diff options
Diffstat (limited to 'tools/testing/selftests/arm64/signal/test_signals_utils.h')
| -rw-r--r-- | tools/testing/selftests/arm64/signal/test_signals_utils.h | 73 |
1 files changed, 70 insertions, 3 deletions
diff --git a/tools/testing/selftests/arm64/signal/test_signals_utils.h b/tools/testing/selftests/arm64/signal/test_signals_utils.h index 6772b5c8d274..36fc12b3cd60 100644 --- a/tools/testing/selftests/arm64/signal/test_signals_utils.h +++ b/tools/testing/selftests/arm64/signal/test_signals_utils.h @@ -6,8 +6,11 @@ #include <assert.h> #include <stdio.h> +#include <stdint.h> #include <string.h> +#include <linux/compiler.h> + #include "test_signals.h" int test_init(struct tdescr *td); @@ -16,8 +19,48 @@ void test_cleanup(struct tdescr *td); int test_run(struct tdescr *td); void test_result(struct tdescr *td); +#ifndef __NR_prctl +#define __NR_prctl 167 +#endif + +/* + * The prctl takes 1 argument but we need to ensure that the other + * values passed in registers to the syscall are zero since the kernel + * validates them. + */ +#define gcs_set_state(state) \ + ({ \ + register long _num __asm__ ("x8") = __NR_prctl; \ + register long _arg1 __asm__ ("x0") = PR_SET_SHADOW_STACK_STATUS; \ + register long _arg2 __asm__ ("x1") = (long)(state); \ + 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; \ + }) + +static inline __attribute__((always_inline)) uint64_t get_gcspr_el0(void) +{ + uint64_t val; + + asm volatile("mrs %0, S3_3_C2_C5_1" : "=r" (val)); + + return val; +} + static inline bool feats_ok(struct tdescr *td) { + if (td->feats_incompatible & td->feats_supported) + return false; return (td->feats_required & td->feats_supported) == td->feats_required; } @@ -54,16 +97,29 @@ static inline bool feats_ok(struct tdescr *td) * at sizeof(ucontext_t). */ static __always_inline bool get_current_context(struct tdescr *td, - ucontext_t *dest_uc) + ucontext_t *dest_uc, + size_t dest_sz) { static volatile bool seen_already; + int i; + char *uc = (char *)dest_uc; assert(td && dest_uc); /* it's a genuine invocation..reinit */ seen_already = 0; td->live_uc_valid = 0; - td->live_sz = sizeof(*dest_uc); - memset(dest_uc, 0x00, td->live_sz); + td->live_sz = dest_sz; + + /* + * This is a memset() but we don't want the compiler to + * optimise it into either instructions or a library call + * which might be incompatible with streaming mode. + */ + for (i = 0; i < td->live_sz; i++) { + uc[i] = 0; + OPTIMIZER_HIDE_VAR(uc[0]); + } + td->live_uc = dest_uc; /* * Grab ucontext_t triggering a SIGTRAP. @@ -101,6 +157,17 @@ static __always_inline bool get_current_context(struct tdescr *td, : "memory"); /* + * If we were grabbing a streaming mode context then we may + * have entered streaming mode behind the system's back and + * libc or compiler generated code might decide to do + * something invalid in streaming mode, or potentially even + * the state of ZA. Issue a SMSTOP to exit both now we have + * grabbed the state. + */ + if (td->feats_supported & FEAT_SME) + asm volatile("msr S0_3_C4_C6_3, xzr"); + + /* * If we get here with seen_already==1 it implies the td->live_uc * context has been used to get back here....this probably means * a test has failed to cause a SEGV...anyway live_uc does not |