Commit-ID: 5b0c2cac54d44ea40d5c5aec7cbf14353b2a903e Gitweb: https://git.kernel.org/tip/5b0c2cac54d44ea40d5c5aec7cbf14353b2a903e Author: Dave Hansen <[email protected]> AuthorDate: Fri, 28 Sep 2018 09:02:25 -0700 Committer: Peter Zijlstra <[email protected]> CommitDate: Tue, 9 Oct 2018 16:51:16 +0200
x86/mm: Add clarifying comments for user addr space The SMAP and Reserved checking do not have nice comments. Add some to clarify and make it match everything else. Cc: [email protected] Cc: Jann Horn <[email protected]> Cc: Sean Christopherson <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Andy Lutomirski <[email protected]> Signed-off-by: Dave Hansen <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Link: http://lkml.kernel.org/r/[email protected] --- arch/x86/mm/fault.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 0d1f5d39fc63..1d838701a5f7 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -1276,9 +1276,17 @@ void do_user_addr_fault(struct pt_regs *regs, 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;
