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From: Andrii Nakryiko <andrii@kernel.org>
To: <bpf@vger.kernel.org>, <ast@kernel.org>, <daniel@iogearbox.net>,
	<martin.lau@kernel.org>, <lmb@isovalent.com>, <timo@incline.eu>,
	<robin.goegge@isovalent.com>
Cc: <andrii@kernel.org>, <kernel-team@meta.com>
Subject: [PATCH bpf-next 1/8] bpf: ignore verifier log reset in BPF_LOG_KERNEL mode
Date: Wed, 29 Mar 2023 21:16:35 -0700	[thread overview]
Message-ID: <20230330041642.1118787-2-andrii@kernel.org> (raw)
In-Reply-To: <20230330041642.1118787-1-andrii@kernel.org>

Verifier log position reset is meaningless in BPF_LOG_KERNEL mode, so
just exit early in bpf_vlog_reset() if log->level is BPF_LOG_KERNEL.

This avoid meaningless put_user() into NULL log->ubuf.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
---
 kernel/bpf/log.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/bpf/log.c b/kernel/bpf/log.c
index beab7c7f52a7..0bcc0c5ce697 100644
--- a/kernel/bpf/log.c
+++ b/kernel/bpf/log.c
@@ -104,7 +104,7 @@ void bpf_vlog_reset(struct bpf_verifier_log *log, u64 new_pos)
 	char zero = 0;
 	u32 pos;
 
-	if (!bpf_verifier_log_needed(log))
+	if (!bpf_verifier_log_needed(log) || log->level == BPF_LOG_KERNEL)
 		return;
 
 	/* if position to which we reset is beyond current log window,
-- 
2.34.1


  reply	other threads:[~2023-03-30  4:18 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-03-30  4:16 [PATCH bpf-next 0/8] Teach verifier to determine necessary log buffer size Andrii Nakryiko
2023-03-30  4:16 ` Andrii Nakryiko [this message]
2023-03-30  4:16 ` [PATCH bpf-next 2/8] bpf: fix missing -EFAULT return on user log buf error in btf_parse() Andrii Nakryiko
2023-03-30  4:16 ` [PATCH bpf-next 3/8] bpf: avoid incorrect -EFAULT error in BPF_LOG_KERNEL mode Andrii Nakryiko
2023-03-30  4:16 ` [PATCH bpf-next 4/8] bpf: simplify logging related error conditions handling Andrii Nakryiko
2023-03-30  4:16 ` [PATCH bpf-next 5/8] bpf: keep track of total log content size in both fixed and rolling modes Andrii Nakryiko
2023-03-30  4:16 ` [PATCH bpf-next 6/8] bpf: add log_size_actual output field to return log contents size Andrii Nakryiko
2023-03-30  4:16 ` [PATCH bpf-next 7/8] libbpf: wire through log_size_actual value returned from kernel Andrii Nakryiko
2023-03-30  4:16 ` [PATCH bpf-next 8/8] selftests/bpf: add tests to validate log_size_actual feature Andrii Nakryiko

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