Commit a28b1ba2 authored by Rong Tao's avatar Rong Tao Committed by Andrii Nakryiko
Browse files

selftests/bpf: trace_helpers.c: Add a global ksyms initialization mutex 

As Jirka said [0], we just need to make sure that global ksyms
initialization won't race.

[0] https://lore.kernel.org/lkml/ZPCbAs3ItjRd8XVh@krava/



Signed-off-by: default avatarRong Tao <rongtao@cestc.cn>
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Acked-by: default avatarJiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/tencent_5D0A837E219E2CFDCB0495DAD7D5D1204407@qq.com
parent c698eaeb

tools/testing/selftests/bpf/trace_helpers.c

+4 −0
Original line number Diff line number Diff line
@@ -7,6 +7,7 @@ 
#include <errno.h>

#include <fcntl.h>

#include <poll.h>

#include <pthread.h>

#include <unistd.h>

#include <linux/perf_event.h>

#include <sys/mman.h>
@@ -26,6 +27,7 @@ struct ksyms { 
};



static struct ksyms *ksyms;

static pthread_mutex_t ksyms_mutex = PTHREAD_MUTEX_INITIALIZER;



static int ksyms__add_symbol(struct ksyms *ksyms, const char *name,

			     unsigned long addr)
@@ -109,8 +111,10 @@ struct ksyms *load_kallsyms_local(void) 


int load_kallsyms(void)

{

	pthread_mutex_lock(&ksyms_mutex);

	if (!ksyms)

		ksyms = load_kallsyms_local();

	pthread_mutex_unlock(&ksyms_mutex);

	return ksyms ? 0 : 1;

}