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-rw-r--r--include/linux/vmalloc.h1
-rw-r--r--mm/vmalloc.c31
2 files changed, 25 insertions, 7 deletions
diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
index 31e9ffd936e3..5ca8d4dd149d 100644
--- a/include/linux/vmalloc.h
+++ b/include/linux/vmalloc.h
@@ -61,6 +61,7 @@ struct vm_struct {
unsigned int nr_pages;
phys_addr_t phys_addr;
const void *caller;
+ unsigned long requested_size;
};
struct vmap_area {
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 3ed720a787ec..2d7511654831 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -1940,7 +1940,7 @@ static inline void setup_vmalloc_vm(struct vm_struct *vm,
{
vm->flags = flags;
vm->addr = (void *)va->va_start;
- vm->size = va_size(va);
+ vm->size = vm->requested_size = va_size(va);
vm->caller = caller;
va->vm = vm;
}
@@ -3133,6 +3133,7 @@ struct vm_struct *__get_vm_area_node(unsigned long size,
area->flags = flags;
area->caller = caller;
+ area->requested_size = requested_size;
va = alloc_vmap_area(size, align, start, end, node, gfp_mask, 0, area);
if (IS_ERR(va)) {
@@ -4063,6 +4064,8 @@ EXPORT_SYMBOL(vzalloc_node_noprof);
*/
void *vrealloc_noprof(const void *p, size_t size, gfp_t flags)
{
+ struct vm_struct *vm = NULL;
+ size_t alloced_size = 0;
size_t old_size = 0;
void *n;
@@ -4072,15 +4075,17 @@ void *vrealloc_noprof(const void *p, size_t size, gfp_t flags)
}
if (p) {
- struct vm_struct *vm;
-
vm = find_vm_area(p);
if (unlikely(!vm)) {
WARN(1, "Trying to vrealloc() nonexistent vm area (%p)\n", p);
return NULL;
}
- old_size = get_vm_area_size(vm);
+ alloced_size = get_vm_area_size(vm);
+ old_size = vm->requested_size;
+ if (WARN(alloced_size < old_size,
+ "vrealloc() has mismatched area vs requested sizes (%p)\n", p))
+ return NULL;
}
/*
@@ -4088,14 +4093,26 @@ void *vrealloc_noprof(const void *p, size_t size, gfp_t flags)
* would be a good heuristic for when to shrink the vm_area?
*/
if (size <= old_size) {
- /* Zero out spare memory. */
- if (want_init_on_alloc(flags))
+ /* Zero out "freed" memory. */
+ if (want_init_on_free())
memset((void *)p + size, 0, old_size - size);
+ vm->requested_size = size;
kasan_poison_vmalloc(p + size, old_size - size);
- kasan_unpoison_vmalloc(p, size, KASAN_VMALLOC_PROT_NORMAL);
return (void *)p;
}
+ /*
+ * We already have the bytes available in the allocation; use them.
+ */
+ if (size <= alloced_size) {
+ kasan_unpoison_vmalloc(p + old_size, size - old_size,
+ KASAN_VMALLOC_PROT_NORMAL);
+ /* Zero out "alloced" memory. */
+ if (want_init_on_alloc(flags))
+ memset((void *)p + old_size, 0, size - old_size);
+ vm->requested_size = size;
+ }
+
/* TODO: Grow the vm_area, i.e. allocate and map additional pages. */
n = __vmalloc_noprof(size, flags);
if (!n)