From: Dave Hansen <[email protected]>
The SMAP and Reserved checking do not have nice comments. Add some to clarify and make it match everything else. Signed-off-by: Dave Hansen <[email protected]> Cc: Sean Christopherson <[email protected]> Cc: "Peter Zijlstra (Intel)" <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: Andy Lutomirski <[email protected]> --- b/arch/x86/mm/fault.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff -puN arch/x86/mm/fault.c~pkeys-fault-warnings-02 arch/x86/mm/fault.c --- a/arch/x86/mm/fault.c~pkeys-fault-warnings-02 2018-09-07 11:21:47.182751900 -0700 +++ b/arch/x86/mm/fault.c 2018-09-07 11:21:47.185751900 -0700 @@ -1274,9 +1274,17 @@ void do_user_addr_space_fault(struct pt_ if (unlikely(kprobes_fault(regs))) return; + /* + * Reserved bits are never expected to be set on + * entries in the user portion of the page tables. + */ if (unlikely(hw_error_code & X86_PF_RSVD)) pgtable_bad(regs, hw_error_code, address); + /* + * Check for invalid kernel (supervisor) access to user + * pages in the user address space. + */ if (unlikely(smap_violation(hw_error_code, regs))) { bad_area_nosemaphore(regs, hw_error_code, address, NULL); return; _
