a kworker to
cancel it again
Considering that the current implementation of hrtimer_cancel() will try
to acquire a being held softirq_expiry_lock when the current timer is
running, these steps above are reasonable. However, it also has
downside. When the timer is running, the cancelling of the timer is
delayed when releasing the last map uref. The delay is also fixable
(e.g., break the cancelling of bpf timer into two parts: one part in
locked scope, another one in unlocked scope), it can be revised later if
necessary.
It is a bit hard to decide the right fix tag. One reason is that the
problem depends on PREEMPT_RT which is enabled in v6.12. Considering the
softirq_expiry_lock lock exists since v5.4 and bpf_timer is introduced
in v5.15, the bpf_timer commit is used in the fixes tag and an extra
depends-on tag is added to state the dependency on PREEMPT_RT.
Fixes: b00628b ("bpf: Introduce bpf timers.")
Depends-on: v6.12+ with PREEMPT_RT enabled
Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Closes: https://lore.kernel.org/bpf/20241106084527.4gPrMnHt@linutronix.de
Signed-off-by: Hou Tao <houtao1@huawei.com>
Reviewed-by: Toke Høiland-Jørgensen <toke@kernel.org>
kernel-patches-daemon-bpf bot
pushed a commit
that referenced
this pull request
Jan 17, 2025
Under PREEMPT_RT, it is not safe to use GPF_ATOMIC kmalloc when
preemption or irq is disabled. The following warning is reported when
running test_progs under PREEMPT_RT:
BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48
in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 675, name: test_progs
preempt_count: 1, expected: 0
RCU nest depth: 0, expected: 0
2 locks held by test_progs/675:
#0: ffffffff864b0240 (rcu_read_lock_trace){....}-{0:0}, at: bpf_prog_test_run_syscall+0x2c0/0x830
#1: ffff8881f4ec40c8 ((&c->lock)){....}-{2:2}, at: ___slab_alloc+0xbc/0x1280
Preemption disabled at:
[<ffffffff8175ae2b>] __bpf_async_init+0xbb/0xb10
CPU: 1 UID: 0 PID: 675 Comm: test_progs Tainted: G O 6.12.0+ #11
Tainted: [O]=OOT_MODULE
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) ...
Call Trace:
<TASK>
dump_stack_lvl+0x57/0x70
dump_stack+0x10/0x20
__might_resched+0x337/0x4d0
rt_spin_lock+0xd4/0x230
___slab_alloc+0xbc/0x1280
__slab_alloc.isra.0+0x5d/0xa0
__kmalloc_node_noprof+0xf7/0x4f0
bpf_map_kmalloc_node+0xf5/0x6b0
__bpf_async_init+0x20e/0xb10
bpf_timer_init+0x30/0x40
bpf_prog_c7e2dc9ff3d5ba62_start_cb+0x55/0x85
bpf_prog_4eb421be69ae82fa_start_timer+0x5d/0x7e
bpf_prog_test_run_syscall+0x322/0x830
__sys_bpf+0x135d/0x3ca0
__x64_sys_bpf+0x75/0xb0
x64_sys_call+0x1b5/0xa10
do_syscall_64+0x3b/0xc0
entry_SYSCALL_64_after_hwframe+0x4b/0x53
Fix the problem by using bpf_global_ma to allocate bpf_async_cb when
PREEMPT_RT is enabled. The reason for still using kmalloc for
no-PREEMPT_RT case is that bpf_global_ma doesn't support accouting the
allocated memory to specific memcg. Also doing the memory allocation
before invoking __bpf_spin_lock_irqsave() to reduce the possibility of
-ENOMEM for bpf_global_ma.
Signed-off-by: Hou Tao <houtao1@huawei.com>
kernel-patches-daemon-bpf bot
pushed a commit
that referenced
this pull request
Jan 17, 2025
During the update procedure, when overwrite element in a pre-allocated
htab, the freeing of old_element is protected by the bucket lock. The
reason why the bucket lock is necessary is that the old_element has
already been stashed in htab->extra_elems after alloc_htab_elem()
returns. If freeing the old_element after the bucket lock is unlocked,
the stashed element may be reused by concurrent update procedure and the
freeing of old_element will run concurrently with the reuse of the
old_element. However, the invocation of check_and_free_fields() may
acquire a spin-lock which violates the lockdep rule because its caller
has already held a raw-spin-lock (bucket lock). The following warning
will be reported when such race happens:
BUG: scheduling while atomic: test_progs/676/0x00000003
3 locks held by test_progs/676:
#0: ffffffff864b0240 (rcu_read_lock_trace){....}-{0:0}, at: bpf_prog_test_run_syscall+0x2c0/0x830
#1: ffff88810e961188 (&htab->lockdep_key){....}-{2:2}, at: htab_map_update_elem+0x306/0x1500
#2: ffff8881f4eac1b8 (&base->softirq_expiry_lock){....}-{2:2}, at: hrtimer_cancel_wait_running+0xe9/0x1b0
Modules linked in: bpf_testmod(O)
Preemption disabled at:
[<ffffffff817837a3>] htab_map_update_elem+0x293/0x1500
CPU: 0 UID: 0 PID: 676 Comm: test_progs Tainted: G ... 6.12.0+ #11
Tainted: [W]=WARN, [O]=OOT_MODULE
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)...
Call Trace:
<TASK>
dump_stack_lvl+0x57/0x70
dump_stack+0x10/0x20
__schedule_bug+0x120/0x170
__schedule+0x300c/0x4800
schedule_rtlock+0x37/0x60
rtlock_slowlock_locked+0x6d9/0x54c0
rt_spin_lock+0x168/0x230
hrtimer_cancel_wait_running+0xe9/0x1b0
hrtimer_cancel+0x24/0x30
bpf_timer_delete_work+0x1d/0x40
bpf_timer_cancel_and_free+0x5e/0x80
bpf_obj_free_fields+0x262/0x4a0
check_and_free_fields+0x1d0/0x280
htab_map_update_elem+0x7fc/0x1500
bpf_prog_9f90bc20768e0cb9_overwrite_cb+0x3f/0x43
bpf_prog_ea601c4649694dbd_overwrite_timer+0x5d/0x7e
bpf_prog_test_run_syscall+0x322/0x830
__sys_bpf+0x135d/0x3ca0
__x64_sys_bpf+0x75/0xb0
x64_sys_call+0x1b5/0xa10
do_syscall_64+0x3b/0xc0
entry_SYSCALL_64_after_hwframe+0x4b/0x53
...
</TASK>
It seems feasible to break the reuse and refill of per-cpu extra_elems
into two independent parts: reuse the per-cpu extra_elems with bucket
lock being held and refill the old_element as per-cpu extra_elems after
the bucket lock is unlocked. However, it will make the concurrent
overwrite procedures on the same CPU return unexpected -E2BIG error when
the map is full.
Therefore, the patch fixes the lock problem by breaking the cancelling
of bpf_timer into two steps for PREEMPT_RT:
1) use hrtimer_try_to_cancel() and check its return value
2) if the timer is running, use hrtimer_cancel() through a kworker to
cancel it again
Considering that the current implementation of hrtimer_cancel() will try
to acquire a being held softirq_expiry_lock when the current timer is
running, these steps above are reasonable. However, it also has
downside. When the timer is running, the cancelling of the timer is
delayed when releasing the last map uref. The delay is also fixable
(e.g., break the cancelling of bpf timer into two parts: one part in
locked scope, another one in unlocked scope), it can be revised later if
necessary.
It is a bit hard to decide the right fix tag. One reason is that the
problem depends on PREEMPT_RT which is enabled in v6.12. Considering the
softirq_expiry_lock lock exists since v5.4 and bpf_timer is introduced
in v5.15, the bpf_timer commit is used in the fixes tag and an extra
depends-on tag is added to state the dependency on PREEMPT_RT.
Fixes: b00628b ("bpf: Introduce bpf timers.")
Depends-on: v6.12+ with PREEMPT_RT enabled
Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Closes: https://lore.kernel.org/bpf/20241106084527.4gPrMnHt@linutronix.de
Signed-off-by: Hou Tao <houtao1@huawei.com>
Reviewed-by: Toke Høiland-Jørgensen <toke@kernel.org>
kernel-patches-daemon-bpf bot
pushed a commit
that referenced
this pull request
Jan 17, 2025
During the update procedure, when overwrite element in a pre-allocated
htab, the freeing of old_element is protected by the bucket lock. The
reason why the bucket lock is necessary is that the old_element has
already been stashed in htab->extra_elems after alloc_htab_elem()
returns. If freeing the old_element after the bucket lock is unlocked,
the stashed element may be reused by concurrent update procedure and the
freeing of old_element will run concurrently with the reuse of the
old_element. However, the invocation of check_and_free_fields() may
acquire a spin-lock which violates the lockdep rule because its caller
has already held a raw-spin-lock (bucket lock). The following warning
will be reported when such race happens:
BUG: scheduling while atomic: test_progs/676/0x00000003
3 locks held by test_progs/676:
#0: ffffffff864b0240 (rcu_read_lock_trace){....}-{0:0}, at: bpf_prog_test_run_syscall+0x2c0/0x830
#1: ffff88810e961188 (&htab->lockdep_key){....}-{2:2}, at: htab_map_update_elem+0x306/0x1500
#2: ffff8881f4eac1b8 (&base->softirq_expiry_lock){....}-{2:2}, at: hrtimer_cancel_wait_running+0xe9/0x1b0
Modules linked in: bpf_testmod(O)
Preemption disabled at:
[<ffffffff817837a3>] htab_map_update_elem+0x293/0x1500
CPU: 0 UID: 0 PID: 676 Comm: test_progs Tainted: G ... 6.12.0+ #11
Tainted: [W]=WARN, [O]=OOT_MODULE
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)...
Call Trace:
<TASK>
dump_stack_lvl+0x57/0x70
dump_stack+0x10/0x20
__schedule_bug+0x120/0x170
__schedule+0x300c/0x4800
schedule_rtlock+0x37/0x60
rtlock_slowlock_locked+0x6d9/0x54c0
rt_spin_lock+0x168/0x230
hrtimer_cancel_wait_running+0xe9/0x1b0
hrtimer_cancel+0x24/0x30
bpf_timer_delete_work+0x1d/0x40
bpf_timer_cancel_and_free+0x5e/0x80
bpf_obj_free_fields+0x262/0x4a0
check_and_free_fields+0x1d0/0x280
htab_map_update_elem+0x7fc/0x1500
bpf_prog_9f90bc20768e0cb9_overwrite_cb+0x3f/0x43
bpf_prog_ea601c4649694dbd_overwrite_timer+0x5d/0x7e
bpf_prog_test_run_syscall+0x322/0x830
__sys_bpf+0x135d/0x3ca0
__x64_sys_bpf+0x75/0xb0
x64_sys_call+0x1b5/0xa10
do_syscall_64+0x3b/0xc0
entry_SYSCALL_64_after_hwframe+0x4b/0x53
...
</TASK>
It seems feasible to break the reuse and refill of per-cpu extra_elems
into two independent parts: reuse the per-cpu extra_elems with bucket
lock being held and refill the old_element as per-cpu extra_elems after
the bucket lock is unlocked. However, it will make the concurrent
overwrite procedures on the same CPU return unexpected -E2BIG error when
the map is full.
Therefore, the patch fixes the lock problem by breaking the cancelling
of bpf_timer into two steps for PREEMPT_RT:
1) use hrtimer_try_to_cancel() and check its return value
2) if the timer is running, use hrtimer_cancel() through a kworker to
cancel it again
Considering that the current implementation of hrtimer_cancel() will try
to acquire a being held softirq_expiry_lock when the current timer is
running, these steps above are reasonable. However, it also has
downside. When the timer is running, the cancelling of the timer is
delayed when releasing the last map uref. The delay is also fixable
(e.g., break the cancelling of bpf timer into two parts: one part in
locked scope, another one in unlocked scope), it can be revised later if
necessary.
It is a bit hard to decide the right fix tag. One reason is that the
problem depends on PREEMPT_RT which is enabled in v6.12. Considering the
softirq_expiry_lock lock exists since v5.4 and bpf_timer is introduced
in v5.15, the bpf_timer commit is used in the fixes tag and an extra
depends-on tag is added to state the dependency on PREEMPT_RT.
Fixes: b00628b ("bpf: Introduce bpf timers.")
Depends-on: v6.12+ with PREEMPT_RT enabled
Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Closes: https://lore.kernel.org/bpf/20241106084527.4gPrMnHt@linutronix.de
Signed-off-by: Hou Tao <houtao1@huawei.com>
Reviewed-by: Toke Høiland-Jørgensen <toke@kernel.org>
kernel-patches-daemon-bpf bot
pushed a commit
that referenced
this pull request
Jan 20, 2025
During the update procedure, when overwrite element in a pre-allocated
htab, the freeing of old_element is protected by the bucket lock. The
reason why the bucket lock is necessary is that the old_element has
already been stashed in htab->extra_elems after alloc_htab_elem()
returns. If freeing the old_element after the bucket lock is unlocked,
the stashed element may be reused by concurrent update procedure and the
freeing of old_element will run concurrently with the reuse of the
old_element. However, the invocation of check_and_free_fields() may
acquire a spin-lock which violates the lockdep rule because its caller
has already held a raw-spin-lock (bucket lock). The following warning
will be reported when such race happens:
BUG: scheduling while atomic: test_progs/676/0x00000003
3 locks held by test_progs/676:
#0: ffffffff864b0240 (rcu_read_lock_trace){....}-{0:0}, at: bpf_prog_test_run_syscall+0x2c0/0x830
#1: ffff88810e961188 (&htab->lockdep_key){....}-{2:2}, at: htab_map_update_elem+0x306/0x1500
#2: ffff8881f4eac1b8 (&base->softirq_expiry_lock){....}-{2:2}, at: hrtimer_cancel_wait_running+0xe9/0x1b0
Modules linked in: bpf_testmod(O)
Preemption disabled at:
[<ffffffff817837a3>] htab_map_update_elem+0x293/0x1500
CPU: 0 UID: 0 PID: 676 Comm: test_progs Tainted: G ... 6.12.0+ #11
Tainted: [W]=WARN, [O]=OOT_MODULE
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)...
Call Trace:
<TASK>
dump_stack_lvl+0x57/0x70
dump_stack+0x10/0x20
__schedule_bug+0x120/0x170
__schedule+0x300c/0x4800
schedule_rtlock+0x37/0x60
rtlock_slowlock_locked+0x6d9/0x54c0
rt_spin_lock+0x168/0x230
hrtimer_cancel_wait_running+0xe9/0x1b0
hrtimer_cancel+0x24/0x30
bpf_timer_delete_work+0x1d/0x40
bpf_timer_cancel_and_free+0x5e/0x80
bpf_obj_free_fields+0x262/0x4a0
check_and_free_fields+0x1d0/0x280
htab_map_update_elem+0x7fc/0x1500
bpf_prog_9f90bc20768e0cb9_overwrite_cb+0x3f/0x43
bpf_prog_ea601c4649694dbd_overwrite_timer+0x5d/0x7e
bpf_prog_test_run_syscall+0x322/0x830
__sys_bpf+0x135d/0x3ca0
__x64_sys_bpf+0x75/0xb0
x64_sys_call+0x1b5/0xa10
do_syscall_64+0x3b/0xc0
entry_SYSCALL_64_after_hwframe+0x4b/0x53
...
</TASK>
It seems feasible to break the reuse and refill of per-cpu extra_elems
into two independent parts: reuse the per-cpu extra_elems with bucket
lock being held and refill the old_element as per-cpu extra_elems after
the bucket lock is unlocked. However, it will make the concurrent
overwrite procedures on the same CPU return unexpected -E2BIG error when
the map is full.
Therefore, the patch fixes the lock problem by breaking the cancelling
of bpf_timer into two steps for PREEMPT_RT:
1) use hrtimer_try_to_cancel() and check its return value
2) if the timer is running, use hrtimer_cancel() through a kworker to
cancel it again
Considering that the current implementation of hrtimer_cancel() will try
to acquire a being held softirq_expiry_lock when the current timer is
running, these steps above are reasonable. However, it also has
downside. When the timer is running, the cancelling of the timer is
delayed when releasing the last map uref. The delay is also fixable
(e.g., break the cancelling of bpf timer into two parts: one part in
locked scope, another one in unlocked scope), it can be revised later if
necessary.
It is a bit hard to decide the right fix tag. One reason is that the
problem depends on PREEMPT_RT which is enabled in v6.12. Considering the
softirq_expiry_lock lock exists since v5.4 and bpf_timer is introduced
in v5.15, the bpf_timer commit is used in the fixes tag and an extra
depends-on tag is added to state the dependency on PREEMPT_RT.
Fixes: b00628b ("bpf: Introduce bpf timers.")
Depends-on: v6.12+ with PREEMPT_RT enabled
Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Closes: https://lore.kernel.org/bpf/20241106084527.4gPrMnHt@linutronix.de
Signed-off-by: Hou Tao <houtao1@huawei.com>
Reviewed-by: Toke Høiland-Jørgensen <toke@kernel.org>
Link: https://lore.kernel.org/r/20250117101816.2101857-5-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
kernel-patches-daemon-bpf bot
pushed a commit
that referenced
this pull request
Feb 3, 2025
libtraceevent parses and returns an array of argument fields, sometimes
larger than RAW_SYSCALL_ARGS_NUM (6) because it includes "__syscall_nr",
idx will traverse to index 6 (7th element) whereas sc->fmt->arg holds 6
elements max, creating an out-of-bounds access. This runtime error is
found by UBsan. The error message:
$ sudo UBSAN_OPTIONS=print_stacktrace=1 ./perf trace -a --max-events=1
builtin-trace.c:1966:35: runtime error: index 6 out of bounds for type 'syscall_arg_fmt [6]'
#0 0x5c04956be5fe in syscall__alloc_arg_fmts /home/howard/hw/linux-perf/tools/perf/builtin-trace.c:1966
#1 0x5c04956c0510 in trace__read_syscall_info /home/howard/hw/linux-perf/tools/perf/builtin-trace.c:2110
#2 0x5c04956c372b in trace__syscall_info /home/howard/hw/linux-perf/tools/perf/builtin-trace.c:2436
#3 0x5c04956d2f39 in trace__init_syscalls_bpf_prog_array_maps /home/howard/hw/linux-perf/tools/perf/builtin-trace.c:3897
#4 0x5c04956d6d25 in trace__run /home/howard/hw/linux-perf/tools/perf/builtin-trace.c:4335
#5 0x5c04956e112e in cmd_trace /home/howard/hw/linux-perf/tools/perf/builtin-trace.c:5502
#6 0x5c04956eda7d in run_builtin /home/howard/hw/linux-perf/tools/perf/perf.c:351
#7 0x5c04956ee0a8 in handle_internal_command /home/howard/hw/linux-perf/tools/perf/perf.c:404
#8 0x5c04956ee37f in run_argv /home/howard/hw/linux-perf/tools/perf/perf.c:448
#9 0x5c04956ee8e9 in main /home/howard/hw/linux-perf/tools/perf/perf.c:556
#10 0x79eb3622a3b7 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58
#11 0x79eb3622a47a in __libc_start_main_impl ../csu/libc-start.c:360
#12 0x5c04955422d4 in _start (/home/howard/hw/linux-perf/tools/perf/perf+0x4e02d4) (BuildId: 5b6cab2d59e96a4341741765ad6914a4d784dbc6)
0.000 ( 0.014 ms): Chrome_ChildIO/117244 write(fd: 238, buf: !, count: 1) = 1
Fixes: 5e58fcf ("perf trace: Allow allocating sc->arg_fmt even without the syscall tracepoint")
Signed-off-by: Howard Chu <howardchu95@gmail.com>
Link: https://lore.kernel.org/r/20250122025519.361873-1-howardchu95@gmail.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
kernel-patches-daemon-bpf bot
pushed a commit
that referenced
this pull request
Feb 4, 2025
On an aarch64 kernel with CONFIG_PAGE_SIZE_64KB=y (64k pages), arena_htab tests cause a segmentation fault and soft lockup. $ sudo ./test_progs -t arena_htab Caught signal #11! Stack trace: ./test_progs(crash_handler+0x1c)[0x7bd4d8] linux-vdso.so.1(__kernel_rt_sigreturn+0x0)[0xffffb34a0968] ./test_progs[0x420f74] ./test_progs(htab_lookup_elem+0x3c)[0x421090] ./test_progs[0x421320] ./test_progs[0x421bb8] ./test_progs(test_arena_htab+0x40)[0x421c14] ./test_progs[0x7bda84] ./test_progs(main+0x65c)[0x7bf670] /usr/lib64/libc.so.6(+0x2caa0)[0xffffb31ecaa0] /usr/lib64/libc.so.6(__libc_start_main+0x98)[0xffffb31ecb78] ./test_progs(_start+0x30)[0x41b4f0] Message from syslogd@bpfol9aarch64 at Feb 4 08:50:09 ... kernel:watchdog: BUG: soft lockup - CPU#1 stuck for 26s! [kworker/u8:4:7589] The same failure is not observed with 4k pages on aarch64. Investigating further, it turns out arena_map_free() was calling apply_to_existing_page_range() with the address returned by bpf_arena_get_kern_vm_start(). If this address is not page-aligned - as is the case for a 64k page kernel - we wind up calling apply_to_pte_range() with that unaligned address. The problem is apply_to_pte_range() implicitly assumes that the addr passed in is page-aligned, specifically in this loop: do { if (create || !pte_none(ptep_get(pte))) { err = fn(pte++, addr, data); if (err) break; } } while (addr += PAGE_SIZE, addr != end); If addr is _not_ page-aligned, it will never equal end exactly. One solution is to round up the address returned by bpf_arena_get_kern_vm_start() to a page-aligned value. With that change in place the test passes: $ sudo ./test_progs -t arena_htab Summary: 1/1 PASSED, 1 SKIPPED, 0 FAILED Reported-by: Colm Harrington <colm.harrington@oracle.com> Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
kernel-patches-daemon-bpf bot
pushed a commit
that referenced
this pull request
Feb 5, 2025
On an aarch64 kernel with CONFIG_PAGE_SIZE_64KB=y (64k pages), arena_htab tests cause a segmentation fault and soft lockup. $ sudo ./test_progs -t arena_htab Caught signal #11! Stack trace: ./test_progs(crash_handler+0x1c)[0x7bd4d8] linux-vdso.so.1(__kernel_rt_sigreturn+0x0)[0xffffb34a0968] ./test_progs[0x420f74] ./test_progs(htab_lookup_elem+0x3c)[0x421090] ./test_progs[0x421320] ./test_progs[0x421bb8] ./test_progs(test_arena_htab+0x40)[0x421c14] ./test_progs[0x7bda84] ./test_progs(main+0x65c)[0x7bf670] /usr/lib64/libc.so.6(+0x2caa0)[0xffffb31ecaa0] /usr/lib64/libc.so.6(__libc_start_main+0x98)[0xffffb31ecb78] ./test_progs(_start+0x30)[0x41b4f0] Message from syslogd@bpfol9aarch64 at Feb 4 08:50:09 ... kernel:watchdog: BUG: soft lockup - CPU#1 stuck for 26s! [kworker/u8:4:7589] The same failure is not observed with 4k pages on aarch64. Investigating further, it turns out arena_map_free() was calling apply_to_existing_page_range() with the address returned by bpf_arena_get_kern_vm_start(). If this address is not page-aligned - as is the case for a 64k page kernel - we wind up calling apply_to_pte_range() with that unaligned address. The problem is apply_to_pte_range() implicitly assumes that the addr passed in is page-aligned, specifically in this loop: do { if (create || !pte_none(ptep_get(pte))) { err = fn(pte++, addr, data); if (err) break; } } while (addr += PAGE_SIZE, addr != end); If addr is _not_ page-aligned, it will never equal end exactly. One solution is to round up GUARD_SZ to PAGE_SIZE << 1 so that the division by 2 in bpf_arena_get_kern_vm_start() returns a page-aligned value. With that change in place, the test passes: $ sudo ./test_progs -t arena_htab Summary: 1/1 PASSED, 1 SKIPPED, 0 FAILED Fixes: 3174603 ("bpf: Introduce bpf_arena.") Reported-by: Colm Harrington <colm.harrington@oracle.com> Suggested-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
kernel-patches-daemon-bpf bot
pushed a commit
that referenced
this pull request
Feb 5, 2025
On an aarch64 kernel with CONFIG_PAGE_SIZE_64KB=y (64k pages), arena_htab tests cause a segmentation fault and soft lockup. $ sudo ./test_progs -t arena_htab Caught signal #11! Stack trace: ./test_progs(crash_handler+0x1c)[0x7bd4d8] linux-vdso.so.1(__kernel_rt_sigreturn+0x0)[0xffffb34a0968] ./test_progs[0x420f74] ./test_progs(htab_lookup_elem+0x3c)[0x421090] ./test_progs[0x421320] ./test_progs[0x421bb8] ./test_progs(test_arena_htab+0x40)[0x421c14] ./test_progs[0x7bda84] ./test_progs(main+0x65c)[0x7bf670] /usr/lib64/libc.so.6(+0x2caa0)[0xffffb31ecaa0] /usr/lib64/libc.so.6(__libc_start_main+0x98)[0xffffb31ecb78] ./test_progs(_start+0x30)[0x41b4f0] Message from syslogd@bpfol9aarch64 at Feb 4 08:50:09 ... kernel:watchdog: BUG: soft lockup - CPU#1 stuck for 26s! [kworker/u8:4:7589] The same failure is not observed with 4k pages on aarch64. Investigating further, it turns out arena_map_free() was calling apply_to_existing_page_range() with the address returned by bpf_arena_get_kern_vm_start(). If this address is not page-aligned - as is the case for a 64k page kernel - we wind up calling apply_to_pte_range() with that unaligned address. The problem is apply_to_pte_range() implicitly assumes that the addr passed in is page-aligned, specifically in this loop: do { if (create || !pte_none(ptep_get(pte))) { err = fn(pte++, addr, data); if (err) break; } } while (addr += PAGE_SIZE, addr != end); If addr is _not_ page-aligned, it will never equal end exactly. One solution is to round up GUARD_SZ to PAGE_SIZE << 1 so that the division by 2 in bpf_arena_get_kern_vm_start() returns a page-aligned value. With that change in place, the test passes: $ sudo ./test_progs -t arena_htab Summary: 1/1 PASSED, 1 SKIPPED, 0 FAILED Fixes: 3174603 ("bpf: Introduce bpf_arena.") Reported-by: Colm Harrington <colm.harrington@oracle.com> Suggested-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
kernel-patches-daemon-bpf bot
pushed a commit
that referenced
this pull request
Feb 5, 2025
On an aarch64 kernel with CONFIG_PAGE_SIZE_64KB=y (64k pages), arena_htab tests cause a segmentation fault and soft lockup. $ sudo ./test_progs -t arena_htab Caught signal #11! Stack trace: ./test_progs(crash_handler+0x1c)[0x7bd4d8] linux-vdso.so.1(__kernel_rt_sigreturn+0x0)[0xffffb34a0968] ./test_progs[0x420f74] ./test_progs(htab_lookup_elem+0x3c)[0x421090] ./test_progs[0x421320] ./test_progs[0x421bb8] ./test_progs(test_arena_htab+0x40)[0x421c14] ./test_progs[0x7bda84] ./test_progs(main+0x65c)[0x7bf670] /usr/lib64/libc.so.6(+0x2caa0)[0xffffb31ecaa0] /usr/lib64/libc.so.6(__libc_start_main+0x98)[0xffffb31ecb78] ./test_progs(_start+0x30)[0x41b4f0] Message from syslogd@bpfol9aarch64 at Feb 4 08:50:09 ... kernel:watchdog: BUG: soft lockup - CPU#1 stuck for 26s! [kworker/u8:4:7589] The same failure is not observed with 4k pages on aarch64. Investigating further, it turns out arena_map_free() was calling apply_to_existing_page_range() with the address returned by bpf_arena_get_kern_vm_start(). If this address is not page-aligned - as is the case for a 64k page kernel - we wind up calling apply_to_pte_range() with that unaligned address. The problem is apply_to_pte_range() implicitly assumes that the addr passed in is page-aligned, specifically in this loop: do { if (create || !pte_none(ptep_get(pte))) { err = fn(pte++, addr, data); if (err) break; } } while (addr += PAGE_SIZE, addr != end); If addr is _not_ page-aligned, it will never equal end exactly. One solution is to round up GUARD_SZ to PAGE_SIZE << 1 so that the division by 2 in bpf_arena_get_kern_vm_start() returns a page-aligned value. With that change in place, the test passes: $ sudo ./test_progs -t arena_htab Summary: 1/1 PASSED, 1 SKIPPED, 0 FAILED Fixes: 3174603 ("bpf: Introduce bpf_arena.") Reported-by: Colm Harrington <colm.harrington@oracle.com> Suggested-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Pull request for series with
subject: samples: bpf: refactor xdp_sample_pkts_kern with BTF-defined map
version: 1
url: https://patchwork.ozlabs.org/project/netdev/list/?series=199711