#include "efistub.h"
+bool __nokaslr;
+
static int efi_secureboot_enabled(efi_system_table_t *sys_table_arg)
{
static efi_guid_t const var_guid = EFI_GLOBAL_VARIABLE_GUID;
pr_efi_err(sys_table, "Failed to find DRAM base\n");
goto fail;
}
- status = handle_kernel_image(sys_table, image_addr, &image_size,
- &reserve_addr,
- &reserve_size,
- dram_base, image);
- if (status != EFI_SUCCESS) {
- pr_efi_err(sys_table, "Failed to relocate kernel\n");
- goto fail;
- }
/*
* Get the command line from EFI, using the LOADED_IMAGE
cmdline_ptr = efi_convert_cmdline(sys_table, image, &cmdline_size);
if (!cmdline_ptr) {
pr_efi_err(sys_table, "getting command line via LOADED_IMAGE_PROTOCOL\n");
- goto fail_free_image;
+ goto fail;
+ }
+
+ /* check whether 'nokaslr' was passed on the command line */
+ if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) {
+ static const u8 default_cmdline[] = CONFIG_CMDLINE;
+ const u8 *str, *cmdline = cmdline_ptr;
+
+ if (IS_ENABLED(CONFIG_CMDLINE_FORCE))
+ cmdline = default_cmdline;
+ str = strstr(cmdline, "nokaslr");
+ if (str == cmdline || (str > cmdline && *(str - 1) == ' '))
+ __nokaslr = true;
+ }
+
+ status = handle_kernel_image(sys_table, image_addr, &image_size,
+ &reserve_addr,
+ &reserve_size,
+ dram_base, image);
+ if (status != EFI_SUCCESS) {
+ pr_efi_err(sys_table, "Failed to relocate kernel\n");
+ goto fail_free_cmdline;
}
status = efi_parse_options(cmdline_ptr);
if (status != EFI_SUCCESS) {
pr_efi_err(sys_table, "Failed to load device tree!\n");
- goto fail_free_cmdline;
+ goto fail_free_image;
}
}
efi_free(sys_table, initrd_size, initrd_addr);
efi_free(sys_table, fdt_size, fdt_addr);
-fail_free_cmdline:
- efi_free(sys_table, cmdline_size, (unsigned long)cmdline_ptr);
-
fail_free_image:
efi_free(sys_table, image_size, *image_addr);
efi_free(sys_table, reserve_size, reserve_addr);
+fail_free_cmdline:
+ efi_free(sys_table, cmdline_size, (unsigned long)cmdline_ptr);
fail:
return EFI_ERROR;
}
#include <asm/efi.h>
#include <asm/sections.h>
+#include "efistub.h"
+
+extern bool __nokaslr;
+
efi_status_t __init handle_kernel_image(efi_system_table_t *sys_table_arg,
unsigned long *image_addr,
unsigned long *image_size,
{
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
* 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;
}
projects / firefly-linux-kernel-4.4.55.git / commitdiff