[musl] [PATCH 1/1] ldso: continue searching if wrong architecture is found first

[Markus Mayer <mmayer@broadcom.com>]

When LD_LIBRARY_PATH is being used, the shared library loader may end up
finding a shared library with the correct name but from a wrong
architecture. This primarily happens when a 32-bit / 64-bit mismatch
occurs.

Rather than giving up immediately and aborting, the shared library
loader should continue to look in all known locations for a matching
library that may work.

Signed-off-by: Markus Mayer <mmayer@broadcom.com>
---
 ldso/dynlink.c | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/ldso/dynlink.c b/ldso/dynlink.c
index fd09ca69932c..d7f085b0a212 100644
--- a/ldso/dynlink.c
+++ b/ldso/dynlink.c
@@ -1019,6 +1019,7 @@ static struct dso *load_library(const char *name, struct dso *needed_by)
 	size_t alloc_size;
 	int n_th = 0;
 	int is_self = 0;
+	int is_using_env_path = 0;
 
 	if (!*name) {
 		errno = EINVAL;
@@ -1072,7 +1073,11 @@ static struct dso *load_library(const char *name, struct dso *needed_by)
 		}
 		if (strlen(name) > NAME_MAX) return 0;
 		fd = -1;
-		if (env_path) fd = path_open(name, env_path, buf, sizeof buf);
+		if (env_path) {
+			fd = path_open(name, env_path, buf, sizeof buf);
+			is_using_env_path = (fd >= 0);
+		}
+retry:
 		for (p=needed_by; fd == -1 && p; p=p->needed_by) {
 			if (fixup_rpath(p, buf, sizeof buf) < 0)
 				fd = -2; /* Inhibit further search. */
@@ -1138,7 +1143,16 @@ static struct dso *load_library(const char *name, struct dso *needed_by)
 	}
 	map = noload ? 0 : map_library(fd, &temp_dso);
 	close(fd);
-	if (!map) return 0;
+	if (!map) {
+		if (is_using_env_path) {
+			/* If LD_LIBARY_PATH resulted in a library that couldn't
+			 * be loaded, let's try the default locations. */
+			fd = -1;
+			is_using_env_path = 0;
+			goto retry;
+		}
+		return 0;
+	}
 
 	/* Avoid the danger of getting two versions of libc mapped into the
 	 * same process when an absolute pathname was used. The symbols
-- 
2.43.0