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authorDave Hansen <dave.hansen@linux.intel.com>2018-09-28 09:02:25 -0700
committerPeter Zijlstra <peterz@infradead.org>2018-10-09 16:51:16 +0200
commit5b0c2cac54d44ea40d5c5aec7cbf14353b2a903e (patch)
tree6b6ad59f522d8bbacd38a200b3eba413be345f8f /arch/x86/mm
parentaa37c51b9421d66f7931c5fdcb9ce80c450974be (diff)
downloadlinux-5b0c2cac54d44ea40d5c5aec7cbf14353b2a903e.tar.bz2
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: x86@kernel.org Cc: Jann Horn <jannh@google.com> Cc: Sean Christopherson <sean.j.christopherson@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@kernel.org> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: http://lkml.kernel.org/r/20180928160225.FFD44B8D@viggo.jf.intel.com
Diffstat (limited to 'arch/x86/mm')
-rw-r--r--arch/x86/mm/fault.c8
1 files changed, 8 insertions, 0 deletions
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;