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charset="UTF-8" X-Rspam-User: X-Rspamd-Server: rspam03 X-Stat-Signature: sg6gmn6so541x4hzksg768h76ufzqedk X-Rspamd-Queue-Id: 23563140002 X-HE-Tag: 1675900700-646320 X-HE-Meta: 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 RMk1q2k9 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, Feb 1, 2023 at 5:58 AM Jiri Olsa wrote: > > The test attaches bpf program to sched_process_exec tracepoint > and gets build of executed file from bprm->file object. > > Signed-off-by: Jiri Olsa > --- > .../selftests/bpf/prog_tests/file_build_id.c | 70 +++++++++++++++++++ > .../selftests/bpf/progs/file_build_id.c | 34 +++++++++ > tools/testing/selftests/bpf/trace_helpers.c | 35 ++++++++++ > tools/testing/selftests/bpf/trace_helpers.h | 1 + > 4 files changed, 140 insertions(+) > create mode 100644 tools/testing/selftests/bpf/prog_tests/file_build_id.c > create mode 100644 tools/testing/selftests/bpf/progs/file_build_id.c > > diff --git a/tools/testing/selftests/bpf/prog_tests/file_build_id.c b/tools/testing/selftests/bpf/prog_tests/file_build_id.c > new file mode 100644 > index 000000000000..a7b6307cc0f7 > --- /dev/null > +++ b/tools/testing/selftests/bpf/prog_tests/file_build_id.c > @@ -0,0 +1,70 @@ > +// SPDX-License-Identifier: GPL-2.0 > + > +#include > +#include > +#include "file_build_id.skel.h" > +#include "trace_helpers.h" > + > +#define BUILDID_STR_SIZE (BPF_BUILD_ID_SIZE*2 + 1) > + > +void test_file_build_id(void) > +{ > + int go[2], err, child_pid, child_status, c = 1, i; > + char bpf_build_id[BUILDID_STR_SIZE] = {}; > + struct file_build_id *skel; > + char *bid = NULL; > + > + skel = file_build_id__open_and_load(); > + if (!ASSERT_OK_PTR(skel, "file_build_id__open_and_load")) > + return; > + > + if (!ASSERT_OK(pipe(go), "pipe")) > + goto out; > + > + child_pid = fork(); > + if (child_pid < 0) > + goto out; > + > + /* child */ > + if (child_pid == 0) { > + /* wait for parent's pid update */ > + err = read(go[0], &c, 1); > + if (!ASSERT_EQ(err, 1, "child_read_pipe")) > + exit(err); > + > + execle("/bin/bash", "bash", "-c", "exit 0", NULL, NULL); > + exit(errno); > + } > + > + /* parent, update child's pid and kick it */ > + skel->bss->pid = child_pid; > + > + err = file_build_id__attach(skel); > + if (!ASSERT_OK(err, "file_build_id__attach")) > + goto out; > + > + err = write(go[1], &c, 1); > + if (!ASSERT_EQ(err, 1, "child_write_pipe")) > + goto out; > + > + /* wait for child to exit */ > + waitpid(child_pid, &child_status, 0); > + if (!ASSERT_EQ(WEXITSTATUS(child_status), 0, "child_exit_value")) > + goto out; > + > + if (!ASSERT_OK(read_buildid("/bin/bash", &bid), "read_buildid")) can we use urandom_read for build_id ? And it would also be nice to check that build id fetching works for liburandom_read.so as well. > + goto out; > + > + ASSERT_EQ(skel->bss->build_id_size, strlen(bid)/2, "build_id_size"); > + > + /* Convert bpf build id to string, so we can compare it later. */ > + for (i = 0; i < skel->bss->build_id_size; i++) { > + sprintf(bpf_build_id + i*2, "%02x", > + (unsigned char) skel->bss->build_id[i]); > + } > + ASSERT_STREQ(bpf_build_id, bid, "build_id_data"); > + > +out: > + file_build_id__destroy(skel); > + free(bid); > +} > diff --git a/tools/testing/selftests/bpf/progs/file_build_id.c b/tools/testing/selftests/bpf/progs/file_build_id.c > new file mode 100644 > index 000000000000..639a7217a927 > --- /dev/null > +++ b/tools/testing/selftests/bpf/progs/file_build_id.c > @@ -0,0 +1,34 @@ > +// SPDX-License-Identifier: GPL-2.0 > + > +#include "vmlinux.h" > +#include > +#include > +#include > + > +char _license[] SEC("license") = "GPL"; > + > +int pid; > +u32 build_id_size; > +char build_id[20]; > + > +SEC("tp_btf/sched_process_exec") > +int BPF_PROG(prog, struct task_struct *p, pid_t old_pid, struct linux_binprm *bprm) > +{ > + int cur_pid = bpf_get_current_pid_tgid() >> 32; > + struct build_id *bid; > + > + if (pid != cur_pid) > + return 0; > + > + if (!bprm->file || !bprm->file->f_bid) > + return 0; > + > + bid = bprm->file->f_bid; > + build_id_size = bid->sz; > + > + if (build_id_size > 20) > + return 0; > + > + memcpy(build_id, bid->data, 20); > + return 0; > +} > diff --git a/tools/testing/selftests/bpf/trace_helpers.c b/tools/testing/selftests/bpf/trace_helpers.c > index 09a16a77bae4..f5557890e383 100644 > --- a/tools/testing/selftests/bpf/trace_helpers.c > +++ b/tools/testing/selftests/bpf/trace_helpers.c > @@ -9,6 +9,7 @@ > #include > #include > #include > +#include > #include > #include "trace_helpers.h" > > @@ -230,3 +231,37 @@ ssize_t get_rel_offset(uintptr_t addr) > fclose(f); > return -EINVAL; > } > + > +int read_buildid(const char *path, char **build_id) > +{ > + char tmp[] = "/tmp/dataXXXXXX"; > + char buf[PATH_MAX + 200]; > + int err, fd; > + FILE *f; > + > + fd = mkstemp(tmp); > + if (fd == -1) > + return -1; > + close(fd); > + > + snprintf(buf, sizeof(buf), > + "readelf -n %s 2>/dev/null | grep 'Build ID' | awk '{print $3}' > %s", > + path, tmp); > + shelling out to readelf for this is unfortunate... maybe let's write a libelf-based helper to fetch build ID from .note section? > + err = system(buf); > + if (err) > + goto out; > + > + f = fopen(tmp, "r"); > + if (f) { > + if (fscanf(f, "%ms$*\n", build_id) != 1) { > + *build_id = NULL; > + err = -1; > + } > + fclose(f); > + } > + > +out: > + unlink(tmp); > + return err; > +} > diff --git a/tools/testing/selftests/bpf/trace_helpers.h b/tools/testing/selftests/bpf/trace_helpers.h > index 53efde0e2998..1a38c808b6c2 100644 > --- a/tools/testing/selftests/bpf/trace_helpers.h > +++ b/tools/testing/selftests/bpf/trace_helpers.h > @@ -23,4 +23,5 @@ void read_trace_pipe(void); > ssize_t get_uprobe_offset(const void *addr); > ssize_t get_rel_offset(uintptr_t addr); > > +int read_buildid(const char *path, char **build_id); > #endif > -- > 2.39.1 >