ARM: Update page fault handling for new OOM techniques

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c
index 1bb38712c86b630542b2ef39199844a2a17b1ebb..501304f7e30c0bbf5563921d00328a45972c26c3 100644 (file)
--- a/arch/arm/mm/fault.c
+++ b/arch/arm/mm/fault.c
@@ -223,37 +223,18 @@ good_area:
                goto out;
 
        /*
-        * If for any reason at all we couldn't handle
-        * the fault, make sure we exit gracefully rather
-        * than endlessly redo the fault.
+        * If for any reason at all we couldn't handle the fault, make
+        * sure we exit gracefully rather than endlessly redo the fault.
         */
-survive:
        fault = handle_mm_fault(mm, vma, addr & PAGE_MASK, (fsr & FSR_WRITE) ? FAULT_FLAG_WRITE : 0);
-       if (unlikely(fault & VM_FAULT_ERROR)) {
-               if (fault & VM_FAULT_OOM)
-                       goto out_of_memory;
-               else if (fault & VM_FAULT_SIGBUS)
-                       return fault;
-               BUG();
-       }
+       if (unlikely(fault & VM_FAULT_ERROR))
+               return fault;
        if (fault & VM_FAULT_MAJOR)
                tsk->maj_flt++;
        else
                tsk->min_flt++;
        return fault;
 
-out_of_memory:
-       if (!is_global_init(tsk))
-               goto out;
-
-       /*
-        * If we are out of memory for pid1, sleep for a while and retry
-        */
-       up_read(&mm->mmap_sem);
-       yield();
-       down_read(&mm->mmap_sem);
-       goto survive;
-
 check_stack:
        if (vma->vm_flags & VM_GROWSDOWN && !expand_stack(vma, addr))
                goto good_area;
@@ -301,6 +282,16 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
        if (likely(!(fault & (VM_FAULT_ERROR | VM_FAULT_BADMAP | VM_FAULT_BADACCESS))))
                return 0;
 
+       if (fault & VM_FAULT_OOM) {
+               /*
+                * We ran out of memory, call the OOM killer, and return to
+                * userspace (which will retry the fault, or kill us if we
+                * got oom-killed)
+                */
+               pagefault_out_of_memory();
+               return 0;
+       }
+
        /*
         * If we are in kernel mode at this point, we
         * have no context to handle this fault with.
@@ -308,16 +299,6 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
        if (!user_mode(regs))
                goto no_context;
 
-       if (fault & VM_FAULT_OOM) {
-               /*
-                * We ran out of memory, or some other thing
-                * happened to us that made us unable to handle
-                * the page fault gracefully.
-                */
-               printk("VM: killing process %s\n", tsk->comm);
-               do_group_exit(SIGKILL);
-               return 0;
-       }
        if (fault & VM_FAULT_SIGBUS) {
                /*
                 * We had some memory, but were unable to