From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from out03.mta.xmission.com ([166.70.13.233]:59688 "EHLO out03.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727705AbeIPXEe (ORCPT ); Sun, 16 Sep 2018 19:04:34 -0400 From: ebiederm@xmission.com (Eric W. Biederman) To: Jeff Layton Cc: viro@zeniv.linux.org.uk, berrange@redhat.com, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Oleg Nesterov References: <20180914105310.6454-1-jlayton@kernel.org> <87a7ohs5ow.fsf@xmission.com> Date: Sun, 16 Sep 2018 19:40:43 +0200 In-Reply-To: <87a7ohs5ow.fsf@xmission.com> (Eric W. Biederman's message of "Sun, 16 Sep 2018 19:38:55 +0200") Message-ID: <87y3c1qr1g.fsf_-_@xmission.com> MIME-Version: 1.0 Content-Type: text/plain Subject: [RFC][PATCH 2/3] exec: Simplify unshare_files Sender: linux-fsdevel-owner@vger.kernel.org List-ID: Now that exec calls unshare_files after the point of no return there is no reason to return displaced. Signed-off-by: "Eric W. Biederman" --- fs/coredump.c | 5 +---- fs/exec.c | 5 +---- include/linux/fdtable.h | 2 +- kernel/fork.c | 12 ++++++------ 4 files changed, 9 insertions(+), 15 deletions(-) diff --git a/fs/coredump.c b/fs/coredump.c index 1e2c87acac9b..968ee5744bf9 100644 --- a/fs/coredump.c +++ b/fs/coredump.c @@ -546,7 +546,6 @@ void do_coredump(const siginfo_t *siginfo) struct cred *cred; int retval = 0; int ispipe; - struct files_struct *displaced; /* require nonrelative corefile path and be extra careful */ bool need_suid_safe = false; bool core_dumped = false; @@ -747,11 +746,9 @@ void do_coredump(const siginfo_t *siginfo) } /* get us an unshared descriptor table; almost always a no-op */ - retval = unshare_files(&displaced); + retval = unshare_files(); if (retval) goto close_fail; - if (displaced) - put_files_struct(displaced); if (!dump_interrupted()) { file_start_write(cprm.file); core_dumped = binfmt->core_dump(&cprm); diff --git a/fs/exec.c b/fs/exec.c index 6f6167ec08eb..7eeffa7d98c6 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1252,7 +1252,6 @@ void __set_task_comm(struct task_struct *tsk, const char *buf, bool exec) */ int flush_old_exec(struct linux_binprm * bprm) { - struct files_struct *displaced; int retval; /* @@ -1292,11 +1291,9 @@ int flush_old_exec(struct linux_binprm * bprm) flush_thread(); current->personality &= ~bprm->per_clear; - retval = unshare_files(&displaced); + retval = unshare_files(); if (retval) goto out; - if (displaced) - put_files_struct(displaced); /* * We have to apply CLOEXEC before we change whether the process is diff --git a/include/linux/fdtable.h b/include/linux/fdtable.h index 41615f38bcff..e65379336c4c 100644 --- a/include/linux/fdtable.h +++ b/include/linux/fdtable.h @@ -108,7 +108,7 @@ struct task_struct; struct files_struct *get_files_struct(struct task_struct *); void put_files_struct(struct files_struct *fs); void reset_files_struct(struct files_struct *); -int unshare_files(struct files_struct **); +int unshare_files(void); struct files_struct *dup_fd(struct files_struct *, int *) __latent_entropy; void do_close_on_exec(struct files_struct *); int iterate_fd(struct files_struct *, unsigned, diff --git a/kernel/fork.c b/kernel/fork.c index d896e9ca38b0..a06a609075eb 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -2564,21 +2564,21 @@ SYSCALL_DEFINE1(unshare, unsigned long, unshare_flags) * the exec layer of the kernel. */ -int unshare_files(struct files_struct **displaced) +int unshare_files(void) { struct task_struct *task = current; - struct files_struct *copy = NULL; + struct files_struct *files, *copy = NULL; int error; error = unshare_fd(CLONE_FILES, ©); - if (error || !copy) { - *displaced = NULL; + if (error || !copy) return error; - } - *displaced = task->files; + + files = task->files; task_lock(task); task->files = copy; task_unlock(task); + put_files_struct(files); return 0; } -- 2.17.1