commit: 02522463c84748b3b8ad770f9424bcfa70a5b4c4 From: Will Deacon <[email protected]> Date: Wed, 9 Jan 2013 11:08:10 +0000 Subject: arm64: mm: only wrprotect clean ptes if they are present
Marking non-present ptes as read-only can corrupt file ptes, breaking things like swap and file mappings. This patch ensures that we only manipulate user pte bits when the pte is marked present. Cc: <[email protected]> Signed-off-by: Will Deacon <[email protected]> Signed-off-by: Catalin Marinas <[email protected]> --- arch/arm64/include/asm/pgtable.h | 16 +++++++++------- 1 files changed, 9 insertions(+), 7 deletions(-) diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index 64b1339..7adf414 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -132,9 +132,8 @@ extern struct page *empty_zero_page; #define pte_write(pte) (!(pte_val(pte) & PTE_RDONLY)) #define pte_exec(pte) (!(pte_val(pte) & PTE_UXN)) -#define pte_present_exec_user(pte) \ - ((pte_val(pte) & (PTE_VALID | PTE_USER | PTE_UXN)) == \ - (PTE_VALID | PTE_USER)) +#define pte_present_user(pte) \ + ((pte_val(pte) & (PTE_VALID | PTE_USER)) == (PTE_VALID | PTE_USER)) #define PTE_BIT_FUNC(fn,op) \ static inline pte_t pte_##fn(pte_t pte) { pte_val(pte) op; return pte; } @@ -157,10 +156,13 @@ 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_present_exec_user(pte)) - __sync_icache_dcache(pte, addr); - if (!pte_dirty(pte)) - pte = pte_wrprotect(pte); + if (pte_present_user(pte)) { + if (pte_exec(pte)) + __sync_icache_dcache(pte, addr); + if (!pte_dirty(pte)) + pte = pte_wrprotect(pte); + } + set_pte(ptep, pte); } -- 1.7.3.4 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
