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Message-ID: <549d8438-cae7-4c81-8f2e-1513a5e2dd5d@collabora.com>
Date: Thu, 11 Jan 2024 13:12:23 +0100
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Subject: Re: [PATCH] ARM: unwind: Add missing "Call trace:" line
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To: Kees Cook <keescook@chromium.org>, Russell King <linux@armlinux.org.uk>
Cc: Mark Brown <broonie@kernel.org>, Ard Biesheuvel <ardb@kernel.org>,
 Arnd Bergmann <arnd@arndb.de>, Linus Walleij <linus.walleij@linaro.org>,
 Vladimir Murzin <vladimir.murzin@arm.com>,
 Zhen Lei <thunder.leizhen@huawei.com>, Keith Packard <keithpac@amazon.com>,
 Haibo Li <haibo.li@mediatek.com>, linux-arm-kernel@lists.infradead.org,
 Matthias Brugger <matthias.bgg@gmail.com>,
 Alexandre Mergnat <amergnat@baylibre.com>, linux-kernel@vger.kernel.org,
 linux-hardening@vger.kernel.org
References: <20240110215554.work.460-kees@kernel.org>
From: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
In-Reply-To: <20240110215554.work.460-kees@kernel.org>
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Il 10/01/24 22:56, Kees Cook ha scritto:
> Every other architecture in Linux includes the line "Call trace:" before
> backtraces. In some cases ARM would print "Backtrace:", but this was
> only via 1 specific call path, and wasn't included in CPU Oops nor things
> like KASAN, UBSAN, etc that called dump_stack(). Regularize this line
> so CI systems and other things (like LKDTM) that depend on parsing
> "Call trace:" out of dmesg will see it for ARM.
> 
> Before this patch:
> 
> 	UBSAN: array-index-out-of-bounds in ../drivers/misc/lkdtm/bugs.c:376:16
> 	index 8 is out of range for type 'char [8]'
> 	CPU: 0 PID: 1402 Comm: cat Not tainted 6.7.0-rc2 #1
> 	Hardware name: Generic DT based system
> 	 dump_backtrace from show_stack+0x20/0x24
> 	 r7:00000042 r6:00000000 r5:60070013 r4:80cf5d7c
> 	 show_stack from dump_stack_lvl+0x88/0x98
> 	 dump_stack_lvl from dump_stack+0x18/0x1c
> 	 r7:00000042 r6:00000008 r5:00000008 r4:80fab118
> 	 dump_stack from ubsan_epilogue+0x10/0x3c
> 	 ubsan_epilogue from __ubsan_handle_out_of_bounds+0x80/0x84
> 	...
> 
> After this patch:
> 
> 	UBSAN: array-index-out-of-bounds in ../drivers/misc/lkdtm/bugs.c:376:16
> 	index 8 is out of range for type 'char [8]'
> 	CPU: 0 PID: 1402 Comm: cat Not tainted 6.7.0-rc2 #1
> 	Hardware name: Generic DT based system
> 	Call trace:
> 	 dump_backtrace from show_stack+0x20/0x24
> 	 r7:00000042 r6:00000000 r5:60070013 r4:80cf5d7c
> 	 show_stack from dump_stack_lvl+0x88/0x98
> 	 dump_stack_lvl from dump_stack+0x18/0x1c
> 	 r7:00000042 r6:00000008 r5:00000008 r4:80fab118
> 	 dump_stack from ubsan_epilogue+0x10/0x3c
> 	 ubsan_epilogue from __ubsan_handle_out_of_bounds+0x80/0x84
> 	...
> 
> Reported-by: Mark Brown <broonie@kernel.org>
> Cc: Russell King <linux@armlinux.org.uk>
> Cc: Ard Biesheuvel <ardb@kernel.org>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Linus Walleij <linus.walleij@linaro.org>
> Cc: Vladimir Murzin <vladimir.murzin@arm.com>
> Cc: Zhen Lei <thunder.leizhen@huawei.com>
> Cc: Keith Packard <keithpac@amazon.com>
> Cc: Haibo Li <haibo.li@mediatek.com>
> Cc: linux-arm-kernel@lists.infradead.org
> Signed-off-by: Kees Cook <keescook@chromium.org>

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>