Messages in this thread | | | Date | Fri, 22 Jul 2022 17:13:39 +0800 | Subject | Re: [PATCH v1 1/2] arm64: run softirqs on the per-CPU IRQ stack | From | Qi Zheng <> |
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On 2022/7/22 17:04, Will Deacon wrote: > On Fri, Jul 08, 2022 at 05:49:49PM +0800, Qi Zheng wrote: >> Currently arm64 supports per-CPU IRQ stack, but softirqs >> are still handled in the task context. >> >> Since any call to local_bh_enable() at any level in the task's >> call stack may trigger a softirq processing run, which could >> potentially cause a task stack overflow if the combined stack >> footprints exceed the stack's size, let's run these softirqs >> on the IRQ stack as well. >> >> Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com> >> --- >> arch/arm64/Kconfig | 1 + >> arch/arm64/kernel/irq.c | 13 +++++++++++++ >> 2 files changed, 14 insertions(+) >> >> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig >> index 4c1e1d2d2f8b..be0a9f0052ee 100644 >> --- a/arch/arm64/Kconfig >> +++ b/arch/arm64/Kconfig >> @@ -230,6 +230,7 @@ config ARM64 >> select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD >> select TRACE_IRQFLAGS_SUPPORT >> select TRACE_IRQFLAGS_NMI_SUPPORT >> + select HAVE_SOFTIRQ_ON_OWN_STACK >> help >> ARM 64-bit (AArch64) Linux support. >> >> diff --git a/arch/arm64/kernel/irq.c b/arch/arm64/kernel/irq.c >> index bda49430c9ea..c36ad20a52f3 100644 >> --- a/arch/arm64/kernel/irq.c >> +++ b/arch/arm64/kernel/irq.c >> @@ -22,6 +22,7 @@ >> #include <linux/vmalloc.h> >> #include <asm/daifflags.h> >> #include <asm/vmap_stack.h> >> +#include <asm/exception.h> >> >> /* Only access this in an NMI enter/exit */ >> DEFINE_PER_CPU(struct nmi_ctx, nmi_contexts); >> @@ -71,6 +72,18 @@ static void init_irq_stacks(void) >> } >> #endif >> >> +#ifndef CONFIG_PREEMPT_RT >> +static void ____do_softirq(struct pt_regs *regs) >> +{ >> + __do_softirq(); >> +} >> + >> +void do_softirq_own_stack(void) >> +{ >> + call_on_irq_stack(NULL, ____do_softirq); >> +} >> +#endif > > Acked-by: Will Deacon <will@kernel.org> > > Please can you repost this at -rc1 and we can queue it up for 5.21?
Sure, will do.
Thanks, Qi
> > Thanks, > > Will
-- Thanks, Qi
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