diff options
| author | Catalin Marinas <catalin.marinas@arm.com> | 2014-05-16 16:44:32 +0100 |
|---|---|---|
| committer | Mark Brown <broonie@linaro.org> | 2014-06-04 14:55:37 +0100 |
| commit | 5af70c99ecd544f98f84c4d369d8545fe221dca7 (patch) | |
| tree | 9f30be52a12dd3a5d1911fe9b588939a58b0718b | |
| parent | 3698e46b6e5bcd43d7b2faad9e77a015a3495011 (diff) | |
Revert "arm64: Introduce execute-only page access permissions"
This reverts commit bc07c2c6e9ed125d362af0214b6313dca180cb08.
While the aim is increased security for --x memory maps, it does not
protect against kernel level reads. Until SECCOMP is implemented for
arm64, revert this patch to avoid giving a false idea of execute-only
mappings.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 5a0fdfada3a2aa50d7b947a2e958bf00cbe0d830)
Signed-off-by: Mark Brown <broonie@linaro.org>
| -rw-r--r-- | arch/arm64/include/asm/pgtable.h | 11 | ||||
| -rw-r--r-- | arch/arm64/mm/fault.c | 5 |
2 files changed, 8 insertions, 8 deletions
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index ff13c70ea585..b3f6193036a8 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -86,13 +86,12 @@ extern void __pgd_error(const char *file, int line, unsigned long val); #define PAGE_COPY_EXEC __pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN) #define PAGE_READONLY __pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN | PTE_UXN) #define PAGE_READONLY_EXEC __pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN) -#define PAGE_EXECONLY __pgprot(_PAGE_DEFAULT | PTE_NG | PTE_PXN) #define __P000 PAGE_NONE #define __P001 PAGE_READONLY #define __P010 PAGE_COPY #define __P011 PAGE_COPY -#define __P100 PAGE_EXECONLY +#define __P100 PAGE_READONLY_EXEC #define __P101 PAGE_READONLY_EXEC #define __P110 PAGE_COPY_EXEC #define __P111 PAGE_COPY_EXEC @@ -101,7 +100,7 @@ extern void __pgd_error(const char *file, int line, unsigned long val); #define __S001 PAGE_READONLY #define __S010 PAGE_SHARED #define __S011 PAGE_SHARED -#define __S100 PAGE_EXECONLY +#define __S100 PAGE_READONLY_EXEC #define __S101 PAGE_READONLY_EXEC #define __S110 PAGE_SHARED_EXEC #define __S111 PAGE_SHARED_EXEC @@ -137,8 +136,8 @@ extern struct page *empty_zero_page; #define pte_write(pte) (!!(pte_val(pte) & PTE_WRITE)) #define pte_exec(pte) (!(pte_val(pte) & PTE_UXN)) -#define pte_valid_ng(pte) \ - ((pte_val(pte) & (PTE_VALID | PTE_NG)) == (PTE_VALID | PTE_NG)) +#define pte_valid_user(pte) \ + ((pte_val(pte) & (PTE_VALID | PTE_USER)) == (PTE_VALID | PTE_USER)) static inline pte_t pte_wrprotect(pte_t pte) { @@ -192,7 +191,7 @@ extern void __sync_icache_dcache(pte_t pteval, unsigned long addr); static inline void set_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pte) { - if (pte_valid_ng(pte)) { + if (pte_valid_user(pte)) { if (!pte_special(pte) && pte_exec(pte)) __sync_icache_dcache(pte, addr); if (pte_dirty(pte) && pte_write(pte)) diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index c1b42273c8fa..df4f2fd187c3 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -173,7 +173,8 @@ static int __do_page_fault(struct mm_struct *mm, unsigned long addr, good_area: /* * Check that the permissions on the VMA allow for the fault which - * occurred. + * occurred. If we encountered a write or exec fault, we must have + * appropriate permissions, otherwise we allow any permission. */ if (!(vma->vm_flags & vm_flags)) { fault = VM_FAULT_BADACCESS; @@ -195,7 +196,7 @@ static int __kprobes do_page_fault(unsigned long addr, unsigned int esr, struct task_struct *tsk; struct mm_struct *mm; int fault, sig, code; - unsigned long vm_flags = VM_READ | VM_WRITE; + unsigned long vm_flags = VM_READ | VM_WRITE | VM_EXEC; unsigned int mm_flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; if (esr & ESR_LNX_EXEC) { |