diff options
Diffstat (limited to 'arch/x86_64')
| -rw-r--r-- | arch/x86_64/kernel/mce.c | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/arch/x86_64/kernel/mce.c b/arch/x86_64/kernel/mce.c index f3fb8174559..77fee481be4 100644 --- a/arch/x86_64/kernel/mce.c +++ b/arch/x86_64/kernel/mce.c @@ -465,6 +465,40 @@ void __cpuinit mcheck_init(struct cpuinfo_x86 *c) * Character device to read and clear the MCE log. */ +static DEFINE_SPINLOCK(mce_state_lock); +static int open_count; /* #times opened */ +static int open_exclu; /* already open exclusive? */ + +static int mce_open(struct inode *inode, struct file *file) +{ + spin_lock(&mce_state_lock); + + if (open_exclu || (open_count && (file->f_flags & O_EXCL))) { + spin_unlock(&mce_state_lock); + return -EBUSY; + } + + if (file->f_flags & O_EXCL) + open_exclu = 1; + open_count++; + + spin_unlock(&mce_state_lock); + + return 0; +} + +static int mce_release(struct inode *inode, struct file *file) +{ + spin_lock(&mce_state_lock); + + open_count--; + open_exclu = 0; + + spin_unlock(&mce_state_lock); + + return 0; +} + static void collect_tscs(void *data) { unsigned long *cpu_tsc = (unsigned long *)data; @@ -555,6 +589,8 @@ static int mce_ioctl(struct inode *i, struct file *f,unsigned int cmd, unsigned } static const struct file_operations mce_chrdev_ops = { + .open = mce_open, + .release = mce_release, .read = mce_read, .ioctl = mce_ioctl, }; |