Commit 1acdbf7e authored Jan 13, 2018 by Alexey Dobriyan Committed by Ingo Molnar Feb 13, 2018

x86/asm: Clobber flags in clear_page()



All clear_page() implementations use XOR which resets flags.

Judging by allyesconfig disassembly no code is affected.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20180113185048.GA23111@avx2


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

parent 178e834c

arch/x86/include/asm/page_64.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -47,7 +47,7 @@ static inline void clear_page(void *page)
		clear_page_erms, X86_FEATURE_ERMS,
		"=D" (page),
		"0" (page)
		: "memory", "rax", "rcx");
		: "cc", "memory", "rax", "rcx");
		}

		void copy_page(void to, void from);

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