libbpf: Do not require executable permission for shared libraries

[ Upstream commit 9e32084ef1c33a87a736d6ce3fcb95b60dac9aa1 ]

Currently, resolve_full_path() requires executable permission for both
programs and shared libraries. This causes failures on distos like Debian
since the shared libraries are not installed executable and Linux is not
requiring shared libraries to have executable permissions. Let's remove
executable permission check for shared libraries.

Reported-by: Goro Fuji <goro@fastly.com>
Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220806102021.3867130-1-hengqi.chen@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index f6f4be0a247490a42c7c75a0dc98031a0de770ef..e36c44090720e276714e22815fa61b4f2cb71e54 100644 (file)
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -10667,15 +10667,17 @@ static const char *arch_specific_lib_paths(void)
 static int resolve_full_path(const char *file, char *result, size_t result_sz)
 {
        const char *search_paths[3] = {};
-       int i;
+       int i, perm;
 
        if (str_has_sfx(file, ".so") || strstr(file, ".so.")) {
                search_paths[0] = getenv("LD_LIBRARY_PATH");
                search_paths[1] = "/usr/lib64:/usr/lib";
                search_paths[2] = arch_specific_lib_paths();
+               perm = R_OK;
        } else {
                search_paths[0] = getenv("PATH");
                search_paths[1] = "/usr/bin:/usr/sbin";
+               perm = R_OK | X_OK;
        }
 
        for (i = 0; i < ARRAY_SIZE(search_paths); i++) {
@@ -10694,8 +10696,8 @@ static int resolve_full_path(const char *file, char *result, size_t result_sz)
                        if (!seg_len)
                                continue;
                        snprintf(result, result_sz, "%.*s/%s", seg_len, s, file);
-                       /* ensure it is an executable file/link */
-                       if (access(result, R_OK | X_OK) < 0)
+                       /* ensure it has required permissions */
+                       if (access(result, perm) < 0)
                                continue;
                        pr_debug("resolved '%s' to '%s'\n", file, result);
                        return 0;