#include <linux/mm.h>
#include <linux/module.h>
#include <linux/highmem.h>
+#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <linux/rbtree.h>
#include <linux/radix-tree.h>
#include <linux/rcupdate.h>
-#include <linux/bootmem.h>
#include <linux/pfn.h>
-
+#include <linux/kmemleak.h>
#include <asm/atomic.h>
#include <asm/uaccess.h>
#include <asm/tlbflush.h>
+#include <asm/shmparam.h>
/*** Page table manipulation functions ***/
next = pgd_addr_end(addr, end);
err = vmap_pud_range(pgd, addr, next, prot, pages, &nr);
if (err)
- break;
+ return err;
} while (pgd++, addr = next, addr != end);
- if (unlikely(err))
- return err;
return nr;
}
return ret;
}
-static inline int is_vmalloc_or_module_addr(const void *x)
+int is_vmalloc_or_module_addr(const void *x)
{
/*
* ARM, x86-64 and sparc64 put modules in a special place,
static DEFINE_SPINLOCK(vmap_area_lock);
static struct rb_root vmap_area_root = RB_ROOT;
static LIST_HEAD(vmap_area_list);
+static unsigned long vmap_area_pcpu_hole;
static struct vmap_area *__find_vmap_area(unsigned long addr)
{
RB_CLEAR_NODE(&va->rb_node);
list_del_rcu(&va->list);
+ /*
+ * Track the highest possible candidate for pcpu area
+ * allocation. Areas outside of vmalloc area can be returned
+ * here too, consider only end addresses which fall inside
+ * vmalloc area proper.
+ */
+ if (va->va_end > VMALLOC_START && va->va_end <= VMALLOC_END)
+ vmap_area_pcpu_hole = max(vmap_area_pcpu_hole, va->va_end);
+
call_rcu(&va->rcu_head, rcu_free_va);
}
static atomic_t vmap_lazy_nr = ATOMIC_INIT(0);
+/* for per-CPU blocks */
+static void purge_fragmented_blocks_allcpus(void);
+
/*
* Purges all lazily-freed vmap areas.
*
} else
spin_lock(&purge_lock);
+ if (sync)
+ purge_fragmented_blocks_allcpus();
+
rcu_read_lock();
list_for_each_entry_rcu(va, &vmap_area_list, list) {
if (va->flags & VM_LAZY_FREE) {
}
rcu_read_unlock();
- if (nr) {
- BUG_ON(nr > atomic_read(&vmap_lazy_nr));
+ if (nr)
atomic_sub(nr, &vmap_lazy_nr);
- }
if (nr || force_flush)
flush_tlb_kernel_range(*start, *end);
struct vmap_block_queue {
spinlock_t lock;
struct list_head free;
- struct list_head dirty;
- unsigned int nr_dirty;
};
struct vmap_block {
unsigned long free, dirty;
DECLARE_BITMAP(alloc_map, VMAP_BBMAP_BITS);
DECLARE_BITMAP(dirty_map, VMAP_BBMAP_BITS);
- union {
- struct list_head free_list;
- struct rcu_head rcu_head;
- };
+ struct list_head free_list;
+ struct rcu_head rcu_head;
+ struct list_head purge;
};
/* Queue of free and dirty vmap blocks, for allocation and flushing purposes */
vbq = &get_cpu_var(vmap_block_queue);
vb->vbq = vbq;
spin_lock(&vbq->lock);
- list_add(&vb->free_list, &vbq->free);
+ list_add_rcu(&vb->free_list, &vbq->free);
spin_unlock(&vbq->lock);
- put_cpu_var(vmap_cpu_blocks);
+ put_cpu_var(vmap_block_queue);
return vb;
}
struct vmap_block *tmp;
unsigned long vb_idx;
- BUG_ON(!list_empty(&vb->free_list));
-
vb_idx = addr_to_vb_idx(vb->va->va_start);
spin_lock(&vmap_block_tree_lock);
tmp = radix_tree_delete(&vmap_block_tree, vb_idx);
call_rcu(&vb->rcu_head, rcu_free_vb);
}
+static void purge_fragmented_blocks(int cpu)
+{
+ LIST_HEAD(purge);
+ struct vmap_block *vb;
+ struct vmap_block *n_vb;
+ struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(vb, &vbq->free, free_list) {
+
+ if (!(vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS))
+ continue;
+
+ spin_lock(&vb->lock);
+ if (vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS) {
+ vb->free = 0; /* prevent further allocs after releasing lock */
+ vb->dirty = VMAP_BBMAP_BITS; /* prevent purging it again */
+ bitmap_fill(vb->alloc_map, VMAP_BBMAP_BITS);
+ bitmap_fill(vb->dirty_map, VMAP_BBMAP_BITS);
+ spin_lock(&vbq->lock);
+ list_del_rcu(&vb->free_list);
+ spin_unlock(&vbq->lock);
+ spin_unlock(&vb->lock);
+ list_add_tail(&vb->purge, &purge);
+ } else
+ spin_unlock(&vb->lock);
+ }
+ rcu_read_unlock();
+
+ list_for_each_entry_safe(vb, n_vb, &purge, purge) {
+ list_del(&vb->purge);
+ free_vmap_block(vb);
+ }
+}
+
+static void purge_fragmented_blocks_thiscpu(void)
+{
+ purge_fragmented_blocks(smp_processor_id());
+}
+
+static void purge_fragmented_blocks_allcpus(void)
+{
+ int cpu;
+
+ for_each_possible_cpu(cpu)
+ purge_fragmented_blocks(cpu);
+}
+
static void *vb_alloc(unsigned long size, gfp_t gfp_mask)
{
struct vmap_block_queue *vbq;
struct vmap_block *vb;
unsigned long addr = 0;
unsigned int order;
+ int purge = 0;
BUG_ON(size & ~PAGE_MASK);
BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
int i;
spin_lock(&vb->lock);
+ if (vb->free < 1UL << order)
+ goto next;
+
i = bitmap_find_free_region(vb->alloc_map,
VMAP_BBMAP_BITS, order);
- if (i >= 0) {
- addr = vb->va->va_start + (i << PAGE_SHIFT);
- BUG_ON(addr_to_vb_idx(addr) !=
- addr_to_vb_idx(vb->va->va_start));
- vb->free -= 1UL << order;
- if (vb->free == 0) {
- spin_lock(&vbq->lock);
- list_del_init(&vb->free_list);
- spin_unlock(&vbq->lock);
+ if (i < 0) {
+ if (vb->free + vb->dirty == VMAP_BBMAP_BITS) {
+ /* fragmented and no outstanding allocations */
+ BUG_ON(vb->dirty != VMAP_BBMAP_BITS);
+ purge = 1;
}
- spin_unlock(&vb->lock);
- break;
+ goto next;
+ }
+ addr = vb->va->va_start + (i << PAGE_SHIFT);
+ BUG_ON(addr_to_vb_idx(addr) !=
+ addr_to_vb_idx(vb->va->va_start));
+ vb->free -= 1UL << order;
+ if (vb->free == 0) {
+ spin_lock(&vbq->lock);
+ list_del_rcu(&vb->free_list);
+ spin_unlock(&vbq->lock);
}
spin_unlock(&vb->lock);
+ break;
+next:
+ spin_unlock(&vb->lock);
}
- put_cpu_var(vmap_cpu_blocks);
+
+ if (purge)
+ purge_fragmented_blocks_thiscpu();
+
+ put_cpu_var(vmap_block_queue);
rcu_read_unlock();
if (!addr) {
BUG_ON(!vb);
spin_lock(&vb->lock);
- bitmap_allocate_region(vb->dirty_map, offset >> PAGE_SHIFT, order);
+ BUG_ON(bitmap_allocate_region(vb->dirty_map, offset >> PAGE_SHIFT, order));
vb->dirty += 1UL << order;
if (vb->dirty == VMAP_BBMAP_BITS) {
- BUG_ON(vb->free || !list_empty(&vb->free_list));
+ BUG_ON(vb->free);
spin_unlock(&vb->lock);
free_vmap_block(vb);
} else
vbq = &per_cpu(vmap_block_queue, i);
spin_lock_init(&vbq->lock);
INIT_LIST_HEAD(&vbq->free);
- INIT_LIST_HEAD(&vbq->dirty);
- vbq->nr_dirty = 0;
}
/* Import existing vmlist entries. */
for (tmp = vmlist; tmp; tmp = tmp->next) {
- va = alloc_bootmem(sizeof(struct vmap_area));
+ va = kzalloc(sizeof(struct vmap_area), GFP_NOWAIT);
va->flags = tmp->flags | VM_VM_AREA;
va->va_start = (unsigned long)tmp->addr;
va->va_end = va->va_start + tmp->size;
__insert_vmap_area(va);
}
+
+ vmap_area_pcpu_hole = VMALLOC_END;
+
vmap_initialized = true;
}
DEFINE_RWLOCK(vmlist_lock);
struct vm_struct *vmlist;
+static void insert_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va,
+ unsigned long flags, void *caller)
+{
+ struct vm_struct *tmp, **p;
+
+ vm->flags = flags;
+ vm->addr = (void *)va->va_start;
+ vm->size = va->va_end - va->va_start;
+ vm->caller = caller;
+ va->private = vm;
+ va->flags |= VM_VM_AREA;
+
+ write_lock(&vmlist_lock);
+ for (p = &vmlist; (tmp = *p) != NULL; p = &tmp->next) {
+ if (tmp->addr >= vm->addr)
+ break;
+ }
+ vm->next = *p;
+ *p = vm;
+ write_unlock(&vmlist_lock);
+}
+
static struct vm_struct *__get_vm_area_node(unsigned long size,
- unsigned long flags, unsigned long start, unsigned long end,
- int node, gfp_t gfp_mask, void *caller)
+ unsigned long align, unsigned long flags, unsigned long start,
+ unsigned long end, int node, gfp_t gfp_mask, void *caller)
{
static struct vmap_area *va;
struct vm_struct *area;
- struct vm_struct *tmp, **p;
- unsigned long align = 1;
BUG_ON(in_interrupt());
if (flags & VM_IOREMAP) {
if (unlikely(!size))
return NULL;
- area = kmalloc_node(sizeof(*area), gfp_mask & GFP_RECLAIM_MASK, node);
+ area = kzalloc_node(sizeof(*area), gfp_mask & GFP_RECLAIM_MASK, node);
if (unlikely(!area))
return NULL;
return NULL;
}
- area->flags = flags;
- area->addr = (void *)va->va_start;
- area->size = size;
- area->pages = NULL;
- area->nr_pages = 0;
- area->phys_addr = 0;
- area->caller = caller;
- va->private = area;
- va->flags |= VM_VM_AREA;
-
- write_lock(&vmlist_lock);
- for (p = &vmlist; (tmp = *p) != NULL; p = &tmp->next) {
- if (tmp->addr >= area->addr)
- break;
- }
- area->next = *p;
- *p = area;
- write_unlock(&vmlist_lock);
-
+ insert_vmalloc_vm(area, va, flags, caller);
return area;
}
struct vm_struct *__get_vm_area(unsigned long size, unsigned long flags,
unsigned long start, unsigned long end)
{
- return __get_vm_area_node(size, flags, start, end, -1, GFP_KERNEL,
+ return __get_vm_area_node(size, 1, flags, start, end, -1, GFP_KERNEL,
__builtin_return_address(0));
}
EXPORT_SYMBOL_GPL(__get_vm_area);
unsigned long start, unsigned long end,
void *caller)
{
- return __get_vm_area_node(size, flags, start, end, -1, GFP_KERNEL,
+ return __get_vm_area_node(size, 1, flags, start, end, -1, GFP_KERNEL,
caller);
}
*/
struct vm_struct *get_vm_area(unsigned long size, unsigned long flags)
{
- return __get_vm_area_node(size, flags, VMALLOC_START, VMALLOC_END,
+ return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END,
-1, GFP_KERNEL, __builtin_return_address(0));
}
struct vm_struct *get_vm_area_caller(unsigned long size, unsigned long flags,
void *caller)
{
- return __get_vm_area_node(size, flags, VMALLOC_START, VMALLOC_END,
+ return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END,
-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, flags, VMALLOC_START, VMALLOC_END, node,
- gfp_mask, __builtin_return_address(0));
+ 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)
if (va && va->flags & VM_VM_AREA) {
struct vm_struct *vm = va->private;
struct vm_struct *tmp, **p;
-
- vmap_debug_free_range(va->va_start, va->va_end);
- free_unmap_vmap_area(va);
- vm->size -= PAGE_SIZE;
-
+ /*
+ * remove from list and disallow access to this vm_struct
+ * before unmap. (address range confliction is maintained by
+ * vmap.)
+ */
write_lock(&vmlist_lock);
for (p = &vmlist; (tmp = *p) != vm; p = &tmp->next)
;
*p = tmp->next;
write_unlock(&vmlist_lock);
+ vmap_debug_free_range(va->va_start, va->va_end);
+ free_unmap_vmap_area(va);
+ vm->size -= PAGE_SIZE;
+
return vm;
}
return NULL;
void vfree(const void *addr)
{
BUG_ON(in_interrupt());
+
+ kmemleak_free(addr);
+
__vunmap(addr, 1);
}
EXPORT_SYMBOL(vfree);
might_sleep();
- if (count > num_physpages)
+ if (count > totalram_pages)
return NULL;
area = get_vm_area_caller((count << PAGE_SHIFT), flags,
}
EXPORT_SYMBOL(vmap);
-static void *__vmalloc_node(unsigned long size, gfp_t gfp_mask, pgprot_t prot,
+static void *__vmalloc_node(unsigned long size, unsigned long align,
+ gfp_t gfp_mask, pgprot_t prot,
int node, void *caller);
static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
pgprot_t prot, int node, void *caller)
{
struct page **pages;
unsigned int nr_pages, array_size, i;
+ gfp_t nested_gfp = (gfp_mask & GFP_RECLAIM_MASK) | __GFP_ZERO;
nr_pages = (area->size - PAGE_SIZE) >> PAGE_SHIFT;
array_size = (nr_pages * sizeof(struct page *));
area->nr_pages = nr_pages;
/* Please note that the recursion is strictly bounded. */
if (array_size > PAGE_SIZE) {
- pages = __vmalloc_node(array_size, gfp_mask | __GFP_ZERO,
+ pages = __vmalloc_node(array_size, 1, nested_gfp|__GFP_HIGHMEM,
PAGE_KERNEL, node, caller);
area->flags |= VM_VPAGES;
} else {
- pages = kmalloc_node(array_size,
- (gfp_mask & GFP_RECLAIM_MASK) | __GFP_ZERO,
- node);
+ pages = kmalloc_node(array_size, nested_gfp, node);
}
area->pages = pages;
area->caller = caller;
void *__vmalloc_area(struct vm_struct *area, gfp_t gfp_mask, pgprot_t prot)
{
- return __vmalloc_area_node(area, gfp_mask, prot, -1,
- __builtin_return_address(0));
+ 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
* @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
* 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, gfp_t gfp_mask, pgprot_t prot,
- int node, void *caller)
+static void *__vmalloc_node(unsigned long size, unsigned long align,
+ gfp_t gfp_mask, pgprot_t prot,
+ int node, void *caller)
{
struct vm_struct *area;
+ void *addr;
+ unsigned long real_size = size;
size = PAGE_ALIGN(size);
- if (!size || (size >> PAGE_SHIFT) > num_physpages)
+ if (!size || (size >> PAGE_SHIFT) > totalram_pages)
return NULL;
- area = __get_vm_area_node(size, VM_ALLOC, VMALLOC_START, VMALLOC_END,
- node, gfp_mask, caller);
+ area = __get_vm_area_node(size, align, VM_ALLOC, VMALLOC_START,
+ VMALLOC_END, node, gfp_mask, caller);
if (!area)
return NULL;
- return __vmalloc_area_node(area, gfp_mask, prot, node, caller);
+ addr = __vmalloc_area_node(area, gfp_mask, prot, node, caller);
+
+ /*
+ * 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, real_size, 3, gfp_mask);
+
+ return addr;
}
void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot)
{
- return __vmalloc_node(size, gfp_mask, prot, -1,
+ return __vmalloc_node(size, 1, gfp_mask, prot, -1,
__builtin_return_address(0));
}
EXPORT_SYMBOL(__vmalloc);
*/
void *vmalloc(unsigned long size)
{
- return __vmalloc_node(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL,
+ return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL,
-1, __builtin_return_address(0));
}
EXPORT_SYMBOL(vmalloc);
struct vm_struct *area;
void *ret;
- ret = __vmalloc_node(size, GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO,
+ ret = __vmalloc_node(size, SHMLBA,
+ GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO,
PAGE_KERNEL, -1, __builtin_return_address(0));
if (ret) {
area = find_vm_area(ret);
*/
void *vmalloc_node(unsigned long size, int node)
{
- return __vmalloc_node(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL,
+ return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL,
node, __builtin_return_address(0));
}
EXPORT_SYMBOL(vmalloc_node);
void *vmalloc_exec(unsigned long size)
{
- return __vmalloc_node(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL_EXEC,
+ return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL_EXEC,
-1, __builtin_return_address(0));
}
*/
void *vmalloc_32(unsigned long size)
{
- return __vmalloc_node(size, GFP_VMALLOC32, PAGE_KERNEL,
+ return __vmalloc_node(size, 1, GFP_VMALLOC32, PAGE_KERNEL,
-1, __builtin_return_address(0));
}
EXPORT_SYMBOL(vmalloc_32);
struct vm_struct *area;
void *ret;
- ret = __vmalloc_node(size, GFP_VMALLOC32 | __GFP_ZERO, PAGE_KERNEL,
+ ret = __vmalloc_node(size, 1, GFP_VMALLOC32 | __GFP_ZERO, PAGE_KERNEL,
-1, __builtin_return_address(0));
if (ret) {
area = find_vm_area(ret);
}
EXPORT_SYMBOL(vmalloc_32_user);
+/*
+ * small helper routine , copy contents to buf from addr.
+ * If the page is not present, fill zero.
+ */
+
+static int aligned_vread(char *buf, char *addr, unsigned long count)
+{
+ struct page *p;
+ int copied = 0;
+
+ while (count) {
+ unsigned long offset, length;
+
+ offset = (unsigned long)addr & ~PAGE_MASK;
+ length = PAGE_SIZE - offset;
+ if (length > count)
+ length = count;
+ p = vmalloc_to_page(addr);
+ /*
+ * To do safe access to this _mapped_ area, we need
+ * lock. But adding lock here means that we need to add
+ * overhead of vmalloc()/vfree() calles for this _debug_
+ * interface, rarely used. Instead of that, we'll use
+ * kmap() and get small overhead in this access function.
+ */
+ if (p) {
+ /*
+ * we can expect USER0 is not used (see vread/vwrite's
+ * function description)
+ */
+ void *map = kmap_atomic(p, KM_USER0);
+ memcpy(buf, map + offset, length);
+ kunmap_atomic(map, KM_USER0);
+ } else
+ memset(buf, 0, length);
+
+ addr += length;
+ buf += length;
+ copied += length;
+ count -= length;
+ }
+ return copied;
+}
+
+static int aligned_vwrite(char *buf, char *addr, unsigned long count)
+{
+ struct page *p;
+ int copied = 0;
+
+ while (count) {
+ unsigned long offset, length;
+
+ offset = (unsigned long)addr & ~PAGE_MASK;
+ length = PAGE_SIZE - offset;
+ if (length > count)
+ length = count;
+ p = vmalloc_to_page(addr);
+ /*
+ * To do safe access to this _mapped_ area, we need
+ * lock. But adding lock here means that we need to add
+ * overhead of vmalloc()/vfree() calles for this _debug_
+ * interface, rarely used. Instead of that, we'll use
+ * kmap() and get small overhead in this access function.
+ */
+ if (p) {
+ /*
+ * we can expect USER0 is not used (see vread/vwrite's
+ * function description)
+ */
+ void *map = kmap_atomic(p, KM_USER0);
+ memcpy(map + offset, buf, length);
+ kunmap_atomic(map, KM_USER0);
+ }
+ addr += length;
+ buf += length;
+ copied += length;
+ count -= length;
+ }
+ return copied;
+}
+
+/**
+ * vread() - read vmalloc area in a safe way.
+ * @buf: buffer for reading data
+ * @addr: vm address.
+ * @count: number of bytes to be read.
+ *
+ * Returns # of bytes which addr and buf should be increased.
+ * (same number to @count). Returns 0 if [addr...addr+count) doesn't
+ * includes any intersect with alive vmalloc area.
+ *
+ * This function checks that addr is a valid vmalloc'ed area, and
+ * copy data from that area to a given buffer. If the given memory range
+ * of [addr...addr+count) includes some valid address, data is copied to
+ * proper area of @buf. If there are memory holes, they'll be zero-filled.
+ * IOREMAP area is treated as memory hole and no copy is done.
+ *
+ * If [addr...addr+count) doesn't includes any intersects with alive
+ * vm_struct area, returns 0.
+ * @buf should be kernel's buffer. Because this function uses KM_USER0,
+ * the caller should guarantee KM_USER0 is not used.
+ *
+ * Note: In usual ops, vread() is never necessary because the caller
+ * 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.
+ *
+ */
+
long vread(char *buf, char *addr, unsigned long count)
{
struct vm_struct *tmp;
char *vaddr, *buf_start = buf;
+ unsigned long buflen = count;
unsigned long n;
/* Don't allow overflow */
count = -(unsigned long) addr;
read_lock(&vmlist_lock);
- for (tmp = vmlist; tmp; tmp = tmp->next) {
+ for (tmp = vmlist; count && tmp; tmp = tmp->next) {
vaddr = (char *) tmp->addr;
if (addr >= vaddr + tmp->size - PAGE_SIZE)
continue;
count--;
}
n = vaddr + tmp->size - PAGE_SIZE - addr;
- do {
- if (count == 0)
- goto finished;
- *buf = *addr;
- buf++;
- addr++;
- count--;
- } while (--n > 0);
+ if (n > count)
+ n = count;
+ if (!(tmp->flags & VM_IOREMAP))
+ aligned_vread(buf, addr, n);
+ else /* IOREMAP area is treated as memory hole */
+ memset(buf, 0, n);
+ buf += n;
+ addr += n;
+ count -= n;
}
finished:
read_unlock(&vmlist_lock);
- return buf - buf_start;
+
+ if (buf == buf_start)
+ return 0;
+ /* zero-fill memory holes */
+ if (buf != buf_start + buflen)
+ memset(buf, 0, buflen - (buf - buf_start));
+
+ return buflen;
}
+/**
+ * vwrite() - write vmalloc area in a safe way.
+ * @buf: buffer for source data
+ * @addr: vm address.
+ * @count: number of bytes to be read.
+ *
+ * Returns # of bytes which addr and buf should be incresed.
+ * (same number to @count).
+ * If [addr...addr+count) doesn't includes any intersect with valid
+ * vmalloc area, returns 0.
+ *
+ * This function checks that addr is a valid vmalloc'ed area, and
+ * copy data from a buffer to the given addr. If specified range of
+ * [addr...addr+count) includes some valid address, data is copied from
+ * proper area of @buf. If there are memory holes, no copy to hole.
+ * IOREMAP area is treated as memory hole and no copy is done.
+ *
+ * If [addr...addr+count) doesn't includes any intersects with alive
+ * vm_struct area, returns 0.
+ * @buf should be kernel's buffer. Because this function uses KM_USER0,
+ * the caller should guarantee KM_USER0 is not used.
+ *
+ * Note: In usual ops, vwrite() is never necessary because the caller
+ * 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)
{
struct vm_struct *tmp;
- char *vaddr, *buf_start = buf;
- unsigned long n;
+ char *vaddr;
+ unsigned long n, buflen;
+ int copied = 0;
/* Don't allow overflow */
if ((unsigned long) addr + count < count)
count = -(unsigned long) addr;
+ buflen = count;
read_lock(&vmlist_lock);
- for (tmp = vmlist; tmp; tmp = tmp->next) {
+ for (tmp = vmlist; count && tmp; tmp = tmp->next) {
vaddr = (char *) tmp->addr;
if (addr >= vaddr + tmp->size - PAGE_SIZE)
continue;
count--;
}
n = vaddr + tmp->size - PAGE_SIZE - addr;
- do {
- if (count == 0)
- goto finished;
- *addr = *buf;
- buf++;
- addr++;
- count--;
- } while (--n > 0);
+ if (n > count)
+ n = count;
+ if (!(tmp->flags & VM_IOREMAP)) {
+ aligned_vwrite(buf, addr, n);
+ copied++;
+ }
+ buf += n;
+ addr += n;
+ count -= n;
}
finished:
read_unlock(&vmlist_lock);
- return buf - buf_start;
+ if (!copied)
+ return 0;
+ return buflen;
}
/**
}
EXPORT_SYMBOL_GPL(free_vm_area);
+static struct vmap_area *node_to_va(struct rb_node *n)
+{
+ return n ? rb_entry(n, struct vmap_area, rb_node) : NULL;
+}
+
+/**
+ * pvm_find_next_prev - find the next and prev vmap_area surrounding @end
+ * @end: target address
+ * @pnext: out arg for the next vmap_area
+ * @pprev: out arg for the previous vmap_area
+ *
+ * Returns: %true if either or both of next and prev are found,
+ * %false if no vmap_area exists
+ *
+ * Find vmap_areas end addresses of which enclose @end. ie. if not
+ * NULL, *pnext->va_end > @end and *pprev->va_end <= @end.
+ */
+static bool pvm_find_next_prev(unsigned long end,
+ struct vmap_area **pnext,
+ struct vmap_area **pprev)
+{
+ struct rb_node *n = vmap_area_root.rb_node;
+ struct vmap_area *va = NULL;
+
+ while (n) {
+ va = rb_entry(n, struct vmap_area, rb_node);
+ if (end < va->va_end)
+ n = n->rb_left;
+ else if (end > va->va_end)
+ n = n->rb_right;
+ else
+ break;
+ }
+
+ if (!va)
+ return false;
+
+ if (va->va_end > end) {
+ *pnext = va;
+ *pprev = node_to_va(rb_prev(&(*pnext)->rb_node));
+ } else {
+ *pprev = va;
+ *pnext = node_to_va(rb_next(&(*pprev)->rb_node));
+ }
+ return true;
+}
+
+/**
+ * pvm_determine_end - find the highest aligned address between two vmap_areas
+ * @pnext: in/out arg for the next vmap_area
+ * @pprev: in/out arg for the previous vmap_area
+ * @align: alignment
+ *
+ * Returns: determined end address
+ *
+ * Find the highest aligned address between *@pnext and *@pprev below
+ * VMALLOC_END. *@pnext and *@pprev are adjusted so that the aligned
+ * down address is between the end addresses of the two vmap_areas.
+ *
+ * Please note that the address returned by this function may fall
+ * inside *@pnext vmap_area. The caller is responsible for checking
+ * that.
+ */
+static unsigned long pvm_determine_end(struct vmap_area **pnext,
+ struct vmap_area **pprev,
+ unsigned long align)
+{
+ const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
+ unsigned long addr;
+
+ if (*pnext)
+ addr = min((*pnext)->va_start & ~(align - 1), vmalloc_end);
+ else
+ addr = vmalloc_end;
+
+ while (*pprev && (*pprev)->va_end > addr) {
+ *pnext = *pprev;
+ *pprev = node_to_va(rb_prev(&(*pnext)->rb_node));
+ }
+
+ return addr;
+}
+
+/**
+ * pcpu_get_vm_areas - allocate vmalloc areas for percpu allocator
+ * @offsets: array containing offset of each area
+ * @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.
+ *
+ * Despite its complicated look, this allocator is rather simple. It
+ * does everything top-down and scans areas from the end looking for
+ * matching slot. While scanning, if any of the areas overlaps with
+ * existing vmap_area, the base address is pulled down to fit the
+ * area. Scanning is repeated till all the areas fit and then all
+ * necessary data structres are inserted and the result is returned.
+ */
+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)
+{
+ const unsigned long vmalloc_start = ALIGN(VMALLOC_START, align);
+ const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
+ struct vmap_area **vas, *prev, *next;
+ struct vm_struct **vms;
+ int area, area2, last_area, term_area;
+ 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++) {
+ start = offsets[area];
+ end = start + sizes[area];
+
+ /* is everything aligned properly? */
+ BUG_ON(!IS_ALIGNED(offsets[area], align));
+ BUG_ON(!IS_ALIGNED(sizes[area], align));
+
+ /* detect the area with the highest address */
+ if (start > offsets[last_area])
+ last_area = area;
+
+ for (area2 = 0; area2 < nr_vms; area2++) {
+ unsigned long start2 = offsets[area2];
+ unsigned long end2 = start2 + sizes[area2];
+
+ if (area2 == area)
+ continue;
+
+ BUG_ON(start2 >= start && start2 < end);
+ BUG_ON(end2 <= end && end2 > start);
+ }
+ }
+ last_end = offsets[last_area] + sizes[last_area];
+
+ if (vmalloc_end - vmalloc_start < last_end) {
+ WARN_ON(true);
+ return NULL;
+ }
+
+ vms = kzalloc(sizeof(vms[0]) * nr_vms, gfp_mask);
+ vas = kzalloc(sizeof(vas[0]) * nr_vms, gfp_mask);
+ 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);
+ if (!vas[area] || !vms[area])
+ goto err_free;
+ }
+retry:
+ spin_lock(&vmap_area_lock);
+
+ /* start scanning - we scan from the top, begin with the last area */
+ area = term_area = last_area;
+ start = offsets[area];
+ end = start + sizes[area];
+
+ if (!pvm_find_next_prev(vmap_area_pcpu_hole, &next, &prev)) {
+ base = vmalloc_end - last_end;
+ goto found;
+ }
+ base = pvm_determine_end(&next, &prev, align) - end;
+
+ while (true) {
+ BUG_ON(next && next->va_end <= base + end);
+ BUG_ON(prev && prev->va_end > base + end);
+
+ /*
+ * base might have underflowed, add last_end before
+ * comparing.
+ */
+ if (base + last_end < vmalloc_start + last_end) {
+ spin_unlock(&vmap_area_lock);
+ if (!purged) {
+ purge_vmap_area_lazy();
+ purged = true;
+ goto retry;
+ }
+ goto err_free;
+ }
+
+ /*
+ * If next overlaps, move base downwards so that it's
+ * right below next and then recheck.
+ */
+ if (next && next->va_start < base + end) {
+ base = pvm_determine_end(&next, &prev, align) - end;
+ term_area = area;
+ continue;
+ }
+
+ /*
+ * If prev overlaps, shift down next and prev and move
+ * base so that it's right below new next and then
+ * recheck.
+ */
+ if (prev && prev->va_end > base + start) {
+ next = prev;
+ prev = node_to_va(rb_prev(&next->rb_node));
+ base = pvm_determine_end(&next, &prev, align) - end;
+ term_area = area;
+ continue;
+ }
+
+ /*
+ * This area fits, move on to the previous one. If
+ * the previous one is the terminal one, we're done.
+ */
+ area = (area + nr_vms - 1) % nr_vms;
+ if (area == term_area)
+ break;
+ start = offsets[area];
+ end = start + sizes[area];
+ pvm_find_next_prev(base + end, &next, &prev);
+ }
+found:
+ /* we've found a fitting base, insert all va's */
+ for (area = 0; area < nr_vms; area++) {
+ struct vmap_area *va = vas[area];
+
+ va->va_start = base + offsets[area];
+ va->va_end = va->va_start + sizes[area];
+ __insert_vmap_area(va);
+ }
+
+ vmap_area_pcpu_hole = base + offsets[last_area];
+
+ spin_unlock(&vmap_area_lock);
+
+ /* insert all vm's */
+ for (area = 0; area < nr_vms; area++)
+ insert_vmalloc_vm(vms[area], vas[area], VM_ALLOC,
+ pcpu_get_vm_areas);
+
+ kfree(vas);
+ return vms;
+
+err_free:
+ for (area = 0; area < nr_vms; area++) {
+ if (vas)
+ kfree(vas[area]);
+ if (vms)
+ kfree(vms[area]);
+ }
+ kfree(vas);
+ kfree(vms);
+ return NULL;
+}
+
+/**
+ * pcpu_free_vm_areas - free vmalloc areas for percpu allocator
+ * @vms: vm_struct pointer array returned by pcpu_get_vm_areas()
+ * @nr_vms: the number of allocated areas
+ *
+ * Free vm_structs and the array allocated by pcpu_get_vm_areas().
+ */
+void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms)
+{
+ int i;
+
+ for (i = 0; i < nr_vms; i++)
+ free_vm_area(vms[i]);
+ kfree(vms);
+}
#ifdef CONFIG_PROC_FS
static void *s_start(struct seq_file *m, loff_t *pos)