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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
commit4352b8aee98005853aa63f57d6377282de17a33f (patch)
tree27614d7a9ef05c32d089004e104364ce42324837 /tools/perf/tests/sigtrap.c
downloadlinux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz
linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni: "A new driver this cycle, for the AMD AXI I3C controller. There are also new features such as IBI wakeup support, SETAASA device discovery and ACPI support for the the DAA methods, meaning we can now communicate with the SPD devices on DDR5 modules. New driver: - AMD AXI I3C master controller Subsystem: - I3C Common Command Code (CCC) handling improvements, especially around GET CCCs - SETAASA device discovery support - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as well as I2C devices on I3C bus - IBI-based wakeup support Drivers: - dw: SETAASA support - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C controller support, PIO queue management support for HCI v1.2 - renesas: improve suspend to RAM support, add runtime PM support" * tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits) i3c: dw: reduce do_daa time if there's no client i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2 i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode i3c: dw: rename "pclk" to "apb" to match dt-binding i3c: dw: make struct dw_i3c_cmd smaller i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding i3c: renesas: Don't register devices when ENTDAA times out i3c: master: dw-i3c-master: fix OD timing for first broadcast i3c: mipi-i3c-hci: Advertise IBI wakeup capability i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev() i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI i3c: master: Reject IBI requests from non-IBI-capable devices i3c: master: Add helper to query bus wakeup requirements i3c: master: Report wakeup events for IBIs i3c: master: Support IBI-based wakeup capability i3c: master: Fix potential UAF in i3c_device_match() i3c: master: Fix potential UAF in i3c_device_uevent() i3c: Make dev->desc locking assumptions explicit i3c: master: Fix use-after-free of master->this ...
Diffstat (limited to 'tools/perf/tests/sigtrap.c')
-rw-r--r--tools/perf/tests/sigtrap.c275
1 files changed, 275 insertions, 0 deletions
diff --git a/tools/perf/tests/sigtrap.c b/tools/perf/tests/sigtrap.c
new file mode 100644
index 000000000..a67c756f9
--- /dev/null
+++ b/tools/perf/tests/sigtrap.c
@@ -0,0 +1,275 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Basic test for sigtrap support.
+ *
+ * Copyright (C) 2021, Google LLC.
+ */
+
+#include <errno.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <linux/hw_breakpoint.h>
+#include <linux/string.h>
+#include <pthread.h>
+#include <signal.h>
+#include <sys/ioctl.h>
+#include <sys/syscall.h>
+#include <unistd.h>
+
+#include "cloexec.h"
+#include "debug.h"
+#include "event.h"
+#include "tests.h"
+#include "../perf-sys.h"
+
+#define NUM_THREADS 5
+
+static struct {
+ int tids_want_signal; /* Which threads still want a signal. */
+ int signal_count; /* Sanity check number of signals received. */
+ volatile int iterate_on; /* Variable to set breakpoint on. */
+ siginfo_t first_siginfo; /* First observed siginfo_t. */
+} ctx;
+
+#define TEST_SIG_DATA (~(unsigned long)(&ctx.iterate_on))
+
+static struct perf_event_attr make_event_attr(void)
+{
+ struct perf_event_attr attr = {
+ .type = PERF_TYPE_BREAKPOINT,
+ .size = sizeof(attr),
+ .sample_period = 1,
+ .disabled = 1,
+ .bp_addr = (unsigned long)&ctx.iterate_on,
+ .bp_type = HW_BREAKPOINT_RW,
+ .bp_len = HW_BREAKPOINT_LEN_1,
+ .inherit = 1, /* Children inherit events ... */
+ .inherit_thread = 1, /* ... but only cloned with CLONE_THREAD. */
+ .remove_on_exec = 1, /* Required by sigtrap. */
+ .sigtrap = 1, /* Request synchronous SIGTRAP on event. */
+ .sig_data = TEST_SIG_DATA,
+ .exclude_kernel = 1, /* To allow */
+ .exclude_hv = 1, /* running as !root */
+ };
+ return attr;
+}
+
+#ifdef HAVE_BPF_SKEL
+#include <bpf/btf.h>
+#include <util/btf.h>
+
+static struct btf *btf;
+
+static bool btf__available(void)
+{
+ if (btf == NULL)
+ btf = btf__load_vmlinux_btf();
+
+ return btf != NULL;
+}
+
+static void btf__exit(void)
+{
+ btf__free(btf);
+ btf = NULL;
+}
+
+static bool attr_has_sigtrap(void)
+{
+ int id;
+
+ if (!btf__available()) {
+ /* should be an old kernel */
+ return false;
+ }
+
+ id = btf__find_by_name_kind(btf, "perf_event_attr", BTF_KIND_STRUCT);
+ if (id < 0)
+ return false;
+
+ return __btf_type__find_member_by_name(btf, id, "sigtrap") != NULL;
+}
+
+static bool kernel_with_sleepable_spinlocks(void)
+{
+ const struct btf_member *member;
+ const struct btf_type *type;
+ const char *type_name;
+ int id;
+
+ if (!btf__available())
+ return false;
+
+ id = btf__find_by_name_kind(btf, "spinlock", BTF_KIND_STRUCT);
+ if (id < 0)
+ return false;
+
+ // Only RT has a "lock" member for "struct spinlock"
+ member = __btf_type__find_member_by_name(btf, id, "lock");
+ if (member == NULL)
+ return false;
+
+ // But check its type as well
+ type = btf__type_by_id(btf, member->type);
+ if (!type || !btf_is_struct(type))
+ return false;
+
+ type_name = btf__name_by_offset(btf, type->name_off);
+ return type_name && !strcmp(type_name, "rt_mutex_base");
+}
+#else /* !HAVE_BPF_SKEL */
+static bool attr_has_sigtrap(void)
+{
+ struct perf_event_attr attr = {
+ .type = PERF_TYPE_SOFTWARE,
+ .config = PERF_COUNT_SW_DUMMY,
+ .size = sizeof(attr),
+ .remove_on_exec = 1, /* Required by sigtrap. */
+ .sigtrap = 1, /* Request synchronous SIGTRAP on event. */
+ };
+ int fd;
+ bool ret = false;
+
+ fd = sys_perf_event_open(&attr, 0, -1, -1, perf_event_open_cloexec_flag());
+ if (fd >= 0) {
+ ret = true;
+ close(fd);
+ }
+
+ return ret;
+}
+
+static bool kernel_with_sleepable_spinlocks(void)
+{
+ return false;
+}
+
+static void btf__exit(void)
+{
+}
+#endif /* HAVE_BPF_SKEL */
+
+static void
+sigtrap_handler(int signum __maybe_unused, siginfo_t *info, void *ucontext __maybe_unused)
+{
+ if (!__atomic_fetch_add(&ctx.signal_count, 1, __ATOMIC_RELAXED))
+ ctx.first_siginfo = *info;
+ __atomic_fetch_sub(&ctx.tids_want_signal, syscall(SYS_gettid), __ATOMIC_RELAXED);
+}
+
+static void *test_thread(void *arg)
+{
+ pthread_barrier_t *barrier = (pthread_barrier_t *)arg;
+ pid_t tid = syscall(SYS_gettid);
+ int i;
+
+ pthread_barrier_wait(barrier);
+
+ __atomic_fetch_add(&ctx.tids_want_signal, tid, __ATOMIC_RELAXED);
+ for (i = 0; i < ctx.iterate_on - 1; i++)
+ __atomic_fetch_add(&ctx.tids_want_signal, tid, __ATOMIC_RELAXED);
+
+ return NULL;
+}
+
+static int run_test_threads(pthread_t *threads, pthread_barrier_t *barrier)
+{
+ int i;
+
+ pthread_barrier_wait(barrier);
+ for (i = 0; i < NUM_THREADS; i++)
+ TEST_ASSERT_EQUAL("pthread_join() failed", pthread_join(threads[i], NULL), 0);
+
+ return TEST_OK;
+}
+
+static int run_stress_test(int fd, pthread_t *threads, pthread_barrier_t *barrier)
+{
+ int ret, expected_sigtraps;
+
+ ctx.iterate_on = 3000;
+
+ TEST_ASSERT_EQUAL("misfired signal?", ctx.signal_count, 0);
+ TEST_ASSERT_EQUAL("enable failed", ioctl(fd, PERF_EVENT_IOC_ENABLE, 0), 0);
+ ret = run_test_threads(threads, barrier);
+ TEST_ASSERT_EQUAL("disable failed", ioctl(fd, PERF_EVENT_IOC_DISABLE, 0), 0);
+
+ expected_sigtraps = NUM_THREADS * ctx.iterate_on;
+
+ if (ctx.signal_count < expected_sigtraps && kernel_with_sleepable_spinlocks()) {
+ pr_debug("Expected %d sigtraps, got %d, running on a kernel with sleepable spinlocks.\n",
+ expected_sigtraps, ctx.signal_count);
+ pr_debug("See https://lore.kernel.org/all/e368f2c848d77fbc8d259f44e2055fe469c219cf.camel@gmx.de/\n");
+ return TEST_SKIP;
+ } else
+ TEST_ASSERT_EQUAL("unexpected sigtraps", ctx.signal_count, expected_sigtraps);
+
+ TEST_ASSERT_EQUAL("missing signals or incorrectly delivered", ctx.tids_want_signal, 0);
+ TEST_ASSERT_VAL("unexpected si_addr", ctx.first_siginfo.si_addr == &ctx.iterate_on);
+#if 0 /* FIXME: enable when libc's signal.h has si_perf_{type,data} */
+ TEST_ASSERT_EQUAL("unexpected si_perf_type", ctx.first_siginfo.si_perf_type,
+ PERF_TYPE_BREAKPOINT);
+ TEST_ASSERT_EQUAL("unexpected si_perf_data", ctx.first_siginfo.si_perf_data,
+ TEST_SIG_DATA);
+#endif
+
+ return ret;
+}
+
+static int test__sigtrap(struct test_suite *test __maybe_unused, int subtest __maybe_unused)
+{
+ struct perf_event_attr attr = make_event_attr();
+ struct sigaction action = {};
+ struct sigaction oldact;
+ pthread_t threads[NUM_THREADS];
+ pthread_barrier_t barrier;
+ char sbuf[STRERR_BUFSIZE];
+ int i, fd, ret = TEST_FAIL;
+
+ if (!BP_SIGNAL_IS_SUPPORTED) {
+ pr_debug("Test not supported on this architecture");
+ return TEST_SKIP;
+ }
+
+ pthread_barrier_init(&barrier, NULL, NUM_THREADS + 1);
+
+ action.sa_flags = SA_SIGINFO | SA_NODEFER;
+ action.sa_sigaction = sigtrap_handler;
+ sigemptyset(&action.sa_mask);
+ if (sigaction(SIGTRAP, &action, &oldact)) {
+ pr_debug("FAILED sigaction(): %s\n", str_error_r(errno, sbuf, sizeof(sbuf)));
+ goto out;
+ }
+
+ fd = sys_perf_event_open(&attr, 0, -1, -1, perf_event_open_cloexec_flag());
+ if (fd < 0) {
+ if (attr_has_sigtrap()) {
+ pr_debug("FAILED sys_perf_event_open(): %s\n",
+ str_error_r(errno, sbuf, sizeof(sbuf)));
+ } else {
+ pr_debug("perf_event_attr doesn't have sigtrap\n");
+ ret = TEST_SKIP;
+ }
+ goto out_restore_sigaction;
+ }
+
+ for (i = 0; i < NUM_THREADS; i++) {
+ if (pthread_create(&threads[i], NULL, test_thread, &barrier)) {
+ pr_debug("FAILED pthread_create(): %s\n", str_error_r(errno, sbuf, sizeof(sbuf)));
+ goto out_close_perf_event;
+ }
+ }
+
+ ret = run_stress_test(fd, threads, &barrier);
+
+out_close_perf_event:
+ close(fd);
+out_restore_sigaction:
+ sigaction(SIGTRAP, &oldact, NULL);
+out:
+ pthread_barrier_destroy(&barrier);
+ btf__exit();
+ return ret;
+}
+
+DEFINE_SUITE("Sigtrap", sigtrap);