diff options
Diffstat (limited to 'lib/stack_protector/aarch32/asm_stack_protector.S')
| -rw-r--r-- | lib/stack_protector/aarch32/asm_stack_protector.S | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/lib/stack_protector/aarch32/asm_stack_protector.S b/lib/stack_protector/aarch32/asm_stack_protector.S new file mode 100644 index 0000000..19b7525 --- /dev/null +++ b/lib/stack_protector/aarch32/asm_stack_protector.S @@ -0,0 +1,34 @@ +/* + * Copyright (c) 2017, ARM Limited and Contributors. All rights reserved. + * + * SPDX-License-Identifier: BSD-3-Clause + */ + +#include <arch.h> +#include <asm_macros.S> +#include <assert_macros.S> + + .globl update_stack_protector_canary + +/* ----------------------------------------------------------------------- + * void update_stack_protector_canary(void) + * + * Change the value of the canary used for stack smashing attacks protection. + * Note: This must be called when it is safe to call C code, but this cannot be + * called by C code. Doing this will make the check fail when the calling + * function returns. + * ----------------------------------------------------------------------- + */ + +func update_stack_protector_canary + /* Use r4 as it is callee-saved */ + mov r4, lr + bl plat_get_stack_protector_canary + + /* Update the canary with the returned value */ + ldr r1, =__stack_chk_guard + str r0, [r1] + bx r4 +endfunc update_stack_protector_canary + + |