diff options
| -rw-r--r-- | Documentation/features/debug/stackprotector/arch-support.txt | 2 | ||||
| -rw-r--r-- | arch/xtensa/Kconfig | 1 | ||||
| -rw-r--r-- | arch/xtensa/boot/lib/Makefile | 4 | ||||
| -rw-r--r-- | arch/xtensa/include/asm/stackprotector.h | 40 | ||||
| -rw-r--r-- | arch/xtensa/kernel/asm-offsets.c | 3 | ||||
| -rw-r--r-- | arch/xtensa/kernel/entry.S | 6 | ||||
| -rw-r--r-- | arch/xtensa/kernel/process.c | 6 |
7 files changed, 61 insertions, 1 deletions
diff --git a/Documentation/features/debug/stackprotector/arch-support.txt b/Documentation/features/debug/stackprotector/arch-support.txt index d7acd7bd3619..59a4c9ffb7f3 100644 --- a/Documentation/features/debug/stackprotector/arch-support.txt +++ b/Documentation/features/debug/stackprotector/arch-support.txt @@ -35,5 +35,5 @@ | um: | TODO | | unicore32: | TODO | | x86: | ok | - | xtensa: | TODO | + | xtensa: | ok | ----------------------- diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig index eb1f196c3f6e..fffe05b698ac 100644 --- a/arch/xtensa/Kconfig +++ b/arch/xtensa/Kconfig @@ -15,6 +15,7 @@ config XTENSA select GENERIC_IRQ_SHOW select GENERIC_PCI_IOMAP select GENERIC_SCHED_CLOCK + select HAVE_CC_STACKPROTECTOR select HAVE_DEBUG_KMEMLEAK select HAVE_DMA_API_DEBUG select HAVE_DMA_CONTIGUOUS diff --git a/arch/xtensa/boot/lib/Makefile b/arch/xtensa/boot/lib/Makefile index d2a7f48564a4..2fe182915b63 100644 --- a/arch/xtensa/boot/lib/Makefile +++ b/arch/xtensa/boot/lib/Makefile @@ -15,6 +15,10 @@ CFLAGS_REMOVE_inftrees.o = -pg CFLAGS_REMOVE_inffast.o = -pg endif +CFLAGS_REMOVE_inflate.o += -fstack-protector -fstack-protector-strong +CFLAGS_REMOVE_zmem.o += -fstack-protector -fstack-protector-strong +CFLAGS_REMOVE_inftrees.o += -fstack-protector -fstack-protector-strong +CFLAGS_REMOVE_inffast.o += -fstack-protector -fstack-protector-strong quiet_cmd_copy_zlib = COPY $@ cmd_copy_zlib = cat $< > $@ diff --git a/arch/xtensa/include/asm/stackprotector.h b/arch/xtensa/include/asm/stackprotector.h new file mode 100644 index 000000000000..e368f94fd2af --- /dev/null +++ b/arch/xtensa/include/asm/stackprotector.h @@ -0,0 +1,40 @@ +/* + * GCC stack protector support. + * + * (This is directly adopted from the ARM implementation) + * + * Stack protector works by putting predefined pattern at the start of + * the stack frame and verifying that it hasn't been overwritten when + * returning from the function. The pattern is called stack canary + * and gcc expects it to be defined by a global variable called + * "__stack_chk_guard" on Xtensa. This unfortunately means that on SMP + * we cannot have a different canary value per task. + */ + +#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; + + current->stack_canary = canary; + __stack_chk_guard = current->stack_canary; +} + +#endif /* _ASM_STACKPROTECTOR_H */ diff --git a/arch/xtensa/kernel/asm-offsets.c b/arch/xtensa/kernel/asm-offsets.c index bcb5beb81177..3b119b372efd 100644 --- a/arch/xtensa/kernel/asm-offsets.c +++ b/arch/xtensa/kernel/asm-offsets.c @@ -76,6 +76,9 @@ int main(void) DEFINE(TASK_PID, offsetof (struct task_struct, pid)); DEFINE(TASK_THREAD, offsetof (struct task_struct, thread)); DEFINE(TASK_THREAD_INFO, offsetof (struct task_struct, stack)); +#ifdef CONFIG_CC_STACKPROTECTOR + DEFINE(TASK_STACK_CANARY, offsetof(struct task_struct, stack_canary)); +#endif DEFINE(TASK_STRUCT_SIZE, sizeof (struct task_struct)); /* offsets in thread_info struct */ diff --git a/arch/xtensa/kernel/entry.S b/arch/xtensa/kernel/entry.S index a27a9a65635b..5caff0744f3c 100644 --- a/arch/xtensa/kernel/entry.S +++ b/arch/xtensa/kernel/entry.S @@ -1971,6 +1971,12 @@ ENTRY(_switch_to) s32i a1, a2, THREAD_SP # save stack pointer #endif +#if defined(CONFIG_CC_STACKPROTECTOR) && !defined(CONFIG_SMP) + movi a6, __stack_chk_guard + l32i a8, a3, TASK_STACK_CANARY + s32i a8, a6, 0 +#endif + /* Disable ints while we manipulate the stack pointer. */ irq_save a14, a3 diff --git a/arch/xtensa/kernel/process.c b/arch/xtensa/kernel/process.c index ff4f0ecb03dd..8dd0593fb2c4 100644 --- a/arch/xtensa/kernel/process.c +++ b/arch/xtensa/kernel/process.c @@ -58,6 +58,12 @@ void (*pm_power_off)(void) = NULL; EXPORT_SYMBOL(pm_power_off); +#ifdef CONFIG_CC_STACKPROTECTOR +#include <linux/stackprotector.h> +unsigned long __stack_chk_guard __read_mostly; +EXPORT_SYMBOL(__stack_chk_guard); +#endif + #if XTENSA_HAVE_COPROCESSORS void coprocessor_release_all(struct thread_info *ti) |