1 files changed, 231 insertions, 125 deletions

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 6b8889da69a6..1d34d75366a7 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -31,8 +31,6 @@
 #include <asm/tlbflush.h>
 #include <asm/shmparam.h>
 
-bool vmap_lazy_unmap __read_mostly = true;
-
 /*** Page table manipulation functions ***/
 
 static void vunmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end)
@@ -263,8 +261,15 @@ struct vmap_area {
 };
 
 static DEFINE_SPINLOCK(vmap_area_lock);
-static struct rb_root vmap_area_root = RB_ROOT;
 static LIST_HEAD(vmap_area_list);
+static struct rb_root vmap_area_root = RB_ROOT;
+
+/* The vmap cache globals are protected by vmap_area_lock */
+static struct rb_node *free_vmap_cache;
+static unsigned long cached_hole_size;
+static unsigned long cached_vstart;
+static unsigned long cached_align;
+
 static unsigned long vmap_area_pcpu_hole;
 
 static struct vmap_area *__find_vmap_area(unsigned long addr)
@@ -293,13 +298,13 @@ static void __insert_vmap_area(struct vmap_area *va)
         struct rb_node *tmp;
 
         while (*p) {
-                struct vmap_area *tmp;
+                struct vmap_area *tmp_va;
 
                 parent = *p;
-                tmp = rb_entry(parent, struct vmap_area, rb_node);
-                if (va->va_start < tmp->va_end)
+                tmp_va = rb_entry(parent, struct vmap_area, rb_node);
+                if (va->va_start < tmp_va->va_end)
                         p = &(*p)->rb_left;
-                else if (va->va_end > tmp->va_start)
+                else if (va->va_end > tmp_va->va_start)
                         p = &(*p)->rb_right;
                 else
                         BUG();
@@ -333,9 +338,11 @@ static struct vmap_area *alloc_vmap_area(unsigned long size,
         struct rb_node *n;
         unsigned long addr;
         int purged = 0;
+        struct vmap_area *first;
 
         BUG_ON(!size);
         BUG_ON(size & ~PAGE_MASK);
+        BUG_ON(!is_power_of_2(align));
 
         va = kmalloc_node(sizeof(struct vmap_area),
                         gfp_mask & GFP_RECLAIM_MASK, node);
@@ -343,79 +350,106 @@ static struct vmap_area *alloc_vmap_area(unsigned long size,
                 return ERR_PTR(-ENOMEM);
 
 retry:
-        addr = ALIGN(vstart, align);
-
         spin_lock(&vmap_area_lock);
-        if (addr + size - 1 < addr)
-                goto overflow;
+        /*
+         * Invalidate cache if we have more permissive parameters.
+         * cached_hole_size notes the largest hole noticed _below_
+         * the vmap_area cached in free_vmap_cache: if size fits
+         * into that hole, we want to scan from vstart to reuse
+         * the hole instead of allocating above free_vmap_cache.
+         * Note that __free_vmap_area may update free_vmap_cache
+         * without updating cached_hole_size or cached_align.
+         */
+        if (!free_vmap_cache ||
+                        size < cached_hole_size ||
+                        vstart < cached_vstart ||
+                        align < cached_align) {
+nocache:
+                cached_hole_size = 0;
+                free_vmap_cache = NULL;
+        }
+        /* record if we encounter less permissive parameters */
+        cached_vstart = vstart;
+        cached_align = align;
+
+        /* find starting point for our search */
+        if (free_vmap_cache) {
+                first = rb_entry(free_vmap_cache, struct vmap_area, rb_node);
+                addr = ALIGN(first->va_end, align);
+                if (addr < vstart)
+                        goto nocache;
+                if (addr + size - 1 < addr)
+                        goto overflow;
+
+        } else {
+                addr = ALIGN(vstart, align);
+                if (addr + size - 1 < addr)
+                        goto overflow;
 
-        /* XXX: could have a last_hole cache */
-        n = vmap_area_root.rb_node;
-        if (n) {
-                struct vmap_area *first = NULL;
+                n = vmap_area_root.rb_node;
+                first = NULL;
 
-                do {
+                while (n) {
                         struct vmap_area *tmp;
                         tmp = rb_entry(n, struct vmap_area, rb_node);
                         if (tmp->va_end >= addr) {
-                                if (!first && tmp->va_start < addr + size)
-                                        first = tmp;
-                                n = n->rb_left;
-                        } else {
                                 first = tmp;
+                                if (tmp->va_start <= addr)
+                                        break;
+                                n = n->rb_left;
+                        } else
                                 n = n->rb_right;
-                        }
-                } while (n);
+                }
 
                 if (!first)
                         goto found;
-
-                if (first->va_end < addr) {
-                        n = rb_next(&first->rb_node);
-                        if (n)
-                                first = rb_entry(n, struct vmap_area, rb_node);
-                        else
-                                goto found;
-                }
-
-                while (addr + size > first->va_start && addr + size <= vend) {
-                        addr = ALIGN(first->va_end + PAGE_SIZE, align);
-                        if (addr + size - 1 < addr)
-                                goto overflow;
-
-                        n = rb_next(&first->rb_node);
-                        if (n)
-                                first = rb_entry(n, struct vmap_area, rb_node);
-                        else
-                                goto found;
-                }
         }
-found:
-        if (addr + size > vend) {
-overflow:
-                spin_unlock(&vmap_area_lock);
-                if (!purged) {
-                        purge_vmap_area_lazy();
-                        purged = 1;
-                        goto retry;
-                }
-                if (printk_ratelimit())
-                        printk(KERN_WARNING
-                                "vmap allocation for size %lu failed: "
-                                "use vmalloc=<size> to increase size.\n", size);
-                kfree(va);
-                return ERR_PTR(-EBUSY);
+
+        /* from the starting point, walk areas until a suitable hole is found */
+        while (addr + size > first->va_start && addr + size <= vend) {
+                if (addr + cached_hole_size < first->va_start)
+                        cached_hole_size = first->va_start - addr;
+                addr = ALIGN(first->va_end, align);
+                if (addr + size - 1 < addr)
+                        goto overflow;
+
+                n = rb_next(&first->rb_node);
+                if (n)
+                        first = rb_entry(n, struct vmap_area, rb_node);
+                else
+                        goto found;
         }
 
-        BUG_ON(addr & (align-1));
+found:
+        if (addr + size > vend)
+                goto overflow;
 
         va->va_start = addr;
         va->va_end = addr + size;
         va->flags = 0;
         __insert_vmap_area(va);
+        free_vmap_cache = &va->rb_node;
         spin_unlock(&vmap_area_lock);
 
+        BUG_ON(va->va_start & (align-1));
+        BUG_ON(va->va_start < vstart);
+        BUG_ON(va->va_end > vend);
+
         return va;
+
+overflow:
+        spin_unlock(&vmap_area_lock);
+        if (!purged) {
+                purge_vmap_area_lazy();
+                purged = 1;
+                goto retry;
+        }
+        if (printk_ratelimit())
+                printk(KERN_WARNING
+                        "vmap allocation for size %lu failed: "
+                        "use vmalloc=<size> to increase size.\n", size);
+        kfree(va);
+        return ERR_PTR(-EBUSY);
 }
 
 static void rcu_free_va(struct rcu_head *head)
@@ -428,6 +462,22 @@ static void rcu_free_va(struct rcu_head *head)
 static void __free_vmap_area(struct vmap_area *va)
 {
         BUG_ON(RB_EMPTY_NODE(&va->rb_node));
+
+        if (free_vmap_cache) {
+                if (va->va_end < cached_vstart) {
+                        free_vmap_cache = NULL;
+                } else {
+                        struct vmap_area *cache;
+                        cache = rb_entry(free_vmap_cache, struct vmap_area, rb_node);
+                        if (va->va_start <= cache->va_start) {
+                                free_vmap_cache = rb_prev(&va->rb_node);
+                                /*
+                                 * We don't try to update cached_hole_size or
+                                 * cached_align, but it won't go very wrong.
+                                 */
+                        }
+                }
+        }
         rb_erase(&va->rb_node, &vmap_area_root);
         RB_CLEAR_NODE(&va->rb_node);
         list_del_rcu(&va->list);
@@ -503,9 +553,6 @@ static unsigned long lazy_max_pages(void)
 {
         unsigned int log;
 
-        if (!vmap_lazy_unmap)
-                return 0;
-
         log = fls(num_online_cpus());
 
         return log * (32UL * 1024 * 1024 / PAGE_SIZE);
@@ -517,6 +564,15 @@ static atomic_t vmap_lazy_nr = ATOMIC_INIT(0);
 static void purge_fragmented_blocks_allcpus(void);
 
 /*
+ * called before a call to iounmap() if the caller wants vm_area_struct's
+ * immediately freed.
+ */
+void set_iounmap_nonlazy(void)
+{
+        atomic_set(&vmap_lazy_nr, lazy_max_pages()+1);
+}
+
+/*
  * Purges all lazily-freed vmap areas.
  *
  * If sync is 0 then don't purge if there is already a purge in progress.
@@ -557,7 +613,6 @@ static void __purge_vmap_area_lazy(unsigned long *start, unsigned long *end,
                         if (va->va_end > *end)
                                 *end = va->va_end;
                         nr += (va->va_end - va->va_start) >> PAGE_SHIFT;
-                        unmap_vmap_area(va);
                         list_add_tail(&va->purge_list, &valist);
                         va->flags |= VM_LAZY_FREEING;
                         va->flags &= ~VM_LAZY_FREE;
@@ -602,10 +657,11 @@ static void purge_vmap_area_lazy(void)
 }
 
 /*
- * Free and unmap a vmap area, caller ensuring flush_cache_vunmap had been
- * called for the correct range previously.
+ * Free a vmap area, caller ensuring that the area has been unmapped
+ * and flush_cache_vunmap had been called for the correct range
+ * previously.
  */
-static void free_unmap_vmap_area_noflush(struct vmap_area *va)
+static void free_vmap_area_noflush(struct vmap_area *va)
 {
         va->flags |= VM_LAZY_FREE;
         atomic_add((va->va_end - va->va_start) >> PAGE_SHIFT, &vmap_lazy_nr);
@@ -614,6 +670,16 @@ static void free_unmap_vmap_area_noflush(struct vmap_area *va)
 }
 
 /*
+ * Free and unmap a vmap area, caller ensuring flush_cache_vunmap had been
+ * called for the correct range previously.
+ */
+static void free_unmap_vmap_area_noflush(struct vmap_area *va)
+{
+        unmap_vmap_area(va);
+        free_vmap_area_noflush(va);
+}
+
+/*
  * Free and unmap a vmap area
  */
 static void free_unmap_vmap_area(struct vmap_area *va)
@@ -734,7 +800,7 @@ static struct vmap_block *new_vmap_block(gfp_t gfp_mask)
         va = alloc_vmap_area(VMAP_BLOCK_SIZE, VMAP_BLOCK_SIZE,
                                         VMALLOC_START, VMALLOC_END,
                                         node, gfp_mask);
-        if (unlikely(IS_ERR(va))) {
+        if (IS_ERR(va)) {
                 kfree(vb);
                 return ERR_CAST(va);
         }
@@ -789,7 +855,7 @@ static void free_vmap_block(struct vmap_block *vb)
         spin_unlock(&vmap_block_tree_lock);
         BUG_ON(tmp != vb);
 
-        free_unmap_vmap_area_noflush(vb->va);
+        free_vmap_area_noflush(vb->va);
         call_rcu(&vb->rcu_head, rcu_free_vb);
 }
 
@@ -927,6 +993,8 @@ static void vb_free(const void *addr, unsigned long size)
         rcu_read_unlock();
         BUG_ON(!vb);
 
+        vunmap_page_range((unsigned long)addr, (unsigned long)addr + size);
+
         spin_lock(&vb->lock);
         BUG_ON(bitmap_allocate_region(vb->dirty_map, offset >> PAGE_SHIFT, order));
 
@@ -979,7 +1047,6 @@ void vm_unmap_aliases(void)
 
                                 s = vb->va->va_start + (i << PAGE_SHIFT);
                                 e = vb->va->va_start + (j << PAGE_SHIFT);
-                                vunmap_page_range(s, e);
                                 flush = 1;
 
                                 if (s < start)
@@ -1160,6 +1227,7 @@ void unmap_kernel_range_noflush(unsigned long addr, unsigned long size)
 {
         vunmap_page_range(addr, addr + size);
 }
+EXPORT_SYMBOL_GPL(unmap_kernel_range_noflush);
 
 /**
  * unmap_kernel_range - unmap kernel VM area and flush cache and TLB
@@ -1300,13 +1368,6 @@ struct vm_struct *get_vm_area_caller(unsigned long size, unsigned long flags,
                                                 -1, GFP_KERNEL, caller);
 }
 
-struct vm_struct *get_vm_area_node(unsigned long size, unsigned long flags,
-                                   int node, gfp_t gfp_mask)
-{
-        return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END,
-                                  node, gfp_mask, __builtin_return_address(0));
-}
-
 static struct vm_struct *find_vm_area(const void *addr)
 {
         struct vmap_area *va;
@@ -1473,6 +1534,7 @@ static void *__vmalloc_node(unsigned long size, unsigned long align,
 static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
                                  pgprot_t prot, int node, void *caller)
 {
+        const int order = 0;
         struct page **pages;
         unsigned int nr_pages, array_size, i;
         gfp_t nested_gfp = (gfp_mask & GFP_RECLAIM_MASK) | __GFP_ZERO;
@@ -1499,11 +1561,12 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
 
         for (i = 0; i < area->nr_pages; i++) {
                 struct page *page;
+                gfp_t tmp_mask = gfp_mask | __GFP_NOWARN;
 
                 if (node < 0)
-                        page = alloc_page(gfp_mask);
+                        page = alloc_page(tmp_mask);
                 else
-                        page = alloc_pages_node(node, gfp_mask, 0);
+                        page = alloc_pages_node(node, tmp_mask, order);
 
                 if (unlikely(!page)) {
                         /* Successfully allocated i pages, free them in __vunmap() */
@@ -1518,29 +1581,19 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
         return area->addr;
 
 fail:
+        warn_alloc_failed(gfp_mask, order, "vmalloc: allocation failure, "
+                          "allocated %ld of %ld bytes\n",
+                          (area->nr_pages*PAGE_SIZE), area->size);
         vfree(area->addr);
         return NULL;
 }
 
-void *__vmalloc_area(struct vm_struct *area, gfp_t gfp_mask, pgprot_t prot)
-{
-        void *addr = __vmalloc_area_node(area, gfp_mask, prot, -1,
-                                         __builtin_return_address(0));
-
-        /*
-         * A ref_count = 3 is needed because the vm_struct and vmap_area
-         * structures allocated in the __get_vm_area_node() function contain
-         * references to the virtual address of the vmalloc'ed block.
-         */
-        kmemleak_alloc(addr, area->size - PAGE_SIZE, 3, gfp_mask);
-
-        return addr;
-}
-
 /**
- *      __vmalloc_node  -  allocate virtually contiguous memory
+ *      __vmalloc_node_range  -  allocate virtually contiguous memory
  *      @size:          allocation size
  *      @align:         desired alignment
+ *      @start:         vm area range start
+ *      @end:           vm area range end
  *      @gfp_mask:      flags for the page level allocator
  *      @prot:          protection mask for the allocated pages
  *      @node:          node to use for allocation or -1
@@ -1550,9 +1603,9 @@ void *__vmalloc_area(struct vm_struct *area, gfp_t gfp_mask, pgprot_t prot)
  *      allocator with @gfp_mask flags.  Map them into contiguous
  *      kernel virtual space, using a pagetable protection of @prot.
  */
-static void *__vmalloc_node(unsigned long size, unsigned long align,
-                            gfp_t gfp_mask, pgprot_t prot,
-                            int node, void *caller)
+void *__vmalloc_node_range(unsigned long size, unsigned long align,
+                        unsigned long start, unsigned long end, gfp_t gfp_mask,
+                        pgprot_t prot, int node, void *caller)
 {
         struct vm_struct *area;
         void *addr;
@@ -1562,8 +1615,8 @@ static void *__vmalloc_node(unsigned long size, unsigned long align,
         if (!size || (size >> PAGE_SHIFT) > totalram_pages)
                 return NULL;
 
-        area = __get_vm_area_node(size, align, VM_ALLOC, VMALLOC_START,
-                                  VMALLOC_END, node, gfp_mask, caller);
+        area = __get_vm_area_node(size, align, VM_ALLOC, start, end, node,
+                                  gfp_mask, caller);
 
         if (!area)
                 return NULL;
@@ -1580,6 +1633,27 @@ static void *__vmalloc_node(unsigned long size, unsigned long align,
         return addr;
 }
 
+/**
+ *      __vmalloc_node  -  allocate virtually contiguous memory
+ *      @size:          allocation size
+ *      @align:         desired alignment
+ *      @gfp_mask:      flags for the page level allocator
+ *      @prot:          protection mask for the allocated pages
+ *      @node:          node to use for allocation or -1
+ *      @caller:        caller's return address
+ *
+ *      Allocate enough pages to cover @size from the page level
+ *      allocator with @gfp_mask flags.  Map them into contiguous
+ *      kernel virtual space, using a pagetable protection of @prot.
+ */
+static void *__vmalloc_node(unsigned long size, unsigned long align,
+                            gfp_t gfp_mask, pgprot_t prot,
+                            int node, void *caller)
+{
+        return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END,
+                                gfp_mask, prot, node, caller);
+}
+
 void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot)
 {
         return __vmalloc_node(size, 1, gfp_mask, prot, -1,
@@ -1587,6 +1661,13 @@ void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot)
 }
 EXPORT_SYMBOL(__vmalloc);
 
+static inline void *__vmalloc_node_flags(unsigned long size,
+                                        int node, gfp_t flags)
+{
+        return __vmalloc_node(size, 1, flags, PAGE_KERNEL,
+                                        node, __builtin_return_address(0));
+}
+
 /**
  *      vmalloc  -  allocate virtually contiguous memory
  *      @size:          allocation size
@@ -1598,12 +1679,28 @@ EXPORT_SYMBOL(__vmalloc);
  */
 void *vmalloc(unsigned long size)
 {
-        return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL,
-                                        -1, __builtin_return_address(0));
+        return __vmalloc_node_flags(size, -1, GFP_KERNEL | __GFP_HIGHMEM);
 }
 EXPORT_SYMBOL(vmalloc);
 
 /**
+ *      vzalloc - allocate virtually contiguous memory with zero fill
+ *      @size:  allocation size
+ *      Allocate enough pages to cover @size from the page level
+ *      allocator and map them into contiguous kernel virtual space.
+ *      The memory allocated is set to zero.
+ *
+ *      For tight control over page level allocator and protection flags
+ *      use __vmalloc() instead.
+ */
+void *vzalloc(unsigned long size)
+{
+        return __vmalloc_node_flags(size, -1,
+                                GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO);
+}
+EXPORT_SYMBOL(vzalloc);
+
+/**
  * vmalloc_user - allocate zeroed virtually contiguous memory for userspace
  * @size: allocation size
  *
@@ -1644,6 +1741,25 @@ void *vmalloc_node(unsigned long size, int node)
 }
 EXPORT_SYMBOL(vmalloc_node);
 
+/**
+ * vzalloc_node - allocate memory on a specific node with zero fill
+ * @size:       allocation size
+ * @node:       numa node
+ *
+ * Allocate enough pages to cover @size from the page level
+ * allocator and map them into contiguous kernel virtual space.
+ * The memory allocated is set to zero.
+ *
+ * For tight control over page level allocator and protection flags
+ * use __vmalloc_node() instead.
+ */
+void *vzalloc_node(unsigned long size, int node)
+{
+        return __vmalloc_node_flags(size, node,
+                         GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO);
+}
+EXPORT_SYMBOL(vzalloc_node);
+
 #ifndef PAGE_KERNEL_EXEC
 # define PAGE_KERNEL_EXEC PAGE_KERNEL
 #endif
@@ -1892,8 +2008,6 @@ finished:
  *      should know vmalloc() area is valid and can use memcpy().
  *      This is for routines which have to access vmalloc area without
  *      any informaion, as /dev/kmem.
- *
- *      The caller should guarantee KM_USER1 is not used.
  */
 
 long vwrite(char *buf, char *addr, unsigned long count)
@@ -2039,10 +2153,6 @@ struct vm_struct *alloc_vm_area(size_t size)
                 return NULL;
         }
 
-        /* Make sure the pagetables are constructed in process kernel
-           mappings */
-        vmalloc_sync_all();
-
         return area;
 }
 EXPORT_SYMBOL_GPL(alloc_vm_area);
@@ -2056,6 +2166,7 @@ void free_vm_area(struct vm_struct *area)
 }
 EXPORT_SYMBOL_GPL(free_vm_area);
 
+#ifdef CONFIG_SMP
 static struct vmap_area *node_to_va(struct rb_node *n)
 {
         return n ? rb_entry(n, struct vmap_area, rb_node) : NULL;
@@ -2145,17 +2256,16 @@ static unsigned long pvm_determine_end(struct vmap_area **pnext,
  * @sizes: array containing size of each area
  * @nr_vms: the number of areas to allocate
  * @align: alignment, all entries in @offsets and @sizes must be aligned to this
- * @gfp_mask: allocation mask
  *
  * Returns: kmalloc'd vm_struct pointer array pointing to allocated
  *          vm_structs on success, %NULL on failure
  *
  * Percpu allocator wants to use congruent vm areas so that it can
  * maintain the offsets among percpu areas.  This function allocates
- * congruent vmalloc areas for it.  These areas tend to be scattered
- * pretty far, distance between two areas easily going up to
- * gigabytes.  To avoid interacting with regular vmallocs, these areas
- * are allocated from top.
+ * congruent vmalloc areas for it with GFP_KERNEL.  These areas tend to
+ * be scattered pretty far, distance between two areas easily going up
+ * to gigabytes.  To avoid interacting with regular vmallocs, these
+ * areas are allocated from top.
  *
  * Despite its complicated look, this allocator is rather simple.  It
  * does everything top-down and scans areas from the end looking for
@@ -2166,7 +2276,7 @@ static unsigned long pvm_determine_end(struct vmap_area **pnext,
  */
 struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets,
                                      const size_t *sizes, int nr_vms,
-                                     size_t align, gfp_t gfp_mask)
+                                     size_t align)
 {
         const unsigned long vmalloc_start = ALIGN(VMALLOC_START, align);
         const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
@@ -2176,8 +2286,6 @@ struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets,
         unsigned long base, start, end, last_end;
         bool purged = false;
 
-        gfp_mask &= GFP_RECLAIM_MASK;
-
         /* verify parameters and allocate data structures */
         BUG_ON(align & ~PAGE_MASK || !is_power_of_2(align));
         for (last_area = 0, area = 0; area < nr_vms; area++) {
@@ -2210,14 +2318,14 @@ struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets,
                 return NULL;
         }
 
-        vms = kzalloc(sizeof(vms[0]) * nr_vms, gfp_mask);
-        vas = kzalloc(sizeof(vas[0]) * nr_vms, gfp_mask);
+        vms = kzalloc(sizeof(vms[0]) * nr_vms, GFP_KERNEL);
+        vas = kzalloc(sizeof(vas[0]) * nr_vms, GFP_KERNEL);
         if (!vas || !vms)
                 goto err_free;
 
         for (area = 0; area < nr_vms; area++) {
-                vas[area] = kzalloc(sizeof(struct vmap_area), gfp_mask);
-                vms[area] = kzalloc(sizeof(struct vm_struct), gfp_mask);
+                vas[area] = kzalloc(sizeof(struct vmap_area), GFP_KERNEL);
+                vms[area] = kzalloc(sizeof(struct vm_struct), GFP_KERNEL);
                 if (!vas[area] || !vms[area])
                         goto err_free;
         }
@@ -2336,9 +2444,11 @@ void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms)
                 free_vm_area(vms[i]);
         kfree(vms);
 }
+#endif  /* CONFIG_SMP */
 
 #ifdef CONFIG_PROC_FS
 static void *s_start(struct seq_file *m, loff_t *pos)
+        __acquires(&vmlist_lock)
 {
         loff_t n = *pos;
         struct vm_struct *v;
@@ -2365,6 +2475,7 @@ static void *s_next(struct seq_file *m, void *p, loff_t *pos)
 }
 
 static void s_stop(struct seq_file *m, void *p)
+        __releases(&vmlist_lock)
 {
         read_unlock(&vmlist_lock);
 }
@@ -2395,13 +2506,8 @@ static int s_show(struct seq_file *m, void *p)
         seq_printf(m, "0x%p-0x%p %7ld",
                 v->addr, v->addr + v->size, v->size);
 
-        if (v->caller) {
-                char buff[KSYM_SYMBOL_LEN];
-
-                seq_putc(m, ' ');
-                sprint_symbol(buff, (unsigned long)v->caller);
-                seq_puts(m, buff);
-        }
+        if (v->caller)
+                seq_printf(m, " %pS", v->caller);
 
         if (v->nr_pages)
                 seq_printf(m, " pages=%d", v->nr_pages);