mm, oom: remove statically defined arch functions of same name

out_of_memory() is a globally defined function to call the oom killer.
x86, sh, and powerpc all use a function of the same name within file scope
in their respective fault.c unnecessarily.  Inline the functions into the
pagefault handlers to clean the code up.

Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/powerpc/mm/fault.c

@@ -113,19 +113,6 @@ static int store_updates_sp(struct pt_regs *regs)
 #define MM_FAULT_CONTINUE	-1
 #define MM_FAULT_ERR(sig)	(sig)
 
-static int out_of_memory(struct pt_regs *regs)
-{
-	/*
-	 * We ran out of memory, or some other thing happened to us that made
-	 * us unable to handle the page fault gracefully.
-	 */
-	up_read(&current->mm->mmap_sem);
-	if (!user_mode(regs))
-		return MM_FAULT_ERR(SIGKILL);
-	pagefault_out_of_memory();
-	return MM_FAULT_RETURN;
-}
-
 static int do_sigbus(struct pt_regs *regs, unsigned long address)
 {
 	siginfo_t info;
@@ -169,8 +156,18 @@ static int mm_fault_error(struct pt_regs *regs, unsigned long addr, int fault)
 		return MM_FAULT_CONTINUE;
 
 	/* Out of memory */
-	if (fault & VM_FAULT_OOM)
+	if (fault & VM_FAULT_OOM) {
-		return out_of_memory(regs);
+		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.
+		 */
+		if (!user_mode(regs))
+			return MM_FAULT_ERR(SIGKILL);
+		pagefault_out_of_memory();
+		return MM_FAULT_RETURN;
+	}
 
 	/* Bus error. x86 handles HWPOISON here, we'll add this if/when
 	 * we support the feature in HW

arch/sh/mm/fault.c

@@ -301,17 +301,6 @@ bad_area_access_error(struct pt_regs *regs, unsigned long error_code,
 	__bad_area(regs, error_code, address, SEGV_ACCERR);
 }
 
-static void out_of_memory(void)
-{
-	/*
-	 * 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(&current->mm->mmap_sem);
-
-	pagefault_out_of_memory();
-}
-
 static void
 do_sigbus(struct pt_regs *regs, unsigned long error_code, unsigned long address)
 {
@@ -353,8 +342,14 @@ mm_fault_error(struct pt_regs *regs, unsigned long error_code,
 			no_context(regs, error_code, address);
 			return 1;
 		}
+		up_read(&current->mm->mmap_sem);
 
-		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):
+		 */
+		pagefault_out_of_memory();
 	} else {
 		if (fault & VM_FAULT_SIGBUS)
 			do_sigbus(regs, error_code, address);

arch/x86/mm/fault.c

@@ -803,20 +803,6 @@ bad_area_access_error(struct pt_regs *regs, unsigned long error_code,
 	__bad_area(regs, error_code, address, SEGV_ACCERR);
 }
 
-/* TODO: fixup for "mm-invoke-oom-killer-from-page-fault.patch" */
-static void
-out_of_memory(struct pt_regs *regs, unsigned long error_code,
-	      unsigned long address)
-{
-	/*
-	 * 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(&current->mm->mmap_sem);
-
-	pagefault_out_of_memory();
-}
-
 static void
 do_sigbus(struct pt_regs *regs, unsigned long error_code, unsigned long address,
 	  unsigned int fault)
@@ -879,7 +865,14 @@ mm_fault_error(struct pt_regs *regs, unsigned long error_code,
 			return 1;
 		}
 
-		out_of_memory(regs, error_code, address);
+		up_read(&current->mm->mmap_sem);
+
+		/*
+		 * 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):
+		 */
+		pagefault_out_of_memory();
 	} else {
 		if (fault & (VM_FAULT_SIGBUS|VM_FAULT_HWPOISON|
 			     VM_FAULT_HWPOISON_LARGE))