Adding tests for optimized uprobe/usdt probes.
Checking that we get expected trampoline and attached bpf programs
get executed properly.
Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
---
.../bpf/prog_tests/uprobe_optimized.c | 192 ++++++++++++++++++
.../selftests/bpf/progs/uprobe_optimized.c | 29 +++
2 files changed, 221 insertions(+)
create mode 100644 tools/testing/selftests/bpf/prog_tests/uprobe_optimized.c
create mode 100644 tools/testing/selftests/bpf/progs/uprobe_optimized.c
diff --git a/tools/testing/selftests/bpf/prog_tests/uprobe_optimized.c b/tools/testing/selftests/bpf/prog_tests/uprobe_optimized.c
new file mode 100644
index 000000000000..f6eb4089b1e2
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/uprobe_optimized.c
@@ -0,0 +1,192 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <test_progs.h>
+
+#ifdef __x86_64__
+
+#include "sdt.h"
+#include "uprobe_optimized.skel.h"
+
+#define TRAMP "[uprobes-trampoline]"
+
+__naked noinline void uprobe_test(void)
+{
+ asm volatile (".byte 0x0f, 0x1f, 0x44, 0x00, 0x00\n\t"
+ "ret\n\t");
+}
+
+static int find_uprobes_trampoline(void **start, void **end)
+{
+ char line[128];
+ int ret = -1;
+ FILE *maps;
+
+ maps = fopen("/proc/self/maps", "r");
+ if (!maps) {
+ fprintf(stderr, "cannot open maps\n");
+ return -1;
+ }
+
+ while (fgets(line, sizeof(line), maps)) {
+ int m = -1;
+
+ /* We care only about private r-x mappings. */
+ if (sscanf(line, "%p-%p r-xp %*x %*x:%*x %*u %n", start, end, &m) != 2)
+ continue;
+ if (m < 0)
+ continue;
+ if (!strncmp(&line[m], TRAMP, sizeof(TRAMP)-1)) {
+ ret = 0;
+ break;
+ }
+ }
+
+ fclose(maps);
+ return ret;
+}
+
+static void check_attach(struct uprobe_optimized *skel, void (*trigger)(void))
+{
+ void *tramp_start, *tramp_end;
+ struct __arch_relative_insn {
+ u8 op;
+ s32 raddr;
+ } __packed *call;
+
+ unsigned long delta;
+
+ /* Uprobe gets optimized after first trigger, so let's press twice. */
+ trigger();
+ trigger();
+
+ if (!ASSERT_OK(find_uprobes_trampoline(&tramp_start, &tramp_end), "uprobes_trampoline"))
+ return;
+
+ /* Make sure bpf program got executed.. */
+ ASSERT_EQ(skel->bss->executed, 2, "executed");
+
+ /* .. and check the trampoline is as expected. */
+ call = (struct __arch_relative_insn *) trigger;
+
+ delta = tramp_start > (void *) trigger ?
+ tramp_start - (void *) trigger :
+ (void *) trigger - tramp_start;
+
+ /* and minus call instruction size itself */
+ delta -= 5;
+
+ ASSERT_EQ(call->op, 0xe8, "call");
+ ASSERT_EQ(call->raddr, delta, "delta");
+ ASSERT_EQ(tramp_end - tramp_start, 4096, "size");
+}
+
+static void check_detach(struct uprobe_optimized *skel, void (*trigger)(void))
+{
+ unsigned char nop5[5] = { 0x0f, 0x1f, 0x44, 0x00, 0x00 };
+ void *tramp_start, *tramp_end;
+
+ /* [uprobes_trampoline] stays after detach */
+ ASSERT_OK(find_uprobes_trampoline(&tramp_start, &tramp_end), "uprobes_trampoline");
+ ASSERT_OK(memcmp(trigger, nop5, 5), "nop5");
+}
+
+static void check(struct uprobe_optimized *skel, struct bpf_link *link,
+ void (*trigger)(void))
+{
+ check_attach(skel, trigger);
+ bpf_link__destroy(link);
+ check_detach(skel, uprobe_test);
+}
+
+static void test_uprobe(void)
+{
+ struct uprobe_optimized *skel;
+ unsigned long offset;
+
+ skel = uprobe_optimized__open_and_load();
+ if (!ASSERT_OK_PTR(skel, "uprobe_optimized__open_and_load"))
+ return;
+
+ offset = get_uprobe_offset(&uprobe_test);
+ if (!ASSERT_GE(offset, 0, "get_uprobe_offset"))
+ goto cleanup;
+
+ skel->links.test_1 = bpf_program__attach_uprobe_opts(skel->progs.test_1,
+ 0, "/proc/self/exe", offset, NULL);
+ if (!ASSERT_OK_PTR(skel->links.test_1, "bpf_program__attach_uprobe_opts"))
+ goto cleanup;
+
+ check(skel, skel->links.test_1, uprobe_test);
+ skel->links.test_1 = NULL;
+
+cleanup:
+ uprobe_optimized__destroy(skel);
+}
+
+static void test_uprobe_multi(void)
+{
+ struct uprobe_optimized *skel;
+
+ skel = uprobe_optimized__open_and_load();
+ if (!ASSERT_OK_PTR(skel, "uprobe_optimized__open_and_load"))
+ return;
+
+ skel->links.test_2 = bpf_program__attach_uprobe_multi(skel->progs.test_2,
+ 0, "/proc/self/exe", "uprobe_test", NULL);
+ if (!ASSERT_OK_PTR(skel->links.test_2, "bpf_program__attach_uprobe_multi"))
+ goto cleanup;
+
+ check(skel, skel->links.test_2, uprobe_test);
+ skel->links.test_2 = NULL;
+
+cleanup:
+ uprobe_optimized__destroy(skel);
+}
+
+__naked noinline void usdt_test(void)
+{
+ STAP_PROBE(optimized_uprobe, usdt);
+ asm volatile ("ret\n");
+}
+
+static void test_usdt(void)
+{
+ struct uprobe_optimized *skel;
+
+ skel = uprobe_optimized__open_and_load();
+ if (!ASSERT_OK_PTR(skel, "uprobe_optimized__open_and_load"))
+ return;
+
+ skel->links.test_3 = bpf_program__attach_usdt(skel->progs.test_3,
+ -1 /* all PIDs */, "/proc/self/exe",
+ "optimized_uprobe", "usdt", NULL);
+ if (!ASSERT_OK_PTR(skel->links.test_3, "bpf_program__attach_usdt"))
+ goto cleanup;
+
+ check(skel, skel->links.test_3, usdt_test);
+ skel->links.test_3 = NULL;
+
+cleanup:
+ uprobe_optimized__destroy(skel);
+}
+
+static void test_optimized(void)
+{
+ if (test__start_subtest("uprobe"))
+ test_uprobe();
+ if (test__start_subtest("uprobe_multi"))
+ test_uprobe_multi();
+ if (test__start_subtest("usdt"))
+ test_usdt();
+}
+#else
+static void test_optimized(void)
+{
+ test__skip();
+}
+#endif /* __x86_64__ */
+
+void test_uprobe_optimized(void)
+{
+ test_optimized();
+}
diff --git a/tools/testing/selftests/bpf/progs/uprobe_optimized.c b/tools/testing/selftests/bpf/progs/uprobe_optimized.c
new file mode 100644
index 000000000000..7f29c968b7c4
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/uprobe_optimized.c
@@ -0,0 +1,29 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include "vmlinux.h"
+#include <bpf/bpf_tracing.h>
+#include <bpf/usdt.bpf.h>
+
+char _license[] SEC("license") = "GPL";
+int executed = 0;
+
+SEC("uprobe")
+int BPF_UPROBE(test_1)
+{
+ executed++;
+ return 0;
+}
+
+SEC("uprobe.multi")
+int BPF_UPROBE(test_2)
+{
+ executed++;
+ return 0;
+}
+
+SEC("usdt")
+int test_3(struct pt_regs *ctx)
+{
+ executed++;
+ return 0;
+}
--
2.47.0
