Merge "arm64: Add CONFIG_DEBUG_SET_MODULE_RONX support" (2c236339) · Commits · e / devices / android_kernel_sony_msm8994

arch/arm64/Kconfig.debug

+11 −0

Original line number	Diff line number	Diff line
		@@ -23,4 +23,15 @@ config PID_IN_CONTEXTIDR
		instructions during context switch. Say Y here only if you are
		planning to use hardware trace tools with this kernel.

		config DEBUG_SET_MODULE_RONX
		bool "Set loadable kernel module data as NX and text as RO"
		depends on MODULES
		---help---
		This option helps catch unintended modifications to loadable
		kernel module's text and read-only data. It also prevents execution
		of module data. Such protection may interfere with run-time code
		patching and dynamic kernel tracing - and they might also protect
		against certain classes of kernel exploits.
		If in doubt, say "N".

		endmenu

+4 −0

Original line number	Diff line number	Diff line
		@@ -164,4 +164,8 @@ static inline void flush_cache_vunmap(unsigned long start, unsigned long end)
		{
		}

		int set_memory_ro(unsigned long addr, int numpages);
		int set_memory_rw(unsigned long addr, int numpages);
		int set_memory_x(unsigned long addr, int numpages);
		int set_memory_nx(unsigned long addr, int numpages);
		#endif

+2 −0

Original line number	Diff line number	Diff line
		@@ -156,6 +156,8 @@ PTE_BIT_FUNC(mkdirty, \|= PTE_DIRTY);
		PTE_BIT_FUNC(mkold, &= ~PTE_AF);
		PTE_BIT_FUNC(mkyoung, \|= PTE_AF);
		PTE_BIT_FUNC(mkspecial, \|= PTE_SPECIAL);
		PTE_BIT_FUNC(mkexec, &= ~PTE_PXN);
		PTE_BIT_FUNC(mknexec, \|= PTE_PXN);

		static inline void set_pte(pte_t *ptep, pte_t pte)
		{

+42 −0

Original line number	Diff line number	Diff line
		@@ -122,6 +122,48 @@ static int __init early_cachepolicy(char *p)
		}
		early_param("cachepolicy", early_cachepolicy);

		#define PTE_SET_FN(_name, pteop) \
		static int pte_set_##_name(pte_t *ptep, pgtable_t token, unsigned long addr, \
		void *data) \
		{ \
		pte_t pte = pteop(*ptep); \
		\
		set_pte(ptep, pte); \
		return 0; \
		} \

		#define SET_MEMORY_FN(_name, callback) \
		int set_memory_##_name(unsigned long addr, int numpages) \
		{ \
		unsigned long start = addr; \
		unsigned long size = PAGE_SIZE*numpages; \
		unsigned long end = start + size; \
		\
		if (start < MODULES_VADDR \|\| start >= MODULES_END) \
		return -EINVAL;\
		\
		if (end < MODULES_VADDR \|\| end >= MODULES_END) \
		return -EINVAL; \
		\
		apply_to_page_range(&init_mm, start, size, callback, NULL); \
		flush_tlb_kernel_range(start, end); \
		return 0;\
		}

		PTE_SET_FN(ro, pte_wrprotect)
		PTE_SET_FN(rw, pte_mkwrite)
		PTE_SET_FN(x, pte_mkexec)
		PTE_SET_FN(nx, pte_mknexec)

		SET_MEMORY_FN(ro, pte_set_ro)
		EXPORT_SYMBOL(set_memory_ro);
		SET_MEMORY_FN(rw, pte_set_rw)
		EXPORT_SYMBOL(set_memory_rw);
		SET_MEMORY_FN(x, pte_set_x)
		EXPORT_SYMBOL(set_memory_x);
		SET_MEMORY_FN(nx, pte_set_nx)
		EXPORT_SYMBOL(set_memory_nx);

		/*
		* Adjust the PMD section entries according to the CPU in use.
		*/