perf trace: Consider syscall aliases too (f932184e) · Commits · 戴 / test

When trying to trace the 'umount' syscall on x86_64 I noticed that it was failing: # trace -e umount umount /mnt event syntax error: 'umount' \___ parser error Run 'perf list' for a list of valid events Usage: perf trace [<options>] [<command>] or: perf trace [<options>] -- <command> [<options>] or: perf trace record [<options>] [<command>] or: perf trace record [<options>] -- <command> [<options>] -e, --event <event> event/syscall selector. use 'perf list' to list available events # This is because in the x86-64 we have it just as 'umount2': $ grep umount arch/x86/entry/syscalls/syscall_64.tbl 166 common umount2 __x64_sys_umount $ So if the syscall name fails, try fallbacking to looking at the aliases we have in the syscall_fmts table to then re-lookup, now: # trace -e umount umount -f /mnt umount: /mnt: not mounted. 1.759 ( 0.004 ms): umount/18365 umount2(name: 0x55fbfcbc4480, flags: 1) = -1 EINVAL Invalid argument # Time to beautify the flags arg :-) Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Benjamin Peterson <benjamin@python.org> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Wang Nan <wangnan0@huawei.com> Link: https://lkml.kernel.org/n/tip-ukweodgzbmjd25lfkgryeft1@git.kernel.org Signed-off-by:

Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/builtin-trace.c

+21 −1

Original line number	Diff line number	Diff line
		@@ -862,6 +862,18 @@ static struct syscall_fmt syscall_fmt__find(const char name)
		return bsearch(name, syscall_fmts, nmemb, sizeof(struct syscall_fmt), syscall_fmt__cmp);
		}

		static struct syscall_fmt syscall_fmt__find_by_alias(const char alias)
		{
		int i, nmemb = ARRAY_SIZE(syscall_fmts);

		for (i = 0; i < nmemb; ++i) {
		if (syscall_fmts[i].alias && strcmp(syscall_fmts[i].alias, alias) == 0)
		return &syscall_fmts[i];
		}

		return NULL;
		}

		/*
		* is_exit: is this "exit" or "exit_group"?
		* is_open: is this "open" or "openat"? To associate the fd returned in sys_exit with the pathname in sys_enter.
		@@ -3195,6 +3207,7 @@ static int trace__parse_events_option(const struct option opt, const char str,
		int len = strlen(str) + 1, err = -1, list, idx;
		char *strace_groups_dir = system_path(STRACE_GROUPS_DIR);
		char group_name[PATH_MAX];
		struct syscall_fmt *fmt;

		if (strace_groups_dir == NULL)
		return -1;
		@@ -3212,12 +3225,19 @@ static int trace__parse_events_option(const struct option opt, const char str,
		if (syscalltbl__id(trace->sctbl, s) >= 0 \|\|
		syscalltbl__strglobmatch_first(trace->sctbl, s, &idx) >= 0) {
		list = 1;
		goto do_concat;
		}

		fmt = syscall_fmt__find_by_alias(s);
		if (fmt != NULL) {
		list = 1;
		s = fmt->name;
		} else {
		path__join(group_name, sizeof(group_name), strace_groups_dir, s);
		if (access(group_name, R_OK) == 0)
		list = 1;
		}

		do_concat:
		if (lists[list]) {
		sprintf(lists[list] + strlen(lists[list]), ",%s", s);
		} else {

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