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authorArd Biesheuvel <ardb@kernel.org>2021-10-05 09:15:39 +0200
committerArd Biesheuvel <ardb@kernel.org>2021-12-03 15:11:31 +0100
commit4ab6827081c63b83011a18d8e27f621ed34b1194 (patch)
treec47ae449b8c9cb2343f187c1b27993c953c54298 /arch/arm/kernel/traps.c
parent8cdfdf7fe4fec5a952edfb8927ee7cc639c58184 (diff)
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/traps.c')
-rw-r--r--arch/arm/kernel/traps.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
index e4698605bb72..89be21ec3b52 100644
--- a/arch/arm/kernel/traps.c
+++ b/arch/arm/kernel/traps.c
@@ -74,7 +74,8 @@ void dump_backtrace_entry(unsigned long where, unsigned long from,
loglvl, where, from);
#endif
- if (in_entry_text(from) && end <= ALIGN(frame, THREAD_SIZE))
+ if (!IS_ENABLED(CONFIG_UNWINDER_ARM) &&
+ in_entry_text(from) && end <= ALIGN(frame, THREAD_SIZE))
dump_mem(loglvl, "Exception stack", frame + 4, end);
}