Harden logging, perror() replaced with fatal(), unlink() failure recorded

diff --git a/util.c b/util.c
index 4b8dd155d3498d3c4f516f2da6251a152d7a2948..1743ed673370756819c04aabc2098fc1b7adbf7a 100644 (file)
--- a/util.c
+++ b/util.c
@@ -107,16 +107,34 @@ path_max(const char *path)
 #endif
 }
 
+/*
+ * Warn about failure writing to the log file and then exit.
+ */
+static void
+warn_log_fail(void)
+{
+       extern struct conf *conf;
+
+       /* Note: Can't call fatal() since that would lead to recursion. */
+       fprintf(stderr, "ccache: error: Failed to write to %s: %s\n",
+               conf->log_file, strerror(errno));
+       exit(EXIT_FAILURE);
+}
+
 static void
 vlog(const char *format, va_list ap, bool log_updated_time)
 {
+       int rc1, rc2;
        if (!init_log()) {
                return;
        }
 
        log_prefix(log_updated_time);
-       vfprintf(logfile, format, ap);
-       fprintf(logfile, "\n");
+       rc1 = vfprintf(logfile, format, ap);
+       rc2 = fprintf(logfile, "\n");
+       if (rc1 < 0 || rc2 < 0) {
+               warn_log_fail();
+       }
 }
 
 /*
@@ -153,6 +171,7 @@ cc_bulklog(const char *format, ...)
 void
 cc_log_argv(const char *prefix, char **argv)
 {
+       int rc;
        if (!init_log()) {
                return;
        }
@@ -160,7 +179,9 @@ cc_log_argv(const char *prefix, char **argv)
        log_prefix(true);
        fputs(prefix, logfile);
        print_command(logfile, argv);
-       fflush(logfile);
+       rc = fflush(logfile);
+       if (rc)
+               warn_log_fail();
 }
 
 /* something went badly wrong! */
@@ -827,7 +848,7 @@ traverse(const char *dir, void (*fn)(const char *, struct stat *))
                fname = format("%s/%s", dir, de->d_name);
                if (lstat(fname, &st)) {
                        if (errno != ENOENT) {
-                               perror(fname);
+                               fatal("lstat %s failed: %s", fname, strerror(errno));
                        }
                        free(fname);
                        continue;
@@ -1413,8 +1434,13 @@ x_rename(const char *oldpath, const char *newpath)
 int
 tmp_unlink(const char *path)
 {
+       int rc;
        cc_log("Unlink %s", path);
-       return unlink(path);
+       rc = unlink(path);
+       if (rc) {
+               cc_log("Unlink failed: %s", strerror(errno));
+       }
+       return rc;
 }
 
 /*
@@ -1430,19 +1456,25 @@ x_unlink(const char *path)
         */
        char *tmp_name = format("%s.rm.%s", path, tmp_string());
        int result = 0;
+       int saved_errno;
        cc_log("Unlink %s via %s", path, tmp_name);
        if (x_rename(path, tmp_name) == -1) {
                result = -1;
+               saved_errno = errno;
                goto out;
        }
        if (unlink(tmp_name) == -1) {
                /* If it was released in a race, that's OK. */
                if (errno != ENOENT) {
                        result = -1;
+                       saved_errno = errno;
                }
        }
 out:
        free(tmp_name);
+       if (result) {
+               cc_log("x_unlink failed: %s", strerror(saved_errno));
+       }
        return result;
 }