Commit 28f9e391 authored by Steven Rostedt (Google)'s avatar Steven Rostedt (Google) Committed by Zheng Zengkai
Browse files

tracing: Stop current tracer when resizing buffer

stable inclusion
from stable-v6.6.7
commit 12c48e88e5c7dff3c26217e7527eaddcf4a5809c
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I8SSQ4

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=12c48e88e5c7dff3c26217e7527eaddcf4a5809c

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commit d78ab792705c7be1b91243b2544d1a79406a2ad7 upstream.

When the ring buffer is being resized, it can cause side effects to the
running tracer. For instance, there's a race with irqsoff tracer that
swaps individual per cpu buffers between the main buffer and the snapshot
buffer. The resize operation modifies the main buffer and then the
snapshot buffer. If a swap happens in between those two operations it will
break the tracer.

Simply stop the running tracer before resizing the buffers and enable it
again when finished.

Link: https://lkml.kernel.org/r/20231205220010.748996423@goodmis.org



Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Fixes: 3928a8a2 ("ftrace: make work with new ring buffer")
Signed-off-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarZheng Zengkai <zhengzengkai@huawei.com>
parent d7e9cb39
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