efi_loader: Fix loaded image alignment
We are ignoring the alignment communicated via the PE/COFF header.
Starting 5.10 the Linux kernel will loudly complain about it. For more
details look at [1] (in linux kernel).
So add a function that can allocate aligned EFI memory and use it for our
relocated loaded image.
[1] c32ac11da3f83 ("efi/libstub: arm64: Double check image alignment at entry")
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Tested-by: Vincent Stehlé <vincent.stehle@arm.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
diff --git a/include/efi_loader.h b/include/efi_loader.h
index c440962..5cdc723 100644
--- a/include/efi_loader.h
+++ b/include/efi_loader.h
@@ -675,6 +675,8 @@
#define efi_size_in_pages(size) (((size) + EFI_PAGE_MASK) >> EFI_PAGE_SHIFT)
/* Generic EFI memory allocator, call this to get memory */
void *efi_alloc(uint64_t len, int memory_type);
+/* Allocate pages on the specified alignment */
+void *efi_alloc_aligned_pages(u64 len, int memory_type, size_t align);
/* More specific EFI memory allocator, called by EFI payloads */
efi_status_t efi_allocate_pages(enum efi_allocate_type type,
enum efi_memory_type memory_type,
diff --git a/lib/efi_loader/efi_image_loader.c b/lib/efi_loader/efi_image_loader.c
index e9572d4..eb95580 100644
--- a/lib/efi_loader/efi_image_loader.c
+++ b/lib/efi_loader/efi_image_loader.c
@@ -898,9 +898,9 @@
image_base = opt->ImageBase;
efi_set_code_and_data_type(loaded_image_info, opt->Subsystem);
handle->image_type = opt->Subsystem;
- virt_size = ALIGN(virt_size, opt->SectionAlignment);
- efi_reloc = efi_alloc(virt_size,
- loaded_image_info->image_code_type);
+ efi_reloc = efi_alloc_aligned_pages(virt_size,
+ loaded_image_info->image_code_type,
+ opt->SectionAlignment);
if (!efi_reloc) {
log_err("Out of memory\n");
ret = EFI_OUT_OF_RESOURCES;
@@ -914,9 +914,9 @@
image_base = opt->ImageBase;
efi_set_code_and_data_type(loaded_image_info, opt->Subsystem);
handle->image_type = opt->Subsystem;
- virt_size = ALIGN(virt_size, opt->SectionAlignment);
- efi_reloc = efi_alloc(virt_size,
- loaded_image_info->image_code_type);
+ efi_reloc = efi_alloc_aligned_pages(virt_size,
+ loaded_image_info->image_code_type,
+ opt->SectionAlignment);
if (!efi_reloc) {
log_err("Out of memory\n");
ret = EFI_OUT_OF_RESOURCES;
diff --git a/lib/efi_loader/efi_memory.c b/lib/efi_loader/efi_memory.c
index f4acbee..7f0b507 100644
--- a/lib/efi_loader/efi_memory.c
+++ b/lib/efi_loader/efi_memory.c
@@ -550,6 +550,58 @@
}
/**
+ * efi_alloc_aligned_pages - allocate
+ *
+ * @len: len in bytes
+ * @memory_type: usage type of the allocated memory
+ * @align: alignment in bytes
+ * Return: aligned memory or NULL
+ */
+void *efi_alloc_aligned_pages(u64 len, int memory_type, size_t align)
+{
+ u64 req_pages = efi_size_in_pages(len);
+ u64 true_pages = req_pages + efi_size_in_pages(align) - 1;
+ u64 free_pages;
+ u64 aligned_mem;
+ efi_status_t r;
+ u64 mem;
+
+ /* align must be zero or a power of two */
+ if (align & (align - 1))
+ return NULL;
+
+ /* Check for overflow */
+ if (true_pages < req_pages)
+ return NULL;
+
+ if (align < EFI_PAGE_SIZE) {
+ r = efi_allocate_pages(EFI_ALLOCATE_ANY_PAGES, memory_type,
+ req_pages, &mem);
+ return (r == EFI_SUCCESS) ? (void *)(uintptr_t)mem : NULL;
+ }
+
+ r = efi_allocate_pages(EFI_ALLOCATE_ANY_PAGES, memory_type,
+ true_pages, &mem);
+ if (r != EFI_SUCCESS)
+ return NULL;
+
+ aligned_mem = ALIGN(mem, align);
+ /* Free pages before alignment */
+ free_pages = efi_size_in_pages(aligned_mem - mem);
+ if (free_pages)
+ efi_free_pages(mem, free_pages);
+
+ /* Free trailing pages */
+ free_pages = true_pages - (req_pages + free_pages);
+ if (free_pages) {
+ mem = aligned_mem + req_pages * EFI_PAGE_SIZE;
+ efi_free_pages(mem, free_pages);
+ }
+
+ return (void *)(uintptr_t)aligned_mem;
+}
+
+/**
* efi_allocate_pool - allocate memory from pool
*
* @pool_type: type of the pool from which memory is to be allocated