From f9f83b3344f9ed6e1d33a87810f38eca5ed6a14f Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Fri, 14 Jul 2017 10:13:56 -0300 Subject: perf trace beauty: Allow accessing syscall args values in a syscall arg formatter For instance, fcntl's upcoming 'arg' formatter needs to look at the 'cmd' value to decide how to format its value, sometimes it is a file flags, sometimes an fd, a pointer to a structure, etc. Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: http://lkml.kernel.org/n/tip-2tw2jfaqm48dtw8a4addghze@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/builtin-trace.c | 23 ++++++++++++++++------- 1 file changed, 16 insertions(+), 7 deletions(-) (limited to 'tools/perf/builtin-trace.c') diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c index b7f79dea3c44..40bc0a326096 100644 --- a/tools/perf/builtin-trace.c +++ b/tools/perf/builtin-trace.c @@ -1369,19 +1369,32 @@ out: * variable to read it. Most notably this avoids extended load instructions * on unaligned addresses */ +static unsigned long __syscall_arg__val(unsigned char *args, u8 idx) +{ + unsigned long val; + unsigned char *p = args + sizeof(unsigned long) * idx; + + memcpy(&val, p, sizeof(val)); + return val; +} + +unsigned long syscall_arg__val(struct syscall_arg *arg, u8 idx) +{ + return __syscall_arg__val(arg->args, idx); +} static size_t syscall__scnprintf_args(struct syscall *sc, char *bf, size_t size, unsigned char *args, struct trace *trace, struct thread *thread) { size_t printed = 0; - unsigned char *p; unsigned long val; if (sc->args != NULL) { struct format_field *field; u8 bit = 1; struct syscall_arg arg = { + .args = args, .idx = 0, .mask = 0, .trace = trace, @@ -1393,9 +1406,7 @@ static size_t syscall__scnprintf_args(struct syscall *sc, char *bf, size_t size, if (arg.mask & bit) continue; - /* special care for unaligned accesses */ - p = args + sizeof(unsigned long) * arg.idx; - memcpy(&val, p, sizeof(val)); + val = syscall_arg__val(&arg, arg.idx); /* * Suppress this argument if its value is zero and @@ -1431,9 +1442,7 @@ static size_t syscall__scnprintf_args(struct syscall *sc, char *bf, size_t size, int i = 0; while (i < 6) { - /* special care for unaligned accesses */ - p = args + sizeof(unsigned long) * i; - memcpy(&val, p, sizeof(val)); + val = __syscall_arg__val(args, i); printed += scnprintf(bf + printed, size - printed, "%sarg%d: %ld", printed ? ", " : "", i, val); -- cgit v1.2.3-55-g7522