From 2f78c73f78c39dabc5c44ad8dd61fd6ec65636d6 Mon Sep 17 00:00:00 2001 From: Mao Han Date: Fri, 11 Oct 2019 10:56:55 +0800 Subject: csky: Initial stack protector support This is a basic -fstack-protector support without per-task canary switching. The protector will report something like when stack corruption is detected: It's tested with strcpy local array overflow in sys_kill and get: stack-protector: Kernel stack is corrupted in: sys_kill+0x23c/0x23c TODO: - Support task switch for different cannary Signed-off-by: Mao Han Signed-off-by: Guo Ren --- arch/csky/include/asm/stackprotector.h | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) create mode 100644 arch/csky/include/asm/stackprotector.h (limited to 'arch/csky/include/asm/stackprotector.h') diff --git a/arch/csky/include/asm/stackprotector.h b/arch/csky/include/asm/stackprotector.h new file mode 100644 index 000000000000..d7cd4e51edd9 --- /dev/null +++ b/arch/csky/include/asm/stackprotector.h @@ -0,0 +1,29 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_STACKPROTECTOR_H +#define _ASM_STACKPROTECTOR_H 1 + +#include +#include + +extern unsigned long __stack_chk_guard; + +/* + * Initialize the stackprotector canary value. + * + * NOTE: this must only be called from functions that never return, + * and it must always be inlined. + */ +static __always_inline void boot_init_stack_canary(void) +{ + unsigned long canary; + + /* Try to get a semi random initial value. */ + get_random_bytes(&canary, sizeof(canary)); + canary ^= LINUX_VERSION_CODE; + canary &= CANARY_MASK; + + current->stack_canary = canary; + __stack_chk_guard = current->stack_canary; +} + +#endif /* __ASM_SH_STACKPROTECTOR_H */ -- cgit v1.2.3