Run dlmopen in a child process.

Author: gordonmessmer

tools/elfdeps.c

@@ -72,24 +72,60 @@ static char *getLibtoolVer(const char *filename)
 	    }
 	    break;
 	} else {
-	    return NULL;
+	    break;
 	}
     }
     return NULL;
 }
 
+/*
+ * Rather than re-implement path searching for shared objects, use
+ * dlmopen().  This will still perform initialization and finalization
+ * functions, which isn't necessarily safe, so do that in a separate
+ * process.
+ */
 static char *getLibtoolVerFromShLink(const char *filename)
 {
-    void *dl_handle;
-    struct link_map *linkmap;
-    char *version = NULL;
-    dl_handle = dlmopen(LM_ID_NEWLM, filename, RTLD_LAZY);
-    if (dl_handle == NULL) return NULL;
-    if (dlinfo(dl_handle, RTLD_DI_LINKMAP, &linkmap) != -1) {
-	version = getLibtoolVer(linkmap->l_name);
+    char dest[PATH_MAX];
+    int pipefd[2];
+    pid_t cpid;
+
+    if (pipe(pipefd) == -1) {
+	return NULL;  // Should this be a fatal error instead?
+    }
+    cpid = fork();
+    if (cpid == -1) {
+	return NULL;  // Should this be a fatal error instead?
+    }
+    if (cpid == 0) {
+	void *dl_handle;
+	struct link_map *linkmap;
+	char *version = NULL;
+
+	close(pipefd[0]);
+	dl_handle = dlmopen(LM_ID_NEWLM, filename, RTLD_LAZY);
+	if (dl_handle == NULL) _exit(0);
+	if (dlinfo(dl_handle, RTLD_DI_LINKMAP, &linkmap) != -1) {
+	    version = getLibtoolVer(linkmap->l_name);
+	}
+	write(pipefd[1], version, strlen(version));
+	close(pipefd[1]);
+	free(version);
+	dlclose(dl_handle);
+	_exit(0);
+    } else {
+	ssize_t len;
+	close(pipefd[1]);
+	dest[0] = 0;
+	len = read(pipefd[0], dest, sizeof(dest));
+	if (len > 0) dest[len] = 0;
+	close(pipefd[0]);
+	wait(NULL);
     }
-    dlclose(dl_handle);
-    return version;
+    if (strlen(dest) > 0)
+	return strdup(dest);
+    else
+	return NULL;
 }
 
 /*