libcutils: fs_config: target_out_path assumed /system breaking partitions
(cherry picked from commit 6e9cb8fd79ef5d933194eed02baf3af6394c500f)
Strip off trailing / then /system and then add back the appropriate
config directory. This fixes an issue with reading vendor, oem or odm
partitions.
Test: manual build successfully interprets all etc/fs_config_* files.
Test: manual incremental build successfully interprets all etc/fs_config_* files.
Bug: 36071012
Change-Id: Iba363f0731bb8d15e595bb45c56db97722edabc2
diff --git a/libcutils/fs_config.c b/libcutils/fs_config.c
index a2f5816..b19a2fd 100644
--- a/libcutils/fs_config.c
+++ b/libcutils/fs_config.c
@@ -227,21 +227,24 @@
/* clang-format on */
};
+static size_t strip(const char* path, size_t len, const char suffix[]) {
+ if (len < strlen(suffix)) return len;
+ if (strncmp(path + len - strlen(suffix), suffix, strlen(suffix))) return len;
+ return len - strlen(suffix);
+}
+
static int fs_config_open(int dir, int which, const char* target_out_path) {
int fd = -1;
if (target_out_path && *target_out_path) {
/* target_out_path is the path to the directory holding content of
- * system partition but as we cannot guaranty it ends with '/system'
- * we need this below skip_len logic */
+ * system partition but as we cannot guarantee it ends with '/system'
+ * or with or without a trailing slash, need to strip them carefully. */
char* name = NULL;
- int target_out_path_len = strlen(target_out_path);
- int skip_len = strlen("/system");
-
- if (target_out_path[target_out_path_len] == '/') {
- skip_len++;
- }
- if (asprintf(&name, "%s%s", target_out_path, conf[which][dir] + skip_len) != -1) {
+ size_t len = strlen(target_out_path);
+ len = strip(target_out_path, len, "/");
+ len = strip(target_out_path, len, "/system");
+ if (asprintf(&name, "%.*s%s", (int)len, target_out_path, conf[which][dir]) != -1) {
fd = TEMP_FAILURE_RETRY(open(name, O_RDONLY | O_BINARY));
free(name);
}