Merge tag 'efi-2019-07-rc1' of git://git.denx.de/u-boot-efi

Pull request for UEFI sub-system for v2019.07-rc1

The patch series adds support for the BootNext and BootCurrent variables.

The rest is mostly bug fixes. With the bug fixes in place it becomes
possible to use the EFI Shell `edit` command.

A new unit test is supplied to check the image base and size fields of the
loaded image protocol.

An inline check when freeing memory from the pool safeguards against double
frees.

1 files changed, 60 insertions, 20 deletions

diff --git a/lib/efi_loader/efi_memory.c b/lib/efi_loader/efi_memory.c
index 55622d2fb4..dbe29b8960 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
  *
@@ -204,8 +229,8 @@ uint64_t efi_add_memory_map(uint64_t start, uint64_t pages, int memory_type,
 	bool carve_again;
 	uint64_t carved_pages = 0;
 
-	debug("%s: 0x%llx 0x%llx %d %s\n", __func__,
-	      start, pages, memory_type, overlap_only_ram ? "yes" : "no");
+	EFI_PRINT("%s: 0x%llx 0x%llx %d %s\n", __func__,
+		  start, pages, memory_type, overlap_only_ram ? "yes" : "no");
 
 	if (memory_type >= EFI_MAX_MEMORY_TYPE)
 		return EFI_INVALID_PARAMETER;
@@ -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);