diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index caede9b574cb1..47365161b6fc4 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -196,11 +196,12 @@ endif # Filter out -static for liburandom_read.so and its dependent targets so that static builds # do not fail. Static builds leave urandom_read relying on system-wide shared libraries. -$(OUTPUT)/liburandom_read.so: urandom_read_lib1.c urandom_read_lib2.c +$(OUTPUT)/liburandom_read.so: urandom_read_lib1.c urandom_read_lib2.c liburandom_read.map $(call msg,LIB,,$@) $(Q)$(CLANG) $(filter-out -static,$(CFLAGS) $(LDFLAGS)) \ - $^ $(filter-out -static,$(LDLIBS)) \ + $(filter %.c,$^) $(filter-out -static,$(LDLIBS)) \ -fuse-ld=$(LLD) -Wl,-znoseparate-code -Wl,--build-id=sha1 \ + -Wl,--version-script=liburandom_read.map \ -fPIC -shared -o $@ $(OUTPUT)/urandom_read: urandom_read.c urandom_read_aux.c $(OUTPUT)/liburandom_read.so diff --git a/tools/testing/selftests/bpf/liburandom_read.map b/tools/testing/selftests/bpf/liburandom_read.map new file mode 100644 index 0000000000000..38a97a419a043 --- /dev/null +++ b/tools/testing/selftests/bpf/liburandom_read.map @@ -0,0 +1,15 @@ +LIBURANDOM_READ_1.0.0 { + global: + urandlib_api; + urandlib_api_sameoffset; + urandlib_read_without_sema; + urandlib_read_with_sema; + urandlib_read_with_sema_semaphore; + local: + *; +}; + +LIBURANDOM_READ_2.0.0 { + global: + urandlib_api; +} LIBURANDOM_READ_1.0.0; diff --git a/tools/testing/selftests/bpf/prog_tests/uprobe.c b/tools/testing/selftests/bpf/prog_tests/uprobe.c new file mode 100644 index 0000000000000..cf3e0e7a64fae --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/uprobe.c @@ -0,0 +1,95 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2023 Hengqi Chen */ + +#include +#include "test_uprobe.skel.h" + +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); + errno = EINVAL; + 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; +} + +void test_uprobe(void) +{ + LIBBPF_OPTS(bpf_uprobe_opts, uprobe_opts); + struct test_uprobe *skel; + FILE *urand_pipe = NULL; + int urand_pid = 0, err; + + skel = test_uprobe__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; + + skel->bss->my_pid = urand_pid; + + /* Manual attach uprobe to urandlib_api + * There are two `urandlib_api` symbols in .dynsym section: + * - urandlib_api@LIBURANDOM_READ_1.0.0 + * - urandlib_api@@LIBURANDOM_READ_2.0.0 + * Both are global bind and would cause a conflict if user + * specify the symbol name without a version suffix + */ + uprobe_opts.func_name = "urandlib_api"; + skel->links.test4 = bpf_program__attach_uprobe_opts(skel->progs.test4, + urand_pid, + "./liburandom_read.so", + 0 /* offset */, + &uprobe_opts); + if (!ASSERT_ERR_PTR(skel->links.test4, "urandlib_api_attach_conflict")) + goto cleanup; + + uprobe_opts.func_name = "urandlib_api@LIBURANDOM_READ_1.0.0"; + skel->links.test4 = bpf_program__attach_uprobe_opts(skel->progs.test4, + urand_pid, + "./liburandom_read.so", + 0 /* offset */, + &uprobe_opts); + if (!ASSERT_OK_PTR(skel->links.test4, "urandlib_api_attach_ok")) + goto cleanup; + + /* Auto attach 3 u[ret]probes to urandlib_api_sameoffset */ + err = test_uprobe__attach(skel); + if (!ASSERT_OK(err, "skel_attach")) + goto cleanup; + + /* trigger urandom_read */ + ASSERT_OK(urand_trigger(&urand_pipe), "urand_exit_code"); + + ASSERT_EQ(skel->bss->test1_result, 1, "urandlib_api_sameoffset"); + ASSERT_EQ(skel->bss->test2_result, 1, "urandlib_api_sameoffset@v1"); + ASSERT_EQ(skel->bss->test3_result, 3, "urandlib_api_sameoffset@@v2"); + ASSERT_EQ(skel->bss->test4_result, 1, "urandlib_api"); + +cleanup: + if (urand_pipe) + pclose(urand_pipe); + test_uprobe__destroy(skel); +} diff --git a/tools/testing/selftests/bpf/progs/test_uprobe.c b/tools/testing/selftests/bpf/progs/test_uprobe.c new file mode 100644 index 0000000000000..896c88a4960df --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_uprobe.c @@ -0,0 +1,61 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2023 Hengqi Chen */ + +#include "vmlinux.h" +#include +#include + +pid_t my_pid = 0; + +int test1_result = 0; +int test2_result = 0; +int test3_result = 0; +int test4_result = 0; + +SEC("uprobe/./liburandom_read.so:urandlib_api_sameoffset") +int BPF_UPROBE(test1) +{ + pid_t pid = bpf_get_current_pid_tgid() >> 32; + + if (pid != my_pid) + return 0; + + test1_result = 1; + return 0; +} + +SEC("uprobe/./liburandom_read.so:urandlib_api_sameoffset@LIBURANDOM_READ_1.0.0") +int BPF_UPROBE(test2) +{ + pid_t pid = bpf_get_current_pid_tgid() >> 32; + + if (pid != my_pid) + return 0; + + test2_result = 1; + return 0; +} + +SEC("uretprobe/./liburandom_read.so:urandlib_api_sameoffset@@LIBURANDOM_READ_2.0.0") +int BPF_URETPROBE(test3, int ret) +{ + pid_t pid = bpf_get_current_pid_tgid() >> 32; + + if (pid != my_pid) + return 0; + + test3_result = ret; + return 0; +} + +SEC("uprobe") +int BPF_UPROBE(test4) +{ + pid_t pid = bpf_get_current_pid_tgid() >> 32; + + if (pid != my_pid) + return 0; + + test4_result = 1; + return 0; +} diff --git a/tools/testing/selftests/bpf/urandom_read.c b/tools/testing/selftests/bpf/urandom_read.c index e92644d0fa75a..b28e910a8fbb4 100644 --- a/tools/testing/selftests/bpf/urandom_read.c +++ b/tools/testing/selftests/bpf/urandom_read.c @@ -21,6 +21,11 @@ void urand_read_without_sema(int iter_num, int iter_cnt, int read_sz); 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); +int urandlib_api(void); +__asm__(".symver urandlib_api_old,urandlib_api@LIBURANDOM_READ_1.0.0"); +int urandlib_api_old(void); +int urandlib_api_sameoffset(void); + unsigned short urand_read_with_sema_semaphore SEC(".probes"); static __attribute__((noinline)) @@ -83,6 +88,10 @@ int main(int argc, char *argv[]) urandom_read(fd, count); + urandlib_api(); + urandlib_api_old(); + urandlib_api_sameoffset(); + close(fd); return 0; } diff --git a/tools/testing/selftests/bpf/urandom_read_lib1.c b/tools/testing/selftests/bpf/urandom_read_lib1.c index 86186e24b7409..403b0735e2235 100644 --- a/tools/testing/selftests/bpf/urandom_read_lib1.c +++ b/tools/testing/selftests/bpf/urandom_read_lib1.c @@ -11,3 +11,44 @@ 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); } + +/* Symbol versioning is different between static and shared library. + * Properly versioned symbols are needed for shared library, but + * only the symbol of the new version is needed for static library. + * Starting with GNU C 10, use symver attribute instead of .symver assembler + * directive, which works better with GCC LTO builds. + */ +#if defined(__GNUC__) && __GNUC__ >= 10 + +#define DEFAULT_VERSION(internal_name, api_name, version) \ + __attribute__((symver(#api_name "@@" #version))) +#define COMPAT_VERSION(internal_name, api_name, version) \ + __attribute__((symver(#api_name "@" #version))) + +#else + +#define COMPAT_VERSION(internal_name, api_name, version) \ + asm(".symver " #internal_name "," #api_name "@" #version); +#define DEFAULT_VERSION(internal_name, api_name, version) \ + asm(".symver " #internal_name "," #api_name "@@" #version); + +#endif + +COMPAT_VERSION(urandlib_api_v1, urandlib_api, LIBURANDOM_READ_1.0.0) +int urandlib_api_v1(void) +{ + return 1; +} + +DEFAULT_VERSION(urandlib_api_v2, urandlib_api, LIBURANDOM_READ_2.0.0) +int urandlib_api_v2(void) +{ + return 2; +} + +COMPAT_VERSION(urandlib_api_sameoffset, urandlib_api_sameoffset, LIBURANDOM_READ_1.0.0) +DEFAULT_VERSION(urandlib_api_sameoffset, urandlib_api_sameoffset, LIBURANDOM_READ_2.0.0) +int urandlib_api_sameoffset(void) +{ + return 3; +}