Re: [PATCH 1/2] do_coredump: factor out put_cred() calls

Oleg Nesterov
2009-06-26T23:48:55Z

On 06/26, Roland McGrath wrote:
>
> > if (!binfmt || !binfmt->core_dump)
> > - goto fail;
> > + goto out;
> [...]
> > +out:
> > return;
> > }
>
> If the label does nothing, just use "return" instead of goto.

But this is what the current code does, I just renamed "fail" to "out"
to make sure I didn't miss a goto.

And in fact I am not sure return is better, "goto out" looks more
consistent to me.

But OK, please find the updated patch below.

--------------------------------------------------------------------------
[PATCH 1/2] do_coredump: factor out put_cred() calls

Given that do_coredump() calls put_cred() on exit path, it is a bit ugly
to do put_cred() + "goto fail" twice, just add the new "fail_creds" label.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>

--- WAIT/fs/exec.c~CD_1_PUT_CRED 2009-06-15 12:48:28.000000000 +0200
+++ WAIT/fs/exec.c 2009-06-26 22:30:28.000000000 +0200
@@ -1732,13 +1732,11 @@ void do_coredump(long signr, int exit_co

binfmt = current->binfmt;
if (!binfmt || !binfmt->core_dump)
- goto fail;
+ return;

cred = prepare_creds();
- if (!cred) {
- retval = -ENOMEM;
- goto fail;
- }
+ if (!cred)
+ return;

down_write(&mm->mmap_sem);
/*
@@ -1746,8 +1744,7 @@ void do_coredump(long signr, int exit_co
*/
if (mm->core_state || !get_dumpable(mm)) {
up_write(&mm->mmap_sem);
- put_cred(cred);
- goto fail;
+ goto fail_creds;
}

/*
@@ -1761,10 +1758,8 @@ void do_coredump(long signr, int exit_co
}

retval = coredump_wait(exit_code, &core_state);
- if (retval < 0) {
- put_cred(cred);
- goto fail;
- }
+ if (retval < 0)
+ goto fail_creds;

old_cred = override_creds(cred);

@@ -1862,9 +1857,8 @@ fail_unlock:
if (helper_argv)
argv_free(helper_argv);

+ coredump_finish(mm);
revert_creds(old_cred);
+fail_creds:
put_cred(cred);
- coredump_finish(mm);
-fail:
- return;
}