Commit 5b0c2cac authored Sep 28, 2018 by Dave Hansen Committed by Peter Zijlstra Oct 09, 2018

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

parent aa37c51b

arch/x86/mm/fault.c

+8 −0

Original line number	Diff line number	Diff line
		@@ -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;

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