Messages in this thread Patch in this message | | | Subject | [PATCH 2/9] x86, pkeys: add fault handling for PF_PK page fault bit | From | Dave Hansen <> | Date | Wed, 09 Mar 2016 14:00:11 -0800 |
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From: Dave Hansen <dave.hansen@linux.intel.com>
PF_PK means that a memory access violated the protection key access restrictions. It is unconditionally an access_error() because the permissions set on the VMA don't matter (the PKRU value overrides it), and we never "resolve" PK faults (like how a COW can "resolve write fault).
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> ---
b/arch/x86/mm/fault.c | 9 +++++++++ 1 file changed, 9 insertions(+)
diff -puN arch/x86/mm/fault.c~pkeys-105-add-pk-to-fault arch/x86/mm/fault.c --- a/arch/x86/mm/fault.c~pkeys-105-add-pk-to-fault 2016-03-09 13:55:19.682431296 -0800 +++ b/arch/x86/mm/fault.c 2016-03-09 13:55:19.685431432 -0800 @@ -1121,6 +1121,15 @@ access_error(unsigned long error_code, s { /* This is only called for the current mm, so: */ bool foreign = false; + + /* + * Read or write was blocked by protection keys. This is + * always an unconditional error and can never result in + * a follow-up action to resolve the fault, like a COW. + */ + if (error_code & PF_PK) + return 1; + /* * Make sure to check the VMA so that we do not perform * faults just to hit a PF_PK as soon as we fill in a _
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