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Commit 8b1bde93 authored by Jan Beulich's avatar Jan Beulich Committed by Linus Torvalds
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[PATCH] x86_64: Adjust page fault handling 



Adjust page fault protection error check before considering it to be
a vmalloc synchronization candidate.

Signed-off-by: default avatarAndi Kleen <ak@suse.de>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 505cc4e1

arch/x86_64/mm/fault.c

+4 −3
Original line number Diff line number Diff line
@@ -299,7 +299,8 @@ int exception_trace = 1; 
 *	bit 0 == 0 means no page found, 1 means protection fault

 *	bit 1 == 0 means read, 1 means write

 *	bit 2 == 0 means kernel, 1 means user-mode

 *      bit 3 == 1 means fault was an instruction fetch

 *	bit 3 == 1 means use of reserved bit detected

 *	bit 4 == 1 means fault was an instruction fetch

 */

asmlinkage void __kprobes do_page_fault(struct pt_regs *regs,

					unsigned long error_code)
@@ -342,10 +343,10 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs, 
	 *

	 * This verifies that the fault happens in kernel space

	 * (error_code & 4) == 0, and that the fault was not a

	 * protection error (error_code & 1) == 0.

	 * protection error (error_code & 9) == 0.

	 */

	if (unlikely(address >= TASK_SIZE64)) {

		if (!(error_code & 5) &&

		if (!(error_code & 0xd) &&

		      ((address >= VMALLOC_START && address < VMALLOC_END) ||

		       (address >= MODULES_VADDR && address < MODULES_END))) {

			if (vmalloc_fault(address) < 0)