Allow test programs to use the shadow stack helpers on arm64.
Signed-off-by: Mark Brown broonie@kernel.org --- tools/testing/selftests/ksft_shstk.h | 37 ++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+)
diff --git a/tools/testing/selftests/ksft_shstk.h b/tools/testing/selftests/ksft_shstk.h index 85d0747c1802..223e24b4eb80 100644 --- a/tools/testing/selftests/ksft_shstk.h +++ b/tools/testing/selftests/ksft_shstk.h @@ -50,6 +50,43 @@ static inline __attribute__((always_inline)) void enable_shadow_stack(void)
#endif
+#ifdef __aarch64__ +#define PR_SET_SHADOW_STACK_STATUS 72 +# define PR_SHADOW_STACK_ENABLE (1UL << 0) + +#define my_syscall2(num, arg1, arg2) \ +({ \ + register long _num __asm__ ("x8") = (num); \ + register long _arg1 __asm__ ("x0") = (long)(arg1); \ + register long _arg2 __asm__ ("x1") = (long)(arg2); \ + register long _arg3 __asm__ ("x2") = 0; \ + register long _arg4 __asm__ ("x3") = 0; \ + register long _arg5 __asm__ ("x4") = 0; \ + \ + __asm__ volatile ( \ + "svc #0\n" \ + : "=r"(_arg1) \ + : "r"(_arg1), "r"(_arg2), \ + "r"(_arg3), "r"(_arg4), \ + "r"(_arg5), "r"(_num) \ + : "memory", "cc" \ + ); \ + _arg1; \ +}) + +#define ENABLE_SHADOW_STACK +static inline __attribute__((always_inline)) void enable_shadow_stack(void) +{ + int ret; + + ret = my_syscall2(__NR_prctl, PR_SET_SHADOW_STACK_STATUS, + PR_SHADOW_STACK_ENABLE); + if (ret == 0) + shadow_stack_enabled = true; +} + +#endif + #ifndef __NR_map_shadow_stack #define __NR_map_shadow_stack 453 #endif