Messages in this thread Patch in this message |  | | Subject | [PATCH 1/8] x86, pkeys: add fault handling for PF_PK page fault bit | | From | Dave Hansen <> | | Date | Mon, 11 Apr 2016 08:54:24 -0700 |
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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 2016-04-11 08:38:40.474232702 -0700 +++ b/arch/x86/mm/fault.c 2016-04-11 08:38:40.478232883 -0700 @@ -1107,6 +1107,15 @@ 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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