If efi_random_alloc() fails, we still try to use EFI_KIMG_ALIGN
instead of MIN_KIMG_ALIGN to check the kernel image alignment,
which is incorrect, we need to fallback to MIN_KIMG_ALIGN (2M).
This removes the not-that-useful min_kimg_align helper and instead
uses the appropriate aligment in the respective call sites:
efi_random_alloc() always wants EFI_KIMG_ALIGN as this is only
used when kaslr is on, and all other cases go into alignment
check code which always need to check (and enforce) MIN_KIMG_ALIGN
Signed-off-by: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Fixes: 7c116db24d94 (efi/libstub/arm64: Retain 2MB kernel Image alignment if !KASLR)
---
drivers/firmware/efi/libstub/arm64-stub.c | 27 ++++++++++-------------
1 file changed, 12 insertions(+), 15 deletions(-)
diff --git a/drivers/firmware/efi/libstub/arm64-stub.c b/drivers/firmware/efi/libstub/arm64-stub.c
index 7bf0a7acae5e..e264ff90ba03 100644
--- a/drivers/firmware/efi/libstub/arm64-stub.c
+++ b/drivers/firmware/efi/libstub/arm64-stub.c
@@ -34,18 +34,6 @@ efi_status_t check_platform_features(void)
return EFI_SUCCESS;
}
-/*
- * Although relocatable kernels can fix up the misalignment with respect to
- * MIN_KIMG_ALIGN, the resulting virtual text addresses are subtly out of
- * sync with those recorded in the vmlinux when kaslr is disabled but the
- * image required relocation anyway. Therefore retain 2M alignment unless
- * KASLR is in use.
- */
-static u64 min_kimg_align(void)
-{
- return efi_nokaslr ? MIN_KIMG_ALIGN : EFI_KIMG_ALIGN;
-}
-
efi_status_t handle_kernel_image(unsigned long *image_addr,
unsigned long *image_size,
unsigned long *reserve_addr,
@@ -84,15 +72,24 @@ efi_status_t handle_kernel_image(unsigned long *image_addr,
/*
* If KASLR is enabled, and we have some randomness available,
* locate the kernel at a randomized offset in physical memory.
+ *
+ * In that case, we don't need to preserve the 2M alignment
*/
- status = efi_random_alloc(*reserve_size, min_kimg_align(),
+ status = efi_random_alloc(*reserve_size, EFI_KIMG_ALIGN,
reserve_addr, phys_seed);
} else {
status = EFI_OUT_OF_RESOURCES;
}
if (status != EFI_SUCCESS) {
- if (IS_ALIGNED((u64)_text, min_kimg_align())) {
+ /*
+ * Although relocatable kernels can fix up the misalignment with respect to
+ * MIN_KIMG_ALIGN, the resulting virtual text addresses are subtly out of
+ * sync with those recorded in the vmlinux when kaslr is disabled but the
+ * image required relocation anyway. Therefore retain 2M alignment unless
+ * KASLR is in use.
+ */
+ if (IS_ALIGNED((u64)_text, MIN_KIMG_ALIGN)) {
/*
* Just execute from wherever we were loaded by the
* UEFI PE/COFF loader if the alignment is suitable.
@@ -103,7 +100,7 @@ efi_status_t handle_kernel_image(unsigned long *image_addr,
}
status = efi_allocate_pages_aligned(*reserve_size, reserve_addr,
- ULONG_MAX, min_kimg_align());
+ ULONG_MAX, MIN_KIMG_ALIGN);
if (status != EFI_SUCCESS) {
efi_err("Failed to relocate kernel\n");
