diff options
Diffstat (limited to 'arch/powerpc/mm/fault.c')
| -rw-r--r-- | arch/powerpc/mm/fault.c | 36 |
1 files changed, 20 insertions, 16 deletions
diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c index ec4adcb4bc28..fdbba4206d59 100644 --- a/arch/powerpc/mm/fault.c +++ b/arch/powerpc/mm/fault.c @@ -177,15 +177,15 @@ int __kprobes do_page_fault(struct pt_regs *regs, unsigned long address, /* When running in the kernel we expect faults to occur only to * addresses in user space. All other faults represent errors in the - * kernel and should generate an OOPS. Unfortunatly, in the case of an - * erroneous fault occuring in a code path which already holds mmap_sem + * kernel and should generate an OOPS. Unfortunately, in the case of an + * erroneous fault occurring in a code path which already holds mmap_sem * we will deadlock attempting to validate the fault against the * address space. Luckily the kernel only validly references user * space from well defined areas of code, which are listed in the * exceptions table. * * As the vast majority of faults will be valid we will only perform - * the source reference check when there is a possibilty of a deadlock. + * the source reference check when there is a possibility of a deadlock. * Attempt to lock the address space, if we cannot we then validate the * source. If this is invalid we can skip the address space check, * thus avoiding the deadlock. @@ -267,25 +267,29 @@ good_area: #endif #if defined(CONFIG_4xx) || defined(CONFIG_BOOKE) pte_t *ptep; + pmd_t *pmdp; /* Since 4xx/Book-E supports per-page execute permission, * we lazily flush dcache to icache. */ ptep = NULL; - if (get_pteptr(mm, address, &ptep) && pte_present(*ptep)) { - struct page *page = pte_page(*ptep); - - if (! test_bit(PG_arch_1, &page->flags)) { - flush_dcache_icache_page(page); - set_bit(PG_arch_1, &page->flags); + if (get_pteptr(mm, address, &ptep, &pmdp)) { + spinlock_t *ptl = pte_lockptr(mm, pmdp); + spin_lock(ptl); + if (pte_present(*ptep)) { + struct page *page = pte_page(*ptep); + + if (!test_bit(PG_arch_1, &page->flags)) { + flush_dcache_icache_page(page); + set_bit(PG_arch_1, &page->flags); + } + pte_update(ptep, 0, _PAGE_HWEXEC); + _tlbie(address); + pte_unmap_unlock(ptep, ptl); + up_read(&mm->mmap_sem); + return 0; } - pte_update(ptep, 0, _PAGE_HWEXEC); - _tlbie(address); - pte_unmap(ptep); - up_read(&mm->mmap_sem); - return 0; + pte_unmap_unlock(ptep, ptl); } - if (ptep != NULL) - pte_unmap(ptep); #endif /* a write */ } else if (is_write) { |