[PATCH bpf-next] libbpf: Do not require executable permission for shared libraries

[Hengqi Chen <hengqi.chen@gmail.com>]

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 ([0]). Let's remove
executable permission check for shared libraries.

  [0]: https://www.debian.org/doc/debian-policy/

Reported-by: Goro Fuji <goro@fastly.com>
Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
---
 tools/lib/bpf/libbpf.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 77e3797cf75a..f0ce7423afb8 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -10666,7 +10666,7 @@ 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 = R_OK;
 
 	if (str_has_sfx(file, ".so") || strstr(file, ".so.")) {
 		search_paths[0] = getenv("LD_LIBRARY_PATH");
@@ -10675,6 +10675,7 @@ static int resolve_full_path(const char *file, char *result, size_t result_sz)
 	} else {
 		search_paths[0] = getenv("PATH");
 		search_paths[1] = "/usr/bin:/usr/sbin";
+		perm |= X_OK;
 	}
 
 	for (i = 0; i < ARRAY_SIZE(search_paths); i++) {
@@ -10693,8 +10694,8 @@ 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;
-- 
2.27.0