Add some asserts to make sure the state is consistent.
Simplify and improve the readability of vm_free.
If a NULL pointer is freed, no operation is performed.
Fixes: 3f6fee0d4da4 ("lib/vmalloc: vmalloc support for handling allocation metadata")
Signed-off-by: Claudio Imbrenda <imbrenda@xxxxxxxxxxxxx>
---
lib/vmalloc.c | 22 +++++++++++++---------
1 file changed, 13 insertions(+), 9 deletions(-)
diff --git a/lib/vmalloc.c b/lib/vmalloc.c
index 986a34c..6b52790 100644
--- a/lib/vmalloc.c
+++ b/lib/vmalloc.c
@@ -162,13 +162,16 @@ static void *vm_memalign(size_t alignment, size_t size)
static void vm_free(void *mem)
{
struct metadata *m;
- uintptr_t ptr, end;
+ uintptr_t ptr, page, i;
+ if (!mem)
+ return;
/* the pointer is not page-aligned, it was a single-page allocation */
if (!IS_ALIGNED((uintptr_t)mem, PAGE_SIZE)) {
assert(GET_MAGIC(mem) == VM_MAGIC);
- ptr = virt_to_pte_phys(page_root, mem) & PAGE_MASK;
- free_page(phys_to_virt(ptr));
+ page = virt_to_pte_phys(page_root, mem) & PAGE_MASK;
+ assert(page);
+ free_page(phys_to_virt(page));
return;
}
@@ -176,13 +179,14 @@ static void vm_free(void *mem)
m = GET_METADATA(mem);
assert(m->magic == VM_MAGIC);
assert(m->npages > 0);
+ assert(m->npages < BIT_ULL(BITS_PER_LONG - PAGE_SHIFT));
/* free all the pages including the metadata page */
- ptr = (uintptr_t)mem - PAGE_SIZE;
- end = ptr + m->npages * PAGE_SIZE;
- for ( ; ptr < end; ptr += PAGE_SIZE)
- free_page(phys_to_virt(virt_to_pte_phys(page_root, (void *)ptr)));
- /* free the last one separately to avoid overflow issues */
- free_page(phys_to_virt(virt_to_pte_phys(page_root, (void *)ptr)));
+ ptr = (uintptr_t)m & PAGE_MASK;
+ for (i = 0 ; i < m->npages + 1; i++, ptr += PAGE_SIZE) {
+ page = virt_to_pte_phys(page_root, (void *)ptr) & PAGE_MASK;
+ assert(page);
+ free_page(phys_to_virt(page));
+ }
}
static struct alloc_ops vmalloc_ops = {
--
2.26.2
