Commit 1ad33f5a authored Nov 19, 2018 by Andy Lutomirski Committed by Ingo Molnar Nov 20, 2018

x86/fault: Don't set thread.cr2, etc before OOPSing

The fault handling code sets the cr2, trap_nr, and error_code fields
in thread_struct before OOPSing.  No one reads those fields during
an OOPS, so remove the code to set them.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yu-cheng Yu <yu-cheng.yu@intel.com>
Link: http://lkml.kernel.org/r/d418022aa0fad9cb40467aa7acaf4e95be50ee96.1542667307.git.luto@kernel.org

Signed-off-by: Ingo Molnar <mingo@kernel.org>

parent e49d3cbe

arch/x86/mm/fault.c

+0 −8

Original line number	Diff line number	Diff line
		@@ -621,10 +621,6 @@ pgtable_bad(struct pt_regs *regs, unsigned long error_code,
		tsk->comm, address);
		dump_pagetable(address);

		tsk->thread.cr2 = address;
		tsk->thread.trap_nr = X86_TRAP_PF;
		tsk->thread.error_code = error_code;

		if (__die("Bad pagetable", regs, error_code))
		sig = 0;

		@@ -753,10 +749,6 @@ no_context(struct pt_regs *regs, unsigned long error_code,
		if (task_stack_end_corrupted(tsk))
		printk(KERN_EMERG "Thread overran stack, or stack corrupted\n");

		tsk->thread.cr2 = address;
		tsk->thread.trap_nr = X86_TRAP_PF;
		tsk->thread.error_code = error_code;

		sig = SIGKILL;
		if (__die("Oops", regs, error_code))
		sig = 0;

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