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From: ">" <jonathan.wiepert@gmail.com>
To: bpf@vger.kernel.org
Cc: Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Andrii Nakryiko <andrii@kernel.org>,
	Martin KaFai Lau <martin.lau@kernel.org>,
	Mykyta Yatsenko <yatsenko@meta.com>,
	Yonghong Song <yonghong.song@linux.dev>,
	Jordan Rome <linux@jordanrome.com>, Jiri Olsa <jolsa@kernel.org>,
	Jonathan Wiepert <jonathan.wiepert@gmail.com>,
	Kernel Team <kernel-team@fb.com>
Subject: [PATCH bpf-next] Use thread-safe function pointer in libbpf_print
Date: Thu, 24 Apr 2025 18:14:57 -0400	[thread overview]
Message-ID: <20250424221457.793068-1-jonathan.wiepert@gmail.com> (raw)

From: Jonathan Wiepert <jonathan.wiepert@gmail.com>

This patch fixes a thread safety bug where libbpf_print uses the
global variable storing the print function pointer rather than the local
variable that had the print function set via __atomic_load_n.

Signed-off-by: Jonathan Wiepert <jonathan.wiepert@gmail.com>
---
 tools/lib/bpf/libbpf.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 56250b5ac5b0..ea97a84460cd 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -284,7 +284,7 @@ void libbpf_print(enum libbpf_print_level level, const char *format, ...)
 	old_errno = errno;
 
 	va_start(args, format);
-	__libbpf_pr(level, format, args);
+	print_fn(level, format, args);
 	va_end(args);
 
 	errno = old_errno;
-- 
2.42.0


             reply	other threads:[~2025-04-24 22:15 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-04-24 22:14 > [this message]
2025-04-25  0:31 ` [PATCH bpf-next] Use thread-safe function pointer in libbpf_print Mykyta Yatsenko
2025-04-25 16:28 ` Andrii Nakryiko

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