Re: [PATCH] ARM: unwind: Add missing "Call trace:" line

[AngeloGioacchino Del Regno]

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@xxxxxxxxxx>
> Cc: Russell King <linux@xxxxxxxxxxxxxxx>
> Cc: Ard Biesheuvel <ardb@xxxxxxxxxx>
> Cc: Arnd Bergmann <arnd@xxxxxxxx>
> Cc: Linus Walleij <linus.walleij@xxxxxxxxxx>
> Cc: Vladimir Murzin <vladimir.murzin@xxxxxxx>
> Cc: Zhen Lei <thunder.leizhen@xxxxxxxxxx>
> Cc: Keith Packard <keithpac@xxxxxxxxxx>
> Cc: Haibo Li <haibo.li@xxxxxxxxxxxx>
> Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>

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