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-rw-r--r--tools/testing/selftests/bpf/Makefile11
-rw-r--r--tools/testing/selftests/bpf/prog_tests/usdt.c108
-rw-r--r--tools/testing/selftests/bpf/progs/test_urandom_usdt.c70
-rw-r--r--tools/testing/selftests/bpf/progs/test_usdt_multispec.c2
-rw-r--r--tools/testing/selftests/bpf/urandom_read.c63
-rw-r--r--tools/testing/selftests/bpf/urandom_read_aux.c9
-rw-r--r--tools/testing/selftests/bpf/urandom_read_lib1.c13
-rw-r--r--tools/testing/selftests/bpf/urandom_read_lib2.c8
8 files changed, 275 insertions, 9 deletions
diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index 0f8c55dfd844..bafdc5373a13 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -168,9 +168,15 @@ $(OUTPUT)/%:%.c
$(call msg,BINARY,,$@)
$(Q)$(LINK.c) $^ $(LDLIBS) -o $@
-$(OUTPUT)/urandom_read: urandom_read.c
+$(OUTPUT)/liburandom_read.so: urandom_read_lib1.c urandom_read_lib2.c
+ $(call msg,LIB,,$@)
+ $(Q)$(CC) $(CFLAGS) -fPIC $(LDFLAGS) $^ $(LDLIBS) --shared -o $@
+
+$(OUTPUT)/urandom_read: urandom_read.c urandom_read_aux.c $(OUTPUT)/liburandom_read.so
$(call msg,BINARY,,$@)
- $(Q)$(CC) $(CFLAGS) $(LDFLAGS) $< $(LDLIBS) -Wl,--build-id=sha1 -o $@
+ $(Q)$(CC) $(CFLAGS) $(LDFLAGS) $(filter %.c,$^) \
+ liburandom_read.so $(LDLIBS) \
+ -Wl,-rpath=. -Wl,--build-id=sha1 -o $@
$(OUTPUT)/bpf_testmod.ko: $(VMLINUX_BTF) $(wildcard bpf_testmod/Makefile bpf_testmod/*.[ch])
$(call msg,MOD,,$@)
@@ -493,6 +499,7 @@ TRUNNER_EXTRA_SOURCES := test_progs.c cgroup_helpers.c trace_helpers.c \
btf_helpers.c flow_dissector_load.h \
cap_helpers.c
TRUNNER_EXTRA_FILES := $(OUTPUT)/urandom_read $(OUTPUT)/bpf_testmod.ko \
+ $(OUTPUT)/liburandom_read.so \
ima_setup.sh \
$(wildcard progs/btf_dump_test_case_*.c)
TRUNNER_BPF_BUILD_RULE := CLANG_BPF_BUILD_RULE
diff --git a/tools/testing/selftests/bpf/prog_tests/usdt.c b/tools/testing/selftests/bpf/prog_tests/usdt.c
index 0677c9bfd40b..a71f51bdc08d 100644
--- a/tools/testing/selftests/bpf/prog_tests/usdt.c
+++ b/tools/testing/selftests/bpf/prog_tests/usdt.c
@@ -6,6 +6,7 @@
#include "../sdt.h"
#include "test_usdt.skel.h"
+#include "test_urandom_usdt.skel.h"
int lets_test_this(int);
@@ -304,10 +305,117 @@ cleanup:
test_usdt__destroy(skel);
}
+static FILE *urand_spawn(int *pid)
+{
+ FILE *f;
+
+ /* urandom_read's stdout is wired into f */
+ f = popen("./urandom_read 1 report-pid", "r");
+ if (!f)
+ return NULL;
+
+ if (fscanf(f, "%d", pid) != 1) {
+ pclose(f);
+ return NULL;
+ }
+
+ return f;
+}
+
+static int urand_trigger(FILE **urand_pipe)
+{
+ int exit_code;
+
+ /* pclose() waits for child process to exit and returns their exit code */
+ exit_code = pclose(*urand_pipe);
+ *urand_pipe = NULL;
+
+ return exit_code;
+}
+
+static void subtest_urandom_usdt(bool auto_attach)
+{
+ struct test_urandom_usdt *skel;
+ struct test_urandom_usdt__bss *bss;
+ struct bpf_link *l;
+ FILE *urand_pipe = NULL;
+ int err, urand_pid = 0;
+
+ skel = test_urandom_usdt__open_and_load();
+ if (!ASSERT_OK_PTR(skel, "skel_open"))
+ return;
+
+ urand_pipe = urand_spawn(&urand_pid);
+ if (!ASSERT_OK_PTR(urand_pipe, "urand_spawn"))
+ goto cleanup;
+
+ bss = skel->bss;
+ bss->urand_pid = urand_pid;
+
+ if (auto_attach) {
+ err = test_urandom_usdt__attach(skel);
+ if (!ASSERT_OK(err, "skel_auto_attach"))
+ goto cleanup;
+ } else {
+ l = bpf_program__attach_usdt(skel->progs.urand_read_without_sema,
+ urand_pid, "./urandom_read",
+ "urand", "read_without_sema", NULL);
+ if (!ASSERT_OK_PTR(l, "urand_without_sema_attach"))
+ goto cleanup;
+ skel->links.urand_read_without_sema = l;
+
+ l = bpf_program__attach_usdt(skel->progs.urand_read_with_sema,
+ urand_pid, "./urandom_read",
+ "urand", "read_with_sema", NULL);
+ if (!ASSERT_OK_PTR(l, "urand_with_sema_attach"))
+ goto cleanup;
+ skel->links.urand_read_with_sema = l;
+
+ l = bpf_program__attach_usdt(skel->progs.urandlib_read_without_sema,
+ urand_pid, "./liburandom_read.so",
+ "urandlib", "read_without_sema", NULL);
+ if (!ASSERT_OK_PTR(l, "urandlib_without_sema_attach"))
+ goto cleanup;
+ skel->links.urandlib_read_without_sema = l;
+
+ l = bpf_program__attach_usdt(skel->progs.urandlib_read_with_sema,
+ urand_pid, "./liburandom_read.so",
+ "urandlib", "read_with_sema", NULL);
+ if (!ASSERT_OK_PTR(l, "urandlib_with_sema_attach"))
+ goto cleanup;
+ skel->links.urandlib_read_with_sema = l;
+
+ }
+
+ /* trigger urandom_read USDTs */
+ ASSERT_OK(urand_trigger(&urand_pipe), "urand_exit_code");
+
+ ASSERT_EQ(bss->urand_read_without_sema_call_cnt, 1, "urand_wo_sema_cnt");
+ ASSERT_EQ(bss->urand_read_without_sema_buf_sz_sum, 256, "urand_wo_sema_sum");
+
+ ASSERT_EQ(bss->urand_read_with_sema_call_cnt, 1, "urand_w_sema_cnt");
+ ASSERT_EQ(bss->urand_read_with_sema_buf_sz_sum, 256, "urand_w_sema_sum");
+
+ ASSERT_EQ(bss->urandlib_read_without_sema_call_cnt, 1, "urandlib_wo_sema_cnt");
+ ASSERT_EQ(bss->urandlib_read_without_sema_buf_sz_sum, 256, "urandlib_wo_sema_sum");
+
+ ASSERT_EQ(bss->urandlib_read_with_sema_call_cnt, 1, "urandlib_w_sema_cnt");
+ ASSERT_EQ(bss->urandlib_read_with_sema_buf_sz_sum, 256, "urandlib_w_sema_sum");
+
+cleanup:
+ if (urand_pipe)
+ pclose(urand_pipe);
+ test_urandom_usdt__destroy(skel);
+}
+
void test_usdt(void)
{
if (test__start_subtest("basic"))
subtest_basic_usdt();
if (test__start_subtest("multispec"))
subtest_multispec_usdt();
+ if (test__start_subtest("urand_auto_attach"))
+ subtest_urandom_usdt(true /* auto_attach */);
+ if (test__start_subtest("urand_pid_attach"))
+ subtest_urandom_usdt(false /* auto_attach */);
}
diff --git a/tools/testing/selftests/bpf/progs/test_urandom_usdt.c b/tools/testing/selftests/bpf/progs/test_urandom_usdt.c
new file mode 100644
index 000000000000..3539b02bd5f7
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_urandom_usdt.c
@@ -0,0 +1,70 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */
+
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+#include <bpf/usdt.bpf.h>
+
+int urand_pid;
+
+int urand_read_without_sema_call_cnt;
+int urand_read_without_sema_buf_sz_sum;
+
+SEC("usdt/./urandom_read:urand:read_without_sema")
+int BPF_USDT(urand_read_without_sema, int iter_num, int iter_cnt, int buf_sz)
+{
+ if (urand_pid != (bpf_get_current_pid_tgid() >> 32))
+ return 0;
+
+ __sync_fetch_and_add(&urand_read_without_sema_call_cnt, 1);
+ __sync_fetch_and_add(&urand_read_without_sema_buf_sz_sum, buf_sz);
+
+ return 0;
+}
+
+int urand_read_with_sema_call_cnt;
+int urand_read_with_sema_buf_sz_sum;
+
+SEC("usdt/./urandom_read:urand:read_with_sema")
+int BPF_USDT(urand_read_with_sema, int iter_num, int iter_cnt, int buf_sz)
+{
+ if (urand_pid != (bpf_get_current_pid_tgid() >> 32))
+ return 0;
+
+ __sync_fetch_and_add(&urand_read_with_sema_call_cnt, 1);
+ __sync_fetch_and_add(&urand_read_with_sema_buf_sz_sum, buf_sz);
+
+ return 0;
+}
+
+int urandlib_read_without_sema_call_cnt;
+int urandlib_read_without_sema_buf_sz_sum;
+
+SEC("usdt/./liburandom_read.so:urandlib:read_without_sema")
+int BPF_USDT(urandlib_read_without_sema, int iter_num, int iter_cnt, int buf_sz)
+{
+ if (urand_pid != (bpf_get_current_pid_tgid() >> 32))
+ return 0;
+
+ __sync_fetch_and_add(&urandlib_read_without_sema_call_cnt, 1);
+ __sync_fetch_and_add(&urandlib_read_without_sema_buf_sz_sum, buf_sz);
+
+ return 0;
+}
+
+int urandlib_read_with_sema_call_cnt;
+int urandlib_read_with_sema_buf_sz_sum;
+
+SEC("usdt/./liburandom_read.so:urandlib:read_with_sema")
+int BPF_USDT(urandlib_read_with_sema, int iter_num, int iter_cnt, int buf_sz)
+{
+ if (urand_pid != (bpf_get_current_pid_tgid() >> 32))
+ return 0;
+
+ __sync_fetch_and_add(&urandlib_read_with_sema_call_cnt, 1);
+ __sync_fetch_and_add(&urandlib_read_with_sema_buf_sz_sum, buf_sz);
+
+ return 0;
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/tools/testing/selftests/bpf/progs/test_usdt_multispec.c b/tools/testing/selftests/bpf/progs/test_usdt_multispec.c
index 3a090681f981..aa6de32b50d1 100644
--- a/tools/testing/selftests/bpf/progs/test_usdt_multispec.c
+++ b/tools/testing/selftests/bpf/progs/test_usdt_multispec.c
@@ -26,8 +26,6 @@ int BPF_USDT(usdt_100, int x)
__sync_fetch_and_add(&usdt_100_called, 1);
__sync_fetch_and_add(&usdt_100_sum, x);
- bpf_printk("X is %d, sum is %d", x, usdt_100_sum);
-
return 0;
}
diff --git a/tools/testing/selftests/bpf/urandom_read.c b/tools/testing/selftests/bpf/urandom_read.c
index db781052758d..e92644d0fa75 100644
--- a/tools/testing/selftests/bpf/urandom_read.c
+++ b/tools/testing/selftests/bpf/urandom_read.c
@@ -1,32 +1,85 @@
+#include <stdbool.h>
#include <stdio.h>
#include <unistd.h>
+#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdlib.h>
+#include <signal.h>
+
+#define _SDT_HAS_SEMAPHORES 1
+#include "sdt.h"
+
+#define SEC(name) __attribute__((section(name), used))
#define BUF_SIZE 256
+/* defined in urandom_read_aux.c */
+void urand_read_without_sema(int iter_num, int iter_cnt, int read_sz);
+/* these are coming from urandom_read_lib{1,2}.c */
+void urandlib_read_with_sema(int iter_num, int iter_cnt, int read_sz);
+void urandlib_read_without_sema(int iter_num, int iter_cnt, int read_sz);
+
+unsigned short urand_read_with_sema_semaphore SEC(".probes");
+
static __attribute__((noinline))
void urandom_read(int fd, int count)
{
- char buf[BUF_SIZE];
- int i;
+ char buf[BUF_SIZE];
+ int i;
+
+ for (i = 0; i < count; ++i) {
+ read(fd, buf, BUF_SIZE);
+
+ /* trigger USDTs defined in executable itself */
+ urand_read_without_sema(i, count, BUF_SIZE);
+ STAP_PROBE3(urand, read_with_sema, i, count, BUF_SIZE);
- for (i = 0; i < count; ++i)
- read(fd, buf, BUF_SIZE);
+ /* trigger USDTs defined in shared lib */
+ urandlib_read_without_sema(i, count, BUF_SIZE);
+ urandlib_read_with_sema(i, count, BUF_SIZE);
+ }
+}
+
+static volatile bool parent_ready;
+
+static void handle_sigpipe(int sig)
+{
+ parent_ready = true;
}
int main(int argc, char *argv[])
{
int fd = open("/dev/urandom", O_RDONLY);
int count = 4;
+ bool report_pid = false;
if (fd < 0)
return 1;
- if (argc == 2)
+ if (argc >= 2)
count = atoi(argv[1]);
+ if (argc >= 3) {
+ report_pid = true;
+ /* install SIGPIPE handler to catch when parent closes their
+ * end of the pipe (on the other side of our stdout)
+ */
+ signal(SIGPIPE, handle_sigpipe);
+ }
+
+ /* report PID and wait for parent process to send us "signal" by
+ * closing stdout
+ */
+ if (report_pid) {
+ while (!parent_ready) {
+ fprintf(stdout, "%d\n", getpid());
+ fflush(stdout);
+ }
+ /* at this point stdout is closed, parent process knows our
+ * PID and is ready to trace us
+ */
+ }
urandom_read(fd, count);
diff --git a/tools/testing/selftests/bpf/urandom_read_aux.c b/tools/testing/selftests/bpf/urandom_read_aux.c
new file mode 100644
index 000000000000..6132edcfea74
--- /dev/null
+++ b/tools/testing/selftests/bpf/urandom_read_aux.c
@@ -0,0 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */
+#include "sdt.h"
+
+void urand_read_without_sema(int iter_num, int iter_cnt, int read_sz)
+{
+ /* semaphore-less USDT */
+ STAP_PROBE3(urand, read_without_sema, iter_num, iter_cnt, read_sz);
+}
diff --git a/tools/testing/selftests/bpf/urandom_read_lib1.c b/tools/testing/selftests/bpf/urandom_read_lib1.c
new file mode 100644
index 000000000000..86186e24b740
--- /dev/null
+++ b/tools/testing/selftests/bpf/urandom_read_lib1.c
@@ -0,0 +1,13 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */
+#define _SDT_HAS_SEMAPHORES 1
+#include "sdt.h"
+
+#define SEC(name) __attribute__((section(name), used))
+
+unsigned short urandlib_read_with_sema_semaphore SEC(".probes");
+
+void urandlib_read_with_sema(int iter_num, int iter_cnt, int read_sz)
+{
+ STAP_PROBE3(urandlib, read_with_sema, iter_num, iter_cnt, read_sz);
+}
diff --git a/tools/testing/selftests/bpf/urandom_read_lib2.c b/tools/testing/selftests/bpf/urandom_read_lib2.c
new file mode 100644
index 000000000000..9d401ad9838f
--- /dev/null
+++ b/tools/testing/selftests/bpf/urandom_read_lib2.c
@@ -0,0 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */
+#include "sdt.h"
+
+void urandlib_read_without_sema(int iter_num, int iter_cnt, int read_sz)
+{
+ STAP_PROBE3(urandlib, read_without_sema, iter_num, iter_cnt, read_sz);
+}