Load vmlinux, vmlinux.inline and all module and module.inline entries in /sys/fs/btf; this will allow us to sanity-check
- kernel and its inline representations - in-tree modules and their inline multi-split BTF representations - out-of-tree modules and the kernel relocation done for module and module inline BTF Since bpf_testmod.ko is built as an out-of-tree module, the combination of vmlinux, normal in-tree module BTF and out-of-tree testmod ensures we sanity check relocations for each case. Also test mmap for vmlinux.inline. Signed-off-by: Alan Maguire <[email protected]> --- .../selftests/bpf/prog_tests/btf_sysfs.c | 87 ++++++++++++++++++- 1 file changed, 84 insertions(+), 3 deletions(-) diff --git a/tools/testing/selftests/bpf/prog_tests/btf_sysfs.c b/tools/testing/selftests/bpf/prog_tests/btf_sysfs.c index 3923e64c4c1d..3fde8598189f 100644 --- a/tools/testing/selftests/bpf/prog_tests/btf_sysfs.c +++ b/tools/testing/selftests/bpf/prog_tests/btf_sysfs.c @@ -3,15 +3,21 @@ #include <test_progs.h> #include <bpf/btf.h> +#include <dirent.h> +#include <limits.h> #include <sys/stat.h> #include <sys/mman.h> #include <fcntl.h> #include <unistd.h> +#define BTF_SYSFS_DIR "/sys/kernel/btf" +#define BTF_INLINE_SUFFIX ".inline" + static void test_btf_mmap_sysfs(const char *path, struct btf *base) { struct stat st; __u64 btf_size, end; + size_t mmap_len = 0; void *raw_data = NULL; int fd = -1; long page_size; @@ -26,6 +32,7 @@ static void test_btf_mmap_sysfs(const char *path, struct btf *base) btf_size = st.st_size; end = (btf_size + page_size - 1) / page_size * page_size; + mmap_len = btf_size; fd = open(path, O_RDONLY); if (!ASSERT_GE(fd, 0, "open_btf")) @@ -39,11 +46,13 @@ static void test_btf_mmap_sysfs(const char *path, struct btf *base) if (!ASSERT_EQ(raw_data, MAP_FAILED, "mmap_btf_shared")) goto cleanup; - raw_data = mmap(NULL, end + 1, PROT_READ, MAP_PRIVATE, fd, 0); + mmap_len = end + 1; + raw_data = mmap(NULL, mmap_len, PROT_READ, MAP_PRIVATE, fd, 0); if (!ASSERT_EQ(raw_data, MAP_FAILED, "mmap_btf_invalid_size")) goto cleanup; - raw_data = mmap(NULL, end, PROT_READ, MAP_PRIVATE, fd, 0); + mmap_len = end; + raw_data = mmap(NULL, mmap_len, PROT_READ, MAP_PRIVATE, fd, 0); if (!ASSERT_OK_PTR(raw_data, "mmap_btf")) goto cleanup; @@ -70,12 +79,84 @@ static void test_btf_mmap_sysfs(const char *path, struct btf *base) cleanup: btf__free(btf); if (raw_data && raw_data != MAP_FAILED) - munmap(raw_data, btf_size); + munmap(raw_data, mmap_len); if (fd >= 0) close(fd); } +static void test_btf_inline_sysfs_all(void) +{ + struct btf *vmlinux_btf; + struct dirent *dentry; + DIR *dir; + int err = 0; + + dir = opendir(BTF_SYSFS_DIR); + if (!ASSERT_OK_PTR(dir, "open_btf_sysfs")) + return; + + vmlinux_btf = btf__parse(BTF_SYSFS_DIR "/vmlinux", NULL); + if (!ASSERT_OK_PTR(vmlinux_btf, "parse_vmlinux_btf")) { + closedir(dir); + return; + } + + while ((dentry = readdir(dir)) != NULL) { + struct btf *base_btf = NULL, *module_btf = NULL, *inline_btf = NULL; + char btf_path[PATH_MAX], inline_path[PATH_MAX]; + struct stat st; + + /* Skip ".", ".." and "foo.inline" */ + if (strstr(dentry->d_name, ".")) + continue; + + if (strcmp(dentry->d_name, "vmlinux") == 0) + base_btf = vmlinux_btf; + + if (snprintf(btf_path, sizeof(btf_path), "%s/%s", + BTF_SYSFS_DIR, dentry->d_name) >= sizeof(btf_path) || + snprintf(inline_path, sizeof(inline_path), "%s/%s%s", + BTF_SYSFS_DIR, dentry->d_name, BTF_INLINE_SUFFIX) >= + sizeof(inline_path)) { + ASSERT_FAIL("BTF sysfs path is too long\n"); + break; + } + + if (!base_btf) { + module_btf = btf__parse_split(btf_path, vmlinux_btf); + err = libbpf_get_error(module_btf); + if (err) { + /* A module can be unloaded while its sysfs entry is iterated. */ + if (err == -ENOENT) + continue; + ASSERT_OK(err, "parse_module_btf"); + continue; + } + base_btf = module_btf; + } + if (stat(inline_path, &st)) { + err = errno; + if (err != ENOENT) + ASSERT_OK(err, "stat_inline_btf"); + btf__free(module_btf); + continue; + } + if (base_btf == vmlinux_btf) + test_btf_mmap_sysfs(inline_path, base_btf); + inline_btf = btf__parse_split(inline_path, base_btf); + err = libbpf_get_error(inline_btf); + if (!err) + btf__free(inline_btf); + ASSERT_OK(err, "parse_inline_btf"); + btf__free(module_btf); + } + closedir(dir); + + btf__free(vmlinux_btf); +} + void test_btf_sysfs(void) { test_btf_mmap_sysfs("/sys/kernel/btf/vmlinux", NULL); + test_btf_inline_sysfs_all(); } -- 2.43.5
