From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Wed, 11 Feb 2015 04:16:51 +0000 (+0800)
Subject: 3.18-stable patches
X-Git-Tag: v3.10.69~1
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=ab2f102a703c56c2a495cb1675b199056456d684;p=thirdparty%2Fkernel%2Fstable-queue.git

3.18-stable patches

added patches:
	x86-mm-move-mmap_sem-unlock-from-mm_fault_error-to-caller.patch
---

diff --git a/queue-3.18/series b/queue-3.18/series
index 6c6ef7b8ca5..b2f5993d032 100644
--- a/queue-3.18/series
+++ b/queue-3.18/series
@@ -37,3 +37,4 @@ smpboot-add-missing-get_online_cpus-in-smpboot_register_percpu_thread.patch
 hrtimer-fix-incorrect-tai-offset-calculation-for-non-high-res-timer-systems.patch
 tracing-add-condition-check-to-rcu-lockdep-checks.patch
 x86-tlb-trace-do-not-trace-on-cpu-that-is-offline.patch
+x86-mm-move-mmap_sem-unlock-from-mm_fault_error-to-caller.patch
diff --git a/queue-3.18/x86-mm-move-mmap_sem-unlock-from-mm_fault_error-to-caller.patch b/queue-3.18/x86-mm-move-mmap_sem-unlock-from-mm_fault_error-to-caller.patch
new file mode 100644
index 00000000000..5ee86f5b447
--- /dev/null
+++ b/queue-3.18/x86-mm-move-mmap_sem-unlock-from-mm_fault_error-to-caller.patch
@@ -0,0 +1,65 @@
+From 7fb08eca45270d0ae86e1ad9d39c40b7a55d0190 Mon Sep 17 00:00:00 2001
+From: Linus Torvalds <torvalds@linux-foundation.org>
+Date: Mon, 15 Dec 2014 14:46:06 -0800
+Subject: x86: mm: move mmap_sem unlock from mm_fault_error() to caller
+
+From: Linus Torvalds <torvalds@linux-foundation.org>
+
+commit 7fb08eca45270d0ae86e1ad9d39c40b7a55d0190 upstream.
+
+This replaces four copies in various stages of mm_fault_error() handling
+with just a single one.  It will also allow for more natural placement
+of the unlocking after some further cleanup.
+
+Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ arch/x86/mm/fault.c |    8 +-------
+ 1 file changed, 1 insertion(+), 7 deletions(-)
+
+--- a/arch/x86/mm/fault.c
++++ b/arch/x86/mm/fault.c
+@@ -844,11 +844,8 @@ do_sigbus(struct pt_regs *regs, unsigned
+ 	  unsigned int fault)
+ {
+ 	struct task_struct *tsk = current;
+-	struct mm_struct *mm = tsk->mm;
+ 	int code = BUS_ADRERR;
+ 
+-	up_read(&mm->mmap_sem);
+-
+ 	/* Kernel mode? Handle exceptions or die: */
+ 	if (!(error_code & PF_USER)) {
+ 		no_context(regs, error_code, address, SIGBUS, BUS_ADRERR);
+@@ -879,7 +876,6 @@ mm_fault_error(struct pt_regs *regs, uns
+ 	       unsigned long address, unsigned int fault)
+ {
+ 	if (fatal_signal_pending(current) && !(error_code & PF_USER)) {
+-		up_read(&current->mm->mmap_sem);
+ 		no_context(regs, error_code, address, 0, 0);
+ 		return;
+ 	}
+@@ -887,14 +883,11 @@ mm_fault_error(struct pt_regs *regs, uns
+ 	if (fault & VM_FAULT_OOM) {
+ 		/* Kernel mode? Handle exceptions or die: */
+ 		if (!(error_code & PF_USER)) {
+-			up_read(&current->mm->mmap_sem);
+ 			no_context(regs, error_code, address,
+ 				   SIGSEGV, SEGV_MAPERR);
+ 			return;
+ 		}
+ 
+-		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
+@@ -1249,6 +1242,7 @@ good_area:
+ 		return;
+ 
+ 	if (unlikely(fault & VM_FAULT_ERROR)) {
++		up_read(&mm->mmap_sem);
+ 		mm_fault_error(regs, error_code, address, fault);
+ 		return;
+ 	}