From f06a82f9d31a87878a9295bac1defdadbc77bbc0 Mon Sep 17 00:00:00 2001
From: Jiri Olsa <jolsa@redhat.com>
Date: Thu, 6 Jan 2022 23:20:30 +0100
Subject: [PATCH 1/2] perf trace: Avoid early exit due to running SIGCHLD
 handler before it makes sense to

When running 'perf trace' with an BPF object like:

  # perf trace -e openat,tools/perf/examples/bpf/hello.c

the event parsing eventually calls llvm__get_kbuild_opts() that runs a
script and that ends up with SIGCHLD delivered to the 'perf trace'
handler, which assumes the workload process is done and quits 'perf
trace'.

Move the SIGCHLD handler setup directly to trace__run(), where the event
is parsed and the object is already compiled.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Christy Lee <christyc.y.lee@gmail.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20220106222030.227499-1-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/builtin-trace.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index 0b52e08e558e3..ef94388e83234 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -3925,6 +3925,7 @@ static int trace__run(struct trace *trace, int argc, const char **argv)
 	bool draining = false;
 
 	trace->live = true;
+	signal(SIGCHLD, sig_handler);
 
 	if (!trace->raw_augmented_syscalls) {
 		if (trace->trace_syscalls && trace__add_syscall_newtp(trace))
@@ -4873,7 +4874,6 @@ int cmd_trace(int argc, const char **argv)
 
 	signal(SIGSEGV, sighandler_dump_stack);
 	signal(SIGFPE, sighandler_dump_stack);
-	signal(SIGCHLD, sig_handler);
 	signal(SIGINT, sig_handler);
 
 	trace.evlist = evlist__new();

From dc9f2dd5de04d2bbcccbabdf5df9715c2ddcf25f Mon Sep 17 00:00:00 2001
From: Arnaldo Carvalho de Melo <acme@redhat.com>
Date: Fri, 7 Jan 2022 16:02:54 -0300
Subject: [PATCH 2/2] Revert "libtraceevent: Increase libtraceevent logging
 when verbose"
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

This reverts commit 08efcb4a638d260ef7fcbae64ecf7ceceb3f1841.

This breaks the build as it will prefer using libbpf-devel header files,
even when not using LIBBPF_DYNAMIC=1, breaking the build.

This was detected on OpenSuSE Tumbleweed with libtraceevent-devel 1.3.0,
as described by Jiri Slaby:

=======================================================================
It breaks build with LIBTRACEEVENT_DYNAMIC and version 1.3.0:
> util/debug.c: In function ‘perf_debug_option’:
> util/debug.c:243:17: error: implicit declaration of function
‘tep_set_loglevel’ [-Werror=implicit-function-declaration]
>   243 |                 tep_set_loglevel(TEP_LOG_INFO);
>       |                 ^~~~~~~~~~~~~~~~
> util/debug.c:243:34: error: ‘TEP_LOG_INFO’ undeclared (first use in this
function); did you mean ‘TEP_PRINT_INFO’?
>   243 |                 tep_set_loglevel(TEP_LOG_INFO);
>       |                                  ^~~~~~~~~~~~
>       |                                  TEP_PRINT_INFO
> util/debug.c:243:34: note: each undeclared identifier is reported only once
for each function it appears in
> util/debug.c:245:34: error: ‘TEP_LOG_DEBUG’ undeclared (first use in this
function)
>   245 |                 tep_set_loglevel(TEP_LOG_DEBUG);
>       |                                  ^~~~~~~~~~~~~
> util/debug.c:247:34: error: ‘TEP_LOG_ALL’ undeclared (first use in this
function)
>   247 |                 tep_set_loglevel(TEP_LOG_ALL);
>       |                                  ^~~~~~~~~~~

It is because the gcc's command line looks like:
gcc
...
-I/home/abuild/rpmbuild/BUILD/tools/lib/
...
-DLIBTRACEEVENT_VERSION=65790
...
=======================================================================

The proper way to fix this is more involved and so not suitable for this
late in the 5.16-rc stage.

Reported-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/lkml/bc2b0786-8965-1bcd-2316-9d9bb37b9c31@kernel.org
Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: https://lore.kernel.org/lkml/YddGjjmlMZzxUZbN@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/util/debug.c | 19 -------------------
 1 file changed, 19 deletions(-)

diff --git a/tools/perf/util/debug.c b/tools/perf/util/debug.c
index c7a9fa0ffae9d..2c06abf6dcd26 100644
--- a/tools/perf/util/debug.c
+++ b/tools/perf/util/debug.c
@@ -24,16 +24,6 @@
 #include "util/parse-sublevel-options.h"
 
 #include <linux/ctype.h>
-#include <traceevent/event-parse.h>
-
-#define MAKE_LIBTRACEEVENT_VERSION(a, b, c) ((a)*255*255+(b)*255+(c))
-#ifndef LIBTRACEEVENT_VERSION
-/*
- * If LIBTRACEEVENT_VERSION wasn't computed then set to version 1.1.0 that ships
- * with the Linux kernel tools.
- */
-#define LIBTRACEEVENT_VERSION MAKE_LIBTRACEEVENT_VERSION(1, 1, 0)
-#endif
 
 int verbose;
 int debug_peo_args;
@@ -238,15 +228,6 @@ int perf_debug_option(const char *str)
 	/* Allow only verbose value in range (0, 10), otherwise set 0. */
 	verbose = (verbose < 0) || (verbose > 10) ? 0 : verbose;
 
-#if MAKE_LIBTRACEEVENT_VERSION(1, 3, 0) <= LIBTRACEEVENT_VERSION
-	if (verbose == 1)
-		tep_set_loglevel(TEP_LOG_INFO);
-	else if (verbose == 2)
-		tep_set_loglevel(TEP_LOG_DEBUG);
-	else if (verbose >= 3)
-		tep_set_loglevel(TEP_LOG_ALL);
-#endif
-
 	return 0;
 }