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
  ...

5 files changed, 927 insertions, 0 deletions

diff --git a/tools/testing/selftests/breakpoints/.gitignore b/tools/testing/selftests/breakpoints/.gitignore
new file mode 100644
index 000000000..def2e97da
--- /dev/null
+++ b/tools/testing/selftests/breakpoints/.gitignore
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0-only
+breakpoint_test
+step_after_suspend_test
diff --git a/tools/testing/selftests/breakpoints/Makefile b/tools/testing/selftests/breakpoints/Makefile
new file mode 100644
index 000000000..0b8f5acf7
--- /dev/null
+++ b/tools/testing/selftests/breakpoints/Makefile
@@ -0,0 +1,16 @@
+# SPDX-License-Identifier: GPL-2.0
+# Taken from perf makefile
+ARCH ?= $(shell uname -m 2>/dev/null || echo not)
+override ARCH := $(shell echo $(ARCH) | sed -e s/i.86/x86/ -e s/x86_64/x86/)
+
+TEST_GEN_PROGS := step_after_suspend_test
+
+ifeq ($(ARCH),x86)
+TEST_GEN_PROGS += breakpoint_test
+endif
+ifneq (,$(filter $(ARCH),aarch64 arm64))
+TEST_GEN_PROGS += breakpoint_test_arm64
+endif
+
+include ../lib.mk
+
diff --git a/tools/testing/selftests/breakpoints/breakpoint_test.c b/tools/testing/selftests/breakpoints/breakpoint_test.c
new file mode 100644
index 000000000..1159d8189
--- /dev/null
+++ b/tools/testing/selftests/breakpoints/breakpoint_test.c
@@ -0,0 +1,409 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2011 Red Hat, Inc., Frederic Weisbecker <fweisbec@redhat.com>
+ *
+ * Selftests for breakpoints (and more generally the do_debug() path) in x86.
+ */
+
+
+#include <sys/ptrace.h>
+#include <unistd.h>
+#include <stddef.h>
+#include <sys/user.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <errno.h>
+#include <string.h>
+
+#include "kselftest.h"
+
+#define COUNT_ISN_BPS	4
+#define COUNT_WPS	4
+
+/* Breakpoint access modes */
+enum {
+	BP_X = 1,
+	BP_RW = 2,
+	BP_W = 4,
+};
+
+static pid_t child_pid;
+
+/*
+ * Ensures the child and parent are always "talking" about
+ * the same test sequence. (ie: that we haven't forgotten
+ * to call check_trapped() somewhere).
+ */
+static int nr_tests;
+
+static void set_breakpoint_addr(void *addr, int n)
+{
+	int ret;
+
+	ret = ptrace(PTRACE_POKEUSER, child_pid,
+		     offsetof(struct user, u_debugreg[n]), addr);
+	if (ret)
+		ksft_exit_fail_msg("Can't set breakpoint addr: %s\n",
+			strerror(errno));
+}
+
+static void toggle_breakpoint(int n, int type, int len,
+			      int local, int global, int set)
+{
+	int ret;
+
+	int xtype, xlen;
+	unsigned long vdr7, dr7;
+
+	switch (type) {
+	case BP_X:
+		xtype = 0;
+		break;
+	case BP_W:
+		xtype = 1;
+		break;
+	case BP_RW:
+		xtype = 3;
+		break;
+	}
+
+	switch (len) {
+	case 1:
+		xlen = 0;
+		break;
+	case 2:
+		xlen = 4;
+		break;
+	case 4:
+		xlen = 0xc;
+		break;
+	case 8:
+		xlen = 8;
+		break;
+	}
+
+	dr7 = ptrace(PTRACE_PEEKUSER, child_pid,
+		     offsetof(struct user, u_debugreg[7]), 0);
+
+	vdr7 = (xlen | xtype) << 16;
+	vdr7 <<= 4 * n;
+
+	if (local) {
+		vdr7 |= 1 << (2 * n);
+		vdr7 |= 1 << 8;
+	}
+	if (global) {
+		vdr7 |= 2 << (2 * n);
+		vdr7 |= 1 << 9;
+	}
+
+	if (set)
+		dr7 |= vdr7;
+	else
+		dr7 &= ~vdr7;
+
+	ret = ptrace(PTRACE_POKEUSER, child_pid,
+		     offsetof(struct user, u_debugreg[7]), dr7);
+	if (ret) {
+		ksft_print_msg("Can't set dr7: %s\n", strerror(errno));
+		exit(-1);
+	}
+}
+
+/* Dummy variables to test read/write accesses */
+static unsigned long long dummy_var[4];
+
+/* Dummy functions to test execution accesses */
+static void dummy_func(void) { }
+static void dummy_func1(void) { }
+static void dummy_func2(void) { }
+static void dummy_func3(void) { }
+
+static void (*dummy_funcs[])(void) = {
+	dummy_func,
+	dummy_func1,
+	dummy_func2,
+	dummy_func3,
+};
+
+static int trapped;
+
+static void check_trapped(void)
+{
+	/*
+	 * If we haven't trapped, wake up the parent
+	 * so that it notices the failure.
+	 */
+	if (!trapped)
+		kill(getpid(), SIGUSR1);
+	trapped = 0;
+
+	nr_tests++;
+}
+
+static void write_var(int len)
+{
+	char *pcval; short *psval; int *pival; long long *plval;
+	int i;
+
+	for (i = 0; i < 4; i++) {
+		switch (len) {
+		case 1:
+			pcval = (char *)&dummy_var[i];
+			*pcval = 0xff;
+			break;
+		case 2:
+			psval = (short *)&dummy_var[i];
+			*psval = 0xffff;
+			break;
+		case 4:
+			pival = (int *)&dummy_var[i];
+			*pival = 0xffffffff;
+			break;
+		case 8:
+			plval = (long long *)&dummy_var[i];
+			*plval = 0xffffffffffffffffLL;
+			break;
+		}
+		check_trapped();
+	}
+}
+
+static void read_var(int len)
+{
+	char cval; short sval; int ival; long long lval;
+	int i;
+
+	for (i = 0; i < 4; i++) {
+		switch (len) {
+		case 1:
+			cval = *(char *)&dummy_var[i];
+			break;
+		case 2:
+			sval = *(short *)&dummy_var[i];
+			break;
+		case 4:
+			ival = *(int *)&dummy_var[i];
+			break;
+		case 8:
+			lval = *(long long *)&dummy_var[i];
+			break;
+		}
+		check_trapped();
+	}
+}
+
+/*
+ * Do the r/w/x accesses to trigger the breakpoints. And run
+ * the usual traps.
+ */
+static void trigger_tests(void)
+{
+	int len, local, global, i;
+	char val;
+	int ret;
+
+	ret = ptrace(PTRACE_TRACEME, 0, NULL, 0);
+	if (ret) {
+		ksft_print_msg("Can't be traced? %s\n", strerror(errno));
+		return;
+	}
+
+	/* Wake up father so that it sets up the first test */
+	kill(getpid(), SIGUSR1);
+
+	/* Test instruction breakpoints */
+	for (local = 0; local < 2; local++) {
+		for (global = 0; global < 2; global++) {
+			if (!local && !global)
+				continue;
+
+			for (i = 0; i < COUNT_ISN_BPS; i++) {
+				dummy_funcs[i]();
+				check_trapped();
+			}
+		}
+	}
+
+	/* Test write watchpoints */
+	for (len = 1; len <= sizeof(long); len <<= 1) {
+		for (local = 0; local < 2; local++) {
+			for (global = 0; global < 2; global++) {
+				if (!local && !global)
+					continue;
+				write_var(len);
+			}
+		}
+	}
+
+	/* Test read/write watchpoints (on read accesses) */
+	for (len = 1; len <= sizeof(long); len <<= 1) {
+		for (local = 0; local < 2; local++) {
+			for (global = 0; global < 2; global++) {
+				if (!local && !global)
+					continue;
+				read_var(len);
+			}
+		}
+	}
+
+	/* Icebp trap */
+	asm(".byte 0xf1\n");
+	check_trapped();
+
+	/* Int 3 trap */
+	asm("int $3\n");
+	check_trapped();
+
+	kill(getpid(), SIGUSR1);
+}
+
+static void check_success(const char *msg)
+{
+	int child_nr_tests;
+	int status;
+	int ret;
+
+	/* Wait for the child to SIGTRAP */
+	wait(&status);
+
+	ret = 0;
+
+	if (WSTOPSIG(status) == SIGTRAP) {
+		child_nr_tests = ptrace(PTRACE_PEEKDATA, child_pid,
+					&nr_tests, 0);
+		if (child_nr_tests == nr_tests)
+			ret = 1;
+		if (ptrace(PTRACE_POKEDATA, child_pid, &trapped, 1))
+			ksft_exit_fail_msg("Can't poke: %s\n", strerror(errno));
+	}
+
+	nr_tests++;
+
+	if (ret)
+		ksft_test_result_pass("%s", msg);
+	else
+		ksft_test_result_fail("%s", msg);
+}
+
+static void launch_instruction_breakpoints(char *buf, int local, int global)
+{
+	int i;
+
+	for (i = 0; i < COUNT_ISN_BPS; i++) {
+		set_breakpoint_addr(dummy_funcs[i], i);
+		toggle_breakpoint(i, BP_X, 1, local, global, 1);
+		ptrace(PTRACE_CONT, child_pid, NULL, 0);
+		sprintf(buf, "Test breakpoint %d with local: %d global: %d\n",
+			i, local, global);
+		check_success(buf);
+		toggle_breakpoint(i, BP_X, 1, local, global, 0);
+	}
+}
+
+static void launch_watchpoints(char *buf, int mode, int len,
+			       int local, int global)
+{
+	const char *mode_str;
+	int i;
+
+	if (mode == BP_W)
+		mode_str = "write";
+	else
+		mode_str = "read";
+
+	for (i = 0; i < COUNT_WPS; i++) {
+		set_breakpoint_addr(&dummy_var[i], i);
+		toggle_breakpoint(i, mode, len, local, global, 1);
+		ptrace(PTRACE_CONT, child_pid, NULL, 0);
+		sprintf(buf,
+			"Test %s watchpoint %d with len: %d local: %d global: %d\n",
+			mode_str, i, len, local, global);
+		check_success(buf);
+		toggle_breakpoint(i, mode, len, local, global, 0);
+	}
+}
+
+/* Set the breakpoints and check the child successfully trigger them */
+static void launch_tests(void)
+{
+	char buf[1024];
+	unsigned int tests = 0;
+	int len, local, global, i;
+
+	tests += 3 * COUNT_ISN_BPS;
+	tests += sizeof(long) / 2 * 3 * COUNT_WPS;
+	tests += sizeof(long) / 2 * 3 * COUNT_WPS;
+	tests += 2;
+	ksft_set_plan(tests);
+
+	/* Instruction breakpoints */
+	for (local = 0; local < 2; local++) {
+		for (global = 0; global < 2; global++) {
+			if (!local && !global)
+				continue;
+			launch_instruction_breakpoints(buf, local, global);
+		}
+	}
+
+	/* Write watchpoint */
+	for (len = 1; len <= sizeof(long); len <<= 1) {
+		for (local = 0; local < 2; local++) {
+			for (global = 0; global < 2; global++) {
+				if (!local && !global)
+					continue;
+				launch_watchpoints(buf, BP_W, len,
+						   local, global);
+			}
+		}
+	}
+
+	/* Read-Write watchpoint */
+	for (len = 1; len <= sizeof(long); len <<= 1) {
+		for (local = 0; local < 2; local++) {
+			for (global = 0; global < 2; global++) {
+				if (!local && !global)
+					continue;
+				launch_watchpoints(buf, BP_RW, len,
+						   local, global);
+			}
+		}
+	}
+
+	/* Icebp traps */
+	ptrace(PTRACE_CONT, child_pid, NULL, 0);
+	check_success("Test icebp\n");
+
+	/* Int 3 traps */
+	ptrace(PTRACE_CONT, child_pid, NULL, 0);
+	check_success("Test int 3 trap\n");
+
+	ptrace(PTRACE_CONT, child_pid, NULL, 0);
+}
+
+int main(int argc, char **argv)
+{
+	pid_t pid;
+	int ret;
+
+	ksft_print_header();
+
+	pid = fork();
+	if (!pid) {
+		trigger_tests();
+		exit(0);
+	}
+
+	child_pid = pid;
+
+	wait(NULL);
+
+	launch_tests();
+
+	wait(NULL);
+
+	ksft_exit_pass();
+}
diff --git a/tools/testing/selftests/breakpoints/breakpoint_test_arm64.c b/tools/testing/selftests/breakpoints/breakpoint_test_arm64.c
new file mode 100644
index 000000000..5fc0f37f3
--- /dev/null
+++ b/tools/testing/selftests/breakpoints/breakpoint_test_arm64.c
@@ -0,0 +1,250 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2016 Google, Inc.
+ *
+ * Original Code by Pavel Labath <labath@google.com>
+ *
+ * Code modified by Pratyush Anand <panand@redhat.com>
+ * for testing different byte select for each access size.
+ */
+
+#define _GNU_SOURCE
+
+#include <asm/ptrace.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <sys/ptrace.h>
+#include <sys/param.h>
+#include <sys/uio.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <string.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <elf.h>
+#include <errno.h>
+#include <signal.h>
+
+#include "kselftest.h"
+
+static volatile uint8_t var[96] __attribute__((__aligned__(32)));
+
+static void child(int size, int wr)
+{
+	volatile uint8_t *addr = &var[32 + wr];
+
+	if (ptrace(PTRACE_TRACEME, 0, NULL, NULL) != 0) {
+		ksft_print_msg(
+			"ptrace(PTRACE_TRACEME) failed: %s\n",
+			strerror(errno));
+		_exit(1);
+	}
+
+	if (raise(SIGSTOP) != 0) {
+		ksft_print_msg(
+			"raise(SIGSTOP) failed: %s\n", strerror(errno));
+		_exit(1);
+	}
+
+	if ((uintptr_t) addr % size) {
+		ksft_print_msg(
+			 "Wrong address write for the given size: %s\n",
+			 strerror(errno));
+		_exit(1);
+	}
+
+	switch (size) {
+	case 1:
+		*addr = 47;
+		break;
+	case 2:
+		*(uint16_t *)addr = 47;
+		break;
+	case 4:
+		*(uint32_t *)addr = 47;
+		break;
+	case 8:
+		*(uint64_t *)addr = 47;
+		break;
+	case 16:
+		__asm__ volatile ("stp x29, x30, %0" : "=m" (addr[0]));
+		break;
+	case 32:
+		__asm__ volatile ("stp q29, q30, %0" : "=m" (addr[0]));
+		break;
+	}
+
+	_exit(0);
+}
+
+static bool set_watchpoint(pid_t pid, int size, int wp)
+{
+	const volatile uint8_t *addr = &var[32 + wp];
+	const int offset = (uintptr_t)addr % 8;
+	const unsigned int byte_mask = ((1 << size) - 1) << offset;
+	const unsigned int type = 2; /* Write */
+	const unsigned int enable = 1;
+	const unsigned int control = byte_mask << 5 | type << 3 | enable;
+	struct user_hwdebug_state dreg_state;
+	struct iovec iov;
+
+	memset(&dreg_state, 0, sizeof(dreg_state));
+	dreg_state.dbg_regs[0].addr = (uintptr_t)(addr - offset);
+	dreg_state.dbg_regs[0].ctrl = control;
+	iov.iov_base = &dreg_state;
+	iov.iov_len = offsetof(struct user_hwdebug_state, dbg_regs) +
+				sizeof(dreg_state.dbg_regs[0]);
+	if (ptrace(PTRACE_SETREGSET, pid, NT_ARM_HW_WATCH, &iov) == 0)
+		return true;
+
+	if (errno == EIO)
+		ksft_print_msg(
+			"ptrace(PTRACE_SETREGSET, NT_ARM_HW_WATCH) not supported on this hardware: %s\n",
+			strerror(errno));
+
+	ksft_print_msg(
+		"ptrace(PTRACE_SETREGSET, NT_ARM_HW_WATCH) failed: %s\n",
+		strerror(errno));
+	return false;
+}
+
+static bool run_test(int wr_size, int wp_size, int wr, int wp)
+{
+	int status;
+	siginfo_t siginfo;
+	pid_t pid = fork();
+	pid_t wpid;
+
+	if (pid < 0) {
+		ksft_test_result_fail(
+			"fork() failed: %s\n", strerror(errno));
+		return false;
+	}
+	if (pid == 0)
+		child(wr_size, wr);
+
+	wpid = waitpid(pid, &status, __WALL);
+	if (wpid != pid) {
+		ksft_print_msg(
+			"waitpid() failed: %s\n", strerror(errno));
+		return false;
+	}
+	if (!WIFSTOPPED(status)) {
+		ksft_print_msg(
+			"child did not stop: %s\n", strerror(errno));
+		return false;
+	}
+	if (WSTOPSIG(status) != SIGSTOP) {
+		ksft_print_msg("child did not stop with SIGSTOP\n");
+		return false;
+	}
+
+	if (!set_watchpoint(pid, wp_size, wp))
+		return false;
+
+	if (ptrace(PTRACE_CONT, pid, NULL, NULL) < 0) {
+		ksft_print_msg(
+			"ptrace(PTRACE_CONT) failed: %s\n",
+			strerror(errno));
+		return false;
+	}
+
+	alarm(3);
+	wpid = waitpid(pid, &status, __WALL);
+	if (wpid != pid) {
+		ksft_print_msg(
+			"waitpid() failed: %s\n", strerror(errno));
+		return false;
+	}
+	alarm(0);
+	if (WIFEXITED(status)) {
+		ksft_print_msg("child exited prematurely\n");
+		return false;
+	}
+	if (!WIFSTOPPED(status)) {
+		ksft_print_msg("child did not stop\n");
+		return false;
+	}
+	if (WSTOPSIG(status) != SIGTRAP) {
+		ksft_print_msg("child did not stop with SIGTRAP\n");
+		return false;
+	}
+	if (ptrace(PTRACE_GETSIGINFO, pid, NULL, &siginfo) != 0) {
+		ksft_print_msg(
+			"ptrace(PTRACE_GETSIGINFO): %s\n",
+			strerror(errno));
+		return false;
+	}
+	if (siginfo.si_code != TRAP_HWBKPT) {
+		ksft_print_msg(
+			"Unexpected si_code %d\n", siginfo.si_code);
+		return false;
+	}
+
+	kill(pid, SIGKILL);
+	wpid = waitpid(pid, &status, 0);
+	if (wpid != pid) {
+		ksft_print_msg(
+			"waitpid() failed: %s\n", strerror(errno));
+		return false;
+	}
+	return true;
+}
+
+static void sigalrm(int sig)
+{
+}
+
+int main(int argc, char **argv)
+{
+	int opt;
+	bool succeeded = true;
+	struct sigaction act;
+	int wr, wp, size;
+	bool result;
+
+	ksft_print_header();
+	ksft_set_plan(213);
+
+	act.sa_handler = sigalrm;
+	sigemptyset(&act.sa_mask);
+	act.sa_flags = 0;
+	sigaction(SIGALRM, &act, NULL);
+	for (size = 1; size <= 32; size = size*2) {
+		for (wr = 0; wr <= 32; wr = wr + size) {
+			for (wp = wr - size; wp <= wr + size; wp = wp + size) {
+				result = run_test(size, MIN(size, 8), wr, wp);
+				if ((result && wr == wp) ||
+				    (!result && wr != wp))
+					ksft_test_result_pass(
+						"Test size = %d write offset = %d watchpoint offset = %d\n",
+						size, wr, wp);
+				else {
+					ksft_test_result_fail(
+						"Test size = %d write offset = %d watchpoint offset = %d\n",
+						size, wr, wp);
+					succeeded = false;
+				}
+			}
+		}
+	}
+
+	for (size = 1; size <= 32; size = size*2) {
+		if (run_test(size, 8, -size, -8))
+			ksft_test_result_pass(
+				"Test size = %d write offset = %d watchpoint offset = -8\n",
+				size, -size);
+		else {
+			ksft_test_result_fail(
+				"Test size = %d write offset = %d watchpoint offset = -8\n",
+				size, -size);
+			succeeded = false;
+		}
+	}
+
+	if (succeeded)
+		ksft_exit_pass();
+	else
+		ksft_exit_fail();
+}
diff --git a/tools/testing/selftests/breakpoints/step_after_suspend_test.c b/tools/testing/selftests/breakpoints/step_after_suspend_test.c
new file mode 100644
index 000000000..ca2aaab9e
--- /dev/null
+++ b/tools/testing/selftests/breakpoints/step_after_suspend_test.c
@@ -0,0 +1,249 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2016 Google, Inc.
+ */
+
+#define _GNU_SOURCE
+
+#include <errno.h>
+#include <fcntl.h>
+#include <sched.h>
+#include <signal.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/ptrace.h>
+#include <sys/stat.h>
+#include <sys/timerfd.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+
+#include "kselftest.h"
+
+void child(int cpu)
+{
+	cpu_set_t set;
+
+	CPU_ZERO(&set);
+	CPU_SET(cpu, &set);
+	if (sched_setaffinity(0, sizeof(set), &set) != 0) {
+		ksft_print_msg("sched_setaffinity() failed: %s\n",
+			strerror(errno));
+		_exit(1);
+	}
+
+	if (ptrace(PTRACE_TRACEME, 0, NULL, NULL) != 0) {
+		ksft_print_msg("ptrace(PTRACE_TRACEME) failed: %s\n",
+			strerror(errno));
+		_exit(1);
+	}
+
+	if (raise(SIGSTOP) != 0) {
+		ksft_print_msg("raise(SIGSTOP) failed: %s\n", strerror(errno));
+		_exit(1);
+	}
+
+	_exit(0);
+}
+
+int run_test(int cpu)
+{
+	int status;
+	pid_t pid = fork();
+	pid_t wpid;
+
+	if (pid < 0) {
+		ksft_print_msg("fork() failed: %s\n", strerror(errno));
+		return KSFT_FAIL;
+	}
+	if (pid == 0)
+		child(cpu);
+
+	wpid = waitpid(pid, &status, __WALL);
+	if (wpid != pid) {
+		ksft_print_msg("waitpid() failed: %s\n", strerror(errno));
+		return KSFT_FAIL;
+	}
+	if (!WIFSTOPPED(status)) {
+		ksft_print_msg("child did not stop: %s\n", strerror(errno));
+		return KSFT_FAIL;
+	}
+	if (WSTOPSIG(status) != SIGSTOP) {
+		ksft_print_msg("child did not stop with SIGSTOP: %s\n",
+			strerror(errno));
+		return KSFT_FAIL;
+	}
+
+	if (ptrace(PTRACE_SINGLESTEP, pid, NULL, NULL) < 0) {
+		if (errno == EIO) {
+			ksft_print_msg(
+				"ptrace(PTRACE_SINGLESTEP) not supported on this architecture: %s\n",
+				strerror(errno));
+			return KSFT_SKIP;
+		}
+		ksft_print_msg("ptrace(PTRACE_SINGLESTEP) failed: %s\n",
+			strerror(errno));
+		return KSFT_FAIL;
+	}
+
+	wpid = waitpid(pid, &status, __WALL);
+	if (wpid != pid) {
+		ksft_print_msg("waitpid() failed: %s\n", strerror(errno));
+		return KSFT_FAIL;
+	}
+	if (WIFEXITED(status)) {
+		ksft_print_msg("child did not single-step: %s\n",
+			strerror(errno));
+		return KSFT_FAIL;
+	}
+	if (!WIFSTOPPED(status)) {
+		ksft_print_msg("child did not stop: %s\n", strerror(errno));
+		return KSFT_FAIL;
+	}
+	if (WSTOPSIG(status) != SIGTRAP) {
+		ksft_print_msg("child did not stop with SIGTRAP: %s\n",
+			strerror(errno));
+		return KSFT_FAIL;
+	}
+
+	if (ptrace(PTRACE_CONT, pid, NULL, NULL) < 0) {
+		ksft_print_msg("ptrace(PTRACE_CONT) failed: %s\n",
+			strerror(errno));
+		return KSFT_FAIL;
+	}
+
+	wpid = waitpid(pid, &status, __WALL);
+	if (wpid != pid) {
+		ksft_print_msg("waitpid() failed: %s\n", strerror(errno));
+		return KSFT_FAIL;
+	}
+	if (!WIFEXITED(status)) {
+		ksft_print_msg("child did not exit after PTRACE_CONT: %s\n",
+			strerror(errno));
+		return KSFT_FAIL;
+	}
+
+	return KSFT_PASS;
+}
+
+/*
+ * Reads the suspend success count from sysfs.
+ * Returns the count on success or exits on failure.
+ */
+static int get_suspend_success_count_or_fail(void)
+{
+	FILE *fp;
+	int val;
+
+	fp = fopen("/sys/power/suspend_stats/success", "r");
+	if (!fp)
+		ksft_exit_fail_msg(
+			"Failed to open suspend_stats/success: %s\n",
+			strerror(errno));
+
+	if (fscanf(fp, "%d", &val) != 1) {
+		fclose(fp);
+		ksft_exit_fail_msg(
+			"Failed to read suspend success count\n");
+	}
+
+	fclose(fp);
+	return val;
+}
+
+void suspend(void)
+{
+	int timerfd;
+	int err;
+	int count_before;
+	int count_after;
+	struct itimerspec spec = {};
+
+	if (getuid() != 0)
+		ksft_exit_skip("Please run the test as root - Exiting.\n");
+
+	timerfd = timerfd_create(CLOCK_BOOTTIME_ALARM, 0);
+	if (timerfd < 0)
+		ksft_exit_fail_msg("timerfd_create() failed\n");
+
+	spec.it_value.tv_sec = 5;
+	err = timerfd_settime(timerfd, 0, &spec, NULL);
+	if (err < 0)
+		ksft_exit_fail_msg("timerfd_settime() failed\n");
+
+	count_before = get_suspend_success_count_or_fail();
+
+	system("(echo mem > /sys/power/state) 2> /dev/null");
+
+	count_after = get_suspend_success_count_or_fail();
+	if (count_after <= count_before)
+		ksft_exit_fail_msg("Failed to enter Suspend state\n");
+
+	close(timerfd);
+}
+
+int main(int argc, char **argv)
+{
+	int opt;
+	bool do_suspend = true;
+	bool succeeded = true;
+	unsigned int tests = 0;
+	cpu_set_t available_cpus;
+	int err;
+	int cpu;
+
+	ksft_print_header();
+
+	while ((opt = getopt(argc, argv, "n")) != -1) {
+		switch (opt) {
+		case 'n':
+			do_suspend = false;
+			break;
+		default:
+			printf("Usage: %s [-n]\n", argv[0]);
+			printf("        -n: do not trigger a suspend/resume cycle before the test\n");
+			return -1;
+		}
+	}
+
+	err = sched_getaffinity(0, sizeof(available_cpus), &available_cpus);
+	if (err < 0)
+		ksft_exit_fail_msg("sched_getaffinity() failed\n");
+
+	for (cpu = 0; cpu < CPU_SETSIZE; cpu++) {
+		if (!CPU_ISSET(cpu, &available_cpus))
+			continue;
+		tests++;
+	}
+
+	if (do_suspend)
+		suspend();
+
+	ksft_set_plan(tests);
+	for (cpu = 0; cpu < CPU_SETSIZE; cpu++) {
+		int test_success;
+
+		if (!CPU_ISSET(cpu, &available_cpus))
+			continue;
+
+		test_success = run_test(cpu);
+		switch (test_success) {
+		case KSFT_PASS:
+			ksft_test_result_pass("CPU %d\n", cpu);
+			break;
+		case KSFT_SKIP:
+			ksft_test_result_skip("CPU %d\n", cpu);
+			break;
+		case KSFT_FAIL:
+			ksft_test_result_fail("CPU %d\n", cpu);
+			succeeded = false;
+			break;
+		}
+	}
+
+	if (succeeded)
+		ksft_exit_pass();
+	else
+		ksft_exit_fail();
+}