From: Andrii Nakryiko Date: Tue, 6 Aug 2024 23:03:19 +0000 (-0700) Subject: selftests/bpf: make use of PROCMAP_QUERY ioctl if available X-Git-Tag: v6.12-rc1~112^2~75 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=4e9e07603ecdfd0816838132f354239771c51edd;p=thirdparty%2Fkernel%2Flinux.git selftests/bpf: make use of PROCMAP_QUERY ioctl if available Instead of parsing text-based /proc//maps file, try to use PROCMAP_QUERY ioctl() to simplify and speed up data fetching. This logic is used to do uprobe file offset calculation, so any bugs in this logic would manifest as failing uprobe BPF selftests. This also serves as a simple demonstration of one of the intended uses. Signed-off-by: Andrii Nakryiko Acked-by: Jiri Olsa Link: https://lore.kernel.org/r/20240806230319.869734-1-andrii@kernel.org Signed-off-by: Alexei Starovoitov --- diff --git a/tools/testing/selftests/bpf/test_progs.c b/tools/testing/selftests/bpf/test_progs.c index f45b06791444c..83f390a31681e 100644 --- a/tools/testing/selftests/bpf/test_progs.c +++ b/tools/testing/selftests/bpf/test_progs.c @@ -35,6 +35,8 @@ __weak void backtrace_symbols_fd(void *const *buffer, int size, int fd) dprintf(fd, "\n"); } +int env_verbosity = 0; + static bool verbose(void) { return env.verbosity > VERBOSE_NONE; @@ -973,6 +975,7 @@ static error_t parse_arg(int key, char *arg, struct argp_state *state) return -EINVAL; } } + env_verbosity = env->verbosity; if (verbose()) { if (setenv("SELFTESTS_VERBOSE", "1", 1) == -1) { diff --git a/tools/testing/selftests/bpf/test_progs.h b/tools/testing/selftests/bpf/test_progs.h index 3ad131de14c6e..7767d9a825ae8 100644 --- a/tools/testing/selftests/bpf/test_progs.h +++ b/tools/testing/selftests/bpf/test_progs.h @@ -96,6 +96,8 @@ struct test_state { FILE *stdout_saved; }; +extern int env_verbosity; + struct test_env { struct test_selector test_selector; struct test_selector subtest_selector; diff --git a/tools/testing/selftests/bpf/trace_helpers.c b/tools/testing/selftests/bpf/trace_helpers.c index 465d196c71651..1bfd881c0e07a 100644 --- a/tools/testing/selftests/bpf/trace_helpers.c +++ b/tools/testing/selftests/bpf/trace_helpers.c @@ -10,6 +10,8 @@ #include #include #include +#include +#include #include #include "trace_helpers.h" #include @@ -244,29 +246,91 @@ out: return err; } +#ifdef PROCMAP_QUERY +int env_verbosity __weak = 0; + +int procmap_query(int fd, const void *addr, __u32 query_flags, size_t *start, size_t *offset, int *flags) +{ + char path_buf[PATH_MAX], build_id_buf[20]; + struct procmap_query q; + int err; + + memset(&q, 0, sizeof(q)); + q.size = sizeof(q); + q.query_flags = query_flags; + q.query_addr = (__u64)addr; + q.vma_name_addr = (__u64)path_buf; + q.vma_name_size = sizeof(path_buf); + q.build_id_addr = (__u64)build_id_buf; + q.build_id_size = sizeof(build_id_buf); + + err = ioctl(fd, PROCMAP_QUERY, &q); + if (err < 0) { + err = -errno; + if (err == -ENOTTY) + return -EOPNOTSUPP; /* ioctl() not implemented yet */ + if (err == -ENOENT) + return -ESRCH; /* vma not found */ + return err; + } + + if (env_verbosity >= 1) { + printf("VMA FOUND (addr %08lx): %08lx-%08lx %c%c%c%c %08lx %02x:%02x %ld %s (build ID: %s, %d bytes)\n", + (long)addr, (long)q.vma_start, (long)q.vma_end, + (q.vma_flags & PROCMAP_QUERY_VMA_READABLE) ? 'r' : '-', + (q.vma_flags & PROCMAP_QUERY_VMA_WRITABLE) ? 'w' : '-', + (q.vma_flags & PROCMAP_QUERY_VMA_EXECUTABLE) ? 'x' : '-', + (q.vma_flags & PROCMAP_QUERY_VMA_SHARED) ? 's' : 'p', + (long)q.vma_offset, q.dev_major, q.dev_minor, (long)q.inode, + q.vma_name_size ? path_buf : "", + q.build_id_size ? "YES" : "NO", + q.build_id_size); + } + + *start = q.vma_start; + *offset = q.vma_offset; + *flags = q.vma_flags; + return 0; +} +#else +int procmap_query(int fd, const void *addr, size_t *start, size_t *offset, int *flags) +{ + return -EOPNOTSUPP; +} +#endif + ssize_t get_uprobe_offset(const void *addr) { - size_t start, end, base; - char buf[256]; - bool found = false; + size_t start, base, end; FILE *f; + char buf[256]; + int err, flags; f = fopen("/proc/self/maps", "r"); if (!f) return -errno; - while (fscanf(f, "%zx-%zx %s %zx %*[^\n]\n", &start, &end, buf, &base) == 4) { - if (buf[2] == 'x' && (uintptr_t)addr >= start && (uintptr_t)addr < end) { - found = true; - break; + /* requested executable VMA only */ + err = procmap_query(fileno(f), addr, PROCMAP_QUERY_VMA_EXECUTABLE, &start, &base, &flags); + if (err == -EOPNOTSUPP) { + bool found = false; + + while (fscanf(f, "%zx-%zx %s %zx %*[^\n]\n", &start, &end, buf, &base) == 4) { + if (buf[2] == 'x' && (uintptr_t)addr >= start && (uintptr_t)addr < end) { + found = true; + break; + } + } + if (!found) { + fclose(f); + return -ESRCH; } + } else if (err) { + fclose(f); + return err; } - fclose(f); - if (!found) - return -ESRCH; - #if defined(__powerpc64__) && defined(_CALL_ELF) && _CALL_ELF == 2 #define OP_RT_RA_MASK 0xffff0000UL @@ -307,15 +371,25 @@ ssize_t get_rel_offset(uintptr_t addr) size_t start, end, offset; char buf[256]; FILE *f; + int err, flags; f = fopen("/proc/self/maps", "r"); if (!f) return -errno; - while (fscanf(f, "%zx-%zx %s %zx %*[^\n]\n", &start, &end, buf, &offset) == 4) { - if (addr >= start && addr < end) { - fclose(f); - return (size_t)addr - start + offset; + err = procmap_query(fileno(f), (const void *)addr, 0, &start, &offset, &flags); + if (err == 0) { + fclose(f); + return (size_t)addr - start + offset; + } else if (err != -EOPNOTSUPP) { + fclose(f); + return err; + } else if (err) { + while (fscanf(f, "%zx-%zx %s %zx %*[^\n]\n", &start, &end, buf, &offset) == 4) { + if (addr >= start && addr < end) { + fclose(f); + return (size_t)addr - start + offset; + } } }