Commit-ID:  db2da3f85cd6314321b6a9441a5af8841c93394d
Gitweb:     https://git.kernel.org/tip/db2da3f85cd6314321b6a9441a5af8841c93394d
Author:     Arnaldo Carvalho de Melo <a...@redhat.com>
AuthorDate: Mon, 3 Sep 2018 16:24:09 -0300
Committer:  Arnaldo Carvalho de Melo <a...@redhat.com>
CommitDate: Tue, 4 Sep 2018 16:51:07 -0300

perf trace: Setup augmented_args in the raw_syscalls:sys_enter handler

Without using something to augment the raw_syscalls:sys_enter tracepoint
payload with the pointer contents, this will work just like before, i.e.
the augmented_args arg will be NULL and the augmented_args_size will be
0.

This just paves the way for the next cset where we will associate the
trace__sys_enter tracepoint handler with the augmented "bpf-output"
event named "__augmented_args__".

Cc: Adrian Hunter <adrian.hun...@intel.com>
Cc: David Ahern <dsah...@gmail.com>
Cc: Jiri Olsa <jo...@kernel.org>
Cc: Namhyung Kim <namhy...@kernel.org>
Cc: Wang Nan <wangn...@huawei.com>
Link: https://lkml.kernel.org/n/tip-p8uvt2a6ug3uwlhja3cno...@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <a...@redhat.com>
---
 tools/perf/builtin-trace.c | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index 12356deb6046..2b99a02355cf 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -1697,6 +1697,8 @@ static int trace__sys_enter(struct trace *trace, struct 
perf_evsel *evsel,
        size_t printed = 0;
        struct thread *thread;
        int id = perf_evsel__sc_tp_uint(evsel, id, sample), err = -1;
+       int augmented_args_size = 0;
+       void *augmented_args = NULL;
        struct syscall *sc = trace__syscall_info(trace, evsel, id);
        struct thread_trace *ttrace;
 
@@ -1720,13 +1722,24 @@ static int trace__sys_enter(struct trace *trace, struct 
perf_evsel *evsel,
 
        if (!(trace->duration_filter || trace->summary_only || 
trace->min_stack))
                trace__printf_interrupted_entry(trace);
-
+       /*
+        * If this is raw_syscalls.sys_enter, then it always comes with the 6 
possible
+        * arguments, even if the syscall being handled, say "openat", uses 
only 4 arguments
+        * this breaks syscall__augmented_args() check for augmented args, as 
we calculate
+        * syscall->args_size using each syscalls:sys_enter_NAME tracefs format 
file,
+        * so when handling, say the openat syscall, we end up getting 6 args 
for the
+        * raw_syscalls:sys_enter event, when we expected just 4, we end up 
mistakenly
+        * thinking that the extra 2 u64 args are the augmented filename, so 
just check
+        * here and avoid using augmented syscalls when the evsel is the 
raw_syscalls one.
+        */
+       if (evsel != trace->syscalls.events.sys_enter)
+               augmented_args = syscall__augmented_args(sc, sample, 
&augmented_args_size);
        ttrace->entry_time = sample->time;
        msg = ttrace->entry_str;
        printed += scnprintf(msg + printed, trace__entry_str_size - printed, 
"%s(", sc->name);
 
        printed += syscall__scnprintf_args(sc, msg + printed, 
trace__entry_str_size - printed,
-                                          args, NULL, 0, trace, thread);
+                                          args, augmented_args, 
augmented_args_size, trace, thread);
 
        if (sc->is_exit) {
                if (!(trace->duration_filter || trace->summary_only || 
trace->failure_only || trace->min_stack)) {

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