Merge tag 'devicetree-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/robh...

[~andy/linux] / fs / exec.c

diff --git a/fs/exec.c b/fs/exec.c
index a4cfd1d725e099a7d1a3bb86a6f0121b757b75c7..8875dd10ae7ac77444db95e33c9fde83dde67512 100644 (file)
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -74,6 +74,8 @@ static DEFINE_RWLOCK(binfmt_lock);
 void __register_binfmt(struct linux_binfmt * fmt, int insert)
 {
        BUG_ON(!fmt);
+       if (WARN_ON(!fmt->load_binary))
+               return;
        write_lock(&binfmt_lock);
        insert ? list_add(&fmt->lh, &formats) :
                 list_add_tail(&fmt->lh, &formats);
@@ -1365,13 +1367,15 @@ out:
 }
 EXPORT_SYMBOL(remove_arg_zero);
 
+#define printable(c) (((c)=='\t') || ((c)=='\n') || (0x20<=(c) && (c)<=0x7e))
 /*
  * cycle the list of binary formats handler, until one recognizes the image
  */
 int search_binary_handler(struct linux_binprm *bprm)
 {
-       int try, retval;
+       bool need_retry = IS_ENABLED(CONFIG_MODULES);
        struct linux_binfmt *fmt;
+       int retval;
 
        /* This allows 4 levels of binfmt rewrites before failing hard. */
        if (bprm->recursion_depth > 5)
@@ -1386,50 +1390,35 @@ int search_binary_handler(struct linux_binprm *bprm)
                return retval;
 
        retval = -ENOENT;
-       for (try=0; try<2; try++) {
-               read_lock(&binfmt_lock);
-               list_for_each_entry(fmt, &formats, lh) {
-                       int (*fn)(struct linux_binprm *) = fmt->load_binary;
-                       if (!fn)
-                               continue;
-                       if (!try_module_get(fmt->module))
-                               continue;
-                       read_unlock(&binfmt_lock);
-                       bprm->recursion_depth++;
-                       retval = fn(bprm);
-                       bprm->recursion_depth--;
-                       if (retval >= 0) {
-                               put_binfmt(fmt);
-                               return retval;
-                       }
-                       read_lock(&binfmt_lock);
-                       put_binfmt(fmt);
-                       if (retval != -ENOEXEC || bprm->mm == NULL)
-                               break;
-                       if (!bprm->file) {
-                               read_unlock(&binfmt_lock);
-                               return retval;
-                       }
-               }
+ retry:
+       read_lock(&binfmt_lock);
+       list_for_each_entry(fmt, &formats, lh) {
+               if (!try_module_get(fmt->module))
+                       continue;
                read_unlock(&binfmt_lock);
-#ifdef CONFIG_MODULES
-               if (retval != -ENOEXEC || bprm->mm == NULL) {
-                       break;
-               } else {
-#define printable(c) (((c)=='\t') || ((c)=='\n') || (0x20<=(c) && (c)<=0x7e))
-                       if (printable(bprm->buf[0]) &&
-                           printable(bprm->buf[1]) &&
-                           printable(bprm->buf[2]) &&
-                           printable(bprm->buf[3]))
-                               break; /* -ENOEXEC */
-                       if (try)
-                               break; /* -ENOEXEC */
-                       request_module("binfmt-%04x", *(unsigned short *)(&bprm->buf[2]));
+               bprm->recursion_depth++;
+               retval = fmt->load_binary(bprm);
+               bprm->recursion_depth--;
+               if (retval >= 0 || retval != -ENOEXEC ||
+                   bprm->mm == NULL || bprm->file == NULL) {
+                       put_binfmt(fmt);
+                       return retval;
                }
-#else
-               break;
-#endif
+               read_lock(&binfmt_lock);
+               put_binfmt(fmt);
        }
+       read_unlock(&binfmt_lock);
+
+       if (need_retry && retval == -ENOEXEC) {
+               if (printable(bprm->buf[0]) && printable(bprm->buf[1]) &&
+                   printable(bprm->buf[2]) && printable(bprm->buf[3]))
+                       return retval;
+               if (request_module("binfmt-%04x", *(ushort *)(bprm->buf + 2)) < 0)
+                       return retval;
+               need_retry = false;
+               goto retry;
+       }
+
        return retval;
 }
 EXPORT_SYMBOL(search_binary_handler);