| Message ID | 20240110215554.work.460-kees@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | ARM: unwind: Add missing "Call trace:" line | expand |
On Wed, Jan 10, 2024 at 10:56 PM Kees Cook <keescook@chromium.org> wrote: > 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> Makes sense. Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Yours, Linus Walleij
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>
On Wed, Jan 10, 2024 at 01:56:01PM -0800, Kees Cook wrote: > 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. Reviewed-by: Mark Brown <broonie@kernel.org>
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)
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(-)