bpf: detect build errors for man pages for bpftool and eBPF helpers #16

kernel-patches-bot · 2020-09-07T17:48:39Z

Pull request for series with
subject: bpf: detect build errors for man pages for bpftool and eBPF helpers
version: 1
url: https://patchwork.ozlabs.org/project/netdev/list/?series=200012

kernel-patches-bot · 2020-09-07T17:48:40Z

Master branch: f9bec5d
series: https://patchwork.ozlabs.org/project/netdev/list/?series=200012
version: 1

patch https://patchwork.ozlabs.org/project/netdev/patch/20200907164017.30644-2-quentin@isovalent.com/ applied successfully
patch https://patchwork.ozlabs.org/project/netdev/patch/20200907164017.30644-3-quentin@isovalent.com/ applied successfully

kernel-patches-bot · 2020-09-07T19:24:37Z

Master branch: bc0b5a0
series: https://patchwork.ozlabs.org/project/netdev/list/?series=200012
version: 1

patch https://patchwork.ozlabs.org/project/netdev/patch/20200907164017.30644-2-quentin@isovalent.com/ applied successfully
patch https://patchwork.ozlabs.org/project/netdev/patch/20200907164017.30644-3-quentin@isovalent.com/ applied successfully

kernel-patches-bot · 2020-09-09T03:35:14Z

Master branch: e6054fc
series: https://patchwork.ozlabs.org/project/netdev/list/?series=200012
version: 1

patch https://patchwork.ozlabs.org/project/netdev/patch/20200907164017.30644-2-quentin@isovalent.com/ applied successfully
patch https://patchwork.ozlabs.org/project/netdev/patch/20200907164017.30644-3-quentin@isovalent.com/ applied successfully

kernel-patches-bot · 2020-09-09T16:42:31Z

Master branch: e6054fc
series: https://patchwork.ozlabs.org/project/netdev/list/?series=200562
version: 2

patch https://patchwork.ozlabs.org/project/netdev/patch/20200909162251.15498-2-quentin@isovalent.com/ applied successfully
patch https://patchwork.ozlabs.org/project/netdev/patch/20200909162251.15498-3-quentin@isovalent.com/ applied successfully

can log different levels of information. Let's make it log all levels to keep the RST files clean. Doing so, rst2man complains about double colons, used for literal blocks, that look like underlines for section titles. Let's add the necessary blank lines. v2: - Use "--verbose" instead of "-r 1" (same behaviour but more readable). - Pass it through a RST2MAN_OPTS variable so we can easily pass other options too. Signed-off-by: Quentin Monnet <quentin@isovalent.com> Acked-by: Andrii Nakryiko <andriin@fb.com> --- tools/bpf/bpftool/Documentation/Makefile | 3 ++- tools/bpf/bpftool/Documentation/bpftool-btf.rst | 3 +++ tools/bpf/bpftool/Documentation/bpftool-gen.rst | 4 ++++ tools/bpf/bpftool/Documentation/bpftool-map.rst | 3 +++ 4 files changed, 12 insertions(+), 1 deletion(-)

with different command lines. Let's add one build for bpftool's documentation so as to detect errors or warning reported by rst2man when compiling the man pages. Also add a build to the selftests Makefile to make sure we build bpftool documentation along with bpftool when building the selftests. This also builds and checks warnings for the man page for eBPF helpers, which is built along bpftool's documentation. This change adds rst2man as a dependency for selftests (it comes with Python's "docutils"). v2: - Use "--exit-status=1" option for rst2man instead of counting lines from stderr. - Also build bpftool as part as the selftests build (and not only when the tests are actually run). Signed-off-by: Quentin Monnet <quentin@isovalent.com> --- tools/testing/selftests/bpf/Makefile | 5 +++++ .../selftests/bpf/test_bpftool_build.sh | 21 +++++++++++++++++++ 2 files changed, 26 insertions(+)

kernel-patches-bot · 2020-09-09T20:12:14Z

Master branch: 8081ede
series: https://patchwork.ozlabs.org/project/netdev/list/?series=200562
version: 2

patch https://patchwork.ozlabs.org/project/netdev/patch/20200909162251.15498-2-quentin@isovalent.com/ applied successfully
patch https://patchwork.ozlabs.org/project/netdev/patch/20200909162251.15498-3-quentin@isovalent.com/ applied successfully

kernel-patches-bot · 2020-09-10T21:26:02Z

At least one diff in series https://patchwork.ozlabs.org/project/netdev/list/?series=200562 irrelevant now. Closing PR.

…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>

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>

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>

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>

__apply_to_page_range() is also used to change and/or allocate page-table pages in the vmalloc area of the address space. Make sure these changes get synchronized to other page-tables in the system by calling arch_sync_kernel_mappings() when necessary. The impact appears limited to x86-32, where apply_to_page_range may miss updating the PMD. That leads to explosions in drivers like BUG: unable to handle page fault for address: fe036000 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page *pde = 00000000 Oops: 0002 [#1] SMP CPU: 3 PID: 1300 Comm: gem_concurrent_ Not tainted 5.9.0-rc1+ #16 Hardware name: /NUC6i3SYB, BIOS SYSKLi35.86A.0024.2015.1027.2142 10/27/2015 EIP: __execlists_context_alloc+0x132/0x2d0 [i915] Code: 31 d2 89 f0 e8 2f 55 02 00 89 45 e8 3d 00 f0 ff ff 0f 87 11 01 00 00 8b 4d e8 03 4b 30 b8 5a 5a 5a 5a ba 01 00 00 00 8d 79 04 <c7> 01 5a 5a 5a 5a c7 81 fc 0f 00 00 5a 5a 5a 5a 83 e7 fc 29 f9 81 EAX: 5a5a5a5a EBX: f60ca000 ECX: fe036000 EDX: 00000001 ESI: f43b7340 EDI: fe036004 EBP: f6389cb8 ESP: f6389c9c DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 EFLAGS: 00010286 CR0: 80050033 CR2: fe036000 CR3: 2d361000 CR4: 001506d0 DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000 DR6: fffe0ff0 DR7: 00000400 Call Trace: execlists_context_alloc+0x10/0x20 [i915] intel_context_alloc_state+0x3f/0x70 [i915] __intel_context_do_pin+0x117/0x170 [i915] i915_gem_do_execbuffer+0xcc7/0x2500 [i915] i915_gem_execbuffer2_ioctl+0xcd/0x1f0 [i915] drm_ioctl_kernel+0x8f/0xd0 drm_ioctl+0x223/0x3d0 __ia32_sys_ioctl+0x1ab/0x760 __do_fast_syscall_32+0x3f/0x70 do_fast_syscall_32+0x29/0x60 do_SYSENTER_32+0x15/0x20 entry_SYSENTER_32+0x9f/0xf2 EIP: 0xb7f28559 Code: 03 74 c0 01 10 05 03 74 b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d 76 00 58 b8 77 00 00 00 cd 80 90 8d 76 EAX: ffffffda EBX: 00000005 ECX: c0406469 EDX: bf95556c ESI: b7e68000 EDI: c0406469 EBP: 00000005 ESP: bf9554d8 DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 007b EFLAGS: 00000296 Modules linked in: i915 x86_pkg_temp_thermal intel_powerclamp crc32_pclmul crc32c_intel intel_cstate intel_uncore intel_gtt drm_kms_helper intel_pch_thermal video button autofs4 i2c_i801 i2c_smbus fan CR2: 00000000fe036000 It looks like kasan, xen and i915 are vulnerable. Actual impact is "on thinkpad X60 in 5.9-rc1, screen starts blinking after 30-or-so minutes, and machine is unusable" [sfr@canb.auug.org.au: ARCH_PAGE_TABLE_SYNC_MASK needs vmalloc.h] Link: https://lkml.kernel.org/r/20200825172508.16800a4f@canb.auug.org.au [chris@chris-wilson.co.uk: changelog addition] [pavel@ucw.cz: changelog addition] Fixes: 2ba3e69 ("mm/vmalloc: track which page-table levels were modified") Fixes: 86cf69f ("x86/mm/32: implement arch_sync_kernel_mappings()") Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Tested-by: Chris Wilson <chris@chris-wilson.co.uk> [x86-32] Tested-by: Pavel Machek <pavel@ucw.cz> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: <stable@vger.kernel.org> [5.8+] Link: https://lkml.kernel.org/r/20200821123746.16904-1-joro@8bytes.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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>

Routes are currently processed from a workqueue whereas nexthop objects are processed in system call context. This can result in the driver not finding a suitable nexthop group for a route and issuing a warning [1]. Fix this by ignoring such routes earlier in the process. The subsequent deletion notification will be ignored as well. [1] WARNING: CPU: 2 PID: 7754 at drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:4853 mlxsw_sp_router_fib_event_work+0x1112/0x1e00 [mlxsw_spectrum] [...] CPU: 2 PID: 7754 Comm: kworker/u8:0 Not tainted 5.11.0-rc6-cq-20210207-1 #16 Hardware name: Mellanox Technologies Ltd. MSN2100/SA001390, BIOS 5.6.5 05/24/2018 Workqueue: mlxsw_core_ordered mlxsw_sp_router_fib_event_work [mlxsw_spectrum] RIP: 0010:mlxsw_sp_router_fib_event_work+0x1112/0x1e00 [mlxsw_spectrum] Fixes: cdd6cfc ("mlxsw: spectrum_router: Allow programming routes with nexthop objects") Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reported-by: Alex Veber <alexve@nvidia.com> Tested-by: Alex Veber <alexve@nvidia.com> Reviewed-by: Petr Machata <petrm@nvidia.com> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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>

A sysfs reader can race with a device reset or removal, attempting to read device state when the device is not actually present. eg: [exception RIP: qed_get_current_link+17] kernel-patches#8 [ffffb9e4f2907c48] qede_get_link_ksettings at ffffffffc07a994a [qede] kernel-patches#9 [ffffb9e4f2907cd8] __rh_call_get_link_ksettings at ffffffff992b01a3 kernel-patches#10 [ffffb9e4f2907d38] __ethtool_get_link_ksettings at ffffffff992b04e4 kernel-patches#11 [ffffb9e4f2907d90] duplex_show at ffffffff99260300 kernel-patches#12 [ffffb9e4f2907e38] dev_attr_show at ffffffff9905a01c kernel-patches#13 [ffffb9e4f2907e50] sysfs_kf_seq_show at ffffffff98e0145b kernel-patches#14 [ffffb9e4f2907e68] seq_read at ffffffff98d902e3 kernel-patches#15 [ffffb9e4f2907ec8] vfs_read at ffffffff98d657d1 kernel-patches#16 [ffffb9e4f2907f00] ksys_read at ffffffff98d65c3f kernel-patches#17 [ffffb9e4f2907f38] do_syscall_64 at ffffffff98a052fb crash> struct net_device.state ffff9a9d21336000 state = 5, state 5 is __LINK_STATE_START (0b1) and __LINK_STATE_NOCARRIER (0b100). The device is not present, note lack of __LINK_STATE_PRESENT (0b10). This is the same sort of panic as observed in commit 4224cfd ("net-sysfs: add check for netdevice being present to speed_show"). There are many other callers of __ethtool_get_link_ksettings() which don't have a device presence check. Move this check into ethtool to protect all callers. Fixes: d519e17 ("net: export device speed and duplex via sysfs") Fixes: 4224cfd ("net-sysfs: add check for netdevice being present to speed_show") Signed-off-by: Jamie Bainbridge <jamie.bainbridge@gmail.com> Signed-off-by: NipaLocal <nipa@local>

The arm64 jit blindly saves/restores all callee-saved registers, making the jited result looks a bit too compliated. For example, for an empty prog, the jited result is: 0: bti jc 4: mov x9, lr 8: nop c: paciasp 10: stp fp, lr, [sp, #-16]! 14: mov fp, sp 18: stp x19, x20, [sp, #-16]! 1c: stp x21, x22, [sp, #-16]! 20: stp x26, x25, [sp, #-16]! 24: mov x26, #0 28: stp x26, x25, [sp, #-16]! 2c: mov x26, sp 30: stp x27, x28, [sp, #-16]! 34: mov x25, sp 38: bti j // tailcall target 3c: sub sp, sp, #0 40: mov x7, #0 44: add sp, sp, #0 48: ldp x27, x28, [sp], #16 4c: ldp x26, x25, [sp], #16 50: ldp x26, x25, [sp], #16 54: ldp x21, x22, [sp], #16 58: ldp x19, x20, [sp], #16 5c: ldp fp, lr, [sp], #16 60: mov x0, x7 64: autiasp 68: ret Clearly, there is no need to save/restore unused callee-saved registers. This patch does this change, making the jited image to only save/restore the callee-saved registers it uses. Now the jited result of empty prog is: 0: bti jc 4: mov x9, lr 8: nop c: paciasp 10: stp fp, lr, [sp, #-16]! 14: mov fp, sp 18: stp xzr, x26, [sp, #-16]! 1c: mov x26, sp 20: bti j // tailcall target 24: mov x7, #0 28: ldp xzr, x26, [sp], #16 2c: ldp fp, lr, [sp], #16 30: mov x0, x7 34: autiasp 38: ret Since bpf prog saves/restores its own callee-saved registers as needed, to make tailcall work correctly, the caller needs to restore its saved registers before tailcall, and the callee needs to save its callee-saved registers after tailcall. This extra restoring/saving instructions increases preformance overhead. [1] provides 2 benchmarks for tailcall scenarios. Below is the perf number measured in an arm64 KVM guest. The result indicates that the performance difference before and after the patch in typical tailcall scenarios is negligible. - Before: Performance counter stats for './test_progs -t tailcalls' (5 runs): 4313.43 msec task-clock # 0.874 CPUs utilized ( +- 0.16% ) 574 context-switches # 133.073 /sec ( +- 1.14% ) 0 cpu-migrations # 0.000 /sec 538 page-faults # 124.727 /sec ( +- 0.57% ) 10697772784 cycles # 2.480 GHz ( +- 0.22% ) (61.19%) 25511241955 instructions # 2.38 insn per cycle ( +- 0.08% ) (66.70%) 5108910557 branches # 1.184 G/sec ( +- 0.08% ) (72.38%) 2800459 branch-misses # 0.05% of all branches ( +- 0.51% ) (72.36%) TopDownL1 # 0.60 retiring ( +- 0.09% ) (66.84%) # 0.21 frontend_bound ( +- 0.15% ) (61.31%) # 0.12 bad_speculation ( +- 0.08% ) (50.11%) # 0.07 backend_bound ( +- 0.16% ) (33.30%) 8274201819 L1-dcache-loads # 1.918 G/sec ( +- 0.18% ) (33.15%) 468268 L1-dcache-load-misses # 0.01% of all L1-dcache accesses ( +- 4.69% ) (33.16%) 385383 LLC-loads # 89.345 K/sec ( +- 5.22% ) (33.16%) 38296 LLC-load-misses # 9.94% of all LL-cache accesses ( +- 42.52% ) (38.69%) 6886576501 L1-icache-loads # 1.597 G/sec ( +- 0.35% ) (38.69%) 1848585 L1-icache-load-misses # 0.03% of all L1-icache accesses ( +- 4.52% ) (44.23%) 9043645883 dTLB-loads # 2.097 G/sec ( +- 0.10% ) (44.33%) 416672 dTLB-load-misses # 0.00% of all dTLB cache accesses ( +- 5.15% ) (49.89%) 6925626111 iTLB-loads # 1.606 G/sec ( +- 0.35% ) (55.46%) 66220 iTLB-load-misses # 0.00% of all iTLB cache accesses ( +- 1.88% ) (55.50%) <not supported> L1-dcache-prefetches <not supported> L1-dcache-prefetch-misses 4.9372 +- 0.0526 seconds time elapsed ( +- 1.07% ) Performance counter stats for './test_progs -t flow_dissector' (5 runs): 10924.50 msec task-clock # 0.945 CPUs utilized ( +- 0.08% ) 603 context-switches # 55.197 /sec ( +- 1.13% ) 0 cpu-migrations # 0.000 /sec 566 page-faults # 51.810 /sec ( +- 0.42% ) 27381270695 cycles # 2.506 GHz ( +- 0.18% ) (60.46%) 56996583922 instructions # 2.08 insn per cycle ( +- 0.21% ) (66.11%) 10321647567 branches # 944.816 M/sec ( +- 0.17% ) (71.79%) 3347735 branch-misses # 0.03% of all branches ( +- 3.72% ) (72.15%) TopDownL1 # 0.52 retiring ( +- 0.13% ) (66.74%) # 0.27 frontend_bound ( +- 0.14% ) (61.27%) # 0.14 bad_speculation ( +- 0.19% ) (50.36%) # 0.07 backend_bound ( +- 0.42% ) (33.89%) 18740797617 L1-dcache-loads # 1.715 G/sec ( +- 0.43% ) (33.71%) 13715669 L1-dcache-load-misses # 0.07% of all L1-dcache accesses ( +- 32.85% ) (33.34%) 4087551 LLC-loads # 374.164 K/sec ( +- 29.53% ) (33.26%) 267906 LLC-load-misses # 6.55% of all LL-cache accesses ( +- 23.90% ) (38.76%) 15811864229 L1-icache-loads # 1.447 G/sec ( +- 0.12% ) (38.73%) 2976833 L1-icache-load-misses # 0.02% of all L1-icache accesses ( +- 9.73% ) (44.22%) 20138907471 dTLB-loads # 1.843 G/sec ( +- 0.18% ) (44.15%) 732850 dTLB-load-misses # 0.00% of all dTLB cache accesses ( +- 11.18% ) (49.64%) 15895726702 iTLB-loads # 1.455 G/sec ( +- 0.15% ) (55.13%) 152075 iTLB-load-misses # 0.00% of all iTLB cache accesses ( +- 4.71% ) (54.98%) <not supported> L1-dcache-prefetches <not supported> L1-dcache-prefetch-misses 11.5613 +- 0.0317 seconds time elapsed ( +- 0.27% ) - After: Performance counter stats for './test_progs -t tailcalls' (5 runs): 4278.78 msec task-clock # 0.871 CPUs utilized ( +- 0.15% ) 569 context-switches # 132.982 /sec ( +- 0.58% ) 0 cpu-migrations # 0.000 /sec 539 page-faults # 125.970 /sec ( +- 0.43% ) 10588986432 cycles # 2.475 GHz ( +- 0.20% ) (60.91%) 25303825043 instructions # 2.39 insn per cycle ( +- 0.08% ) (66.48%) 5110756256 branches # 1.194 G/sec ( +- 0.07% ) (72.03%) 2719569 branch-misses # 0.05% of all branches ( +- 2.42% ) (72.03%) TopDownL1 # 0.60 retiring ( +- 0.22% ) (66.31%) # 0.22 frontend_bound ( +- 0.21% ) (60.83%) # 0.12 bad_speculation ( +- 0.26% ) (50.25%) # 0.06 backend_bound ( +- 0.17% ) (33.52%) 8163648527 L1-dcache-loads # 1.908 G/sec ( +- 0.33% ) (33.52%) 694979 L1-dcache-load-misses # 0.01% of all L1-dcache accesses ( +- 30.53% ) (33.52%) 1902347 LLC-loads # 444.600 K/sec ( +- 48.84% ) (33.69%) 96677 LLC-load-misses # 5.08% of all LL-cache accesses ( +- 43.48% ) (39.30%) 6863517589 L1-icache-loads # 1.604 G/sec ( +- 0.37% ) (39.17%) 1871519 L1-icache-load-misses # 0.03% of all L1-icache accesses ( +- 6.78% ) (44.56%) 8927782813 dTLB-loads # 2.087 G/sec ( +- 0.14% ) (44.37%) 438237 dTLB-load-misses # 0.00% of all dTLB cache accesses ( +- 6.00% ) (49.75%) 6886906831 iTLB-loads # 1.610 G/sec ( +- 0.36% ) (55.08%) 67568 iTLB-load-misses # 0.00% of all iTLB cache accesses ( +- 3.27% ) (54.86%) <not supported> L1-dcache-prefetches <not supported> L1-dcache-prefetch-misses 4.9114 +- 0.0309 seconds time elapsed ( +- 0.63% ) Performance counter stats for './test_progs -t flow_dissector' (5 runs): 10948.40 msec task-clock # 0.942 CPUs utilized ( +- 0.05% ) 615 context-switches # 56.173 /sec ( +- 1.65% ) 1 cpu-migrations # 0.091 /sec ( +- 31.62% ) 567 page-faults # 51.788 /sec ( +- 0.44% ) 27334194328 cycles # 2.497 GHz ( +- 0.08% ) (61.05%) 56656528828 instructions # 2.07 insn per cycle ( +- 0.08% ) (66.67%) 10270389422 branches # 938.072 M/sec ( +- 0.10% ) (72.21%) 3453837 branch-misses # 0.03% of all branches ( +- 3.75% ) (72.27%) TopDownL1 # 0.52 retiring ( +- 0.16% ) (66.55%) # 0.27 frontend_bound ( +- 0.09% ) (60.91%) # 0.14 bad_speculation ( +- 0.08% ) (49.85%) # 0.07 backend_bound ( +- 0.16% ) (33.33%) 18982866028 L1-dcache-loads # 1.734 G/sec ( +- 0.24% ) (33.34%) 8802454 L1-dcache-load-misses # 0.05% of all L1-dcache accesses ( +- 52.30% ) (33.31%) 2612962 LLC-loads # 238.661 K/sec ( +- 29.78% ) (33.45%) 264107 LLC-load-misses # 10.11% of all LL-cache accesses ( +- 18.34% ) (39.07%) 15793205997 L1-icache-loads # 1.443 G/sec ( +- 0.15% ) (39.09%) 3930802 L1-icache-load-misses # 0.02% of all L1-icache accesses ( +- 3.72% ) (44.66%) 20097828496 dTLB-loads # 1.836 G/sec ( +- 0.09% ) (44.68%) 961757 dTLB-load-misses # 0.00% of all dTLB cache accesses ( +- 3.32% ) (50.15%) 15838728506 iTLB-loads # 1.447 G/sec ( +- 0.09% ) (55.62%) 167652 iTLB-load-misses # 0.00% of all iTLB cache accesses ( +- 1.28% ) (55.52%) <not supported> L1-dcache-prefetches <not supported> L1-dcache-prefetch-misses 11.6173 +- 0.0268 seconds time elapsed ( +- 0.23% ) [1] https://lore.kernel.org/bpf/20200724123644.5096-1-maciej.fijalkowski@intel.com/ Signed-off-by: Xu Kuohai <xukuohai@huawei.com>

A sysfs reader can race with a device reset or removal, attempting to read device state when the device is not actually present. eg: [exception RIP: qed_get_current_link+17] kernel-patches#8 [ffffb9e4f2907c48] qede_get_link_ksettings at ffffffffc07a994a [qede] kernel-patches#9 [ffffb9e4f2907cd8] __rh_call_get_link_ksettings at ffffffff992b01a3 kernel-patches#10 [ffffb9e4f2907d38] __ethtool_get_link_ksettings at ffffffff992b04e4 kernel-patches#11 [ffffb9e4f2907d90] duplex_show at ffffffff99260300 kernel-patches#12 [ffffb9e4f2907e38] dev_attr_show at ffffffff9905a01c kernel-patches#13 [ffffb9e4f2907e50] sysfs_kf_seq_show at ffffffff98e0145b kernel-patches#14 [ffffb9e4f2907e68] seq_read at ffffffff98d902e3 kernel-patches#15 [ffffb9e4f2907ec8] vfs_read at ffffffff98d657d1 kernel-patches#16 [ffffb9e4f2907f00] ksys_read at ffffffff98d65c3f kernel-patches#17 [ffffb9e4f2907f38] do_syscall_64 at ffffffff98a052fb crash> struct net_device.state ffff9a9d21336000 state = 5, state 5 is __LINK_STATE_START (0b1) and __LINK_STATE_NOCARRIER (0b100). The device is not present, note lack of __LINK_STATE_PRESENT (0b10). This is the same sort of panic as observed in commit 4224cfd ("net-sysfs: add check for netdevice being present to speed_show"). There are many other callers of __ethtool_get_link_ksettings() which don't have a device presence check. Move this check into ethtool to protect all callers. Fixes: d519e17 ("net: export device speed and duplex via sysfs") Fixes: 4224cfd ("net-sysfs: add check for netdevice being present to speed_show") Signed-off-by: Jamie Bainbridge <jamie.bainbridge@gmail.com> Signed-off-by: NipaLocal <nipa@local>

A sysfs reader can race with a device reset or removal, attempting to read device state when the device is not actually present. eg: [exception RIP: qed_get_current_link+17] kernel-patches#8 [ffffb9e4f2907c48] qede_get_link_ksettings at ffffffffc07a994a [qede] kernel-patches#9 [ffffb9e4f2907cd8] __rh_call_get_link_ksettings at ffffffff992b01a3 kernel-patches#10 [ffffb9e4f2907d38] __ethtool_get_link_ksettings at ffffffff992b04e4 kernel-patches#11 [ffffb9e4f2907d90] duplex_show at ffffffff99260300 kernel-patches#12 [ffffb9e4f2907e38] dev_attr_show at ffffffff9905a01c kernel-patches#13 [ffffb9e4f2907e50] sysfs_kf_seq_show at ffffffff98e0145b kernel-patches#14 [ffffb9e4f2907e68] seq_read at ffffffff98d902e3 kernel-patches#15 [ffffb9e4f2907ec8] vfs_read at ffffffff98d657d1 kernel-patches#16 [ffffb9e4f2907f00] ksys_read at ffffffff98d65c3f kernel-patches#17 [ffffb9e4f2907f38] do_syscall_64 at ffffffff98a052fb crash> struct net_device.state ffff9a9d21336000 state = 5, state 5 is __LINK_STATE_START (0b1) and __LINK_STATE_NOCARRIER (0b100). The device is not present, note lack of __LINK_STATE_PRESENT (0b10). This is the same sort of panic as observed in commit 4224cfd ("net-sysfs: add check for netdevice being present to speed_show"). There are many other callers of __ethtool_get_link_ksettings() which don't have a device presence check. Move this check into ethtool to protect all callers. Fixes: d519e17 ("net: export device speed and duplex via sysfs") Fixes: 4224cfd ("net-sysfs: add check for netdevice being present to speed_show") Signed-off-by: Jamie Bainbridge <jamie.bainbridge@gmail.com> Link: https://patch.msgid.link/8bae218864beaa44ed01628140475b9bf641c5b0.1724393671.git.jamie.bainbridge@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>

The arm64 jit blindly saves/restores all callee-saved registers, making the jited result looks a bit too compliated. For example, for an empty prog, the jited result is: 0: bti jc 4: mov x9, lr 8: nop c: paciasp 10: stp fp, lr, [sp, #-16]! 14: mov fp, sp 18: stp x19, x20, [sp, #-16]! 1c: stp x21, x22, [sp, #-16]! 20: stp x26, x25, [sp, #-16]! 24: mov x26, #0 28: stp x26, x25, [sp, #-16]! 2c: mov x26, sp 30: stp x27, x28, [sp, #-16]! 34: mov x25, sp 38: bti j // tailcall target 3c: sub sp, sp, #0 40: mov x7, #0 44: add sp, sp, #0 48: ldp x27, x28, [sp], #16 4c: ldp x26, x25, [sp], #16 50: ldp x26, x25, [sp], #16 54: ldp x21, x22, [sp], #16 58: ldp x19, x20, [sp], #16 5c: ldp fp, lr, [sp], #16 60: mov x0, x7 64: autiasp 68: ret Clearly, there is no need to save/restore unused callee-saved registers. This patch does this change, making the jited image to only save/restore the callee-saved registers it uses. Now the jited result of empty prog is: 0: bti jc 4: mov x9, lr 8: nop c: paciasp 10: stp fp, lr, [sp, #-16]! 14: mov fp, sp 18: stp xzr, x26, [sp, #-16]! 1c: mov x26, sp 20: bti j // tailcall target 24: mov x7, #0 28: ldp xzr, x26, [sp], #16 2c: ldp fp, lr, [sp], #16 30: mov x0, x7 34: autiasp 38: ret Since bpf prog saves/restores its own callee-saved registers as needed, to make tailcall work correctly, the caller needs to restore its saved registers before tailcall, and the callee needs to save its callee-saved registers after tailcall. This extra restoring/saving instructions increases preformance overhead. [1] provides 2 benchmarks for tailcall scenarios. Below is the perf number measured in an arm64 KVM guest. The result indicates that the performance difference before and after the patch in typical tailcall scenarios is negligible. - Before: Performance counter stats for './test_progs -t tailcalls' (5 runs): 4313.43 msec task-clock # 0.874 CPUs utilized ( +- 0.16% ) 574 context-switches # 133.073 /sec ( +- 1.14% ) 0 cpu-migrations # 0.000 /sec 538 page-faults # 124.727 /sec ( +- 0.57% ) 10697772784 cycles # 2.480 GHz ( +- 0.22% ) (61.19%) 25511241955 instructions # 2.38 insn per cycle ( +- 0.08% ) (66.70%) 5108910557 branches # 1.184 G/sec ( +- 0.08% ) (72.38%) 2800459 branch-misses # 0.05% of all branches ( +- 0.51% ) (72.36%) TopDownL1 # 0.60 retiring ( +- 0.09% ) (66.84%) # 0.21 frontend_bound ( +- 0.15% ) (61.31%) # 0.12 bad_speculation ( +- 0.08% ) (50.11%) # 0.07 backend_bound ( +- 0.16% ) (33.30%) 8274201819 L1-dcache-loads # 1.918 G/sec ( +- 0.18% ) (33.15%) 468268 L1-dcache-load-misses # 0.01% of all L1-dcache accesses ( +- 4.69% ) (33.16%) 385383 LLC-loads # 89.345 K/sec ( +- 5.22% ) (33.16%) 38296 LLC-load-misses # 9.94% of all LL-cache accesses ( +- 42.52% ) (38.69%) 6886576501 L1-icache-loads # 1.597 G/sec ( +- 0.35% ) (38.69%) 1848585 L1-icache-load-misses # 0.03% of all L1-icache accesses ( +- 4.52% ) (44.23%) 9043645883 dTLB-loads # 2.097 G/sec ( +- 0.10% ) (44.33%) 416672 dTLB-load-misses # 0.00% of all dTLB cache accesses ( +- 5.15% ) (49.89%) 6925626111 iTLB-loads # 1.606 G/sec ( +- 0.35% ) (55.46%) 66220 iTLB-load-misses # 0.00% of all iTLB cache accesses ( +- 1.88% ) (55.50%) <not supported> L1-dcache-prefetches <not supported> L1-dcache-prefetch-misses 4.9372 +- 0.0526 seconds time elapsed ( +- 1.07% ) Performance counter stats for './test_progs -t flow_dissector' (5 runs): 10924.50 msec task-clock # 0.945 CPUs utilized ( +- 0.08% ) 603 context-switches # 55.197 /sec ( +- 1.13% ) 0 cpu-migrations # 0.000 /sec 566 page-faults # 51.810 /sec ( +- 0.42% ) 27381270695 cycles # 2.506 GHz ( +- 0.18% ) (60.46%) 56996583922 instructions # 2.08 insn per cycle ( +- 0.21% ) (66.11%) 10321647567 branches # 944.816 M/sec ( +- 0.17% ) (71.79%) 3347735 branch-misses # 0.03% of all branches ( +- 3.72% ) (72.15%) TopDownL1 # 0.52 retiring ( +- 0.13% ) (66.74%) # 0.27 frontend_bound ( +- 0.14% ) (61.27%) # 0.14 bad_speculation ( +- 0.19% ) (50.36%) # 0.07 backend_bound ( +- 0.42% ) (33.89%) 18740797617 L1-dcache-loads # 1.715 G/sec ( +- 0.43% ) (33.71%) 13715669 L1-dcache-load-misses # 0.07% of all L1-dcache accesses ( +- 32.85% ) (33.34%) 4087551 LLC-loads # 374.164 K/sec ( +- 29.53% ) (33.26%) 267906 LLC-load-misses # 6.55% of all LL-cache accesses ( +- 23.90% ) (38.76%) 15811864229 L1-icache-loads # 1.447 G/sec ( +- 0.12% ) (38.73%) 2976833 L1-icache-load-misses # 0.02% of all L1-icache accesses ( +- 9.73% ) (44.22%) 20138907471 dTLB-loads # 1.843 G/sec ( +- 0.18% ) (44.15%) 732850 dTLB-load-misses # 0.00% of all dTLB cache accesses ( +- 11.18% ) (49.64%) 15895726702 iTLB-loads # 1.455 G/sec ( +- 0.15% ) (55.13%) 152075 iTLB-load-misses # 0.00% of all iTLB cache accesses ( +- 4.71% ) (54.98%) <not supported> L1-dcache-prefetches <not supported> L1-dcache-prefetch-misses 11.5613 +- 0.0317 seconds time elapsed ( +- 0.27% ) - After: Performance counter stats for './test_progs -t tailcalls' (5 runs): 4278.78 msec task-clock # 0.871 CPUs utilized ( +- 0.15% ) 569 context-switches # 132.982 /sec ( +- 0.58% ) 0 cpu-migrations # 0.000 /sec 539 page-faults # 125.970 /sec ( +- 0.43% ) 10588986432 cycles # 2.475 GHz ( +- 0.20% ) (60.91%) 25303825043 instructions # 2.39 insn per cycle ( +- 0.08% ) (66.48%) 5110756256 branches # 1.194 G/sec ( +- 0.07% ) (72.03%) 2719569 branch-misses # 0.05% of all branches ( +- 2.42% ) (72.03%) TopDownL1 # 0.60 retiring ( +- 0.22% ) (66.31%) # 0.22 frontend_bound ( +- 0.21% ) (60.83%) # 0.12 bad_speculation ( +- 0.26% ) (50.25%) # 0.06 backend_bound ( +- 0.17% ) (33.52%) 8163648527 L1-dcache-loads # 1.908 G/sec ( +- 0.33% ) (33.52%) 694979 L1-dcache-load-misses # 0.01% of all L1-dcache accesses ( +- 30.53% ) (33.52%) 1902347 LLC-loads # 444.600 K/sec ( +- 48.84% ) (33.69%) 96677 LLC-load-misses # 5.08% of all LL-cache accesses ( +- 43.48% ) (39.30%) 6863517589 L1-icache-loads # 1.604 G/sec ( +- 0.37% ) (39.17%) 1871519 L1-icache-load-misses # 0.03% of all L1-icache accesses ( +- 6.78% ) (44.56%) 8927782813 dTLB-loads # 2.087 G/sec ( +- 0.14% ) (44.37%) 438237 dTLB-load-misses # 0.00% of all dTLB cache accesses ( +- 6.00% ) (49.75%) 6886906831 iTLB-loads # 1.610 G/sec ( +- 0.36% ) (55.08%) 67568 iTLB-load-misses # 0.00% of all iTLB cache accesses ( +- 3.27% ) (54.86%) <not supported> L1-dcache-prefetches <not supported> L1-dcache-prefetch-misses 4.9114 +- 0.0309 seconds time elapsed ( +- 0.63% ) Performance counter stats for './test_progs -t flow_dissector' (5 runs): 10948.40 msec task-clock # 0.942 CPUs utilized ( +- 0.05% ) 615 context-switches # 56.173 /sec ( +- 1.65% ) 1 cpu-migrations # 0.091 /sec ( +- 31.62% ) 567 page-faults # 51.788 /sec ( +- 0.44% ) 27334194328 cycles # 2.497 GHz ( +- 0.08% ) (61.05%) 56656528828 instructions # 2.07 insn per cycle ( +- 0.08% ) (66.67%) 10270389422 branches # 938.072 M/sec ( +- 0.10% ) (72.21%) 3453837 branch-misses # 0.03% of all branches ( +- 3.75% ) (72.27%) TopDownL1 # 0.52 retiring ( +- 0.16% ) (66.55%) # 0.27 frontend_bound ( +- 0.09% ) (60.91%) # 0.14 bad_speculation ( +- 0.08% ) (49.85%) # 0.07 backend_bound ( +- 0.16% ) (33.33%) 18982866028 L1-dcache-loads # 1.734 G/sec ( +- 0.24% ) (33.34%) 8802454 L1-dcache-load-misses # 0.05% of all L1-dcache accesses ( +- 52.30% ) (33.31%) 2612962 LLC-loads # 238.661 K/sec ( +- 29.78% ) (33.45%) 264107 LLC-load-misses # 10.11% of all LL-cache accesses ( +- 18.34% ) (39.07%) 15793205997 L1-icache-loads # 1.443 G/sec ( +- 0.15% ) (39.09%) 3930802 L1-icache-load-misses # 0.02% of all L1-icache accesses ( +- 3.72% ) (44.66%) 20097828496 dTLB-loads # 1.836 G/sec ( +- 0.09% ) (44.68%) 961757 dTLB-load-misses # 0.00% of all dTLB cache accesses ( +- 3.32% ) (50.15%) 15838728506 iTLB-loads # 1.447 G/sec ( +- 0.09% ) (55.62%) 167652 iTLB-load-misses # 0.00% of all iTLB cache accesses ( +- 1.28% ) (55.52%) <not supported> L1-dcache-prefetches <not supported> L1-dcache-prefetch-misses 11.6173 +- 0.0268 seconds time elapsed ( +- 0.23% ) [1] https://lore.kernel.org/bpf/20200724123644.5096-1-maciej.fijalkowski@intel.com/ Signed-off-by: Xu Kuohai <xukuohai@huawei.com>

The arm64 jit blindly saves/restores all callee-saved registers, making the jited result looks a bit too compliated. For example, for an empty prog, the jited result is: 0: bti jc 4: mov x9, lr 8: nop c: paciasp 10: stp fp, lr, [sp, #-16]! 14: mov fp, sp 18: stp x19, x20, [sp, #-16]! 1c: stp x21, x22, [sp, #-16]! 20: stp x26, x25, [sp, #-16]! 24: mov x26, #0 28: stp x26, x25, [sp, #-16]! 2c: mov x26, sp 30: stp x27, x28, [sp, #-16]! 34: mov x25, sp 38: bti j // tailcall target 3c: sub sp, sp, #0 40: mov x7, #0 44: add sp, sp, #0 48: ldp x27, x28, [sp], #16 4c: ldp x26, x25, [sp], #16 50: ldp x26, x25, [sp], #16 54: ldp x21, x22, [sp], #16 58: ldp x19, x20, [sp], #16 5c: ldp fp, lr, [sp], #16 60: mov x0, x7 64: autiasp 68: ret Clearly, there is no need to save/restore unused callee-saved registers. This patch does this change, making the jited image to only save/restore the callee-saved registers it uses. Now the jited result of empty prog is: 0: bti jc 4: mov x9, lr 8: nop c: paciasp 10: stp fp, lr, [sp, #-16]! 14: mov fp, sp 18: stp xzr, x26, [sp, #-16]! 1c: mov x26, sp 20: bti j // tailcall target 24: mov x7, #0 28: ldp xzr, x26, [sp], #16 2c: ldp fp, lr, [sp], #16 30: mov x0, x7 34: autiasp 38: ret Since bpf prog saves/restores its own callee-saved registers as needed, to make tailcall work correctly, the caller needs to restore its saved registers before tailcall, and the callee needs to save its callee-saved registers after tailcall. This extra restoring/saving instructions increases preformance overhead. [1] provides 2 benchmarks for tailcall scenarios. Below is the perf number measured in an arm64 KVM guest. The result indicates that the performance difference before and after the patch in typical tailcall scenarios is negligible. - Before: Performance counter stats for './test_progs -t tailcalls' (5 runs): 4313.43 msec task-clock # 0.874 CPUs utilized ( +- 0.16% ) 574 context-switches # 133.073 /sec ( +- 1.14% ) 0 cpu-migrations # 0.000 /sec 538 page-faults # 124.727 /sec ( +- 0.57% ) 10697772784 cycles # 2.480 GHz ( +- 0.22% ) (61.19%) 25511241955 instructions # 2.38 insn per cycle ( +- 0.08% ) (66.70%) 5108910557 branches # 1.184 G/sec ( +- 0.08% ) (72.38%) 2800459 branch-misses # 0.05% of all branches ( +- 0.51% ) (72.36%) TopDownL1 # 0.60 retiring ( +- 0.09% ) (66.84%) # 0.21 frontend_bound ( +- 0.15% ) (61.31%) # 0.12 bad_speculation ( +- 0.08% ) (50.11%) # 0.07 backend_bound ( +- 0.16% ) (33.30%) 8274201819 L1-dcache-loads # 1.918 G/sec ( +- 0.18% ) (33.15%) 468268 L1-dcache-load-misses # 0.01% of all L1-dcache accesses ( +- 4.69% ) (33.16%) 385383 LLC-loads # 89.345 K/sec ( +- 5.22% ) (33.16%) 38296 LLC-load-misses # 9.94% of all LL-cache accesses ( +- 42.52% ) (38.69%) 6886576501 L1-icache-loads # 1.597 G/sec ( +- 0.35% ) (38.69%) 1848585 L1-icache-load-misses # 0.03% of all L1-icache accesses ( +- 4.52% ) (44.23%) 9043645883 dTLB-loads # 2.097 G/sec ( +- 0.10% ) (44.33%) 416672 dTLB-load-misses # 0.00% of all dTLB cache accesses ( +- 5.15% ) (49.89%) 6925626111 iTLB-loads # 1.606 G/sec ( +- 0.35% ) (55.46%) 66220 iTLB-load-misses # 0.00% of all iTLB cache accesses ( +- 1.88% ) (55.50%) <not supported> L1-dcache-prefetches <not supported> L1-dcache-prefetch-misses 4.9372 +- 0.0526 seconds time elapsed ( +- 1.07% ) Performance counter stats for './test_progs -t flow_dissector' (5 runs): 10924.50 msec task-clock # 0.945 CPUs utilized ( +- 0.08% ) 603 context-switches # 55.197 /sec ( +- 1.13% ) 0 cpu-migrations # 0.000 /sec 566 page-faults # 51.810 /sec ( +- 0.42% ) 27381270695 cycles # 2.506 GHz ( +- 0.18% ) (60.46%) 56996583922 instructions # 2.08 insn per cycle ( +- 0.21% ) (66.11%) 10321647567 branches # 944.816 M/sec ( +- 0.17% ) (71.79%) 3347735 branch-misses # 0.03% of all branches ( +- 3.72% ) (72.15%) TopDownL1 # 0.52 retiring ( +- 0.13% ) (66.74%) # 0.27 frontend_bound ( +- 0.14% ) (61.27%) # 0.14 bad_speculation ( +- 0.19% ) (50.36%) # 0.07 backend_bound ( +- 0.42% ) (33.89%) 18740797617 L1-dcache-loads # 1.715 G/sec ( +- 0.43% ) (33.71%) 13715669 L1-dcache-load-misses # 0.07% of all L1-dcache accesses ( +- 32.85% ) (33.34%) 4087551 LLC-loads # 374.164 K/sec ( +- 29.53% ) (33.26%) 267906 LLC-load-misses # 6.55% of all LL-cache accesses ( +- 23.90% ) (38.76%) 15811864229 L1-icache-loads # 1.447 G/sec ( +- 0.12% ) (38.73%) 2976833 L1-icache-load-misses # 0.02% of all L1-icache accesses ( +- 9.73% ) (44.22%) 20138907471 dTLB-loads # 1.843 G/sec ( +- 0.18% ) (44.15%) 732850 dTLB-load-misses # 0.00% of all dTLB cache accesses ( +- 11.18% ) (49.64%) 15895726702 iTLB-loads # 1.455 G/sec ( +- 0.15% ) (55.13%) 152075 iTLB-load-misses # 0.00% of all iTLB cache accesses ( +- 4.71% ) (54.98%) <not supported> L1-dcache-prefetches <not supported> L1-dcache-prefetch-misses 11.5613 +- 0.0317 seconds time elapsed ( +- 0.27% ) - After: Performance counter stats for './test_progs -t tailcalls' (5 runs): 4278.78 msec task-clock # 0.871 CPUs utilized ( +- 0.15% ) 569 context-switches # 132.982 /sec ( +- 0.58% ) 0 cpu-migrations # 0.000 /sec 539 page-faults # 125.970 /sec ( +- 0.43% ) 10588986432 cycles # 2.475 GHz ( +- 0.20% ) (60.91%) 25303825043 instructions # 2.39 insn per cycle ( +- 0.08% ) (66.48%) 5110756256 branches # 1.194 G/sec ( +- 0.07% ) (72.03%) 2719569 branch-misses # 0.05% of all branches ( +- 2.42% ) (72.03%) TopDownL1 # 0.60 retiring ( +- 0.22% ) (66.31%) # 0.22 frontend_bound ( +- 0.21% ) (60.83%) # 0.12 bad_speculation ( +- 0.26% ) (50.25%) # 0.06 backend_bound ( +- 0.17% ) (33.52%) 8163648527 L1-dcache-loads # 1.908 G/sec ( +- 0.33% ) (33.52%) 694979 L1-dcache-load-misses # 0.01% of all L1-dcache accesses ( +- 30.53% ) (33.52%) 1902347 LLC-loads # 444.600 K/sec ( +- 48.84% ) (33.69%) 96677 LLC-load-misses # 5.08% of all LL-cache accesses ( +- 43.48% ) (39.30%) 6863517589 L1-icache-loads # 1.604 G/sec ( +- 0.37% ) (39.17%) 1871519 L1-icache-load-misses # 0.03% of all L1-icache accesses ( +- 6.78% ) (44.56%) 8927782813 dTLB-loads # 2.087 G/sec ( +- 0.14% ) (44.37%) 438237 dTLB-load-misses # 0.00% of all dTLB cache accesses ( +- 6.00% ) (49.75%) 6886906831 iTLB-loads # 1.610 G/sec ( +- 0.36% ) (55.08%) 67568 iTLB-load-misses # 0.00% of all iTLB cache accesses ( +- 3.27% ) (54.86%) <not supported> L1-dcache-prefetches <not supported> L1-dcache-prefetch-misses 4.9114 +- 0.0309 seconds time elapsed ( +- 0.63% ) Performance counter stats for './test_progs -t flow_dissector' (5 runs): 10948.40 msec task-clock # 0.942 CPUs utilized ( +- 0.05% ) 615 context-switches # 56.173 /sec ( +- 1.65% ) 1 cpu-migrations # 0.091 /sec ( +- 31.62% ) 567 page-faults # 51.788 /sec ( +- 0.44% ) 27334194328 cycles # 2.497 GHz ( +- 0.08% ) (61.05%) 56656528828 instructions # 2.07 insn per cycle ( +- 0.08% ) (66.67%) 10270389422 branches # 938.072 M/sec ( +- 0.10% ) (72.21%) 3453837 branch-misses # 0.03% of all branches ( +- 3.75% ) (72.27%) TopDownL1 # 0.52 retiring ( +- 0.16% ) (66.55%) # 0.27 frontend_bound ( +- 0.09% ) (60.91%) # 0.14 bad_speculation ( +- 0.08% ) (49.85%) # 0.07 backend_bound ( +- 0.16% ) (33.33%) 18982866028 L1-dcache-loads # 1.734 G/sec ( +- 0.24% ) (33.34%) 8802454 L1-dcache-load-misses # 0.05% of all L1-dcache accesses ( +- 52.30% ) (33.31%) 2612962 LLC-loads # 238.661 K/sec ( +- 29.78% ) (33.45%) 264107 LLC-load-misses # 10.11% of all LL-cache accesses ( +- 18.34% ) (39.07%) 15793205997 L1-icache-loads # 1.443 G/sec ( +- 0.15% ) (39.09%) 3930802 L1-icache-load-misses # 0.02% of all L1-icache accesses ( +- 3.72% ) (44.66%) 20097828496 dTLB-loads # 1.836 G/sec ( +- 0.09% ) (44.68%) 961757 dTLB-load-misses # 0.00% of all dTLB cache accesses ( +- 3.32% ) (50.15%) 15838728506 iTLB-loads # 1.447 G/sec ( +- 0.09% ) (55.62%) 167652 iTLB-load-misses # 0.00% of all iTLB cache accesses ( +- 1.28% ) (55.52%) <not supported> L1-dcache-prefetches <not supported> L1-dcache-prefetch-misses 11.6173 +- 0.0268 seconds time elapsed ( +- 0.23% ) [1] https://lore.kernel.org/bpf/20200724123644.5096-1-maciej.fijalkowski@intel.com/ Signed-off-by: Xu Kuohai <xukuohai@huawei.com> Link: https://lore.kernel.org/r/20240826071624.350108-3-xukuohai@huaweicloud.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Xu Kuohai says: ==================== bpf, arm64: Simplify jited prologue/epilogue From: Xu Kuohai <xukuohai@huawei.com> The arm64 jit blindly saves/restores all callee-saved registers, making the jited result looks a bit too compliated. For example, for an empty prog, the jited result is: 0: bti jc 4: mov x9, lr 8: nop c: paciasp 10: stp fp, lr, [sp, #-16]! 14: mov fp, sp 18: stp x19, x20, [sp, #-16]! 1c: stp x21, x22, [sp, #-16]! 20: stp x26, x25, [sp, #-16]! 24: mov x26, #0 28: stp x26, x25, [sp, #-16]! 2c: mov x26, sp 30: stp x27, x28, [sp, #-16]! 34: mov x25, sp 38: bti j // tailcall target 3c: sub sp, sp, #0 40: mov x7, #0 44: add sp, sp, #0 48: ldp x27, x28, [sp], #16 4c: ldp x26, x25, [sp], #16 50: ldp x26, x25, [sp], #16 54: ldp x21, x22, [sp], #16 58: ldp x19, x20, [sp], #16 5c: ldp fp, lr, [sp], #16 60: mov x0, x7 64: autiasp 68: ret Clearly, there is no need to save/restore unused callee-saved registers. This patch does this change, making the jited image to only save/restore the callee-saved registers it uses. Now the jited result of empty prog is: 0: bti jc 4: mov x9, lr 8: nop c: paciasp 10: stp fp, lr, [sp, #-16]! 14: mov fp, sp 18: stp xzr, x26, [sp, #-16]! 1c: mov x26, sp 20: bti j // tailcall target 24: mov x7, #0 28: ldp xzr, x26, [sp], #16 2c: ldp fp, lr, [sp], #16 30: mov x0, x7 34: autiasp 38: ret ==================== Acked-by: Puranjay Mohan <puranjay@kernel.org> Link: https://lore.kernel.org/r/20240826071624.350108-1-xukuohai@huaweicloud.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Currently, BPF_CALL is always jited to indirect call. When target is within the range of direct call, BPF_CALL can be jited to direct call. For example, the following BPF_CALL call __htab_map_lookup_elem is always jited to indirect call: mov x10, #0xffffffffffff18f4 movk x10, #0x821, lsl #16 movk x10, #0x8000, lsl #32 blr x10 When the address of target __htab_map_lookup_elem is within the range of direct call, the BPF_CALL can be jited to: bl 0xfffffffffd33bc98 This patch does such jit optimization by emitting arm64 direct calls for BPF_CALL when possible, indirect calls otherwise. Without this patch, the jit works as follows. 1. First pass A. Determine jited position and size for each bpf instruction. B. Computed the jited image size. 2. Allocate jited image with size computed in step 1. 3. Second pass A. Adjust jump offset for jump instructions B. Write the final image. This works because, for a given bpf prog, regardless of where the jited image is allocated, the jited result for each instruction is fixed. The second pass differs from the first only in adjusting the jump offsets, like changing "jmp imm1" to "jmp imm2", while the position and size of the "jmp" instruction remain unchanged. Now considering whether to jit BPF_CALL to arm64 direct or indirect call instruction. The choice depends solely on the jump offset: direct call if the jump offset is within 128MB, indirect call otherwise. For a given BPF_CALL, the target address is known, so the jump offset is decided by the jited address of the BPF_CALL instruction. In other words, for a given bpf prog, the jited result for each BPF_CALL is determined by its jited address. The jited address for a BPF_CALL is the jited image address plus the total jited size of all preceding instructions. For a given bpf prog, there are clearly no BPF_CALL instructions before the first BPF_CALL instruction. Since the jited result for all other instructions other than BPF_CALL are fixed, the total jited size preceding the first BPF_CALL is also fixed. Therefore, once the jited image is allocated, the jited address for the first BPF_CALL is fixed. Now that the jited result for the first BPF_CALL is fixed, the jited results for all instructions preceding the second BPF_CALL are fixed. So the jited address and result for the second BPF_CALL are also fixed. Similarly, we can conclude that the jited addresses and results for all subsequent BPF_CALL instructions are fixed. This means that, for a given bpf prog, once the jited image is allocated, the jited address and result for all instructions, including all BPF_CALL instructions, are fixed. Based on the observation, with this patch, the jit works as follows. 1. First pass Estimate the maximum jited image size. In this pass, all BPF_CALLs are jited to arm64 indirect calls since the jump offsets are unknown because the jited image is not allocated. 2. Allocate jited image with size estimated in step 1. 3. Second pass A. Determine the jited result for each BPF_CALL. B. Determine jited address and size for each bpf instruction. 4. Third pass A. Adjust jump offset for jump instructions. B. Write the final image. Signed-off-by: Xu Kuohai <xukuohai@huawei.com>

Currently, BPF_CALL is always jited to indirect call. When target is within the range of direct call, BPF_CALL can be jited to direct call. For example, the following BPF_CALL call __htab_map_lookup_elem is always jited to indirect call: mov x10, #0xffffffffffff18f4 movk x10, #0x821, lsl #16 movk x10, #0x8000, lsl #32 blr x10 When the address of target __htab_map_lookup_elem is within the range of direct call, the BPF_CALL can be jited to: bl 0xfffffffffd33bc98 This patch does such jit optimization by emitting arm64 direct calls for BPF_CALL when possible, indirect calls otherwise. Without this patch, the jit works as follows. 1. First pass A. Determine jited position and size for each bpf instruction. B. Computed the jited image size. 2. Allocate jited image with size computed in step 1. 3. Second pass A. Adjust jump offset for jump instructions B. Write the final image. This works because, for a given bpf prog, regardless of where the jited image is allocated, the jited result for each instruction is fixed. The second pass differs from the first only in adjusting the jump offsets, like changing "jmp imm1" to "jmp imm2", while the position and size of the "jmp" instruction remain unchanged. Now considering whether to jit BPF_CALL to arm64 direct or indirect call instruction. The choice depends solely on the jump offset: direct call if the jump offset is within 128MB, indirect call otherwise. For a given BPF_CALL, the target address is known, so the jump offset is decided by the jited address of the BPF_CALL instruction. In other words, for a given bpf prog, the jited result for each BPF_CALL is determined by its jited address. The jited address for a BPF_CALL is the jited image address plus the total jited size of all preceding instructions. For a given bpf prog, there are clearly no BPF_CALL instructions before the first BPF_CALL instruction. Since the jited result for all other instructions other than BPF_CALL are fixed, the total jited size preceding the first BPF_CALL is also fixed. Therefore, once the jited image is allocated, the jited address for the first BPF_CALL is fixed. Now that the jited result for the first BPF_CALL is fixed, the jited results for all instructions preceding the second BPF_CALL are fixed. So the jited address and result for the second BPF_CALL are also fixed. Similarly, we can conclude that the jited addresses and results for all subsequent BPF_CALL instructions are fixed. This means that, for a given bpf prog, once the jited image is allocated, the jited address and result for all instructions, including all BPF_CALL instructions, are fixed. Based on the observation, with this patch, the jit works as follows. 1. First pass Estimate the maximum jited image size. In this pass, all BPF_CALLs are jited to arm64 indirect calls since the jump offsets are unknown because the jited image is not allocated. 2. Allocate jited image with size estimated in step 1. 3. Second pass A. Determine the jited result for each BPF_CALL. B. Determine jited address and size for each bpf instruction. 4. Third pass A. Adjust jump offset for jump instructions. B. Write the final image. Signed-off-by: Xu Kuohai <xukuohai@huawei.com> Reviewed-by: Puranjay Mohan <puranjay@kernel.org> Link: https://lore.kernel.org/r/20240903094407.601107-1-xukuohai@huaweicloud.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>

…rnel/git/netfilter/nf-next Pablo Neira Ayuso says: ==================== Netfilter updates for net-next The following patchset contains Netfilter updates for net-next: Patch kernel-patches#1 adds ctnetlink support for kernel side filtering for deletions, from Changliang Wu. Patch kernel-patches#2 updates nft_counter support to Use u64_stats_t, from Sebastian Andrzej Siewior. Patch kernel-patches#3 uses kmemdup_array() in all xtables frontends, from Yan Zhen. Patch kernel-patches#4 is a oneliner to use ERR_CAST() in nf_conntrack instead opencoded casting, from Shen Lichuan. Patch kernel-patches#5 removes unused argument in nftables .validate interface, from Florian Westphal. Patch kernel-patches#6 is a oneliner to correct a typo in nftables kdoc, from Simon Horman. Patch kernel-patches#7 fixes missing kdoc in nftables, also from Simon. Patch kernel-patches#8 updates nftables to handle timeout less than CONFIG_HZ. Patch kernel-patches#9 rejects element expiration if timeout is zero, otherwise it is silently ignored. Patch kernel-patches#10 disallows element expiration larger than timeout. Patch kernel-patches#11 removes unnecessary READ_ONCE annotation while mutex is held. Patch kernel-patches#12 adds missing READ_ONCE/WRITE_ONCE annotation in dynset. Patch kernel-patches#13 annotates data-races around element expiration. Patch kernel-patches#14 allocates timeout and expiration in one single set element extension, they are tighly couple, no reason to keep them separated anymore. Patch kernel-patches#15 updates nftables to interpret zero timeout element as never times out. Note that it is already possible to declare sets with elements that never time out but this generalizes to all kind of set with timeouts. Patch kernel-patches#16 supports for element timeout and expiration updates. * tag 'nf-next-24-09-06' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next: netfilter: nf_tables: set element timeout update support netfilter: nf_tables: zero timeout means element never times out netfilter: nf_tables: consolidate timeout extension for elements netfilter: nf_tables: annotate data-races around element expiration netfilter: nft_dynset: annotate data-races around set timeout netfilter: nf_tables: remove annotation to access set timeout while holding lock netfilter: nf_tables: reject expiration higher than timeout netfilter: nf_tables: reject element expiration with no timeout netfilter: nf_tables: elements with timeout below CONFIG_HZ never expire netfilter: nf_tables: Add missing Kernel doc netfilter: nf_tables: Correct spelling in nf_tables.h netfilter: nf_tables: drop unused 3rd argument from validate callback ops netfilter: conntrack: Convert to use ERR_CAST() netfilter: Use kmemdup_array instead of kmemdup for multiple allocation netfilter: nft_counter: Use u64_stats_t for statistic. netfilter: ctnetlink: support CTA_FILTER for flush ==================== Link: https://patch.msgid.link/20240905232920.5481-1-pablo@netfilter.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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bpf: detect build errors for man pages for bpftool and eBPF helpers #16

bpf: detect build errors for man pages for bpftool and eBPF helpers #16

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bpf: detect build errors for man pages for bpftool and eBPF helpers #16

bpf: detect build errors for man pages for bpftool and eBPF helpers #16

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