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| author | Ard Biesheuvel <ardb@kernel.org> | 2021-10-05 09:15:40 +0200 |
|---|---|---|
| committer | Ard Biesheuvel <ardb@kernel.org> | 2021-12-03 15:11:31 +0100 |
| commit | d4664b6c987f80338407889c1e3f3abe7e16be94 (patch) | |
| tree | 21565f50f64551f10a68d2df793711ac07962c53 /arch/arm/kernel/traps.c | |
| parent | ARM: backtrace-clang: avoid crash on bogus frame pointer (diff) | |
| download | linux-d4664b6c987f80338407889c1e3f3abe7e16be94.tar.xz linux-d4664b6c987f80338407889c1e3f3abe7e16be94.zip | |
ARM: implement IRQ stacks
Now that we no longer rely on the stack pointer to access the current
task struct or thread info, we can implement support for IRQ stacks
cleanly as well.
Define a per-CPU IRQ stack and switch to this stack when taking an IRQ,
provided that we were not already using that stack in the interrupted
context. This is never the case for IRQs taken from user space, but ones
taken while running in the kernel could fire while one taken from user
space has not completed yet.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Keith Packard <keithpac@amazon.com>
Acked-by: Nick Desaulniers <ndesaulniers@google.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.c | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c index 89be21ec3b52..b42c446cec9a 100644 --- a/arch/arm/kernel/traps.c +++ b/arch/arm/kernel/traps.c @@ -66,6 +66,19 @@ void dump_backtrace_entry(unsigned long where, unsigned long from, { unsigned long end = frame + 4 + sizeof(struct pt_regs); + if (IS_ENABLED(CONFIG_UNWINDER_FRAME_POINTER) && + IS_ENABLED(CONFIG_CC_IS_GCC) && + end > ALIGN(frame, THREAD_SIZE)) { + /* + * If we are walking past the end of the stack, it may be due + * to the fact that we are on an IRQ or overflow stack. In this + * case, we can load the address of the other stack from the + * frame record. + */ + frame = ((unsigned long *)frame)[-2] - 4; + end = frame + 4 + sizeof(struct pt_regs); + } + #ifdef CONFIG_KALLSYMS printk("%s[<%08lx>] (%ps) from [<%08lx>] (%pS)\n", loglvl, where, (void *)where, from, (void *)from); @@ -278,7 +291,7 @@ static int __die(const char *str, int err, struct pt_regs *regs) if (!user_mode(regs) || in_interrupt()) { dump_mem(KERN_EMERG, "Stack: ", regs->ARM_sp, - THREAD_SIZE + (unsigned long)task_stack_page(tsk)); + ALIGN(regs->ARM_sp, THREAD_SIZE)); dump_backtrace(regs, tsk, KERN_EMERG); dump_instr(KERN_EMERG, regs); } |