diff options
Diffstat (limited to 'arch/arm/mm/fault.c')
| -rw-r--r-- | arch/arm/mm/fault.c | 35 |
1 files changed, 20 insertions, 15 deletions
diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c index 9055b5a84ec..eb8830a4c5e 100644 --- a/arch/arm/mm/fault.c +++ b/arch/arm/mm/fault.c @@ -247,7 +247,9 @@ good_area: return handle_mm_fault(mm, vma, addr & PAGE_MASK, flags); check_stack: - if (vma->vm_flags & VM_GROWSDOWN && !expand_stack(vma, addr)) + /* Don't allow expansion below FIRST_USER_ADDRESS */ + if (vma->vm_flags & VM_GROWSDOWN && + addr >= FIRST_USER_ADDRESS && !expand_stack(vma, addr)) goto good_area; out: return fault; @@ -259,9 +261,7 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs) struct task_struct *tsk; struct mm_struct *mm; int fault, sig, code; - int write = fsr & FSR_WRITE; - unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE | - (write ? FAULT_FLAG_WRITE : 0); + unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; if (notify_page_fault(regs, fsr)) return 0; @@ -280,6 +280,11 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs) if (in_atomic() || !mm) goto no_context; + if (user_mode(regs)) + flags |= FAULT_FLAG_USER; + if (fsr & FSR_WRITE) + flags |= FAULT_FLAG_WRITE; + /* * As per x86, we may deadlock here. However, since the kernel only * validly references user space from well defined areas of the code, @@ -320,7 +325,7 @@ retry: */ perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, addr); - if (flags & FAULT_FLAG_ALLOW_RETRY) { + if (!(fault & VM_FAULT_ERROR) && flags & FAULT_FLAG_ALLOW_RETRY) { if (fault & VM_FAULT_MAJOR) { tsk->maj_flt++; perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, @@ -334,6 +339,7 @@ retry: /* Clear FAULT_FLAG_ALLOW_RETRY to avoid any risk * of starvation. */ flags &= ~FAULT_FLAG_ALLOW_RETRY; + flags |= FAULT_FLAG_TRIED; goto retry; } } @@ -346,6 +352,13 @@ retry: if (likely(!(fault & (VM_FAULT_ERROR | VM_FAULT_BADMAP | VM_FAULT_BADACCESS)))) return 0; + /* + * If we are in kernel mode at this point, we + * have no context to handle this fault with. + */ + if (!user_mode(regs)) + goto no_context; + if (fault & VM_FAULT_OOM) { /* * We ran out of memory, call the OOM killer, and return to @@ -356,13 +369,6 @@ retry: return 0; } - /* - * If we are in kernel mode at this point, we - * have no context to handle this fault with. - */ - if (!user_mode(regs)) - goto no_context; - if (fault & VM_FAULT_SIGBUS) { /* * We had some memory, but were unable to @@ -430,9 +436,6 @@ do_translation_fault(unsigned long addr, unsigned int fsr, index = pgd_index(addr); - /* - * FIXME: CP15 C1 is write only on ARMv3 architectures. - */ pgd = cpu_get_pgd() + index; pgd_k = init_mm.pgd + index; @@ -491,12 +494,14 @@ do_translation_fault(unsigned long addr, unsigned int fsr, * Some section permission faults need to be handled gracefully. * They can happen due to a __{get,put}_user during an oops. */ +#ifndef CONFIG_ARM_LPAE static int do_sect_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs) { do_bad_area(addr, fsr, regs); return 0; } +#endif /* CONFIG_ARM_LPAE */ /* * This abort handler always returns "fault". |