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 <[email protected]> --- .../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
