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| author | Thomas Gleixner <tglx@linutronix.de> | 2008-02-04 16:48:06 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-02-04 16:48:06 +0100 |
| commit | 331e406588dc90331753e6562e5e3757bb907eb8 (patch) | |
| tree | eff21a6aee567367bc63f4b81ecf9b2582eed1ec /arch/x86 | |
| parent | x86: fix EFI mapping (diff) | |
| download | linux-331e406588dc90331753e6562e5e3757bb907eb8.tar.xz linux-331e406588dc90331753e6562e5e3757bb907eb8.zip | |
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: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/mm/pageattr.c | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index a629cea5e465..f60b93dc2e57 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -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 |