Merge branch 'auto-args'

It's cumbersome to specify arguments of every function.  Since some
functions are well-known, provide `--auto-args` option to enable
recording argument of those functions.

Each function can be specified using -A or -R option and will override
the automatics arguments/return value (if any).

Closes #173.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>

.gitignore

@@ -31,3 +31,6 @@ TAGS
 tags
 cscope.*
 *.pyc
+*.sw[opn]
+*.patch
+*.orig

Makefile

@@ -106,6 +106,7 @@ LIBMCOUNT_UTILS_SRCS += $(srcdir)/utils/symbol.c $(srcdir)/utils/debug.c
 LIBMCOUNT_UTILS_SRCS += $(srcdir)/utils/rbtree.c $(srcdir)/utils/filter.c
 LIBMCOUNT_UTILS_SRCS += $(srcdir)/utils/demangle.c $(srcdir)/utils/utils.c
 LIBMCOUNT_UTILS_SRCS += $(srcdir)/utils/script.c $(srcdir)/utils/script-python.c
+LIBMCOUNT_UTILS_SRCS += $(srcdir)/utils/auto-args.c
 LIBMCOUNT_UTILS_OBJS := $(patsubst $(srcdir)/utils/%.c,$(objdir)/libmcount/%.op,$(LIBMCOUNT_UTILS_SRCS))
 
 LIBMCOUNT_NOP_SRCS := $(srcdir)/libmcount/mcount-nop.c
@@ -194,6 +195,9 @@ $(filter-out $(objdir)/uftrace.o,$(UFTRACE_OBJS)): $(objdir)/%.o: $(srcdir)/%.c
 $(objdir)/version.h: PHONY
 	@$(srcdir)/misc/version.sh $@ $(VERSION_GIT)
 
+$(srcdir)/utils/auto-args.h: $(srcdir)/misc/prototypes.h $(srcdir)/misc/gen-autoargs.py
+	$(QUIET_GEN)$(srcdir)/misc/gen-autoargs.py -i $< -o $@
+
 $(objdir)/uftrace: $(UFTRACE_OBJS) $(UFTRACE_ARCH_OBJS) $(objdir)/libtraceevent/libtraceevent.a
 	$(QUIET_LINK)$(CC) $(UFTRACE_CFLAGS) -o $@ $(UFTRACE_OBJS) $(UFTRACE_ARCH_OBJS) $(UFTRACE_LDFLAGS)
 

cmd-dump.c

@@ -464,7 +464,8 @@ static void get_feature_string(char *buf, size_t sz, uint64_t feature_mask)
 	bool first = true;
 	const char *feat_str[] = { "PLTHOOK", "TASK_SESSION", "KERNEL",
 				   "ARGUMENT", "RETVAL", "SYM_REL_ADDR",
-				   "MAX_STACK", "EVENT", "PERF_EVENT" };
+				   "MAX_STACK", "EVENT", "PERF_EVENT",
+				   "AUTO_ARGS" };
 
 	/* feat_str should match to enum uftrace_feat_bits */
 	for (i = 0; i < FEAT_BIT_MAX; i++) {

cmd-info.c

@@ -20,6 +20,7 @@
 #include "uftrace.h"
 #include "libmcount/mcount.h"
 #include "utils/utils.h"
+#include "utils/filter.h"
 
 #define BUILD_ID_SIZE 20
 #define BUILD_ID_STR_SIZE (BUILD_ID_SIZE * 2 + 1)
@@ -657,60 +658,15 @@ static int read_loadinfo(void *arg)
 static int fill_arg_spec(void *arg)
 {
 	struct fill_handler_arg *fha = arg;
-	char *argspec = NULL;
-	char *retspec = NULL;
-	int n = 0;
+	char *argspec = fha->opts->args;
+	char *retspec = fha->opts->retval;
+	int n;
 
-	/* extract argspec (and retspec) in trigger action */
-	if (fha->opts->trigger) {
-		char *pos, *tmp, *str, *act;
-
-		str = tmp = xstrdup(fha->opts->trigger);
-
-		while ((pos = strsep(&tmp, ";")) != NULL) {
-			char *name = pos;
-			char *args = NULL;
-			char *rval = NULL;
-
-			act = strchr(name, '@');
-			if (act == NULL)
-				continue;
-
-			*act++ = '\0';
-
-			while ((pos = strsep(&act, ",")) != NULL) {
-				if (!strncasecmp(pos, "arg", 3) ||
-				    !strncasecmp(pos, "fparg", 5))
-					args = strjoin(args, pos, ",");
-				if (!strncasecmp(pos, "retval", 6))
-					rval = "retval";
-			}
-
-			if (args) {
-				xasprintf(&act, "%s@%s", name, args);
-				argspec = strjoin(argspec, act, ";");
-				free(act);
-			}
-			if (rval) {
-				xasprintf(&act, "%s@retval", name);
-				retspec = strjoin(retspec, act, ";");
-				free(act);
-			}
-		}
-
-		free(str);
-	}
-
-	if (fha->opts->args)
-		argspec = strjoin(argspec, fha->opts->args, ";");
-	if (fha->opts->retval)
-		retspec = strjoin(retspec, fha->opts->retval, ";");
-
-	n = !!argspec + !!retspec;
-	if (n == 0)
+	n = extract_trigger_args(&argspec, &retspec, fha->opts->trigger);
+	if (n == 0 && !fha->opts->auto_args)
 		return -1;
 
-	dprintf(fha->fd, "argspec:lines=%d\n", n);
+	dprintf(fha->fd, "argspec:lines=%d\n", n + 2 + !!fha->opts->auto_args);
 	if (argspec) {
 		dprintf(fha->fd, "argspec:%s\n", argspec);
 		free(argspec);
@@ -720,6 +676,12 @@ static int fill_arg_spec(void *arg)
 		free(retspec);
 	}
 
+	dprintf(fha->fd, "argauto:%s\n", get_auto_argspec_str());
+	dprintf(fha->fd, "retauto:%s\n", get_auto_retspec_str());
+
+	if (fha->opts->auto_args)
+		dprintf(fha->fd, "auto-args:1\n");
+
 	return 0;
 }
 
@@ -752,13 +714,16 @@ static int read_arg_spec(void *arg)
 		if (getline(&buf, &len, handle->fp) < 0)
 			goto out;
 
-		if (strncmp(&buf[3], "spec:", 5))
-			goto out;
-
-		if (!strncmp(buf, "arg", 3))
+		if (!strncmp(buf, "argspec:", 8))
 			info->argspec = copy_info_str(&buf[8]);
-		else if (!strncmp(buf, "ret", 3))
+		else if (!strncmp(buf, "retspec:", 8))
 			info->retspec = copy_info_str(&buf[8]);
+		else if (!strncmp(buf, "argauto:", 8))
+			info->autoarg = copy_info_str(&buf[8]);
+		else if (!strncmp(buf, "retauto:", 8))
+			info->autoret = copy_info_str(&buf[8]);
+		else if (!strncmp(buf, "auto-args:1", 11))
+			info->auto_args_enabled = 1;
 		else
 			goto out;
 	}
@@ -882,7 +847,7 @@ int read_uftrace_info(uint64_t info_mask, struct ftrace_file_handle *handle)
 			continue;
 
 		if (read_handlers[i].handler(handle) < 0) {
-			pr_dbg("error during read ftrace info (%x)\n",
+			pr_dbg("error during read uftrace info (%x)\n",
 			       (1U << read_handlers[i].bit));
 			return -1;
 		}
@@ -1003,8 +968,10 @@ int command_info(int argc, char *argv[], struct opts *opts)
 		pr_out("\n");
 	}
 
-	if (handle.hdr.info_mask & (1UL << ARG_SPEC))
-		pr_out(fmt, "arguments/retval", handle.info.argspec);
+	if (handle.hdr.info_mask & (1UL << ARG_SPEC)) {
+		pr_out(fmt, "arguments", handle.info.argspec);
+		pr_out(fmt, "return values", handle.info.retspec);
+	}
 
 	if (handle.hdr.info_mask & (1UL << EXIT_STATUS)) {
 		int status = handle.info.exit_status;

cmd-record.c

@@ -66,7 +66,8 @@ static bool can_use_fast_libmcount(struct opts *opts)
 		return false;
 	if (getenv("UFTRACE_FILTER") || getenv("UFTRACE_TRIGGER") ||
 	    getenv("UFTRACE_ARGUMENT") || getenv("UFTRACE_RETVAL") ||
-	    getenv("UFTRACE_PATCH") || getenv("UFTRACE_SCRIPT"))
+	    getenv("UFTRACE_PATCH") || getenv("UFTRACE_SCRIPT") ||
+	    getenv("UFTRACE_AUTO_ARGS"))
 		return false;
 	return true;
 }
@@ -153,6 +154,9 @@ static void setup_child_environ(struct opts *opts, int pfd)
 		}
 	}
 
+	if (opts->auto_args)
+		setenv("UFTRACE_AUTO_ARGS", "1", 1);
+
 	if (opts->patch) {
 		char *patch_str = uftrace_clear_kernel(opts->patch);
 
@@ -291,16 +295,19 @@ static uint64_t calc_feat_mask(struct opts *opts)
 	/* save mcount_max_stack */
 	features |= MAX_STACK;
 
+	/* provide automatic argument/return value spec */
+	features |= AUTO_ARGS;
+
 	if (opts->libcall)
 		features |= PLTHOOK;
 
 	if (opts->kernel)
 		features |= KERNEL;
 
-	if (opts->args)
+	if (opts->args || opts->auto_args)
 		features |= ARGUMENT;
 
-	if (opts->retval)
+	if (opts->retval || opts->auto_args)
 		features |= RETVAL;
 
 	if (opts->event)

doc/uftrace-live.md

@@ -43,6 +43,9 @@ OPTIONS
 -R *SPEC*, \--retval=*SPEC*
 :   Record function return value.  This option can be used more than once.  See *ARGUMENTS*.
 
+\--auto-args
+:   Automatically record arguments and return values of well-known library functions.  Recommend to use it with `--nest-libcall`.
+
 -f *FIELD*, \--output-fields=*FIELD*
 :   Customize field in the output.  Possible values are: duration, tid, time, delta, elapsed and addr.  Multiple fields can be set by using comma.  Special field of 'none' can be used (solely) to hide all fields.  Default is 'duration,tid'.  See *FIELDS*.
 

doc/uftrace-record.md

@@ -81,6 +81,9 @@ OPTIONS
 -R *SPEC*, \--retval=*SPEC*
 :   Record function return values.  This option can be used more than once.  See *ARGUMENTS*.
 
+\--auto-args
+:   Automatically record arguments and return values of well-known library functions.  Recommend to use it with `--nest-libcall`.
+
 \--num-thread=*NUM*
 :   Use NUM threads to record trace data.  Default is 1/4 of online CPUs (but when full kernel tracing is enabled, it will use the full number of CPUs).
 

libmcount/mcount.c

@@ -86,12 +86,21 @@ static void mcount_filter_init(void)
 
 	load_module_symtabs(&symtabs);
 
+	setup_auto_args();
+
 	uftrace_setup_filter(filter_str, &symtabs, &mcount_triggers,
 			     &mcount_filter_mode, false);
 	uftrace_setup_trigger(trigger_str, &symtabs, &mcount_triggers,
 			      &mcount_filter_mode, false);
-	uftrace_setup_argument(argument_str, &symtabs, &mcount_triggers);
-	uftrace_setup_retval(retval_str, &symtabs, &mcount_triggers);
+	uftrace_setup_argument(argument_str, &symtabs, &mcount_triggers, false);
+	uftrace_setup_retval(retval_str, &symtabs, &mcount_triggers, false);
+
+	if (getenv("UFTRACE_AUTO_ARGS")) {
+		uftrace_setup_argument(get_auto_argspec_str(), &symtabs,
+				       &mcount_triggers, true);
+		uftrace_setup_retval(get_auto_retspec_str(), &symtabs,
+				     &mcount_triggers, true);
+	}
 
 	if (getenv("UFTRACE_DEPTH"))
 		mcount_depth = strtol(getenv("UFTRACE_DEPTH"), NULL, 0);
@@ -294,6 +303,8 @@ static void mcount_finish(void)
 		close(pfd);
 		pfd = -1;
 	}
+
+	finish_auto_args();
 }
 
 static bool mcount_check_rstack(struct mcount_thread_data *mtdp)

libmcount/record.c

@@ -19,6 +19,8 @@
 
 #define SHMEM_SESSION_FMT  "/uftrace-%s-%d-%03d" /* session-id, tid, seq */
 
+#define ARG_STR_MAX	98
+
 static struct mcount_shmem_buffer *allocate_shmem_buffer(char *buf, size_t size,
 							 int tid, int idx)
 {
@@ -278,7 +280,15 @@ static unsigned save_to_argbuf(void *argbuf, struct list_head *args_spec,
 				len = 0;
 				for (i = 0; i < max_size - total_size; i++) {
 					dst[i] = str[i];
-					if (!str[i])
+
+					/* truncate long string */
+					if (i > ARG_STR_MAX) {
+						dst[i-3] = '.';
+						dst[i-2] = '.';
+						dst[i-1] = '.';
+						dst[i] = '\0';
+					}
+					if (!dst[i])
 						break;
 					len++;
 				}