diff options
Diffstat (limited to 'arch/x86/kernel/cpu/mcheck/mce.c')
| -rw-r--r-- | arch/x86/kernel/cpu/mcheck/mce.c | 16 |
1 files changed, 11 insertions, 5 deletions
diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c index 28cba46bf32c..8a6f0afa767e 100644 --- a/arch/x86/kernel/cpu/mcheck/mce.c +++ b/arch/x86/kernel/cpu/mcheck/mce.c @@ -26,6 +26,7 @@ #include <linux/sched.h> #include <linux/sysfs.h> #include <linux/types.h> +#include <linux/slab.h> #include <linux/init.h> #include <linux/kmod.h> #include <linux/poll.h> @@ -46,6 +47,13 @@ #include "mce-internal.h" +static DEFINE_MUTEX(mce_read_mutex); + +#define rcu_dereference_check_mce(p) \ + rcu_dereference_check((p), \ + rcu_read_lock_sched_held() || \ + lockdep_is_held(&mce_read_mutex)) + #define CREATE_TRACE_POINTS #include <trace/events/mce.h> @@ -158,7 +166,7 @@ void mce_log(struct mce *mce) mce->finished = 0; wmb(); for (;;) { - entry = rcu_dereference(mcelog.next); + entry = rcu_dereference_check_mce(mcelog.next); for (;;) { /* * When the buffer fills up discard new entries. @@ -1485,8 +1493,6 @@ static void collect_tscs(void *data) rdtscll(cpu_tsc[smp_processor_id()]); } -static DEFINE_MUTEX(mce_read_mutex); - static ssize_t mce_read(struct file *filp, char __user *ubuf, size_t usize, loff_t *off) { @@ -1500,7 +1506,7 @@ static ssize_t mce_read(struct file *filp, char __user *ubuf, size_t usize, return -ENOMEM; mutex_lock(&mce_read_mutex); - next = rcu_dereference(mcelog.next); + next = rcu_dereference_check_mce(mcelog.next); /* Only supports full reads right now */ if (*off != 0 || usize < MCE_LOG_LEN*sizeof(struct mce)) { @@ -1565,7 +1571,7 @@ timeout: static unsigned int mce_poll(struct file *file, poll_table *wait) { poll_wait(file, &mce_wait, wait); - if (rcu_dereference(mcelog.next)) + if (rcu_dereference_check_mce(mcelog.next)) return POLLIN | POLLRDNORM; return 0; } |