diff options
| author | Mao Han | 2019-10-11 10:56:55 +0800 |
|---|---|---|
| committer | Guo Ren | 2020-02-21 15:43:24 +0800 |
| commit | 2f78c73f78c39dabc5c44ad8dd61fd6ec65636d6 (patch) | |
| tree | b9ba43f4bb9d709d612c77b3ed4c260a204a2d38 | |
| parent | fd1d98650ac0042d475155116e65fd17eb379542 (diff) | |
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 <han_mao@c-sky.com>
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
| -rw-r--r-- | arch/csky/Kconfig | 1 | ||||
| -rw-r--r-- | arch/csky/include/asm/stackprotector.h | 29 | ||||
| -rw-r--r-- | arch/csky/kernel/process.c | 6 |
3 files changed, 36 insertions, 0 deletions
diff --git a/arch/csky/Kconfig b/arch/csky/Kconfig index da09c884cc30..ea7f3b890d03 100644 --- a/arch/csky/Kconfig +++ b/arch/csky/Kconfig @@ -49,6 +49,7 @@ config CSKY select HAVE_PERF_USER_STACK_DUMP select HAVE_DMA_API_DEBUG select HAVE_DMA_CONTIGUOUS + select HAVE_STACKPROTECTOR select HAVE_SYSCALL_TRACEPOINTS select MAY_HAVE_SPARSE_IRQ select MODULES_USE_ELF_RELA if MODULES 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 <linux/random.h> +#include <linux/version.h> + +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 */ diff --git a/arch/csky/kernel/process.c b/arch/csky/kernel/process.c index f320d9248a22..5349cd8c0f30 100644 --- a/arch/csky/kernel/process.c +++ b/arch/csky/kernel/process.c @@ -16,6 +16,12 @@ struct cpuinfo_csky cpu_data[NR_CPUS]; +#ifdef CONFIG_STACKPROTECTOR +#include <linux/stackprotector.h> +unsigned long __stack_chk_guard __read_mostly; +EXPORT_SYMBOL(__stack_chk_guard); +#endif + asmlinkage void ret_from_fork(void); asmlinkage void ret_from_kernel_thread(void); |