diff options
| author | Catalin Marinas <catalin.marinas@arm.com> | 2017-01-27 10:54:12 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-05-14 14:00:15 +0200 |
| commit | f46fdb8a2611b4ffe9dda5b712ac02add90e930f (patch) | |
| tree | 16c94a7326cce07bfbc8cf825773d33d283913ee | |
| parent | aadb7e073e813a447ba6c5f5636702f07e8805dd (diff) | |
arm64: Improve detection of user/non-user mappings in set_pte(_at)
commit ec663d967b2276448a416406ca59ff247c0c80c5 upstream.
Commit cab15ce604e5 ("arm64: Introduce execute-only page access
permissions") allowed a valid user PTE to have the PTE_USER bit clear.
As a consequence, the pte_valid_not_user() macro in set_pte() was
replaced with pte_valid_global() under the assumption that only user
pages have the nG bit set. EFI mappings, however, also have the nG bit
set and set_pte() wrongly ignores issuing the DSB+ISB.
This patch reinstates the pte_valid_not_user() macro and adds the
PTE_UXN bit check since all kernel mappings have this bit set. For
clarity, pte_exec() is renamed to pte_user_exec() as it only checks for
the absence of PTE_UXN. Consequently, the user executable check in
set_pte_at() drops the pte_ng() test since pte_user_exec() is
sufficient.
Fixes: cab15ce604e5 ("arm64: Introduce execute-only page access permissions")
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/arm64/include/asm/pgtable.h | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index ffbb9a520563..61e214015b38 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -71,9 +71,8 @@ extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]; #define pte_young(pte) (!!(pte_val(pte) & PTE_AF)) #define pte_special(pte) (!!(pte_val(pte) & PTE_SPECIAL)) #define pte_write(pte) (!!(pte_val(pte) & PTE_WRITE)) -#define pte_exec(pte) (!(pte_val(pte) & PTE_UXN)) +#define pte_user_exec(pte) (!(pte_val(pte) & PTE_UXN)) #define pte_cont(pte) (!!(pte_val(pte) & PTE_CONT)) -#define pte_ng(pte) (!!(pte_val(pte) & PTE_NG)) #ifdef CONFIG_ARM64_HW_AFDBM #define pte_hw_dirty(pte) (pte_write(pte) && !(pte_val(pte) & PTE_RDONLY)) @@ -84,8 +83,12 @@ extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]; #define pte_dirty(pte) (pte_sw_dirty(pte) || pte_hw_dirty(pte)) #define pte_valid(pte) (!!(pte_val(pte) & PTE_VALID)) -#define pte_valid_global(pte) \ - ((pte_val(pte) & (PTE_VALID | PTE_NG)) == PTE_VALID) +/* + * Execute-only user mappings do not have the PTE_USER bit set. All valid + * kernel mappings have the PTE_UXN bit set. + */ +#define pte_valid_not_user(pte) \ + ((pte_val(pte) & (PTE_VALID | PTE_USER | PTE_UXN)) == (PTE_VALID | PTE_UXN)) #define pte_valid_young(pte) \ ((pte_val(pte) & (PTE_VALID | PTE_AF)) == (PTE_VALID | PTE_AF)) @@ -178,7 +181,7 @@ static inline void set_pte(pte_t *ptep, pte_t pte) * Only if the new pte is valid and kernel, otherwise TLB maintenance * or update_mmu_cache() have the necessary barriers. */ - if (pte_valid_global(pte)) { + if (pte_valid_not_user(pte)) { dsb(ishst); isb(); } @@ -212,7 +215,7 @@ static inline void set_pte_at(struct mm_struct *mm, unsigned long addr, pte_val(pte) &= ~PTE_RDONLY; else pte_val(pte) |= PTE_RDONLY; - if (pte_ng(pte) && pte_exec(pte) && !pte_special(pte)) + if (pte_user_exec(pte) && !pte_special(pte)) __sync_icache_dcache(pte, addr); } |