diff options
Diffstat (limited to 'arch/powerpc/mm/hash_utils_64.c')
| -rw-r--r-- | arch/powerpc/mm/hash_utils_64.c | 53 |
1 files changed, 40 insertions, 13 deletions
diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c index 98f262de558..09dffe6efa4 100644 --- a/arch/powerpc/mm/hash_utils_64.c +++ b/arch/powerpc/mm/hash_utils_64.c @@ -871,6 +871,18 @@ static inline int subpage_protection(struct mm_struct *mm, unsigned long ea) } #endif +void hash_failure_debug(unsigned long ea, unsigned long access, + unsigned long vsid, unsigned long trap, + int ssize, int psize, unsigned long pte) +{ + if (!printk_ratelimit()) + return; + pr_info("mm: Hashing failure ! EA=0x%lx access=0x%lx current=%s\n", + ea, access, current->comm); + pr_info(" trap=0x%lx vsid=0x%lx ssize=%d psize=%d pte=0x%lx\n", + trap, vsid, ssize, psize, pte); +} + /* Result code is: * 0 - handled * 1 - normal page fault @@ -955,6 +967,17 @@ int hash_page(unsigned long ea, unsigned long access, unsigned long trap) return 1; } + /* Add _PAGE_PRESENT to the required access perm */ + access |= _PAGE_PRESENT; + + /* Pre-check access permissions (will be re-checked atomically + * in __hash_page_XX but this pre-check is a fast path + */ + if (access & ~pte_val(*ptep)) { + DBG_LOW(" no access !\n"); + return 1; + } + #ifdef CONFIG_HUGETLB_PAGE if (hugeshift) return __hash_page_huge(ea, access, vsid, ptep, trap, local, @@ -967,14 +990,6 @@ int hash_page(unsigned long ea, unsigned long access, unsigned long trap) DBG_LOW(" i-pte: %016lx %016lx\n", pte_val(*ptep), pte_val(*(ptep + PTRS_PER_PTE))); #endif - /* Pre-check access permissions (will be re-checked atomically - * in __hash_page_XX but this pre-check is a fast path - */ - if (access & ~pte_val(*ptep)) { - DBG_LOW(" no access !\n"); - return 1; - } - /* Do actual hashing */ #ifdef CONFIG_PPC_64K_PAGES /* If _PAGE_4K_PFN is set, make sure this is a 4k segment */ @@ -1033,6 +1048,12 @@ int hash_page(unsigned long ea, unsigned long access, unsigned long trap) local, ssize, spp); } + /* Dump some info in case of hash insertion failure, they should + * never happen so it is really useful to know if/when they do + */ + if (rc == -1) + hash_failure_debug(ea, access, vsid, trap, ssize, psize, + pte_val(*ptep)); #ifndef CONFIG_PPC_64K_PAGES DBG_LOW(" o-pte: %016lx\n", pte_val(*ptep)); #else @@ -1051,8 +1072,7 @@ void hash_preload(struct mm_struct *mm, unsigned long ea, void *pgdir; pte_t *ptep; unsigned long flags; - int local = 0; - int ssize; + int rc, ssize, local = 0; BUG_ON(REGION_ID(ea) != USER_REGION_ID); @@ -1098,11 +1118,18 @@ void hash_preload(struct mm_struct *mm, unsigned long ea, /* Hash it in */ #ifdef CONFIG_PPC_HAS_HASH_64K if (mm->context.user_psize == MMU_PAGE_64K) - __hash_page_64K(ea, access, vsid, ptep, trap, local, ssize); + rc = __hash_page_64K(ea, access, vsid, ptep, trap, local, ssize); else #endif /* CONFIG_PPC_HAS_HASH_64K */ - __hash_page_4K(ea, access, vsid, ptep, trap, local, ssize, - subpage_protection(pgdir, ea)); + rc = __hash_page_4K(ea, access, vsid, ptep, trap, local, ssize, + subpage_protection(pgdir, ea)); + + /* Dump some info in case of hash insertion failure, they should + * never happen so it is really useful to know if/when they do + */ + if (rc == -1) + hash_failure_debug(ea, access, vsid, trap, ssize, + mm->context.user_psize, pte_val(*ptep)); local_irq_restore(flags); } |