Messages in this thread | | | Date | Tue, 12 Jan 2021 19:01:32 +0000 | From | Catalin Marinas <> | Subject | Re: [PATCH 05/11] kasan, arm64: allow using KUnit tests with HW_TAGS mode |
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On Tue, Jan 05, 2021 at 07:27:49PM +0100, Andrey Konovalov wrote: > diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c > index 3c40da479899..57d3f165d907 100644 > --- a/arch/arm64/mm/fault.c > +++ b/arch/arm64/mm/fault.c > @@ -302,12 +302,20 @@ static void die_kernel_fault(const char *msg, unsigned long addr, > static void report_tag_fault(unsigned long addr, unsigned int esr, > struct pt_regs *regs) > { > - bool is_write = ((esr & ESR_ELx_WNR) >> ESR_ELx_WNR_SHIFT) != 0; > + static bool reported; > + bool is_write; > + > + if (READ_ONCE(reported)) > + return; > + > + if (mte_report_once()) > + WRITE_ONCE(reported, true);
I guess the assumption here is that you don't get any report before the tests start and temporarily set report_once to false. It's probably fine, if we get a tag check failure we'd notice in the logs anyway.
> /* > * SAS bits aren't set for all faults reported in EL1, so we can't > * find out access size. > */ > + is_write = ((esr & ESR_ELx_WNR) >> ESR_ELx_WNR_SHIFT) != 0;
I now noticed, you could write this in a shorter way:
is_write = !!(esr & ESR_ELx_WNR);
> kasan_report(addr, 0, is_write, regs->pc); > }
The patch looks fine to me.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
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