Commit 331e4065 authored by Thomas Gleixner's avatar Thomas Gleixner Committed by Ingo Molnar
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x86: CPA return early when requested feature is not available 



Mask out the not supported bits (e.g. NX). If the clr/set masks
are empty after the mask return without changing anything.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 1c083eb2

arch/x86/mm/pageattr.c

+12 −2
Original line number Diff line number Diff line
@@ -405,8 +405,18 @@ static int __change_page_attr_set_clr(unsigned long addr, int numpages, 
static int change_page_attr_set_clr(unsigned long addr, int numpages,

				    pgprot_t mask_set, pgprot_t mask_clr)

{

	int ret = __change_page_attr_set_clr(addr, numpages, mask_set,

					     mask_clr);

	int ret;



	/*

	 * Check, if we are requested to change a not supported

	 * feature:

	 */

	mask_set = canon_pgprot(mask_set);

	mask_clr = canon_pgprot(mask_clr);

	if (!pgprot_val(mask_set) && !pgprot_val(mask_clr))

		return 0;



	ret = __change_page_attr_set_clr(addr, numpages, mask_set, mask_clr);



	/*

	 * On success we use clflush, when the CPU supports it to