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path: root/drivers/firmware/efi/libstub/arm64-stub.c
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Diffstat (limited to 'drivers/firmware/efi/libstub/arm64-stub.c')
-rw-r--r--drivers/firmware/efi/libstub/arm64-stub.c112
1 files changed, 83 insertions, 29 deletions
diff --git a/drivers/firmware/efi/libstub/arm64-stub.c b/drivers/firmware/efi/libstub/arm64-stub.c
index 78dfbd34b..a90f6459f 100644
--- a/drivers/firmware/efi/libstub/arm64-stub.c
+++ b/drivers/firmware/efi/libstub/arm64-stub.c
@@ -12,37 +12,87 @@
#include <linux/efi.h>
#include <asm/efi.h>
#include <asm/sections.h>
+#include <asm/sysreg.h>
-efi_status_t __init handle_kernel_image(efi_system_table_t *sys_table_arg,
- unsigned long *image_addr,
- unsigned long *image_size,
- unsigned long *reserve_addr,
- unsigned long *reserve_size,
- unsigned long dram_base,
- efi_loaded_image_t *image)
+#include "efistub.h"
+
+extern bool __nokaslr;
+
+efi_status_t check_platform_features(efi_system_table_t *sys_table_arg)
+{
+ u64 tg;
+
+ /* UEFI mandates support for 4 KB granularity, no need to check */
+ if (IS_ENABLED(CONFIG_ARM64_4K_PAGES))
+ return EFI_SUCCESS;
+
+ tg = (read_cpuid(ID_AA64MMFR0_EL1) >> ID_AA64MMFR0_TGRAN_SHIFT) & 0xf;
+ if (tg != ID_AA64MMFR0_TGRAN_SUPPORTED) {
+ if (IS_ENABLED(CONFIG_ARM64_64K_PAGES))
+ pr_efi_err(sys_table_arg, "This 64 KB granular kernel is not supported by your CPU\n");
+ else
+ pr_efi_err(sys_table_arg, "This 16 KB granular kernel is not supported by your CPU\n");
+ return EFI_UNSUPPORTED;
+ }
+ return EFI_SUCCESS;
+}
+
+efi_status_t handle_kernel_image(efi_system_table_t *sys_table_arg,
+ unsigned long *image_addr,
+ unsigned long *image_size,
+ unsigned long *reserve_addr,
+ unsigned long *reserve_size,
+ unsigned long dram_base,
+ efi_loaded_image_t *image)
{
efi_status_t status;
unsigned long kernel_size, kernel_memsize = 0;
- unsigned long nr_pages;
void *old_image_addr = (void *)*image_addr;
unsigned long preferred_offset;
+ u64 phys_seed = 0;
+
+ if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) {
+ if (!__nokaslr) {
+ status = efi_get_random_bytes(sys_table_arg,
+ sizeof(phys_seed),
+ (u8 *)&phys_seed);
+ if (status == EFI_NOT_FOUND) {
+ pr_efi(sys_table_arg, "EFI_RNG_PROTOCOL unavailable, no randomness supplied\n");
+ } else if (status != EFI_SUCCESS) {
+ pr_efi_err(sys_table_arg, "efi_get_random_bytes() failed\n");
+ return status;
+ }
+ } else {
+ pr_efi(sys_table_arg, "KASLR disabled on kernel command line\n");
+ }
+ }
/*
* 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;
+ preferred_offset = round_down(dram_base, MIN_KIMG_ALIGN) + TEXT_OFFSET;
if (preferred_offset < dram_base)
- preferred_offset += SZ_2M;
+ preferred_offset += MIN_KIMG_ALIGN;
- /* Relocate the image, if required. */
kernel_size = _edata - _text;
- if (*image_addr != preferred_offset) {
- kernel_memsize = kernel_size + (_end - _edata);
+ kernel_memsize = kernel_size + (_end - _edata);
+
+ if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && phys_seed != 0) {
+ /*
+ * If KASLR is enabled, and we have some randomness available,
+ * locate the kernel at a randomized offset in physical memory.
+ */
+ *reserve_size = kernel_memsize + TEXT_OFFSET;
+ status = efi_random_alloc(sys_table_arg, *reserve_size,
+ MIN_KIMG_ALIGN, reserve_addr,
+ phys_seed);
+ *image_addr = *reserve_addr + TEXT_OFFSET;
+ } else {
/*
- * First, try a straight allocation at the preferred offset.
+ * Else, try a straight allocation at the preferred offset.
* This will work around the issue where, if dram_base == 0x0,
* efi_low_alloc() refuses to allocate at 0x0 (to prevent the
* address of the allocation to be mistaken for a FAIL return
@@ -52,27 +102,31 @@ 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'.
*/
+ if (*image_addr == preferred_offset)
+ return EFI_SUCCESS;
+
*image_addr = *reserve_addr = preferred_offset;
- nr_pages = round_up(kernel_memsize, EFI_ALLOC_ALIGN) /
- EFI_PAGE_SIZE;
+ *reserve_size = round_up(kernel_memsize, EFI_ALLOC_ALIGN);
+
status = efi_call_early(allocate_pages, EFI_ALLOCATE_ADDRESS,
- EFI_LOADER_DATA, nr_pages,
+ EFI_LOADER_DATA,
+ *reserve_size / EFI_PAGE_SIZE,
(efi_physical_addr_t *)reserve_addr);
- if (status != EFI_SUCCESS) {
- kernel_memsize += TEXT_OFFSET;
- status = efi_low_alloc(sys_table_arg, kernel_memsize,
- SZ_2M, reserve_addr);
+ }
- if (status != EFI_SUCCESS) {
- pr_efi_err(sys_table_arg, "Failed to relocate kernel\n");
- return status;
- }
- *image_addr = *reserve_addr + TEXT_OFFSET;
+ if (status != EFI_SUCCESS) {
+ *reserve_size = kernel_memsize + TEXT_OFFSET;
+ status = efi_low_alloc(sys_table_arg, *reserve_size,
+ MIN_KIMG_ALIGN, reserve_addr);
+
+ if (status != EFI_SUCCESS) {
+ pr_efi_err(sys_table_arg, "Failed to relocate kernel\n");
+ *reserve_size = 0;
+ return status;
}
- memcpy((void *)*image_addr, old_image_addr, kernel_size);
- *reserve_size = kernel_memsize;
+ *image_addr = *reserve_addr + TEXT_OFFSET;
}
-
+ memcpy((void *)*image_addr, old_image_addr, kernel_size);
return EFI_SUCCESS;
}