diff options
Diffstat (limited to 'arch/powerpc/mm/fault.c')
-rw-r--r-- | arch/powerpc/mm/fault.c | 48 |
1 files changed, 45 insertions, 3 deletions
diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c index 2bef19cc1b98..531177a4ee08 100644 --- a/arch/powerpc/mm/fault.c +++ b/arch/powerpc/mm/fault.c @@ -271,11 +271,16 @@ static bool access_error(bool is_write, bool is_exec, struct vm_area_struct *vma } /* - * Check for a read fault. This could be caused by a read on an - * inaccessible page (i.e. PROT_NONE), or a Radix MMU execute-only page. + * VM_READ, VM_WRITE and VM_EXEC all imply read permissions, as + * defined in protection_map[]. Read faults can only be caused by + * a PROT_NONE mapping, or with a PROT_EXEC-only mapping on Radix. */ - if (unlikely(!(vma->vm_flags & VM_READ))) + if (unlikely(!vma_is_accessible(vma))) return true; + + if (unlikely(radix_enabled() && ((vma->vm_flags & VM_ACCESS_FLAGS) == VM_EXEC))) + return true; + /* * We should ideally do the vma pkey access check here. But in the * fault path, handle_mm_fault() also does the same check. To avoid @@ -469,6 +474,40 @@ static int ___do_page_fault(struct pt_regs *regs, unsigned long address, if (is_exec) flags |= FAULT_FLAG_INSTRUCTION; +#ifdef CONFIG_PER_VMA_LOCK + if (!(flags & FAULT_FLAG_USER)) + goto lock_mmap; + + vma = lock_vma_under_rcu(mm, address); + if (!vma) + goto lock_mmap; + + if (unlikely(access_pkey_error(is_write, is_exec, + (error_code & DSISR_KEYFAULT), vma))) { + vma_end_read(vma); + goto lock_mmap; + } + + if (unlikely(access_error(is_write, is_exec, vma))) { + vma_end_read(vma); + goto lock_mmap; + } + + fault = handle_mm_fault(vma, address, flags | FAULT_FLAG_VMA_LOCK, regs); + vma_end_read(vma); + + if (!(fault & VM_FAULT_RETRY)) { + count_vm_vma_lock_event(VMA_LOCK_SUCCESS); + goto done; + } + count_vm_vma_lock_event(VMA_LOCK_RETRY); + + if (fault_signal_pending(fault, regs)) + return user_mode(regs) ? 0 : SIGBUS; + +lock_mmap: +#endif /* CONFIG_PER_VMA_LOCK */ + /* 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. Unfortunately, in the case of an @@ -545,6 +584,9 @@ retry: mmap_read_unlock(current->mm); +#ifdef CONFIG_PER_VMA_LOCK +done: +#endif if (unlikely(fault & VM_FAULT_ERROR)) return mm_fault_error(regs, address, fault); |