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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/lib/backtrace.S | |
| parent | eae9523fdd7a6c592e80666681962acbd913cda2 (diff) | |
| download | linux-d4664b6c987f80338407889c1e3f3abe7e16be94.tar.bz2 | |
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/lib/backtrace.S')
| -rw-r--r-- | arch/arm/lib/backtrace.S | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/arm/lib/backtrace.S b/arch/arm/lib/backtrace.S index e8408f22d4dc..293a2716bd20 100644 --- a/arch/arm/lib/backtrace.S +++ b/arch/arm/lib/backtrace.S @@ -98,6 +98,14 @@ for_each_frame: tst frame, mask @ Check for address exceptions cmp sv_fp, frame @ next frame must be mov frame, sv_fp @ above the current frame +#ifdef CONFIG_IRQSTACKS + @ + @ Kernel stacks may be discontiguous in memory. If the next + @ frame is below the previous frame, accept it as long as it + @ lives in kernel memory. + @ + cmpls sv_fp, #PAGE_OFFSET +#endif bhi for_each_frame 1006: adr r0, .Lbad |