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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/irq.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/irq.c')
| -rw-r--r-- | arch/arm/kernel/irq.c | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/arch/arm/kernel/irq.c b/arch/arm/kernel/irq.c index b79975bd988c..abb0aa679bba 100644 --- a/arch/arm/kernel/irq.c +++ b/arch/arm/kernel/irq.c @@ -43,6 +43,25 @@ unsigned long irq_err_count; +#ifdef CONFIG_IRQSTACKS + +asmlinkage DEFINE_PER_CPU_READ_MOSTLY(u8 *, irq_stack_ptr); + +static void __init init_irq_stacks(void) +{ + u8 *stack; + int cpu; + + for_each_possible_cpu(cpu) { + stack = (u8 *)__get_free_pages(GFP_KERNEL, THREAD_SIZE_ORDER); + if (WARN_ON(!stack)) + break; + per_cpu(irq_stack_ptr, cpu) = &stack[THREAD_SIZE]; + } +} + +#endif + int arch_show_interrupts(struct seq_file *p, int prec) { #ifdef CONFIG_FIQ @@ -101,6 +120,10 @@ void __init init_IRQ(void) { int ret; +#ifdef CONFIG_IRQSTACKS + init_irq_stacks(); +#endif + if (IS_ENABLED(CONFIG_OF) && !machine_desc->init_irq) irqchip_init(); else |