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> --- .../selftests/bpf/prog_tests/uprobe_syscall.c | 203 ++++++++++++++++++ .../selftests/bpf/progs/uprobe_optimized.c | 29 +++ 2 files changed, 232 insertions(+) create mode 100644 tools/testing/selftests/bpf/progs/uprobe_optimized.c diff --git a/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c b/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c index c397336fe1ed..1dbc26a1130c 100644 --- a/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c +++ b/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c @@ -14,6 +14,8 @@ #include <asm/prctl.h> #include "uprobe_syscall.skel.h" #include "uprobe_syscall_executed.skel.h" +#include "uprobe_optimized.skel.h" +#include "sdt.h" __naked unsigned long uretprobe_regs_trigger(void) { @@ -350,6 +352,186 @@ static void test_uretprobe_shadow_stack(void) ARCH_PRCTL(ARCH_SHSTK_DISABLE, ARCH_SHSTK_SHSTK); } + +#define TRAMP "[uprobes-trampoline]" + +static unsigned char nop5[5] = { 0x0f, 0x1f, 0x44, 0x00, 0x00 }; + +noinline void uprobe_test(void) +{ + asm volatile (" \n" + ".global uprobe_test_nop5 \n" + ".type uprobe_test_nop5, STT_FUNC \n" + "uprobe_test_nop5: \n" + ".byte 0x0f, 0x1f, 0x44, 0x00, 0x00 \n" + ); +} + +extern u8 uprobe_test_nop5[]; + +noinline void usdt_test(void) +{ + STAP_PROBE(optimized_uprobe, usdt); +} + +static void *find_nop5(void *fn) +{ + int i; + + for (i = 0; i < 10; i++) { + if (!memcmp(nop5, fn + i, 5)) + return fn + i; + } + return NULL; +} + +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 *addr) +{ + void *tramp_start, *tramp_end; + struct __arch_relative_insn { + u8 op; + s32 raddr; + } __packed *call; + + s32 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 *) addr; + delta = (unsigned long) tramp_start - ((unsigned long) addr + 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), void *addr) +{ + void *tramp_start, *tramp_end; + + /* [uprobes_trampoline] stays after detach */ + ASSERT_OK(find_uprobes_trampoline(&tramp_start, &tramp_end), "uprobes_trampoline"); + ASSERT_OK(memcmp(addr, nop5, 5), "nop5"); +} + +static void check(struct uprobe_optimized *skel, struct bpf_link *link, + void (*trigger)(void), void *addr) +{ + check_attach(skel, trigger, addr); + bpf_link__destroy(link); + check_detach(skel, trigger, addr); +} + +static void test_uprobe_legacy(void) +{ + struct uprobe_optimized *skel; + struct bpf_link *link; + 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_nop5); + if (!ASSERT_GE(offset, 0, "get_uprobe_offset")) + goto cleanup; + + link = bpf_program__attach_uprobe_opts(skel->progs.test_1, + 0, "/proc/self/exe", offset, NULL); + if (!ASSERT_OK_PTR(link, "bpf_program__attach_uprobe_opts")) + goto cleanup; + + check(skel, link, uprobe_test, uprobe_test_nop5); + +cleanup: + uprobe_optimized__destroy(skel); +} + +static void test_uprobe_multi(void) +{ + struct uprobe_optimized *skel; + struct bpf_link *link; + + skel = uprobe_optimized__open_and_load(); + if (!ASSERT_OK_PTR(skel, "uprobe_optimized__open_and_load")) + return; + + link = bpf_program__attach_uprobe_multi(skel->progs.test_2, + 0, "/proc/self/exe", "uprobe_test_nop5", NULL); + if (!ASSERT_OK_PTR(link, "bpf_program__attach_uprobe_multi")) + goto cleanup; + + check(skel, link, uprobe_test, uprobe_test_nop5); + +cleanup: + uprobe_optimized__destroy(skel); +} + +static void test_uprobe_usdt(void) +{ + struct uprobe_optimized *skel; + struct bpf_link *link; + void *addr; + + errno = 0; + addr = find_nop5(usdt_test); + if (!ASSERT_OK_PTR(addr, "find_nop5")) + return; + + skel = uprobe_optimized__open_and_load(); + if (!ASSERT_OK_PTR(skel, "uprobe_optimized__open_and_load")) + return; + + link = bpf_program__attach_usdt(skel->progs.test_3, + -1 /* all PIDs */, "/proc/self/exe", + "optimized_uprobe", "usdt", NULL); + if (!ASSERT_OK_PTR(link, "bpf_program__attach_usdt")) + goto cleanup; + + check(skel, link, usdt_test, addr); + +cleanup: + uprobe_optimized__destroy(skel); +} #else static void test_uretprobe_regs_equal(void) { @@ -370,6 +552,21 @@ static void test_uretprobe_shadow_stack(void) { test__skip(); } + +static void test_uprobe_legacy(void) +{ + test__skip(); +} + +static void test_uprobe_multi(void) +{ + test__skip(); +} + +static void test_uprobe_usdt(void) +{ + test__skip(); +} #endif void test_uprobe_syscall(void) @@ -382,4 +579,10 @@ void test_uprobe_syscall(void) test_uretprobe_syscall_call(); if (test__start_subtest("uretprobe_shadow_stack")) test_uretprobe_shadow_stack(); + if (test__start_subtest("uprobe_legacy")) + test_uprobe_legacy(); + if (test__start_subtest("uprobe_multi")) + test_uprobe_multi(); + if (test__start_subtest("uprobe_usdt")) + test_uprobe_usdt(); } 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..2441d59960a6 --- /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"; +unsigned long 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