kselftest/arm64: Add test case for POR_EL0 signal frame records

Ensure that we get signal context for POR_EL0 if and only if POE is present
on the system.

Copied from the TPIDR2 test.

Signed-off-by: Joey Gouly <joey.gouly@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Link: https://lore.kernel.org/r/20240822151113.1479789-30-joey.gouly@arm.com
Signed-off-by: Will Deacon <will@kernel.org>

diff --git a/tools/testing/selftests/arm64/signal/.gitignore b/tools/testing/selftests/arm64/signal/.gitignore
index 1ce5b5eac386654a41e39e0b80709eaa1e11fc78..b2f2bfd5c6aa1ad8330c7ea27cad377218690ca2 100644 (file)
--- a/tools/testing/selftests/arm64/signal/.gitignore
+++ b/tools/testing/selftests/arm64/signal/.gitignore
@@ -2,6 +2,7 @@
 mangle_*
 fake_sigreturn_*
 fpmr_*
+poe_*
 sme_*
 ssve_*
 sve_*

diff --git a/tools/testing/selftests/arm64/signal/testcases/poe_siginfo.c b/tools/testing/selftests/arm64/signal/testcases/poe_siginfo.c
new file mode 100644 (file)
index 0000000..36bd994
--- /dev/null
+++ b/tools/testing/selftests/arm64/signal/testcases/poe_siginfo.c
@@ -0,0 +1,86 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2023 Arm Limited
+ *
+ * Verify that the POR_EL0 register context in signal frames is set up as
+ * expected.
+ */
+
+#include <signal.h>
+#include <ucontext.h>
+#include <sys/auxv.h>
+#include <sys/prctl.h>
+#include <unistd.h>
+#include <asm/sigcontext.h>
+
+#include "test_signals_utils.h"
+#include "testcases.h"
+
+static union {
+       ucontext_t uc;
+       char buf[1024 * 128];
+} context;
+
+#define SYS_POR_EL0 "S3_3_C10_C2_4"
+
+static uint64_t get_por_el0(void)
+{
+       uint64_t val;
+
+       asm volatile(
+               "mrs    %0, " SYS_POR_EL0 "\n"
+               : "=r"(val)
+               :
+               : );
+
+       return val;
+}
+
+int poe_present(struct tdescr *td, siginfo_t *si, ucontext_t *uc)
+{
+       struct _aarch64_ctx *head = GET_BUF_RESV_HEAD(context);
+       struct poe_context *poe_ctx;
+       size_t offset;
+       bool in_sigframe;
+       bool have_poe;
+       __u64 orig_poe;
+
+       have_poe = getauxval(AT_HWCAP2) & HWCAP2_POE;
+       if (have_poe)
+               orig_poe = get_por_el0();
+
+       if (!get_current_context(td, &context.uc, sizeof(context)))
+               return 1;
+
+       poe_ctx = (struct poe_context *)
+               get_header(head, POE_MAGIC, td->live_sz, &offset);
+
+       in_sigframe = poe_ctx != NULL;
+
+       fprintf(stderr, "POR_EL0 sigframe %s on system %s POE\n",
+               in_sigframe ? "present" : "absent",
+               have_poe ? "with" : "without");
+
+       td->pass = (in_sigframe == have_poe);
+
+       /*
+        * Check that the value we read back was the one present at
+        * the time that the signal was triggered.
+        */
+       if (have_poe && poe_ctx) {
+               if (poe_ctx->por_el0 != orig_poe) {
+                       fprintf(stderr, "POR_EL0 in frame is %llx, was %llx\n",
+                               poe_ctx->por_el0, orig_poe);
+                       td->pass = false;
+               }
+       }
+
+       return 0;
+}
+
+struct tdescr tde = {
+       .name = "POR_EL0",
+       .descr = "Validate that POR_EL0 is present as expected",
+       .timeout = 3,
+       .run = poe_present,
+};