19 files changed, 517 insertions, 37 deletions

diff --git a/tools/iio/iio_generic_buffer.c b/tools/iio/iio_generic_buffer.c
index 3040830d7797..84545666a09c 100644
--- a/tools/iio/iio_generic_buffer.c
+++ b/tools/iio/iio_generic_buffer.c
@@ -330,7 +330,7 @@ static const struct option longopts[] = {
 
 int main(int argc, char **argv)
 {
-	unsigned long long num_loops = 2;
+	long long num_loops = 2;
 	unsigned long timedelay = 1000000;
 	unsigned long buf_len = 128;
 
diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
index d079f36d342d..ac221f137ed2 100644
--- a/tools/perf/builtin-script.c
+++ b/tools/perf/builtin-script.c
@@ -1681,13 +1681,8 @@ static void perf_sample__fprint_metric(struct perf_script *script,
 		.force_header = false,
 	};
 	struct perf_evsel *ev2;
-	static bool init;
 	u64 val;
 
-	if (!init) {
-		perf_stat__init_shadow_stats();
-		init = true;
-	}
 	if (!evsel->stats)
 		perf_evlist__alloc_stats(script->session->evlist, false);
 	if (evsel_script(evsel->leader)->gnum++ == 0)
@@ -1794,7 +1789,7 @@ static void process_event(struct perf_script *script,
 		return;
 	}
 
-	if (PRINT_FIELD(TRACE)) {
+	if (PRINT_FIELD(TRACE) && sample->raw_data) {
 		event_format__fprintf(evsel->tp_format, sample->cpu,
 				      sample->raw_data, sample->raw_size, fp);
 	}
@@ -2359,6 +2354,8 @@ static int __cmd_script(struct perf_script *script)
 
 	signal(SIGINT, sig_handler);
 
+	perf_stat__init_shadow_stats();
+
 	/* override event processing functions */
 	if (script->show_task_events) {
 		script->tool.comm = process_comm_event;
diff --git a/tools/perf/ui/browsers/annotate.c b/tools/perf/ui/browsers/annotate.c
index 1d00e5ec7906..82e16bf84466 100644
--- a/tools/perf/ui/browsers/annotate.c
+++ b/tools/perf/ui/browsers/annotate.c
@@ -224,20 +224,24 @@ static unsigned int annotate_browser__refresh(struct ui_browser *browser)
 	return ret;
 }
 
-static int disasm__cmp(struct annotation_line *a, struct annotation_line *b)
+static double disasm__cmp(struct annotation_line *a, struct annotation_line *b,
+						  int percent_type)
 {
 	int i;
 
 	for (i = 0; i < a->data_nr; i++) {
-		if (a->data[i].percent == b->data[i].percent)
+		if (a->data[i].percent[percent_type] == b->data[i].percent[percent_type])
 			continue;
-		return a->data[i].percent < b->data[i].percent;
+		return a->data[i].percent[percent_type] -
+			   b->data[i].percent[percent_type];
 	}
 	return 0;
 }
 
-static void disasm_rb_tree__insert(struct rb_root *root, struct annotation_line *al)
+static void disasm_rb_tree__insert(struct annotate_browser *browser,
+				struct annotation_line *al)
 {
+	struct rb_root *root = &browser->entries;
 	struct rb_node **p = &root->rb_node;
 	struct rb_node *parent = NULL;
 	struct annotation_line *l;
@@ -246,7 +250,7 @@ static void disasm_rb_tree__insert(struct rb_root *root, struct annotation_line
 		parent = *p;
 		l = rb_entry(parent, struct annotation_line, rb_node);
 
-		if (disasm__cmp(al, l))
+		if (disasm__cmp(al, l, browser->opts->percent_type) < 0)
 			p = &(*p)->rb_left;
 		else
 			p = &(*p)->rb_right;
@@ -329,7 +333,7 @@ static void annotate_browser__calc_percent(struct annotate_browser *browser,
 			RB_CLEAR_NODE(&pos->al.rb_node);
 			continue;
 		}
-		disasm_rb_tree__insert(&browser->entries, &pos->al);
+		disasm_rb_tree__insert(browser, &pos->al);
 	}
 	pthread_mutex_unlock(&notes->lock);
 
diff --git a/tools/perf/util/cpumap.c b/tools/perf/util/cpumap.c
index 1ccbd3342069..383674f448fc 100644
--- a/tools/perf/util/cpumap.c
+++ b/tools/perf/util/cpumap.c
@@ -134,7 +134,12 @@ struct cpu_map *cpu_map__new(const char *cpu_list)
 	if (!cpu_list)
 		return cpu_map__read_all_cpu_map();
 
-	if (!isdigit(*cpu_list))
+	/*
+	 * must handle the case of empty cpumap to cover
+	 * TOPOLOGY header for NUMA nodes with no CPU
+	 * ( e.g., because of CPU hotplug)
+	 */
+	if (!isdigit(*cpu_list) && *cpu_list != '\0')
 		goto out;
 
 	while (isdigit(*cpu_list)) {
@@ -181,8 +186,10 @@ struct cpu_map *cpu_map__new(const char *cpu_list)
 
 	if (nr_cpus > 0)
 		cpus = cpu_map__trim_new(nr_cpus, tmp_cpus);
-	else
+	else if (*cpu_list != '\0')
 		cpus = cpu_map__default_new();
+	else
+		cpus = cpu_map__dummy_new();
 invalid:
 	free(tmp_cpus);
 out:
diff --git a/tools/perf/util/ordered-events.c b/tools/perf/util/ordered-events.c
index 897589507d97..ea523d3b248f 100644
--- a/tools/perf/util/ordered-events.c
+++ b/tools/perf/util/ordered-events.c
@@ -391,8 +391,10 @@ void ordered_events__free(struct ordered_events *oe)
 	 * Current buffer might not have all the events allocated
 	 * yet, we need to free only allocated ones ...
 	 */
-	list_del(&oe->buffer->list);
-	ordered_events_buffer__free(oe->buffer, oe->buffer_idx, oe);
+	if (oe->buffer) {
+		list_del(&oe->buffer->list);
+		ordered_events_buffer__free(oe->buffer, oe->buffer_idx, oe);
+	}
 
 	/* ... and continue with the rest */
 	list_for_each_entry_safe(buffer, tmp, &oe->to_free, list) {
diff --git a/tools/perf/util/setup.py b/tools/perf/util/setup.py
index 63f758c655d5..64d1f36dee99 100644
--- a/tools/perf/util/setup.py
+++ b/tools/perf/util/setup.py
@@ -17,6 +17,8 @@ if cc == "clang":
             vars[var] = sub("-mcet", "", vars[var])
         if not clang_has_option("-fcf-protection"):
             vars[var] = sub("-fcf-protection", "", vars[var])
+        if not clang_has_option("-fstack-clash-protection"):
+            vars[var] = sub("-fstack-clash-protection", "", vars[var])
 
 from distutils.core import setup, Extension
 
diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
index 1a2bd15c5b6e..400ee81a3043 100644
--- a/tools/testing/selftests/Makefile
+++ b/tools/testing/selftests/Makefile
@@ -10,6 +10,7 @@ TARGETS += drivers/dma-buf
 TARGETS += efivarfs
 TARGETS += exec
 TARGETS += filesystems
+TARGETS += filesystems/binderfs
 TARGETS += firmware
 TARGETS += ftrace
 TARGETS += futex
diff --git a/tools/testing/selftests/cpu-hotplug/cpu-on-off-test.sh b/tools/testing/selftests/cpu-hotplug/cpu-on-off-test.sh
index bab13dd025a6..0d26b5e3f966 100755
--- a/tools/testing/selftests/cpu-hotplug/cpu-on-off-test.sh
+++ b/tools/testing/selftests/cpu-hotplug/cpu-on-off-test.sh
@@ -37,6 +37,10 @@ prerequisite()
 		exit $ksft_skip
 	fi
 
+	present_cpus=`cat $SYSFS/devices/system/cpu/present`
+	present_max=${present_cpus##*-}
+	echo "present_cpus = $present_cpus present_max = $present_max"
+
 	echo -e "\t Cpus in online state: $online_cpus"
 
 	offline_cpus=`cat $SYSFS/devices/system/cpu/offline`
@@ -151,6 +155,8 @@ online_cpus=0
 online_max=0
 offline_cpus=0
 offline_max=0
+present_cpus=0
+present_max=0
 
 while getopts e:ahp: opt; do
 	case $opt in
@@ -190,9 +196,10 @@ if [ $allcpus -eq 0 ]; then
 	online_cpu_expect_success $online_max
 
 	if [[ $offline_cpus -gt 0 ]]; then
-		echo -e "\t offline to online to offline: cpu $offline_max"
-		online_cpu_expect_success $offline_max
-		offline_cpu_expect_success $offline_max
+		echo -e "\t offline to online to offline: cpu $present_max"
+		online_cpu_expect_success $present_max
+		offline_cpu_expect_success $present_max
+		online_cpu $present_max
 	fi
 	exit 0
 else
diff --git a/tools/testing/selftests/filesystems/binderfs/.gitignore b/tools/testing/selftests/filesystems/binderfs/.gitignore
new file mode 100644
index 000000000000..8a5d9bf63dd4
--- /dev/null
+++ b/tools/testing/selftests/filesystems/binderfs/.gitignore
@@ -0,0 +1 @@
+binderfs_test
diff --git a/tools/testing/selftests/filesystems/binderfs/Makefile b/tools/testing/selftests/filesystems/binderfs/Makefile
new file mode 100644
index 000000000000..58cb659b56b4
--- /dev/null
+++ b/tools/testing/selftests/filesystems/binderfs/Makefile
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0
+
+CFLAGS += -I../../../../../usr/include/
+TEST_GEN_PROGS := binderfs_test
+
+include ../../lib.mk
diff --git a/tools/testing/selftests/filesystems/binderfs/binderfs_test.c b/tools/testing/selftests/filesystems/binderfs/binderfs_test.c
new file mode 100644
index 000000000000..8c2ed962e1c7
--- /dev/null
+++ b/tools/testing/selftests/filesystems/binderfs/binderfs_test.c
@@ -0,0 +1,275 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#define _GNU_SOURCE
+#include <errno.h>
+#include <fcntl.h>
+#include <sched.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <sys/mount.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <linux/android/binder.h>
+#include <linux/android/binderfs.h>
+#include "../../kselftest.h"
+
+static ssize_t write_nointr(int fd, const void *buf, size_t count)
+{
+	ssize_t ret;
+again:
+	ret = write(fd, buf, count);
+	if (ret < 0 && errno == EINTR)
+		goto again;
+
+	return ret;
+}
+
+static void write_to_file(const char *filename, const void *buf, size_t count,
+			  int allowed_errno)
+{
+	int fd, saved_errno;
+	ssize_t ret;
+
+	fd = open(filename, O_WRONLY | O_CLOEXEC);
+	if (fd < 0)
+		ksft_exit_fail_msg("%s - Failed to open file %s\n",
+				   strerror(errno), filename);
+
+	ret = write_nointr(fd, buf, count);
+	if (ret < 0) {
+		if (allowed_errno && (errno == allowed_errno)) {
+			close(fd);
+			return;
+		}
+
+		goto on_error;
+	}
+
+	if ((size_t)ret != count)
+		goto on_error;
+
+	close(fd);
+	return;
+
+on_error:
+	saved_errno = errno;
+	close(fd);
+	errno = saved_errno;
+
+	if (ret < 0)
+		ksft_exit_fail_msg("%s - Failed to write to file %s\n",
+				   strerror(errno), filename);
+
+	ksft_exit_fail_msg("Failed to write to file %s\n", filename);
+}
+
+static void change_to_userns(void)
+{
+	int ret;
+	uid_t uid;
+	gid_t gid;
+	/* {g,u}id_map files only allow a max of 4096 bytes written to them */
+	char idmap[4096];
+
+	uid = getuid();
+	gid = getgid();
+
+	ret = unshare(CLONE_NEWUSER);
+	if (ret < 0)
+		ksft_exit_fail_msg("%s - Failed to unshare user namespace\n",
+				   strerror(errno));
+
+	write_to_file("/proc/self/setgroups", "deny", strlen("deny"), ENOENT);
+
+	ret = snprintf(idmap, sizeof(idmap), "0 %d 1", uid);
+	if (ret < 0 || (size_t)ret >= sizeof(idmap))
+		ksft_exit_fail_msg("%s - Failed to prepare uid mapping\n",
+				   strerror(errno));
+
+	write_to_file("/proc/self/uid_map", idmap, strlen(idmap), 0);
+
+	ret = snprintf(idmap, sizeof(idmap), "0 %d 1", gid);
+	if (ret < 0 || (size_t)ret >= sizeof(idmap))
+		ksft_exit_fail_msg("%s - Failed to prepare uid mapping\n",
+				   strerror(errno));
+
+	write_to_file("/proc/self/gid_map", idmap, strlen(idmap), 0);
+
+	ret = setgid(0);
+	if (ret)
+		ksft_exit_fail_msg("%s - Failed to setgid(0)\n",
+				   strerror(errno));
+
+	ret = setuid(0);
+	if (ret)
+		ksft_exit_fail_msg("%s - Failed to setgid(0)\n",
+				   strerror(errno));
+}
+
+static void change_to_mountns(void)
+{
+	int ret;
+
+	ret = unshare(CLONE_NEWNS);
+	if (ret < 0)
+		ksft_exit_fail_msg("%s - Failed to unshare mount namespace\n",
+				   strerror(errno));
+
+	ret = mount(NULL, "/", NULL, MS_REC | MS_PRIVATE, 0);
+	if (ret < 0)
+		ksft_exit_fail_msg("%s - Failed to mount / as private\n",
+				   strerror(errno));
+}
+
+static void rmdir_protect_errno(const char *dir)
+{
+	int saved_errno = errno;
+	(void)rmdir(dir);
+	errno = saved_errno;
+}
+
+static void __do_binderfs_test(void)
+{
+	int fd, ret, saved_errno;
+	size_t len;
+	ssize_t wret;
+	bool keep = false;
+	struct binderfs_device device = { 0 };
+	struct binder_version version = { 0 };
+
+	change_to_mountns();
+
+	ret = mkdir("/dev/binderfs", 0755);
+	if (ret < 0) {
+		if (errno != EEXIST)
+			ksft_exit_fail_msg(
+				"%s - Failed to create binderfs mountpoint\n",
+				strerror(errno));
+
+		keep = true;
+	}
+
+	ret = mount(NULL, "/dev/binderfs", "binder", 0, 0);
+	if (ret < 0) {
+		if (errno != ENODEV)
+			ksft_exit_fail_msg("%s - Failed to mount binderfs\n",
+					   strerror(errno));
+
+		keep ? : rmdir_protect_errno("/dev/binderfs");
+		ksft_exit_skip(
+			"The Android binderfs filesystem is not available\n");
+	}
+
+	/* binderfs mount test passed */
+	ksft_inc_pass_cnt();
+
+	memcpy(device.name, "my-binder", strlen("my-binder"));
+
+	fd = open("/dev/binderfs/binder-control", O_RDONLY | O_CLOEXEC);
+	if (fd < 0)
+		ksft_exit_fail_msg(
+			"%s - Failed to open binder-control device\n",
+			strerror(errno));
+
+	ret = ioctl(fd, BINDER_CTL_ADD, &device);
+	saved_errno = errno;
+	close(fd);
+	errno = saved_errno;
+	if (ret < 0) {
+		keep ? : rmdir_protect_errno("/dev/binderfs");
+		ksft_exit_fail_msg(
+			"%s - Failed to allocate new binder device\n",
+			strerror(errno));
+	}
+
+	ksft_print_msg(
+		"Allocated new binder device with major %d, minor %d, and name %s\n",
+		device.major, device.minor, device.name);
+
+	/* binder device allocation test passed */
+	ksft_inc_pass_cnt();
+
+	fd = open("/dev/binderfs/my-binder", O_CLOEXEC | O_RDONLY);
+	if (fd < 0) {
+		keep ? : rmdir_protect_errno("/dev/binderfs");
+		ksft_exit_fail_msg("%s - Failed to open my-binder device\n",
+				   strerror(errno));
+	}
+
+	ret = ioctl(fd, BINDER_VERSION, &version);
+	saved_errno = errno;
+	close(fd);
+	errno = saved_errno;
+	if (ret < 0) {
+		keep ? : rmdir_protect_errno("/dev/binderfs");
+		ksft_exit_fail_msg(
+			"%s - Failed to open perform BINDER_VERSION request\n",
+			strerror(errno));
+	}
+
+	ksft_print_msg("Detected binder version: %d\n",
+		       version.protocol_version);
+
+	/* binder transaction with binderfs binder device passed */
+	ksft_inc_pass_cnt();
+
+	ret = unlink("/dev/binderfs/my-binder");
+	if (ret < 0) {
+		keep ? : rmdir_protect_errno("/dev/binderfs");
+		ksft_exit_fail_msg("%s - Failed to delete binder device\n",
+				   strerror(errno));
+	}
+
+	/* binder device removal passed */
+	ksft_inc_pass_cnt();
+
+	ret = unlink("/dev/binderfs/binder-control");
+	if (!ret) {
+		keep ? : rmdir_protect_errno("/dev/binderfs");
+		ksft_exit_fail_msg("Managed to delete binder-control device\n");
+	} else if (errno != EPERM) {
+		keep ? : rmdir_protect_errno("/dev/binderfs");
+		ksft_exit_fail_msg(
+			"%s - Failed to delete binder-control device but exited with unexpected error code\n",
+			strerror(errno));
+	}
+
+	/* binder-control device removal failed as expected */
+	ksft_inc_xfail_cnt();
+
+on_error:
+	ret = umount2("/dev/binderfs", MNT_DETACH);
+	keep ?: rmdir_protect_errno("/dev/binderfs");
+	if (ret < 0)
+		ksft_exit_fail_msg("%s - Failed to unmount binderfs\n",
+				   strerror(errno));
+
+	/* binderfs unmount test passed */
+	ksft_inc_pass_cnt();
+}
+
+static void binderfs_test_privileged()
+{
+	if (geteuid() != 0)
+		ksft_print_msg(
+			"Tests are not run as root. Skipping privileged tests\n");
+	else
+		__do_binderfs_test();
+}
+
+static void binderfs_test_unprivileged()
+{
+	change_to_userns();
+	__do_binderfs_test();
+}
+
+int main(int argc, char *argv[])
+{
+	binderfs_test_privileged();
+	binderfs_test_unprivileged();
+	ksft_exit_pass();
+}
diff --git a/tools/testing/selftests/filesystems/binderfs/config b/tools/testing/selftests/filesystems/binderfs/config
new file mode 100644
index 000000000000..02dd6cc9cf99
--- /dev/null
+++ b/tools/testing/selftests/filesystems/binderfs/config
@@ -0,0 +1,3 @@
+CONFIG_ANDROID=y
+CONFIG_ANDROID_BINDERFS=y
+CONFIG_ANDROID_BINDER_IPC=y
diff --git a/tools/testing/selftests/ir/Makefile b/tools/testing/selftests/ir/Makefile
index f4ba8eb84b95..ad06489c22a5 100644
--- a/tools/testing/selftests/ir/Makefile
+++ b/tools/testing/selftests/ir/Makefile
@@ -1,5 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
 TEST_PROGS := ir_loopback.sh
 TEST_GEN_PROGS_EXTENDED := ir_loopback
+APIDIR := ../../../include/uapi
+CFLAGS += -Wall -O2 -I$(APIDIR)
 
 include ../lib.mk
diff --git a/tools/testing/selftests/net/Makefile b/tools/testing/selftests/net/Makefile
index f8f3e90700c0..1e6d14d2825c 100644
--- a/tools/testing/selftests/net/Makefile
+++ b/tools/testing/selftests/net/Makefile
@@ -21,6 +21,6 @@ TEST_GEN_PROGS += reuseport_dualstack reuseaddr_conflict tls
 KSFT_KHDR_INSTALL := 1
 include ../lib.mk
 
-$(OUTPUT)/reuseport_bpf_numa: LDFLAGS += -lnuma
+$(OUTPUT)/reuseport_bpf_numa: LDLIBS += -lnuma
 $(OUTPUT)/tcp_mmap: LDFLAGS += -lpthread
 $(OUTPUT)/tcp_inq: LDFLAGS += -lpthread
diff --git a/tools/testing/selftests/proc/.gitignore b/tools/testing/selftests/proc/.gitignore
index 82121a81681f..29bac5ef9a93 100644
--- a/tools/testing/selftests/proc/.gitignore
+++ b/tools/testing/selftests/proc/.gitignore
@@ -10,4 +10,5 @@
 /proc-uptime-002
 /read
 /self
+/setns-dcache
 /thread-self
diff --git a/tools/testing/selftests/proc/Makefile b/tools/testing/selftests/proc/Makefile
index 1c12c34cf85d..434d033ee067 100644
--- a/tools/testing/selftests/proc/Makefile
+++ b/tools/testing/selftests/proc/Makefile
@@ -14,6 +14,7 @@ TEST_GEN_PROGS += proc-uptime-001
 TEST_GEN_PROGS += proc-uptime-002
 TEST_GEN_PROGS += read
 TEST_GEN_PROGS += self
+TEST_GEN_PROGS += setns-dcache
 TEST_GEN_PROGS += thread-self
 
 include ../lib.mk
diff --git a/tools/testing/selftests/proc/setns-dcache.c b/tools/testing/selftests/proc/setns-dcache.c
new file mode 100644
index 000000000000..60ab197a73fc
--- /dev/null
+++ b/tools/testing/selftests/proc/setns-dcache.c
@@ -0,0 +1,129 @@
+/*
+ * Copyright © 2019 Alexey Dobriyan <adobriyan@gmail.com>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+/*
+ * Test that setns(CLONE_NEWNET) points to new /proc/net content even
+ * if old one is in dcache.
+ *
+ * FIXME /proc/net/unix is under CONFIG_UNIX which can be disabled.
+ */
+#undef NDEBUG
+#include <assert.h>
+#include <errno.h>
+#include <sched.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <sys/socket.h>
+
+static pid_t pid = -1;
+
+static void f(void)
+{
+	if (pid > 0) {
+		kill(pid, SIGTERM);
+	}
+}
+
+int main(void)
+{
+	int fd[2];
+	char _ = 0;
+	int nsfd;
+
+	atexit(f);
+
+	/* Check for priviledges and syscall availability straight away. */
+	if (unshare(CLONE_NEWNET) == -1) {
+		if (errno == ENOSYS || errno == EPERM) {
+			return 4;
+		}
+		return 1;
+	}
+	/* Distinguisher between two otherwise empty net namespaces. */
+	if (socket(AF_UNIX, SOCK_STREAM, 0) == -1) {
+		return 1;
+	}
+
+	if (pipe(fd) == -1) {
+		return 1;
+	}
+
+	pid = fork();
+	if (pid == -1) {
+		return 1;
+	}
+
+	if (pid == 0) {
+		if (unshare(CLONE_NEWNET) == -1) {
+			return 1;
+		}
+
+		if (write(fd[1], &_, 1) != 1) {
+			return 1;
+		}
+
+		pause();
+
+		return 0;
+	}
+
+	if (read(fd[0], &_, 1) != 1) {
+		return 1;
+	}
+
+	{
+		char buf[64];
+		snprintf(buf, sizeof(buf), "/proc/%u/ns/net", pid);
+		nsfd = open(buf, O_RDONLY);
+		if (nsfd == -1) {
+			return 1;
+		}
+	}
+
+	/* Reliably pin dentry into dcache. */
+	(void)open("/proc/net/unix", O_RDONLY);
+
+	if (setns(nsfd, CLONE_NEWNET) == -1) {
+		return 1;
+	}
+
+	kill(pid, SIGTERM);
+	pid = 0;
+
+	{
+		char buf[4096];
+		ssize_t rv;
+		int fd;
+
+		fd = open("/proc/net/unix", O_RDONLY);
+		if (fd == -1) {
+			return 1;
+		}
+
+#define S "Num       RefCount Protocol Flags    Type St Inode Path\n"
+		rv = read(fd, buf, sizeof(buf));
+
+		assert(rv == strlen(S));
+		assert(memcmp(buf, S, strlen(S)) == 0);
+	}
+
+	return 0;
+}
diff --git a/tools/testing/selftests/seccomp/seccomp_bpf.c b/tools/testing/selftests/seccomp/seccomp_bpf.c
index 496a9a8c773a..7e632b465ab4 100644
--- a/tools/testing/selftests/seccomp/seccomp_bpf.c
+++ b/tools/testing/selftests/seccomp/seccomp_bpf.c
@@ -1608,7 +1608,16 @@ TEST_F(TRACE_poke, getpid_runs_normally)
 #ifdef SYSCALL_NUM_RET_SHARE_REG
 # define EXPECT_SYSCALL_RETURN(val, action)	EXPECT_EQ(-1, action)
 #else
-# define EXPECT_SYSCALL_RETURN(val, action)	EXPECT_EQ(val, action)
+# define EXPECT_SYSCALL_RETURN(val, action)		\
+	do {						\
+		errno = 0;				\
+		if (val < 0) {				\
+			EXPECT_EQ(-1, action);		\
+			EXPECT_EQ(-(val), errno);	\
+		} else {				\
+			EXPECT_EQ(val, action);		\
+		}					\
+	} while (0)
 #endif
 
 /* Use PTRACE_GETREGS and PTRACE_SETREGS when available. This is useful for
@@ -1647,7 +1656,7 @@ int get_syscall(struct __test_metadata *_metadata, pid_t tracee)
 
 /* Architecture-specific syscall changing routine. */
 void change_syscall(struct __test_metadata *_metadata,
-		    pid_t tracee, int syscall)
+		    pid_t tracee, int syscall, int result)
 {
 	int ret;
 	ARCH_REGS regs;
@@ -1706,7 +1715,7 @@ void change_syscall(struct __test_metadata *_metadata,
 #ifdef SYSCALL_NUM_RET_SHARE_REG
 		TH_LOG("Can't modify syscall return on this architecture");
 #else
-		regs.SYSCALL_RET = EPERM;
+		regs.SYSCALL_RET = result;
 #endif
 
 #ifdef HAVE_GETREGS
@@ -1734,14 +1743,19 @@ void tracer_syscall(struct __test_metadata *_metadata, pid_t tracee,
 	case 0x1002:
 		/* change getpid to getppid. */
 		EXPECT_EQ(__NR_getpid, get_syscall(_metadata, tracee));
-		change_syscall(_metadata, tracee, __NR_getppid);
+		change_syscall(_metadata, tracee, __NR_getppid, 0);
 		break;
 	case 0x1003:
-		/* skip gettid. */
+		/* skip gettid with valid return code. */
 		EXPECT_EQ(__NR_gettid, get_syscall(_metadata, tracee));
-		change_syscall(_metadata, tracee, -1);
+		change_syscall(_metadata, tracee, -1, 45000);
 		break;
 	case 0x1004:
+		/* skip openat with error. */
+		EXPECT_EQ(__NR_openat, get_syscall(_metadata, tracee));
+		change_syscall(_metadata, tracee, -1, -ESRCH);
+		break;
+	case 0x1005:
 		/* do nothing (allow getppid) */
 		EXPECT_EQ(__NR_getppid, get_syscall(_metadata, tracee));
 		break;
@@ -1774,9 +1788,11 @@ void tracer_ptrace(struct __test_metadata *_metadata, pid_t tracee,
 	nr = get_syscall(_metadata, tracee);
 
 	if (nr == __NR_getpid)
-		change_syscall(_metadata, tracee, __NR_getppid);
+		change_syscall(_metadata, tracee, __NR_getppid, 0);
+	if (nr == __NR_gettid)
+		change_syscall(_metadata, tracee, -1, 45000);
 	if (nr == __NR_openat)
-		change_syscall(_metadata, tracee, -1);
+		change_syscall(_metadata, tracee, -1, -ESRCH);
 }
 
 FIXTURE_DATA(TRACE_syscall) {
@@ -1793,8 +1809,10 @@ FIXTURE_SETUP(TRACE_syscall)
 		BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1002),
 		BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_gettid, 0, 1),
 		BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1003),
-		BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
+		BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_openat, 0, 1),
 		BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1004),
+		BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
+		BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1005),
 		BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
 	};
 
@@ -1842,15 +1860,26 @@ TEST_F(TRACE_syscall, ptrace_syscall_redirected)
 	EXPECT_NE(self->mypid, syscall(__NR_getpid));
 }
 
-TEST_F(TRACE_syscall, ptrace_syscall_dropped)
+TEST_F(TRACE_syscall, ptrace_syscall_errno)
+{
+	/* Swap SECCOMP_RET_TRACE tracer for PTRACE_SYSCALL tracer. */
+	teardown_trace_fixture(_metadata, self->tracer);
+	self->tracer = setup_trace_fixture(_metadata, tracer_ptrace, NULL,
+					   true);
+
+	/* Tracer should skip the open syscall, resulting in ESRCH. */
+	EXPECT_SYSCALL_RETURN(-ESRCH, syscall(__NR_openat));
+}
+
+TEST_F(TRACE_syscall, ptrace_syscall_faked)
 {
 	/* Swap SECCOMP_RET_TRACE tracer for PTRACE_SYSCALL tracer. */
 	teardown_trace_fixture(_metadata, self->tracer);
 	self->tracer = setup_trace_fixture(_metadata, tracer_ptrace, NULL,
 					   true);
 
-	/* Tracer should skip the open syscall, resulting in EPERM. */
-	EXPECT_SYSCALL_RETURN(EPERM, syscall(__NR_openat));
+	/* Tracer should skip the gettid syscall, resulting fake pid. */
+	EXPECT_SYSCALL_RETURN(45000, syscall(__NR_gettid));
 }
 
 TEST_F(TRACE_syscall, syscall_allowed)
@@ -1883,7 +1912,21 @@ TEST_F(TRACE_syscall, syscall_redirected)
 	EXPECT_NE(self->mypid, syscall(__NR_getpid));
 }
 
-TEST_F(TRACE_syscall, syscall_dropped)
+TEST_F(TRACE_syscall, syscall_errno)
+{
+	long ret;
+
+	ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
+	ASSERT_EQ(0, ret);
+
+	ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
+	ASSERT_EQ(0, ret);
+
+	/* openat has been skipped and an errno return. */
+	EXPECT_SYSCALL_RETURN(-ESRCH, syscall(__NR_openat));
+}
+
+TEST_F(TRACE_syscall, syscall_faked)
 {
 	long ret;
 
@@ -1894,8 +1937,7 @@ TEST_F(TRACE_syscall, syscall_dropped)
 	ASSERT_EQ(0, ret);
 
 	/* gettid has been skipped and an altered return value stored. */
-	EXPECT_SYSCALL_RETURN(EPERM, syscall(__NR_gettid));
-	EXPECT_NE(self->mytid, syscall(__NR_gettid));
+	EXPECT_SYSCALL_RETURN(45000, syscall(__NR_gettid));
 }
 
 TEST_F(TRACE_syscall, skip_after_RET_TRACE)
diff --git a/tools/testing/selftests/timers/Makefile b/tools/testing/selftests/timers/Makefile
index c02683cfb6c9..7656c7ce79d9 100644
--- a/tools/testing/selftests/timers/Makefile
+++ b/tools/testing/selftests/timers/Makefile
@@ -1,6 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0
 CFLAGS += -O3 -Wl,-no-as-needed -Wall
-LDFLAGS += -lrt -lpthread -lm
+LDLIBS += -lrt -lpthread -lm
 
 # these are all "safe" tests that don't modify
 # system time or require escalated privileges