From: Steven Rostedt <rostedt@goodmis.org>
To: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>, Ard Biesheuvel <ardb@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Pengutronix Kernel Team <kernel@pengutronix.de>,
linux-arm-kernel@lists.infradead.org
Subject: Re: FUNCTION_GRAPH_TRACER + UNWINDER_FRAME_POINTER broken on arm
Date: Mon, 27 May 2024 18:56:27 -0400 [thread overview]
Message-ID: <20240527185627.5b1b01c5@rorschach.local.home> (raw)
In-Reply-To: <tqocmnkjgci3whkmqwgoneqsnusp6vf6fjw5lq77zc6u7u6mkm@o5ibt5uuvoy3>
On Mon, 27 May 2024 14:25:52 +0200
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> wrote:
> Completing it would mean adding the numerous __notrace annotions??
as long as it only affects arm.
Note, the history of HAVE_FUNCTION_GRAPH_FP_TEST is from gcc making a
copy of the stack frame, and when the function graph tracer went to
modify the return address, it only modified the copy (not the actual
return address) causing the shadow stack to become out of sync with the
real addresses and returning to the wrong address. This caused random
crashes. I added the FP_TEST to catch if this ever happens again.
See 71e308a239c09 ("function-graph: add stack frame test")
-- Steve
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prev parent reply other threads:[~2024-05-27 22:56 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-25 7:59 FUNCTION_GRAPH_TRACER + UNWINDER_FRAME_POINTER broken on arm Uwe Kleine-König
2024-05-27 8:39 ` Linux regression tracking (Thorsten Leemhuis)
2024-05-27 8:42 ` Thorsten Leemhuis
2024-05-27 9:18 ` Arnd Bergmann
2024-05-27 12:25 ` Uwe Kleine-König
2024-05-27 13:33 ` Arnd Bergmann
2024-05-27 22:56 ` Steven Rostedt [this message]
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