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authorArd Biesheuvel <ard.biesheuvel@linaro.org>2015-10-29 15:07:25 +0100
committerWill Deacon <will.deacon@arm.com>2015-10-29 16:10:58 +0000
commit73effccb9196ccc0241c3fb51dfd8de1d14ae8ed (patch)
treeb5cc57b7c2930d53923b1edc704de3ff74df6231
parent9702970c7bd3e2d6fecb642a190269131d4ac16c (diff)
arm64/efi: do not assume DRAM base is aligned to 2 MB
The current arm64 Image relocation code in the UEFI stub assumes that the dram_base argument it receives is always a multiple of 2 MB. In reality, it is simply the lowest start address of all RAM entries in the UEFI memory map, which means it could be any multiple of 4 KB. Since the arm64 kernel Image needs to reside TEXT_OFFSET bytes beyond a 2 MB aligned base, or it will fail to boot, make sure we round dram_base to 2 MB before using it to calculate the relocation address. Fixes: e38457c361b30c5a ("arm64: efi: prefer AllocatePages() over efi_low_alloc() for vmlinux") Reported-by: Timur Tabi <timur@codeaurora.org> Tested-by: Timur Tabi <timur@codeaurora.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
-rw-r--r--arch/arm64/kernel/efi-stub.c14
1 files changed, 12 insertions, 2 deletions
diff --git a/arch/arm64/kernel/efi-stub.c b/arch/arm64/kernel/efi-stub.c
index 816120ece6bc..78dfbd34b6bf 100644
--- a/arch/arm64/kernel/efi-stub.c
+++ b/arch/arm64/kernel/efi-stub.c
@@ -25,10 +25,20 @@ efi_status_t __init handle_kernel_image(efi_system_table_t *sys_table_arg,
unsigned long kernel_size, kernel_memsize = 0;
unsigned long nr_pages;
void *old_image_addr = (void *)*image_addr;
+ unsigned long preferred_offset;
+
+ /*
+ * The preferred offset of the kernel Image is TEXT_OFFSET bytes beyond
+ * a 2 MB aligned base, which itself may be lower than dram_base, as
+ * long as the resulting offset equals or exceeds it.
+ */
+ preferred_offset = round_down(dram_base, SZ_2M) + TEXT_OFFSET;
+ if (preferred_offset < dram_base)
+ preferred_offset += SZ_2M;
/* Relocate the image, if required. */
kernel_size = _edata - _text;
- if (*image_addr != (dram_base + TEXT_OFFSET)) {
+ if (*image_addr != preferred_offset) {
kernel_memsize = kernel_size + (_end - _edata);
/*
@@ -42,7 +52,7 @@ efi_status_t __init handle_kernel_image(efi_system_table_t *sys_table_arg,
* Mustang), we can still place the kernel at the address
* 'dram_base + TEXT_OFFSET'.
*/
- *image_addr = *reserve_addr = dram_base + TEXT_OFFSET;
+ *image_addr = *reserve_addr = preferred_offset;
nr_pages = round_up(kernel_memsize, EFI_ALLOC_ALIGN) /
EFI_PAGE_SIZE;
status = efi_call_early(allocate_pages, EFI_ALLOCATE_ADDRESS,