From: Andrii Nakryiko <andriin@fb.com>
To: <bpf@vger.kernel.org>, <netdev@vger.kernel.org>, <ast@fb.com>,
<daniel@iogearbox.net>
Cc: <andrii.nakryiko@gmail.com>, <kernel-team@fb.com>,
Andrii Nakryiko <andriin@fb.com>, Christoph Hellwig <hch@lst.de>
Subject: [PATCH bpf 1/2] bpf: bpf_probe_read_kernel_str() has to return amount of data read on success
Date: Mon, 15 Jun 2020 22:04:30 -0700 [thread overview]
Message-ID: <20200616050432.1902042-1-andriin@fb.com> (raw)
During recent refactorings, bpf_probe_read_kernel_str() started returning 0 on
success, instead of amount of data successfully read. This majorly breaks
applications relying on bpf_probe_read_kernel_str() and bpf_probe_read_str()
and their results. Fix this by returning actual number of bytes read.
Cc: Christoph Hellwig <hch@lst.de>
Fixes: 8d92db5c04d1 ("bpf: rework the compat kernel probe handling")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
---
kernel/trace/bpf_trace.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index e729c9e587a0..a3ac7de98baa 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -241,7 +241,7 @@ bpf_probe_read_kernel_str_common(void *dst, u32 size, const void *unsafe_ptr)
if (unlikely(ret < 0))
goto fail;
- return 0;
+ return ret;
fail:
memset(dst, 0, size);
return ret;
--
2.24.1
next reply other threads:[~2020-06-16 5:04 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-16 5:04 Andrii Nakryiko [this message]
2020-06-16 5:04 ` [PATCH bpf 2/2] selftests/bpf: add variable-length data concatenation pattern test Andrii Nakryiko
2020-06-16 20:21 ` Daniel Borkmann
2020-06-16 21:27 ` Andrii Nakryiko
2020-06-16 22:23 ` Daniel Borkmann
2020-06-16 23:14 ` Andrii Nakryiko
2020-06-17 15:51 ` Daniel Borkmann
2020-06-18 19:09 ` John Fastabend
2020-06-18 21:59 ` Andrii Nakryiko
2020-06-18 23:48 ` John Fastabend
2020-06-19 0:09 ` Andrii Nakryiko
2020-06-16 6:54 ` [PATCH bpf 1/2] bpf: bpf_probe_read_kernel_str() has to return amount of data read on success Christoph Hellwig
2020-06-16 7:01 ` John Fastabend
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