From 8ced928019353eaecbffee566d7ed6a9a9e60e78 Mon Sep 17 00:00:00 2001 From: Mark Brown Date: Tue, 27 Dec 2022 14:20:43 +0000 Subject: [PATCH] kselftest/arm64: Add test case for TPIDR2 signal frame records Ensure that we get signal context for TPIDR2 if and only if SME is present on the system. Since TPIDR2 is owned by libc we merely validate that the value is whatever it was set to, this isn't ideal since it's likely to just be the default of 0 with current systems but it avoids future false positives. Signed-off-by: Mark Brown Link: https://lore.kernel.org/r/20221208-arm64-tpidr2-sig-v3-4-c77c6c8775f4@kernel.org Signed-off-by: Catalin Marinas --- .../testing/selftests/arm64/signal/.gitignore | 1 + .../arm64/signal/testcases/tpidr2_siginfo.c | 90 +++++++++++++++++++ 2 files changed, 91 insertions(+) create mode 100644 tools/testing/selftests/arm64/signal/testcases/tpidr2_siginfo.c diff --git a/tools/testing/selftests/arm64/signal/.gitignore b/tools/testing/selftests/arm64/signal/.gitignore index e8d2b57f73ec1..e1b6c4d961b57 100644 --- a/tools/testing/selftests/arm64/signal/.gitignore +++ b/tools/testing/selftests/arm64/signal/.gitignore @@ -4,5 +4,6 @@ fake_sigreturn_* sme_* ssve_* sve_* +tpidr2_siginfo za_* !*.[ch] diff --git a/tools/testing/selftests/arm64/signal/testcases/tpidr2_siginfo.c b/tools/testing/selftests/arm64/signal/testcases/tpidr2_siginfo.c new file mode 100644 index 0000000000000..6a2c82bf7ead1 --- /dev/null +++ b/tools/testing/selftests/arm64/signal/testcases/tpidr2_siginfo.c @@ -0,0 +1,90 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2022 ARM Limited + * + * Verify that the TPIDR2 register context in signal frames is set up as + * expected. + */ + +#include +#include +#include +#include +#include +#include + +#include "test_signals_utils.h" +#include "testcases.h" + +static union { + ucontext_t uc; + char buf[1024 * 128]; +} context; + +#define SYS_TPIDR2 "S3_3_C13_C0_5" + +static uint64_t get_tpidr2(void) +{ + uint64_t val; + + asm volatile ( + "mrs %0, " SYS_TPIDR2 "\n" + : "=r"(val) + : + : "cc"); + + return val; +} + +int tpidr2_present(struct tdescr *td, siginfo_t *si, ucontext_t *uc) +{ + struct _aarch64_ctx *head = GET_BUF_RESV_HEAD(context); + struct tpidr2_context *tpidr2_ctx; + size_t offset; + bool in_sigframe; + bool have_sme; + __u64 orig_tpidr2; + + have_sme = getauxval(AT_HWCAP2) & HWCAP2_SME; + if (have_sme) + orig_tpidr2 = get_tpidr2(); + + if (!get_current_context(td, &context.uc, sizeof(context))) + return 1; + + tpidr2_ctx = (struct tpidr2_context *) + get_header(head, TPIDR2_MAGIC, td->live_sz, &offset); + + in_sigframe = tpidr2_ctx != NULL; + + fprintf(stderr, "TPIDR2 sigframe %s on system %s SME\n", + in_sigframe ? "present" : "absent", + have_sme ? "with" : "without"); + + td->pass = (in_sigframe == have_sme); + + /* + * Check that the value we read back was the one present at + * the time that the signal was triggered. TPIDR2 is owned by + * libc so we can't safely choose the value and it is possible + * that we may need to revisit this in future if something + * starts deciding to set a new TPIDR2 between us reading and + * the signal. + */ + if (have_sme && tpidr2_ctx) { + if (tpidr2_ctx->tpidr2 != orig_tpidr2) { + fprintf(stderr, "TPIDR2 in frame is %llx, was %llx\n", + tpidr2_ctx->tpidr2, orig_tpidr2); + td->pass = false; + } + } + + return 0; +} + +struct tdescr tde = { + .name = "TPIDR2", + .descr = "Validate that TPIDR2 is present as expected", + .timeout = 3, + .run = tpidr2_present, +}; -- 2.30.2