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. Signed-off-by: Alan Maguire <[email protected]> --- .../selftests/bpf/prog_tests/btf_sysfs.c | 74 +++++++++++++++++++ 1 file changed, 74 insertions(+) diff --git a/tools/testing/selftests/bpf/prog_tests/btf_sysfs.c b/tools/testing/selftests/bpf/prog_tests/btf_sysfs.c index 3923e64c4c1d..97eccfd7c134 100644 --- a/tools/testing/selftests/bpf/prog_tests/btf_sysfs.c +++ b/tools/testing/selftests/bpf/prog_tests/btf_sysfs.c @@ -3,11 +3,16 @@ #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; @@ -75,7 +80,76 @@ static void test_btf_mmap_sysfs(const char *path, struct btf *base) 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) + continue; + ASSERT_OK(err, "stat_inline_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
