selftests/bpf: Add sleepable tests

Modify few tests to sanity test sleepable bpf functionality.

Running 'bench trig-fentry-sleep' vs 'bench trig-fentry' and 'perf report':
sleepable with SRCU:
   3.86%  bench     [k] __srcu_read_unlock
   3.22%  bench     [k] __srcu_read_lock
   0.92%  bench     [k] bpf_prog_740d4210cdcd99a3_bench_trigger_fentry_sleep
   0.50%  bench     [k] bpf_trampoline_10297
   0.26%  bench     [k] __bpf_prog_exit_sleepable
   0.21%  bench     [k] __bpf_prog_enter_sleepable

sleepable with RCU_TRACE:
   0.79%  bench     [k] bpf_prog_740d4210cdcd99a3_bench_trigger_fentry_sleep
   0.72%  bench     [k] bpf_trampoline_10381
   0.31%  bench     [k] __bpf_prog_exit_sleepable
   0.29%  bench     [k] __bpf_prog_enter_sleepable

non-sleepable with RCU:
   0.88%  bench     [k] bpf_prog_740d4210cdcd99a3_bench_trigger_fentry
   0.84%  bench     [k] bpf_trampoline_10297
   0.13%  bench     [k] __bpf_prog_enter
   0.12%  bench     [k] __bpf_prog_exit

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: KP Singh <kpsingh@google.com>
Link: https://lore.kernel.org/bpf/20200827220114.69225-6-alexei.starovoitov@gmail.com

tools/testing/selftests/bpf/bench.c

@@ -317,6 +317,7 @@ extern const struct bench bench_trig_tp;
 extern const struct bench bench_trig_rawtp;
 extern const struct bench bench_trig_kprobe;
 extern const struct bench bench_trig_fentry;
+extern const struct bench bench_trig_fentry_sleep;
 extern const struct bench bench_trig_fmodret;
 extern const struct bench bench_rb_libbpf;
 extern const struct bench bench_rb_custom;
@@ -338,6 +339,7 @@ static const struct bench *benchs[] = {
 	&bench_trig_rawtp,
 	&bench_trig_kprobe,
 	&bench_trig_fentry,
+	&bench_trig_fentry_sleep,
 	&bench_trig_fmodret,
 	&bench_rb_libbpf,
 	&bench_rb_custom,

tools/testing/selftests/bpf/benchs/bench_trigger.c

@@ -90,6 +90,12 @@ static void trigger_fentry_setup()
 	attach_bpf(ctx.skel->progs.bench_trigger_fentry);
 }
 
+static void trigger_fentry_sleep_setup()
+{
+	setup_ctx();
+	attach_bpf(ctx.skel->progs.bench_trigger_fentry_sleep);
+}
+
 static void trigger_fmodret_setup()
 {
 	setup_ctx();
@@ -155,6 +161,17 @@ const struct bench bench_trig_fentry = {
 	.report_final = hits_drops_report_final,
 };
 
+const struct bench bench_trig_fentry_sleep = {
+	.name = "trig-fentry-sleep",
+	.validate = trigger_validate,
+	.setup = trigger_fentry_sleep_setup,
+	.producer_thread = trigger_producer,
+	.consumer_thread = trigger_consumer,
+	.measure = trigger_measure,
+	.report_progress = hits_drops_report_progress,
+	.report_final = hits_drops_report_final,
+};
+
 const struct bench bench_trig_fmodret = {
 	.name = "trig-fmodret",
 	.validate = trigger_validate,

tools/testing/selftests/bpf/prog_tests/test_lsm.c

@@ -10,6 +10,7 @@
 #include <unistd.h>
 #include <malloc.h>
 #include <stdlib.h>
+#include <unistd.h>
 
 #include "lsm.skel.h"
 
@@ -55,6 +56,7 @@ void test_test_lsm(void)
 {
 	struct lsm *skel = NULL;
 	int err, duration = 0;
+	int buf = 1234;
 
 	skel = lsm__open_and_load();
 	if (CHECK(!skel, "skel_load", "lsm skeleton failed\n"))
@@ -81,6 +83,13 @@ void test_test_lsm(void)
 	CHECK(skel->bss->mprotect_count != 1, "mprotect_count",
 	      "mprotect_count = %d\n", skel->bss->mprotect_count);
 
+	syscall(__NR_setdomainname, &buf, -2L);
+	syscall(__NR_setdomainname, 0, -3L);
+	syscall(__NR_setdomainname, ~0L, -4L);
+
+	CHECK(skel->bss->copy_test != 3, "copy_test",
+	      "copy_test = %d\n", skel->bss->copy_test);
+
 close_prog:
 	lsm__destroy(skel);
 }

tools/testing/selftests/bpf/progs/lsm.c

@@ -9,16 +9,41 @@
 #include <bpf/bpf_tracing.h>
 #include  <errno.h>
 
+struct {
+	__uint(type, BPF_MAP_TYPE_ARRAY);
+	__uint(max_entries, 1);
+	__type(key, __u32);
+	__type(value, __u64);
+} array SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__uint(max_entries, 1);
+	__type(key, __u32);
+	__type(value, __u64);
+} hash SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_LRU_HASH);
+	__uint(max_entries, 1);
+	__type(key, __u32);
+	__type(value, __u64);
+} lru_hash SEC(".maps");
+
 char _license[] SEC("license") = "GPL";
 
 int monitored_pid = 0;
 int mprotect_count = 0;
 int bprm_count = 0;
 
-SEC("lsm/file_mprotect")
+SEC("lsm.s/file_mprotect")
 int BPF_PROG(test_int_hook, struct vm_area_struct *vma,
 	     unsigned long reqprot, unsigned long prot, int ret)
 {
+	char args[64];
+	__u32 key = 0;
+	__u64 *value;
+
 	if (ret != 0)
 		return ret;
 
@@ -28,6 +53,18 @@ int BPF_PROG(test_int_hook, struct vm_area_struct *vma,
 	is_stack = (vma->vm_start <= vma->vm_mm->start_stack &&
 		    vma->vm_end >= vma->vm_mm->start_stack);
 
+	bpf_copy_from_user(args, sizeof(args), (void *)vma->vm_mm->arg_start);
+
+	value = bpf_map_lookup_elem(&array, &key);
+	if (value)
+		*value = 0;
+	value = bpf_map_lookup_elem(&hash, &key);
+	if (value)
+		*value = 0;
+	value = bpf_map_lookup_elem(&lru_hash, &key);
+	if (value)
+		*value = 0;
+
 	if (is_stack && monitored_pid == pid) {
 		mprotect_count++;
 		ret = -EPERM;
@@ -36,7 +73,7 @@ int BPF_PROG(test_int_hook, struct vm_area_struct *vma,
 	return ret;
 }
 
-SEC("lsm/bprm_committed_creds")
+SEC("lsm.s/bprm_committed_creds")
 int BPF_PROG(test_void_hook, struct linux_binprm *bprm)
 {
 	__u32 pid = bpf_get_current_pid_tgid() >> 32;
@@ -46,3 +83,28 @@ int BPF_PROG(test_void_hook, struct linux_binprm *bprm)
 
 	return 0;
 }
+SEC("lsm/task_free") /* lsm/ is ok, lsm.s/ fails */
+int BPF_PROG(test_task_free, struct task_struct *task)
+{
+	return 0;
+}
+
+int copy_test = 0;
+
+SEC("fentry.s/__x64_sys_setdomainname")
+int BPF_PROG(test_sys_setdomainname, struct pt_regs *regs)
+{
+	void *ptr = (void *)PT_REGS_PARM1(regs);
+	int len = PT_REGS_PARM2(regs);
+	int buf = 0;
+	long ret;
+
+	ret = bpf_copy_from_user(&buf, sizeof(buf), ptr);
+	if (len == -2 && ret == 0 && buf == 1234)
+		copy_test++;
+	if (len == -3 && ret == -EFAULT)
+		copy_test++;
+	if (len == -4 && ret == -EFAULT)
+		copy_test++;
+	return 0;
+}

tools/testing/selftests/bpf/progs/trigger_bench.c

@@ -39,6 +39,13 @@ int bench_trigger_fentry(void *ctx)
 	return 0;
 }
 
+SEC("fentry.s/__x64_sys_getpgid")
+int bench_trigger_fentry_sleep(void *ctx)
+{
+	__sync_add_and_fetch(&hits, 1);
+	return 0;
+}
+
 SEC("fmod_ret/__x64_sys_getpgid")
 int bench_trigger_fmodret(void *ctx)
 {