media: saa7164: fix remove_proc_entry warning

if saa7164_proc_create() fails, saa7164_fini() will trigger a warning,

name 'saa7164'
WARNING: CPU: 1 PID: 6311 at fs/proc/generic.c:672 remove_proc_entry+0x1e8/0x3a0
  ? remove_proc_entry+0x1e8/0x3a0
  ? try_stop_module+0x7b/0x240
  ? proc_readdir+0x70/0x70
  ? rcu_read_lock_sched_held+0xd7/0x100
  saa7164_fini+0x13/0x1f [saa7164]
  __x64_sys_delete_module+0x30c/0x480
  ? __ia32_sys_delete_module+0x480/0x480
  ? __x64_sys_clock_gettime+0x11e/0x1c0
  ? __x64_sys_timer_create+0x1a0/0x1a0
  ? trace_hardirqs_off_caller+0x40/0x180
  ? do_syscall_64+0x18/0x450
  do_syscall_64+0x9f/0x450
  entry_SYSCALL_64_after_hwframe+0x49/0xbe

Fix it by checking the return of proc_create_single() before
calling remove_proc_entry().

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
[hverkuil-cisco@xs4all.nl: use 0444 instead of S_IRUGO]
[hverkuil-cisco@xs4all.nl: use pr_info instead of KERN_INFO]
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
This commit is contained in:
Kefeng Wang 2019-05-27 08:14:55 -04:00 committed by Mauro Carvalho Chehab
parent 518fa4e0e0
commit 50710eeefb

View File

@ -1122,16 +1122,25 @@ static int saa7164_proc_show(struct seq_file *m, void *v)
return 0;
}
static struct proc_dir_entry *saa7164_pe;
static int saa7164_proc_create(void)
{
struct proc_dir_entry *pe;
pe = proc_create_single("saa7164", S_IRUGO, NULL, saa7164_proc_show);
if (!pe)
saa7164_pe = proc_create_single("saa7164", 0444, NULL, saa7164_proc_show);
if (!saa7164_pe)
return -ENOMEM;
return 0;
}
static void saa7164_proc_destroy(void)
{
if (saa7164_pe)
remove_proc_entry("saa7164", NULL);
}
#else
static int saa7164_proc_create(void) { return 0; }
static void saa7164_proc_destroy(void) {}
#endif
static int saa7164_thread_function(void *data)
@ -1503,19 +1512,21 @@ static struct pci_driver saa7164_pci_driver = {
static int __init saa7164_init(void)
{
printk(KERN_INFO "saa7164 driver loaded\n");
int ret = pci_register_driver(&saa7164_pci_driver);
if (ret)
return ret;
#ifdef CONFIG_PROC_FS
saa7164_proc_create();
#endif
return pci_register_driver(&saa7164_pci_driver);
pr_info("saa7164 driver loaded\n");
return 0;
}
static void __exit saa7164_fini(void)
{
#ifdef CONFIG_PROC_FS
remove_proc_entry("saa7164", NULL);
#endif
saa7164_proc_destroy();
pci_unregister_driver(&saa7164_pci_driver);
}