x86, pageattr: Make set_memory_(x|nx) aware of NX support (583140af) · Commits · 戴 / test

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 <hpa@zytor.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Tejun Heo <tj@kernel.org> Cc: Tim Starling <tstarling@wikimedia.org> Cc: Hannes Eder <hannes@hanneseder.net> LKML-Reference: <1258154897-6770-4-git-send-email-hpa@zytor.com> Acked-by:

Kees Cook <kees.cook@canonical.com>

arch/x86/kernel/machine_kexec_32.c

+2 −4

Original line number	Diff line number	Diff line
		@@ -157,7 +157,6 @@ int machine_kexec_prepare(struct kimage *image)
		{
		int error;

		if (nx_enabled)
		set_pages_x(image->control_code_page, 1);
		error = machine_kexec_alloc_page_tables(image);
		if (error)
		@@ -172,7 +171,6 @@ 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);
		machine_kexec_free_page_tables(image);
		}

arch/x86/mm/pageattr.c

+6 −0

Original line number	Diff line number	Diff line
		@@ -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);

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