switch {alloc,free}_bprm() to CLASS()

All linux_binprm instances come from alloc_bprm() and are unconditionally
destroyed by free_bprm() in the end of the same scope.  IOW, CLASS()
machinery is a decent fit for those.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/exec.c b/fs/exec.c
index 9e799af13602b7e259be8fa28735fbe96452a347..5dd8ff61f27a8aaadd98e76b12176af71f8291f1 100644 (file)
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1465,6 +1465,9 @@ out_free:
        return ERR_PTR(retval);
 }
 
+DEFINE_CLASS(bprm, struct linux_binprm *, if (!IS_ERR(_T)) free_bprm(_T),
+       alloc_bprm(fd, name, flags), int fd, struct filename *name, int flags)
+
 int bprm_change_interp(const char *interp, struct linux_binprm *bprm)
 {
        /* If a binfmt changed the interp, free it first. */
@@ -1779,7 +1782,6 @@ static int do_execveat_common(int fd, struct filename *filename,
                              struct user_arg_ptr envp,
                              int flags)
 {
-       struct linux_binprm *bprm;
        int retval;
 
        /*
@@ -1796,36 +1798,36 @@ static int do_execveat_common(int fd, struct filename *filename,
         * further execve() calls fail. */
        current->flags &= ~PF_NPROC_EXCEEDED;
 
-       bprm = alloc_bprm(fd, filename, flags);
+       CLASS(bprm, bprm)(fd, filename, flags);
        if (IS_ERR(bprm))
                return PTR_ERR(bprm);
 
        retval = count(argv, MAX_ARG_STRINGS);
        if (retval < 0)
-               goto out_free;
+               return retval;
        bprm->argc = retval;
 
        retval = count(envp, MAX_ARG_STRINGS);
        if (retval < 0)
-               goto out_free;
+               return retval;
        bprm->envc = retval;
 
        retval = bprm_stack_limits(bprm);
        if (retval < 0)
-               goto out_free;
+               return retval;
 
        retval = copy_string_kernel(bprm->filename, bprm);
        if (retval < 0)
-               goto out_free;
+               return retval;
        bprm->exec = bprm->p;
 
        retval = copy_strings(bprm->envc, envp, bprm);
        if (retval < 0)
-               goto out_free;
+               return retval;
 
        retval = copy_strings(bprm->argc, argv, bprm);
        if (retval < 0)
-               goto out_free;
+               return retval;
 
        /*
         * When argv is empty, add an empty string ("") as argv[0] to
@@ -1836,24 +1838,19 @@ static int do_execveat_common(int fd, struct filename *filename,
        if (bprm->argc == 0) {
                retval = copy_string_kernel("", bprm);
                if (retval < 0)
-                       goto out_free;
+                       return retval;
                bprm->argc = 1;
 
                pr_warn_once("process '%s' launched '%s' with NULL argv: empty string added\n",
                             current->comm, bprm->filename);
        }
 
-       retval = bprm_execve(bprm);
-out_free:
-       free_bprm(bprm);
-       return retval;
+       return bprm_execve(bprm);
 }
 
 int kernel_execve(const char *kernel_filename,
                  const char *const *argv, const char *const *envp)
 {
-       struct linux_binprm *bprm;
-       int fd = AT_FDCWD;
        int retval;
 
        /* It is non-sense for kernel threads to call execve */
@@ -1861,43 +1858,40 @@ int kernel_execve(const char *kernel_filename,
                return -EINVAL;
 
        CLASS(filename_kernel, filename)(kernel_filename);
-       bprm = alloc_bprm(fd, filename, 0);
+       CLASS(bprm, bprm)(AT_FDCWD, filename, 0);
        if (IS_ERR(bprm))
                return PTR_ERR(bprm);
 
        retval = count_strings_kernel(argv);
        if (WARN_ON_ONCE(retval == 0))
-               retval = -EINVAL;
+               return -EINVAL;
        if (retval < 0)
-               goto out_free;
+               return retval;
        bprm->argc = retval;
 
        retval = count_strings_kernel(envp);
        if (retval < 0)
-               goto out_free;
+               return retval;
        bprm->envc = retval;
 
        retval = bprm_stack_limits(bprm);
        if (retval < 0)
-               goto out_free;
+               return retval;
 
        retval = copy_string_kernel(bprm->filename, bprm);
        if (retval < 0)
-               goto out_free;
+               return retval;
        bprm->exec = bprm->p;
 
        retval = copy_strings_kernel(bprm->envc, envp, bprm);
        if (retval < 0)
-               goto out_free;
+               return retval;
 
        retval = copy_strings_kernel(bprm->argc, argv, bprm);
        if (retval < 0)
-               goto out_free;
+               return retval;
 
-       retval = bprm_execve(bprm);
-out_free:
-       free_bprm(bprm);
-       return retval;
+       return bprm_execve(bprm);
 }
 
 void set_binfmt(struct linux_binfmt *new)