diff --git a/arch/um/kernel/trap.c b/arch/um/kernel/trap.c
index 44e490419495..7384d8accfe7 100644
--- a/arch/um/kernel/trap.c
+++ b/arch/um/kernel/trap.c
@@ -64,11 +64,10 @@ int handle_page_fault(unsigned long address, unsigned long ip,
do {
int fault;
-survive:
+
fault = handle_mm_fault(mm, vma, address, is_write);
if (unlikely(fault & VM_FAULT_ERROR)) {
if (fault & VM_FAULT_OOM) {
- err = -ENOMEM;
goto out_of_memory;
} else if (fault & VM_FAULT_SIGBUS) {
err = -EACCES;
@@ -104,18 +103,14 @@ int handle_page_fault(unsigned long address, unsigned long ip,
out_nosemaphore:
return err;
-/*
- * We ran out of memory, or some other thing happened to us that made
- * us unable to handle the page fault gracefully.
- */
out_of_memory:
- if (is_global_init(current)) {
- up_read(&mm->mmap_sem);
- yield();
- down_read(&mm->mmap_sem);
- goto survive;
- }
- goto out;
+ /*
+ * We ran out of memory, call the OOM killer, and return the userspace
+ * (which will retry the fault, or kill us if we got oom-killed).
+ */
+ up_read(&mm->mmap_sem);
+ pagefault_out_of_memory();
+ return 0;
}
static void bad_segv(struct faultinfo fi, unsigned long ip)
@@ -214,9 +209,6 @@ unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user,
si.si_addr = (void __user *)address;
current->thread.arch.faultinfo = fi;
force_sig_info(SIGBUS, &si, current);
- } else if (err == -ENOMEM) {
- printk(KERN_INFO "VM: killing process %s\n", current->comm);
- do_exit(SIGKILL);
} else {
BUG_ON(err != -EFAULT);
si.si_signo = SIGSEGV;
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 57ec8c86a877..9e268b6b204e 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -667,7 +667,6 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code)
if (unlikely(in_atomic() || !mm))
goto bad_area_nosemaphore;
-again:
/*
* When running in the kernel we expect faults to occur only to
* addresses in user space. All other faults represent errors in the
@@ -859,25 +858,14 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code)
oops_end(flags, regs, sig);
#endif
-/*
- * We ran out of memory, or some other thing happened to us that made
- * us unable to handle the page fault gracefully.
- */
out_of_memory:
+ /*
+ * We ran out of memory, call the OOM killer, and return the userspace
+ * (which will retry the fault, or kill us if we got oom-killed).
+ */
up_read(&mm->mmap_sem);
- if (is_global_init(tsk)) {
- yield();
- /*
- * Re-lookup the vma - in theory the vma tree might
- * have changed:
- */
- goto again;
- }
-
- printk("VM: killing process %s\n", tsk->comm);
- if (error_code & PF_USER)
- do_group_exit(SIGKILL);
- goto no_context;
+ pagefault_out_of_memory();
+ return;
do_sigbus:
up_read(&mm->mmap_sem);
diff --git a/include/linux/mm.h b/include/linux/mm.h
index aaa8b843be28..4a3d28c86443 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -717,6 +717,11 @@ static inline int page_mapped(struct page *page)
#define VM_FAULT_ERROR (VM_FAULT_OOM | VM_FAULT_SIGBUS)
+/*
+ * Can be called by the pagefault handler when it gets a VM_FAULT_OOM.
+ */
+extern void pagefault_out_of_memory(void);
+
#define offset_in_page(p) ((unsigned long)(p) & ~PAGE_MASK)
extern void show_free_areas(void);
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 558f9afe6e4e..c592965dab2f 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -509,6 +509,69 @@ void clear_zonelist_oom(struct zonelist *zonelist, gfp_t gfp_mask)
spin_unlock(&zone_scan_mutex);
}
+/*
+ * Must be called with tasklist_lock held for read.
+ */
+static void __out_of_memory(gfp_t gfp_mask, int order)
+{
+ if (sysctl_oom_kill_allocating_task) {
+ oom_kill_process(current, gfp_mask, order, 0, NULL,
+ "Out of memory (oom_kill_allocating_task)");
+
+ } else {
+ unsigned long points;
+ struct task_struct *p;
+
+retry:
+ /*
+ * Rambo mode: Shoot down a process and hope it solves whatever
+ * issues we may have.
+ */
+ p = select_bad_process(&points, NULL);
+
+ if (PTR_ERR(p) == -1UL)
+ return;
+
+ /* Found nothing?!?! Either we hang forever, or we panic. */
+ if (!p) {
+ read_unlock(&tasklist_lock);
+ panic("Out of memory and no killable processes...\n");
+ }
+
+ if (oom_kill_process(p, gfp_mask, order, points, NULL,
+ "Out of memory"))
+ goto retry;
+ }
+}
+
+/*
+ * pagefault handler calls into here because it is out of memory but
+ * doesn't know exactly how or why.
+ */
+void pagefault_out_of_memory(void)
+{
+ unsigned long freed = 0;
+
+ blocking_notifier_call_chain(&oom_notify_list, 0, &freed);
+ if (freed > 0)
+ /* Got some memory back in the last second. */
+ return;
+
+ if (sysctl_panic_on_oom)
+ panic("out of memory from page fault. panic_on_oom is selected.\n");
+
+ read_lock(&tasklist_lock);
+ __out_of_memory(0, 0); /* unknown gfp_mask and order */
+ read_unlock(&tasklist_lock);
+
+ /*
+ * Give "p" a good chance of killing itself before we
+ * retry to allocate memory.
+ */
+ if (!test_thread_flag(TIF_MEMDIE))
+ schedule_timeout_uninterruptible(1);
+}
+
/**
* out_of_memory - kill the "best" process when we run out of memory
* @zonelist: zonelist pointer
@@ -522,8 +585,6 @@ void clear_zonelist_oom(struct zonelist *zonelist, gfp_t gfp_mask)
*/
void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask, int order)
{
- struct task_struct *p;
- unsigned long points = 0;
unsigned long freed = 0;
enum oom_constraint constraint;
@@ -544,7 +605,7 @@ void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask, int order)
switch (constraint) {
case CONSTRAINT_MEMORY_POLICY:
- oom_kill_process(current, gfp_mask, order, points, NULL,
+ oom_kill_process(current, gfp_mask, order, 0, NULL,
"No available memory (MPOL_BIND)");
break;
@@ -553,35 +614,10 @@ void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask, int order)
panic("out of memory. panic_on_oom is selected\n");
/* Fall-through */
case CONSTRAINT_CPUSET:
- if (sysctl_oom_kill_allocating_task) {
- oom_kill_process(current, gfp_mask, order, points, NULL,
- "Out of memory (oom_kill_allocating_task)");
- break;
- }
-retry:
- /*
- * Rambo mode: Shoot down a process and hope it solves whatever
- * issues we may have.
- */
- p = select_bad_process(&points, NULL);
-
- if (PTR_ERR(p) == -1UL)
- goto out;
-
- /* Found nothing?!?! Either we hang forever, or we panic. */
- if (!p) {
- read_unlock(&tasklist_lock);
- panic("Out of memory and no killable processes...\n");
- }
-
- if (oom_kill_process(p, gfp_mask, order, points, NULL,
- "Out of memory"))
- goto retry;
-
+ __out_of_memory(gfp_mask, order);
break;
}
-out:
read_unlock(&tasklist_lock);
/*