diff options
Diffstat (limited to 'arch/powerpc/mm/fault.c')
| -rw-r--r-- | arch/powerpc/mm/fault.c | 84 |
1 files changed, 41 insertions, 43 deletions
diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c index 51def8a515be..3a7d580fdc59 100644 --- a/arch/powerpc/mm/fault.c +++ b/arch/powerpc/mm/fault.c @@ -120,8 +120,6 @@ static int do_sigbus(struct pt_regs *regs, unsigned long address, siginfo_t info; unsigned int lsb = 0; - up_read(¤t->mm->mmap_sem); - if (!user_mode(regs)) return MM_FAULT_ERR(SIGBUS); @@ -154,13 +152,6 @@ static int mm_fault_error(struct pt_regs *regs, unsigned long addr, int fault) * continue the pagefault. */ if (fatal_signal_pending(current)) { - /* - * If we have retry set, the mmap semaphore will have - * alrady been released in __lock_page_or_retry(). Else - * we release it now. - */ - if (!(fault & VM_FAULT_RETRY)) - up_read(¤t->mm->mmap_sem); /* Coming from kernel, we need to deal with uaccess fixups */ if (user_mode(regs)) return MM_FAULT_RETURN; @@ -173,8 +164,6 @@ static int mm_fault_error(struct pt_regs *regs, unsigned long addr, int fault) /* Out of memory */ if (fault & VM_FAULT_OOM) { - up_read(¤t->mm->mmap_sem); - /* * We ran out of memory, or some other thing happened to us that * made us unable to handle the page fault gracefully. @@ -298,7 +287,7 @@ int do_page_fault(struct pt_regs *regs, unsigned long address, * can result in fault, which will cause a deadlock when called with * mmap_sem held */ - if (user_mode(regs)) + if (!is_exec && user_mode(regs)) store_update_sp = store_updates_sp(regs); if (user_mode(regs)) @@ -458,9 +447,30 @@ good_area: * the fault. */ fault = handle_mm_fault(vma, address, flags); + + /* + * Handle the retry right now, the mmap_sem has been released in that + * case. + */ + if (unlikely(fault & VM_FAULT_RETRY)) { + /* We retry only once */ + if (flags & FAULT_FLAG_ALLOW_RETRY) { + /* + * Clear FAULT_FLAG_ALLOW_RETRY to avoid any risk + * of starvation. + */ + flags &= ~FAULT_FLAG_ALLOW_RETRY; + flags |= FAULT_FLAG_TRIED; + if (!fatal_signal_pending(current)) + goto retry; + } + /* We will enter mm_fault_error() below */ + } else + up_read(¤t->mm->mmap_sem); + if (unlikely(fault & (VM_FAULT_RETRY|VM_FAULT_ERROR))) { if (fault & VM_FAULT_SIGSEGV) - goto bad_area; + goto bad_area_nosemaphore; rc = mm_fault_error(regs, address, fault); if (rc >= MM_FAULT_RETURN) goto bail; @@ -469,41 +479,29 @@ good_area: } /* - * Major/minor page fault accounting is only done on the - * initial attempt. If we go through a retry, it is extremely - * likely that the page will be found in page cache at that point. + * Major/minor page fault accounting. */ - if (flags & FAULT_FLAG_ALLOW_RETRY) { - if (fault & VM_FAULT_MAJOR) { - current->maj_flt++; - perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, - regs, address); + if (fault & VM_FAULT_MAJOR) { + current->maj_flt++; + perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, + regs, address); #ifdef CONFIG_PPC_SMLPAR - if (firmware_has_feature(FW_FEATURE_CMO)) { - u32 page_ins; - - preempt_disable(); - page_ins = be32_to_cpu(get_lppaca()->page_ins); - page_ins += 1 << PAGE_FACTOR; - get_lppaca()->page_ins = cpu_to_be32(page_ins); - preempt_enable(); - } -#endif /* CONFIG_PPC_SMLPAR */ - } else { - current->min_flt++; - perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, - regs, address); - } - if (fault & VM_FAULT_RETRY) { - /* Clear FAULT_FLAG_ALLOW_RETRY to avoid any risk - * of starvation. */ - flags &= ~FAULT_FLAG_ALLOW_RETRY; - flags |= FAULT_FLAG_TRIED; - goto retry; + if (firmware_has_feature(FW_FEATURE_CMO)) { + u32 page_ins; + + preempt_disable(); + page_ins = be32_to_cpu(get_lppaca()->page_ins); + page_ins += 1 << PAGE_FACTOR; + get_lppaca()->page_ins = cpu_to_be32(page_ins); + preempt_enable(); } +#endif /* CONFIG_PPC_SMLPAR */ + } else { + current->min_flt++; + perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, + regs, address); } - up_read(&mm->mmap_sem); goto bail; bad_area: |