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Diffstat (limited to 'lib/efi_loader/efi_memory.c')
-rw-r--r--lib/efi_loader/efi_memory.c76
1 files changed, 58 insertions, 18 deletions
diff --git a/lib/efi_loader/efi_memory.c b/lib/efi_loader/efi_memory.c
index 55622d2fb4..1136f4f733 100644
--- a/lib/efi_loader/efi_memory.c
+++ b/lib/efi_loader/efi_memory.c
@@ -15,6 +15,9 @@
DECLARE_GLOBAL_DATA_PTR;
+/* Magic number identifying memory allocated from pool */
+#define EFI_ALLOC_POOL_MAGIC 0x1fe67ddf6491caa2
+
efi_uintn_t efi_memory_map_key;
struct efi_mem_list {
@@ -33,7 +36,12 @@ LIST_HEAD(efi_mem);
void *efi_bounce_buffer;
#endif
-/*
+/**
+ * efi_pool_allocation - memory block allocated from pool
+ *
+ * @num_pages: number of pages allocated
+ * @checksum: checksum
+ *
* U-Boot services each EFI AllocatePool request as a separate
* (multiple) page allocation. We have to track the number of pages
* to be able to free the correct amount later.
@@ -43,9 +51,26 @@ void *efi_bounce_buffer;
*/
struct efi_pool_allocation {
u64 num_pages;
+ u64 checksum;
char data[] __aligned(ARCH_DMA_MINALIGN);
};
+/**
+ * checksum() - calculate checksum for memory allocated from pool
+ *
+ * @alloc: allocation header
+ * Return: checksum, always non-zero
+ */
+static u64 checksum(struct efi_pool_allocation *alloc)
+{
+ u64 addr = (uintptr_t)alloc;
+ u64 ret = (addr >> 32) ^ (addr << 32) ^ alloc->num_pages ^
+ EFI_ALLOC_POOL_MAGIC;
+ if (!ret)
+ ++ret;
+ return ret;
+}
+
/*
* Sorts the memory list from highest address to lowest address
*
@@ -409,17 +434,24 @@ void *efi_alloc(uint64_t len, int memory_type)
return NULL;
}
-/*
- * Free memory pages.
+/**
+ * efi_free_pages() - free memory pages
*
- * @memory start of the memory area to be freed
- * @pages number of pages to be freed
- * @return status code
+ * @memory: start of the memory area to be freed
+ * @pages: number of pages to be freed
+ * Return: status code
*/
efi_status_t efi_free_pages(uint64_t memory, efi_uintn_t pages)
{
uint64_t r = 0;
+ /* Sanity check */
+ if (!memory || (memory & EFI_PAGE_MASK)) {
+ printf("%s: illegal free 0x%llx, 0x%zx\n", __func__,
+ memory, pages);
+ return EFI_INVALID_PARAMETER;
+ }
+
r = efi_add_memory_map(memory, pages, EFI_CONVENTIONAL_MEMORY, false);
/* Merging of adjacent free regions is missing */
@@ -429,13 +461,13 @@ efi_status_t efi_free_pages(uint64_t memory, efi_uintn_t pages)
return EFI_NOT_FOUND;
}
-/*
- * Allocate memory from pool.
+/**
+ * efi_allocate_pool - allocate memory from pool
*
- * @pool_type type of the pool from which memory is to be allocated
- * @size number of bytes to be allocated
- * @buffer allocated memory
- * @return status code
+ * @pool_type: type of the pool from which memory is to be allocated
+ * @size: number of bytes to be allocated
+ * @buffer: allocated memory
+ * Return: status code
*/
efi_status_t efi_allocate_pool(int pool_type, efi_uintn_t size, void **buffer)
{
@@ -458,17 +490,18 @@ efi_status_t efi_allocate_pool(int pool_type, efi_uintn_t size, void **buffer)
if (r == EFI_SUCCESS) {
alloc = (struct efi_pool_allocation *)(uintptr_t)addr;
alloc->num_pages = num_pages;
+ alloc->checksum = checksum(alloc);
*buffer = alloc->data;
}
return r;
}
-/*
- * Free memory from pool.
+/**
+ * efi_free_pool() - free memory from pool
*
- * @buffer start of memory to be freed
- * @return status code
+ * @buffer: start of memory to be freed
+ * Return: status code
*/
efi_status_t efi_free_pool(void *buffer)
{
@@ -479,8 +512,15 @@ efi_status_t efi_free_pool(void *buffer)
return EFI_INVALID_PARAMETER;
alloc = container_of(buffer, struct efi_pool_allocation, data);
- /* Sanity check, was the supplied address returned by allocate_pool */
- assert(((uintptr_t)alloc & EFI_PAGE_MASK) == 0);
+
+ /* Check that this memory was allocated by efi_allocate_pool() */
+ if (((uintptr_t)alloc & EFI_PAGE_MASK) ||
+ alloc->checksum != checksum(alloc)) {
+ printf("%s: illegal free 0x%p\n", __func__, buffer);
+ return EFI_INVALID_PARAMETER;
+ }
+ /* Avoid double free */
+ alloc->checksum = 0;
r = efi_free_pages((uintptr_t)alloc, alloc->num_pages);