Messages in this thread | | | Subject | Re: [PATCH v2 3/4] arm64: mte: Enable async tag check fault | From | Vincenzo Frascino <> | Date | Thu, 14 Jan 2021 14:57:03 +0000 |
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On 1/14/21 2:25 PM, Catalin Marinas wrote: > On Thu, Jan 14, 2021 at 10:24:25AM +0000, Vincenzo Frascino wrote: >> On 1/13/21 6:11 PM, Catalin Marinas wrote: >>> On Thu, Jan 07, 2021 at 05:29:07PM +0000, Vincenzo Frascino wrote: >>>> static inline void mte_sync_tags(pte_t *ptep, pte_t pte) >>>> { >>>> } >>>> diff --git a/arch/arm64/kernel/entry-common.c b/arch/arm64/kernel/entry-common.c >>>> index 5346953e4382..74b020ce72d7 100644 >>>> --- a/arch/arm64/kernel/entry-common.c >>>> +++ b/arch/arm64/kernel/entry-common.c >>>> @@ -37,6 +37,8 @@ static void noinstr enter_from_kernel_mode(struct pt_regs *regs) >>>> lockdep_hardirqs_off(CALLER_ADDR0); >>>> rcu_irq_enter_check_tick(); >>>> trace_hardirqs_off_finish(); >>>> + >>>> + mte_check_tfsr_el1(); >>>> } >>>> >>>> /* >>>> @@ -47,6 +49,8 @@ static void noinstr exit_to_kernel_mode(struct pt_regs *regs) >>>> { >>>> lockdep_assert_irqs_disabled(); >>>> >>>> + mte_check_tfsr_el1(); >>>> + >>>> if (interrupts_enabled(regs)) { >>>> if (regs->exit_rcu) { >>>> trace_hardirqs_on_prepare(); >>>> @@ -243,6 +247,8 @@ asmlinkage void noinstr enter_from_user_mode(void) >>>> >>>> asmlinkage void noinstr exit_to_user_mode(void) >>>> { >>>> + mte_check_tfsr_el1(); >>> >>> While for kernel entry the asynchronous faults are sync'ed automatically >>> with TFSR_EL1, we don't have this for exit, so we'd need an explicit >>> DSB. But rather than placing it here, it's better if we add a bool sync >>> argument to mte_check_tfsr_el1() which issues a dsb() before checking >>> the register. I think that's the only place where such argument would be >>> true (for now). >> >> Good point, I will add the dsb() in mte_check_tfsr_el1() but instead of a bool >> parameter I will add something more explicit. > > Or rename the function to mte_check_tfsr_el1_no_sync() and have a static > inline mte_check_tfsr_el1() which issues a dsb() before calling the > *no_sync variant. > > Adding an enum instead here is not worth it (if that's what you meant by > not using a bool). >
I like this option more, thanks for pointing it out.
-- Regards, Vincenzo
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