From: Dave Hansen <dave.han...@linux.intel.com>
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 <dave.han...@linux.intel.com>
Cc: Sean Christopherson <sean.j.christopher...@intel.com>
Cc: "Peter Zijlstra (Intel)" <pet...@infradead.org>
Cc: Thomas Gleixner <t...@linutronix.de>
Cc: x...@kernel.org
Cc: Andy Lutomirski <l...@kernel.org>
---
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;
_
