Merge "arm: mm: program ptes for access restriction" (3cb56f01) · Commits · e / devices / android_kernel_fairphone_FP3

arch/arm/mm/init.c

+54 −4

Original line number	Original line	Diff line number	Diff line
	@@ -630,6 +630,9 @@ struct section_perm {
	pmdval_t mask;		pmdval_t mask;
	pmdval_t prot;		pmdval_t prot;
	pmdval_t clear;		pmdval_t clear;
			pteval_t ptemask;
			pteval_t pteprot;
			pteval_t pteclear;
	};		};

	/* First section-aligned location at or after __start_rodata. */		/* First section-aligned location at or after __start_rodata. */
	@@ -643,6 +646,8 @@ static struct section_perm nx_perms[] = {
	.end = (unsigned long)_stext,		.end = (unsigned long)_stext,
	.mask = ~PMD_SECT_XN,		.mask = ~PMD_SECT_XN,
	.prot = PMD_SECT_XN,		.prot = PMD_SECT_XN,
			.ptemask = ~L_PTE_XN,
			.pteprot = L_PTE_XN,
	},		},
	/* Make init RW (set NX). */		/* Make init RW (set NX). */
	{		{
	@@ -651,6 +656,8 @@ static struct section_perm nx_perms[] = {
	.end = (unsigned long)_sdata,		.end = (unsigned long)_sdata,
	.mask = ~PMD_SECT_XN,		.mask = ~PMD_SECT_XN,
	.prot = PMD_SECT_XN,		.prot = PMD_SECT_XN,
			.ptemask = ~L_PTE_XN,
			.pteprot = L_PTE_XN,
	},		},
	/* Make rodata NX (set RO in ro_perms below). */		/* Make rodata NX (set RO in ro_perms below). */
	{		{
	@@ -659,6 +666,8 @@ static struct section_perm nx_perms[] = {
	.end = (unsigned long)__init_begin,		.end = (unsigned long)__init_begin,
	.mask = ~PMD_SECT_XN,		.mask = ~PMD_SECT_XN,
	.prot = PMD_SECT_XN,		.prot = PMD_SECT_XN,
			.ptemask = ~L_PTE_XN,
			.pteprot = L_PTE_XN,
	},		},
	};		};

	@@ -676,6 +685,8 @@ static struct section_perm ro_perms[] = {
	.prot = PMD_SECT_APX \| PMD_SECT_AP_WRITE,		.prot = PMD_SECT_APX \| PMD_SECT_AP_WRITE,
	.clear = PMD_SECT_AP_WRITE,		.clear = PMD_SECT_AP_WRITE,
	#endif		#endif
			.ptemask = ~L_PTE_RDONLY,
			.pteprot = L_PTE_RDONLY,
	},		},
	};		};

	@@ -684,6 +695,35 @@ static struct section_perm ro_perms[] = {
	* copied into each mm). During startup, this is the init_mm. Is only		* copied into each mm). During startup, this is the init_mm. Is only
	* safe to be called with preemption disabled, as under stop_machine().		* safe to be called with preemption disabled, as under stop_machine().
	*/		*/
			struct pte_data {
			pteval_t mask;
			pteval_t val;
			};

			static int __pte_update(pte_t *ptep, pgtable_t token, unsigned long addr,
			void *d)
			{
			struct pte_data *data = d;
			pte_t pte = *ptep;

			pte = __pte((pte_val(*ptep) & data->mask) \| data->val);
			set_pte_ext(ptep, pte, 0);

			return 0;
			}

			static inline void pte_update(unsigned long addr, pteval_t mask,
			pteval_t prot, struct mm_struct *mm)
			{
			struct pte_data data;

			data.mask = mask;
			data.val = prot;

			apply_to_page_range(mm, addr, SECTION_SIZE, __pte_update, &data);
			flush_tlb_kernel_range(addr, addr + SECTION_SIZE);
			}

	static inline void section_update(unsigned long addr, pmdval_t mask,		static inline void section_update(unsigned long addr, pmdval_t mask,
	pmdval_t prot, struct mm_struct *mm)		pmdval_t prot, struct mm_struct *mm)
	{		{
	@@ -732,11 +772,21 @@ void set_section_perms(struct section_perm *perms, int n, bool set,

	for (addr = perms[i].start;		for (addr = perms[i].start;
	addr < perms[i].end;		addr < perms[i].end;
	addr += SECTION_SIZE)		addr += SECTION_SIZE) {
			pmd_t *pmd;

			pmd = pmd_offset(pud_offset(pgd_offset(mm, addr),
			addr), addr);
			if (pmd_bad(*pmd))
	section_update(addr, perms[i].mask,		section_update(addr, perms[i].mask,
	set ? perms[i].prot : perms[i].clear, mm);		set ? perms[i].prot : perms[i].clear,
			mm);
			else
			pte_update(addr, perms[i].ptemask,
			set ? perms[i].pteprot : perms[i].pteclear,
			mm);
			}
	}		}

	}		}

	static void update_sections_early(struct section_perm perms[], int n)		static void update_sections_early(struct section_perm perms[], int n)