Messages in this thread | | | Date | Thu, 6 Apr 2017 17:36:25 +0100 | From | Catalin Marinas <> | Subject | Re: [PATCH v4] arm64: print a fault message when attempting to write RO memory |
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On Wed, Apr 05, 2017 at 12:18:31PM -0700, Stephen Boyd wrote: > If a page is marked read only we should print out that fact, > instead of printing out that there was a page fault. Right now we > get a cryptic error message that something went wrong with an > unhandled fault, but we don't evaluate the esr to figure out that > it was a read/write permission fault. > > Instead of seeing: > > Unable to handle kernel paging request at virtual address ffff000008e460d8 > pgd = ffff800003504000 > [ffff000008e460d8] *pgd=0000000083473003, *pud=0000000083503003, *pmd=0000000000000000 > Internal error: Oops: 9600004f [#1] PREEMPT SMP > > we'll see: > > Unable to handle kernel write to read-only memory at virtual address ffff000008e760d8 > pgd = ffff80003d3de000 > [ffff000008e760d8] *pgd=0000000083472003, *pud=0000000083435003, *pmd=0000000000000000 > Internal error: Oops: 9600004f [#1] PREEMPT SMP > > We also add a userspace address check into is_permission_fault() > so that the function doesn't return true for ttbr0 PAN faults > when it shouldn't. > > Reviewed-by: James Morse <james.morse@arm.com> > Tested-by: James Morse <james.morse@arm.com> > Acked-by: Laura Abbott <labbott@redhat.com> > Cc: Mark Rutland <mark.rutland@arm.com> > Signed-off-by: Stephen Boyd <stephen.boyd@linaro.org>
Queued for 4.12. Thanks.
-- Catalin
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