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path: root/arch/powerpc/mm/fault.c
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Diffstat (limited to 'arch/powerpc/mm/fault.c')
-rw-r--r--arch/powerpc/mm/fault.c84
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(&current->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(&current->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(&current->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(&current->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: