Merge commit 'v2.6.38.4' into linaro-2.6.38

6 files changed, 54 insertions, 75 deletions

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 113e35c4750..8f765619441 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -244,24 +244,28 @@ static ssize_t single_flag_show(struct kobject *kobj,
 				struct kobj_attribute *attr, char *buf,
 				enum transparent_hugepage_flag flag)
 {
-	if (test_bit(flag, &transparent_hugepage_flags))
-		return sprintf(buf, "[yes] no\n");
-	else
-		return sprintf(buf, "yes [no]\n");
+	return sprintf(buf, "%d\n",
+		       !!test_bit(flag, &transparent_hugepage_flags));
 }
+
 static ssize_t single_flag_store(struct kobject *kobj,
 				 struct kobj_attribute *attr,
 				 const char *buf, size_t count,
 				 enum transparent_hugepage_flag flag)
 {
-	if (!memcmp("yes", buf,
-		    min(sizeof("yes")-1, count))) {
+	unsigned long value;
+	int ret;
+
+	ret = kstrtoul(buf, 10, &value);
+	if (ret < 0)
+		return ret;
+	if (value > 1)
+		return -EINVAL;
+
+	if (value)
 		set_bit(flag, &transparent_hugepage_flags);
-	} else if (!memcmp("no", buf,
-			   min(sizeof("no")-1, count))) {
+	else
 		clear_bit(flag, &transparent_hugepage_flags);
-	} else
-		return -EINVAL;
 
 	return count;
 }
diff --git a/mm/memory.c b/mm/memory.c
index dc955dad52a..2d820aa2637 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1416,6 +1416,13 @@ no_page_table:
 	return page;
 }
 
+static inline int stack_guard_page(struct vm_area_struct *vma, unsigned long addr)
+{
+	return (vma->vm_flags & VM_GROWSDOWN) &&
+		(vma->vm_start == addr) &&
+		!vma_stack_continue(vma->vm_prev, addr);
+}
+
 int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
 		     unsigned long start, int nr_pages, unsigned int gup_flags,
 		     struct page **pages, struct vm_area_struct **vmas,
@@ -1445,7 +1452,6 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
 		vma = find_extend_vma(mm, start);
 		if (!vma && in_gate_area(tsk, start)) {
 			unsigned long pg = start & PAGE_MASK;
-			struct vm_area_struct *gate_vma = get_gate_vma(tsk);
 			pgd_t *pgd;
 			pud_t *pud;
 			pmd_t *pmd;
@@ -1470,10 +1476,11 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
 				pte_unmap(pte);
 				return i ? : -EFAULT;
 			}
+			vma = get_gate_vma(tsk);
 			if (pages) {
 				struct page *page;
 
-				page = vm_normal_page(gate_vma, start, *pte);
+				page = vm_normal_page(vma, start, *pte);
 				if (!page) {
 					if (!(gup_flags & FOLL_DUMP) &&
 					     is_zero_pfn(pte_pfn(*pte)))
@@ -1487,12 +1494,7 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
 				get_page(page);
 			}
 			pte_unmap(pte);
-			if (vmas)
-				vmas[i] = gate_vma;
-			i++;
-			start += PAGE_SIZE;
-			nr_pages--;
-			continue;
+			goto next_page;
 		}
 
 		if (!vma ||
@@ -1506,6 +1508,13 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
 			continue;
 		}
 
+		/*
+		 * If we don't actually want the page itself,
+		 * and it's the stack guard page, just skip it.
+		 */
+		if (!pages && stack_guard_page(vma, start))
+			goto next_page;
+
 		do {
 			struct page *page;
 			unsigned int foll_flags = gup_flags;
@@ -1578,6 +1587,7 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
 				flush_anon_page(vma, page, start);
 				flush_dcache_page(page);
 			}
+next_page:
 			if (vmas)
 				vmas[i] = vma;
 			i++;
diff --git a/mm/mlock.c b/mm/mlock.c
index c3924c7f00b..da23be42c90 100644
--- a/mm/mlock.c
+++ b/mm/mlock.c
@@ -135,13 +135,6 @@ void munlock_vma_page(struct page *page)
 	}
 }
 
-static inline int stack_guard_page(struct vm_area_struct *vma, unsigned long addr)
-{
-	return (vma->vm_flags & VM_GROWSDOWN) &&
-		(vma->vm_start == addr) &&
-		!vma_stack_continue(vma->vm_prev, addr);
-}
-
 /**
  * __mlock_vma_pages_range() -  mlock a range of pages in the vma.
  * @vma:   target vma
@@ -188,12 +181,6 @@ static long __mlock_vma_pages_range(struct vm_area_struct *vma,
 	if (vma->vm_flags & VM_LOCKED)
 		gup_flags |= FOLL_MLOCK;
 
-	/* We don't try to access the guard page of a stack vma */
-	if (stack_guard_page(vma, start)) {
-		addr += PAGE_SIZE;
-		nr_pages--;
-	}
-
 	return __get_user_pages(current, mm, addr, nr_pages, gup_flags,
 				NULL, NULL, nonblocking);
 }
diff --git a/mm/mmap.c b/mm/mmap.c
index 2ec8eb5a9cd..e27e0cf0de0 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -259,7 +259,7 @@ SYSCALL_DEFINE1(brk, unsigned long, brk)
 	 * randomize_va_space to 2, which will still cause mm->start_brk
 	 * to be arbitrarily shifted
 	 */
-	if (mm->start_brk > PAGE_ALIGN(mm->end_data))
+	if (current->brk_randomized)
 		min_brk = mm->start_brk;
 	else
 		min_brk = mm->end_data;
@@ -1814,11 +1814,14 @@ static int expand_downwards(struct vm_area_struct *vma,
 		size = vma->vm_end - address;
 		grow = (vma->vm_start - address) >> PAGE_SHIFT;
 
-		error = acct_stack_growth(vma, size, grow);
-		if (!error) {
-			vma->vm_start = address;
-			vma->vm_pgoff -= grow;
-			perf_event_mmap(vma);
+		error = -ENOMEM;
+		if (grow <= vma->vm_pgoff) {
+			error = acct_stack_growth(vma, size, grow);
+			if (!error) {
+				vma->vm_start = address;
+				vma->vm_pgoff -= grow;
+				perf_event_mmap(vma);
+			}
 		}
 	}
 	vma_unlock_anon_vma(vma);
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 33b58615072..ea16f720705 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -84,24 +84,6 @@ static bool has_intersects_mems_allowed(struct task_struct *tsk,
 #endif /* CONFIG_NUMA */
 
 /*
- * If this is a system OOM (not a memcg OOM) and the task selected to be
- * killed is not already running at high (RT) priorities, speed up the
- * recovery by boosting the dying task to the lowest FIFO priority.
- * That helps with the recovery and avoids interfering with RT tasks.
- */
-static void boost_dying_task_prio(struct task_struct *p,
-				  struct mem_cgroup *mem)
-{
-	struct sched_param param = { .sched_priority = 1 };
-
-	if (mem)
-		return;
-
-	if (!rt_task(p))
-		sched_setscheduler_nocheck(p, SCHED_FIFO, &param);
-}
-
-/*
  * The process p may have detached its own ->mm while exiting or through
  * use_mm(), but one or more of its subthreads may still have a valid
  * pointer.  Return p, or any of its subthreads with a valid ->mm, with
@@ -452,13 +434,6 @@ static int oom_kill_task(struct task_struct *p, struct mem_cgroup *mem)
 	set_tsk_thread_flag(p, TIF_MEMDIE);
 	force_sig(SIGKILL, p);
 
-	/*
-	 * We give our sacrificial lamb high priority and access to
-	 * all the memory it needs. That way it should be able to
-	 * exit() and clear out its resources quickly...
-	 */
-	boost_dying_task_prio(p, mem);
-
 	return 0;
 }
 #undef K
@@ -482,7 +457,6 @@ static int oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order,
 	 */
 	if (p->flags & PF_EXITING) {
 		set_tsk_thread_flag(p, TIF_MEMDIE);
-		boost_dying_task_prio(p, mem);
 		return 0;
 	}
 
@@ -701,7 +675,6 @@ void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask,
 	 */
 	if (fatal_signal_pending(current)) {
 		set_thread_flag(TIF_MEMDIE);
-		boost_dying_task_prio(current, NULL);
 		return;
 	}
 
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 3b4a41d7248..06655208884 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -41,6 +41,7 @@
 #include <linux/memcontrol.h>
 #include <linux/delayacct.h>
 #include <linux/sysctl.h>
+#include <linux/oom.h>
 
 #include <asm/tlbflush.h>
 #include <asm/div64.h>
@@ -1988,17 +1989,12 @@ static bool zone_reclaimable(struct zone *zone)
 	return zone->pages_scanned < zone_reclaimable_pages(zone) * 6;
 }
 
-/*
- * As hibernation is going on, kswapd is freezed so that it can't mark
- * the zone into all_unreclaimable. It can't handle OOM during hibernation.
- * So let's check zone's unreclaimable in direct reclaim as well as kswapd.
- */
+/* All zones in zonelist are unreclaimable? */
 static bool all_unreclaimable(struct zonelist *zonelist,
 		struct scan_control *sc)
 {
 	struct zoneref *z;
 	struct zone *zone;
-	bool all_unreclaimable = true;
 
 	for_each_zone_zonelist_nodemask(zone, z, zonelist,
 			gfp_zone(sc->gfp_mask), sc->nodemask) {
@@ -2006,13 +2002,11 @@ static bool all_unreclaimable(struct zonelist *zonelist,
 			continue;
 		if (!cpuset_zone_allowed_hardwall(zone, GFP_KERNEL))
 			continue;
-		if (zone_reclaimable(zone)) {
-			all_unreclaimable = false;
-			break;
-		}
+		if (!zone->all_unreclaimable)
+			return false;
 	}
 
-	return all_unreclaimable;
+	return true;
 }
 
 /*
@@ -2108,6 +2102,14 @@ out:
 	if (sc->nr_reclaimed)
 		return sc->nr_reclaimed;
 
+	/*
+	 * As hibernation is going on, kswapd is freezed so that it can't mark
+	 * the zone into all_unreclaimable. Thus bypassing all_unreclaimable
+	 * check.
+	 */
+	if (oom_killer_disabled)
+		return 0;
+
 	/* top priority shrink_zones still had more to do? don't OOM, then */
 	if (scanning_global_lru(sc) && !all_unreclaimable(zonelist, sc))
 		return 1;