From: Alexander Shishkin <alexander.shishkin@linux.intel.com>
To: Qianqiang Liu <qianqiang.liu@163.com>, namhyung@kernel.org
Cc: linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org,
Qianqiang Liu <qianqiang.liu@163.com>,
alexander.shishkin@linux.intel.com
Subject: Re: [PATCH] perf/x86/intel/pt: Fix NULL pointer dereference in pt_buffer_reset_markers
Date: Thu, 24 Oct 2024 14:16:06 +0300 [thread overview]
Message-ID: <87bjz9vjih.fsf@ubik.fi.intel.com> (raw)
In-Reply-To: <20241001082757.111385-2-qianqiang.liu@163.com>
Qianqiang Liu <qianqiang.liu@163.com> writes:
> The buf->stop_te and buf->intr_te may be NULL, so we need to check
> for NULL pointers before using them.
Iirc, this has come up before, because static analyzers get the idea
that at that point ->stop_te and ->intr_te can be NULL, but in reality,
they can't. When the buffer is created, stop_pos and intr_pos are set to
-1, which will always force ->stop_te and ->intr_te to be set the first
time around.
So no, not a bug. It might deserve a comment explaining the above logic,
so that more versions of this patch don't get generated from static
analyzers' reports.
Regards,
--
Alex
next prev parent reply other threads:[~2024-10-24 11:16 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-10-01 8:27 [PATCH] perf/x86/intel/pt: Fix NULL pointer dereference in pt_buffer_reset_markers Qianqiang Liu
2024-10-24 11:16 ` Alexander Shishkin [this message]
2024-10-25 6:17 ` Qianqiang Liu
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