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| author | Ard Biesheuvel <ardb@kernel.org> | 2021-10-05 09:15:39 +0200 |
|---|---|---|
| committer | Ard Biesheuvel <ardb@kernel.org> | 2021-12-03 15:11:31 +0100 |
| commit | 4ab6827081c63b83011a18d8e27f621ed34b1194 (patch) | |
| tree | c47ae449b8c9cb2343f187c1b27993c953c54298 /arch/arm/kernel/unwind.c | |
| parent | ARM: export dump_mem() to other objects (diff) | |
| download | linux-4ab6827081c63b83011a18d8e27f621ed34b1194.tar.xz linux-4ab6827081c63b83011a18d8e27f621ed34b1194.zip | |
ARM: unwind: dump exception stack from calling frame
The existing code that dumps the contents of the pt_regs structure
passed to __entry routines does so while unwinding the callee frame, and
dereferences the stack pointer as a struct pt_regs*. This will no longer
work when we enable support for IRQ or overflow stacks, because the
struct pt_regs may live on the task stack, while we are executing from
another stack.
The unwinder has access to this information, but only while unwinding
the calling frame. So let's combine the exception stack dumping code
with the handling of the calling frame as well. By printing it before
dumping the caller/callee addresses, the output order is preserved.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Keith Packard <keithpac@amazon.com>
Tested-by: Marc Zyngier <maz@kernel.org>
Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M
Diffstat (limited to 'arch/arm/kernel/unwind.c')
| -rw-r--r-- | arch/arm/kernel/unwind.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/arch/arm/kernel/unwind.c b/arch/arm/kernel/unwind.c index 9cb9af3fc433..b7a6141c342f 100644 --- a/arch/arm/kernel/unwind.c +++ b/arch/arm/kernel/unwind.c @@ -29,6 +29,7 @@ #include <linux/spinlock.h> #include <linux/list.h> +#include <asm/sections.h> #include <asm/stacktrace.h> #include <asm/traps.h> #include <asm/unwind.h> @@ -459,6 +460,7 @@ int unwind_frame(struct stackframe *frame) frame->sp = ctrl.vrs[SP]; frame->lr = ctrl.vrs[LR]; frame->pc = ctrl.vrs[PC]; + frame->sp_low = ctrl.sp_low; return URC_OK; } @@ -502,7 +504,11 @@ void unwind_backtrace(struct pt_regs *regs, struct task_struct *tsk, urc = unwind_frame(&frame); if (urc < 0) break; - dump_backtrace_entry(where, frame.pc, frame.sp - 4, loglvl); + if (in_entry_text(where)) + dump_mem(loglvl, "Exception stack", frame.sp_low, + frame.sp_low + sizeof(struct pt_regs)); + + dump_backtrace_entry(where, frame.pc, 0, loglvl); } } |