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From: Andrii Nakryiko <andrii@kernel.org>
To: <bpf@vger.kernel.org>, <netdev@vger.kernel.org>, <ast@fb.com>,
	<daniel@iogearbox.net>
Cc: <andrii@kernel.org>, <kernel-team@fb.com>
Subject: [PATCH bpf-next 1/6] bpf: fix bpf_put_raw_tracepoint()'s use of __module_address()
Date: Thu, 19 Nov 2020 15:22:39 -0800	[thread overview]
Message-ID: <20201119232244.2776720-2-andrii@kernel.org> (raw)
In-Reply-To: <20201119232244.2776720-1-andrii@kernel.org>

__module_address() needs to be called with preemption disabled or with
module_mutex taken. preempt_disable() is enough for read-only uses, which is
what this fix does.

Fixes: a38d1107f937 ("bpf: support raw tracepoints in modules")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
---
 kernel/trace/bpf_trace.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index d255bc9b2bfa..bb98a377050a 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -2060,7 +2060,11 @@ struct bpf_raw_event_map *bpf_get_raw_tracepoint(const char *name)
 
 void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp)
 {
-	struct module *mod = __module_address((unsigned long)btp);
+	struct module *mod;
+
+	preempt_disable();
+	mod = __module_address((unsigned long)btp);
+	preempt_enable();
 
 	if (mod)
 		module_put(mod);
-- 
2.24.1


  reply	other threads:[~2020-11-19 23:23 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-19 23:22 [PATCH bpf-next 0/6] libbpf: add support for kernel module BTF CO-RE relocations Andrii Nakryiko
2020-11-19 23:22 ` Andrii Nakryiko [this message]
2020-11-20 17:55   ` [PATCH bpf-next 1/6] bpf: fix bpf_put_raw_tracepoint()'s use of __module_address() Martin KaFai Lau
2020-11-24  5:49   ` Alexei Starovoitov
2020-11-24  7:49     ` Andrii Nakryiko
2020-11-19 23:22 ` [PATCH bpf-next 2/6] libbpf: add internal helper to load BTF data by FD Andrii Nakryiko
2020-11-20 18:20   ` Martin KaFai Lau
2020-11-20 18:25     ` Andrii Nakryiko
2020-11-19 23:22 ` [PATCH bpf-next 3/6] libbpf: refactor CO-RE relocs to not assume a single BTF object Andrii Nakryiko
2020-11-20 22:11   ` Martin KaFai Lau
2020-11-19 23:22 ` [PATCH bpf-next 4/6] libbpf: add kernel module BTF support for CO-RE relocations Andrii Nakryiko
2020-11-20  0:46   ` Maciej Fijalkowski
2020-11-20  1:24     ` Andrii Nakryiko
2020-11-20  2:05       ` Maciej Fijalkowski
2020-11-20  3:31         ` Andrii Nakryiko
2020-11-20 23:05   ` Martin KaFai Lau
2020-11-20 23:12     ` Andrii Nakryiko
2020-11-19 23:22 ` [PATCH bpf-next 5/6] selftests/bpf: add bpf_sidecar kernel module for testing Andrii Nakryiko
2020-11-20 23:21   ` Martin KaFai Lau
2020-11-19 23:22 ` [PATCH bpf-next 6/6] selftests/bpf: add CO-RE relocs selftest relying on kernel module BTF Andrii Nakryiko
2020-11-20 23:27   ` Martin KaFai Lau

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