linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* [PATCH] ARM: unwind: Add missing "Call trace:" line
@ 2024-01-10 21:56 Kees Cook
  2024-01-10 23:46 ` Linus Walleij
                   ` (2 more replies)
  0 siblings, 3 replies; 4+ messages in thread
From: Kees Cook @ 2024-01-10 21:56 UTC (permalink / raw)
  To: Russell King
  Cc: Kees Cook, Mark Brown, Ard Biesheuvel, Arnd Bergmann,
	Linus Walleij, Vladimir Murzin, Zhen Lei, Keith Packard,
	Haibo Li, linux-arm-kernel, Matthias Brugger,
	AngeloGioacchino Del Regno, Alexandre Mergnat, linux-kernel,
	linux-hardening

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>
---
 arch/arm/kernel/traps.c  | 2 +-
 arch/arm/kernel/unwind.c | 2 ++
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
index 3bad79db5d6e..72c82a4d63ac 100644
--- a/arch/arm/kernel/traps.c
+++ b/arch/arm/kernel/traps.c
@@ -220,7 +220,7 @@ void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk,
 	unsigned int fp, mode;
 	int ok = 1;
 
-	printk("%sBacktrace: ", loglvl);
+	printk("%sCall trace: ", loglvl);
 
 	if (!tsk)
 		tsk = current;
diff --git a/arch/arm/kernel/unwind.c b/arch/arm/kernel/unwind.c
index 9d2192156087..f60547dadc93 100644
--- a/arch/arm/kernel/unwind.c
+++ b/arch/arm/kernel/unwind.c
@@ -524,6 +524,8 @@ void unwind_backtrace(struct pt_regs *regs, struct task_struct *tsk,
 {
 	struct stackframe frame;
 
+	printk("%sCall trace: ", loglvl);
+
 	pr_debug("%s(regs = %p tsk = %p)\n", __func__, regs, tsk);
 
 	if (!tsk)
-- 
2.34.1


^ permalink raw reply related	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2024-01-11 15:49 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2024-01-10 21:56 [PATCH] ARM: unwind: Add missing "Call trace:" line Kees Cook
2024-01-10 23:46 ` Linus Walleij
2024-01-11 12:12 ` AngeloGioacchino Del Regno
2024-01-11 15:49 ` Mark Brown

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).