From 583140afb989f24d115e80be5c91e503b58ccfc0 Mon Sep 17 00:00:00 2001 From: "H. Peter Anvin" Date: Fri, 13 Nov 2009 15:28:15 -0800 Subject: [PATCH] x86, pageattr: Make set_memory_(x|nx) aware of NX support Make set_memory_x/set_memory_nx directly aware of if NX is supported in the system or not, rather than requiring that every caller assesses that support independently. Signed-off-by: H. Peter Anvin Cc: Huang Ying Cc: Venkatesh Pallipadi Cc: Suresh Siddha Cc: Tejun Heo Cc: Tim Starling Cc: Hannes Eder LKML-Reference: <1258154897-6770-4-git-send-email-hpa@zytor.com> Acked-by: Kees Cook --- arch/x86/kernel/machine_kexec_32.c | 6 ++---- arch/x86/mm/pageattr.c | 6 ++++++ 2 files changed, 8 insertions(+), 4 deletions(-) diff --git a/arch/x86/kernel/machine_kexec_32.c b/arch/x86/kernel/machine_kexec_32.c index c1c429d0013..03657e784fd 100644 --- a/arch/x86/kernel/machine_kexec_32.c +++ b/arch/x86/kernel/machine_kexec_32.c @@ -157,8 +157,7 @@ int machine_kexec_prepare(struct kimage *image) { int error; - if (nx_enabled) - set_pages_x(image->control_code_page, 1); + set_pages_x(image->control_code_page, 1); error = machine_kexec_alloc_page_tables(image); if (error) return error; @@ -172,8 +171,7 @@ int machine_kexec_prepare(struct kimage *image) */ void machine_kexec_cleanup(struct kimage *image) { - if (nx_enabled) - set_pages_nx(image->control_code_page, 1); + set_pages_nx(image->control_code_page, 1); machine_kexec_free_page_tables(image); } diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index 09a140ca7be..1d4eb93d333 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -1085,12 +1085,18 @@ EXPORT_SYMBOL(set_memory_array_wb); int set_memory_x(unsigned long addr, int numpages) { + if (!(__supported_pte_mask & _PAGE_NX)) + return 0; + return change_page_attr_clear(&addr, numpages, __pgprot(_PAGE_NX), 0); } EXPORT_SYMBOL(set_memory_x); int set_memory_nx(unsigned long addr, int numpages) { + if (!(__supported_pte_mask & _PAGE_NX)) + return 0; + return change_page_attr_set(&addr, numpages, __pgprot(_PAGE_NX), 0); } EXPORT_SYMBOL(set_memory_nx); -- 2.20.1