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authorLi Zefan <lizefan@huawei.com>2013-08-01 09:51:47 +0800
committerTejun Heo <tj@kernel.org>2013-08-01 09:29:41 -0400
commit876ede8b2b9880615be0de3ec7b8afd0a1786e76 (patch)
treeb2c238a5939a6daf9f43b6eba1b1ceaf3dc2c372 /kernel/cgroup.c
parente14880f7bb7e0dc0933af304998371dd543ceb40 (diff)
cgroup: restructure the failure path in cgroup_write_event_control()
It uses a single label and checks the validity of each pointer. This is err-prone, and actually we had a bug because one of the check was insufficient. Use multi lables as we do in other places. v2: - drop initializations of local variables. Signed-off-by: Li Zefan <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'kernel/cgroup.c')
-rw-r--r--kernel/cgroup.c39
1 files changed, 18 insertions, 21 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 3f6593333525..9f6dab22289e 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -3934,11 +3934,11 @@ static void cgroup_event_ptable_queue_proc(struct file *file,
static int cgroup_write_event_control(struct cgroup *cgrp, struct cftype *cft,
const char *buffer)
{
- struct cgroup_event *event = NULL;
+ struct cgroup_event *event;
struct cgroup *cgrp_cfile;
unsigned int efd, cfd;
- struct file *efile = NULL;
- struct file *cfile = NULL;
+ struct file *efile;
+ struct file *cfile;
char *endp;
int ret;
@@ -3964,31 +3964,31 @@ static int cgroup_write_event_control(struct cgroup *cgrp, struct cftype *cft,
efile = eventfd_fget(efd);
if (IS_ERR(efile)) {
ret = PTR_ERR(efile);
- goto fail;
+ goto out_kfree;
}
event->eventfd = eventfd_ctx_fileget(efile);
if (IS_ERR(event->eventfd)) {
ret = PTR_ERR(event->eventfd);
- goto fail;
+ goto out_put_efile;
}
cfile = fget(cfd);
if (!cfile) {
ret = -EBADF;
- goto fail;
+ goto out_put_eventfd;
}
/* the process need read permission on control file */
/* AV: shouldn't we check that it's been opened for read instead? */
ret = inode_permission(file_inode(cfile), MAY_READ);
if (ret < 0)
- goto fail;
+ goto out_put_cfile;
event->cft = __file_cft(cfile);
if (IS_ERR(event->cft)) {
ret = PTR_ERR(event->cft);
- goto fail;
+ goto out_put_cfile;
}
/*
@@ -3998,18 +3998,18 @@ static int cgroup_write_event_control(struct cgroup *cgrp, struct cftype *cft,
cgrp_cfile = __d_cgrp(cfile->f_dentry->d_parent);
if (cgrp_cfile != cgrp) {
ret = -EINVAL;
- goto fail;
+ goto out_put_cfile;
}
if (!event->cft->register_event || !event->cft->unregister_event) {
ret = -EINVAL;
- goto fail;
+ goto out_put_cfile;
}
ret = event->cft->register_event(cgrp, event->cft,
event->eventfd, buffer);
if (ret)
- goto fail;
+ goto out_put_cfile;
efile->f_op->poll(efile, &event->pt);
@@ -4029,16 +4029,13 @@ static int cgroup_write_event_control(struct cgroup *cgrp, struct cftype *cft,
return 0;
-fail:
- if (cfile)
- fput(cfile);
-
- if (event && event->eventfd && !IS_ERR(event->eventfd))
- eventfd_ctx_put(event->eventfd);
-
- if (!IS_ERR_OR_NULL(efile))
- fput(efile);
-
+out_put_cfile:
+ fput(cfile);
+out_put_eventfd:
+ eventfd_ctx_put(event->eventfd);
+out_put_efile:
+ fput(efile);
+out_kfree:
kfree(event);
return ret;