Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck...

[deliverable/linux.git] / arch / x86 / kernel / cpu / mcheck / mce.c

diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index e535533d5ab89313ba51937ad8dd5740413f119e..95cf78d44ab4046e5d91cad89441572119865c01 100644 (file)
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -53,9 +53,12 @@
 static DEFINE_MUTEX(mce_chrdev_read_mutex);
 
 #define rcu_dereference_check_mce(p) \
-       rcu_dereference_index_check((p), \
-                             rcu_read_lock_sched_held() || \
-                             lockdep_is_held(&mce_chrdev_read_mutex))
+({ \
+       rcu_lockdep_assert(rcu_read_lock_sched_held() || \
+                          lockdep_is_held(&mce_chrdev_read_mutex), \
+                          "suspicious rcu_dereference_check_mce() usage"); \
+       smp_load_acquire(&(p)); \
+})
 
 #define CREATE_TRACE_POINTS
 #include <trace/events/mce.h>
@@ -708,6 +711,7 @@ static int mce_no_way_out(struct mce *m, char **msg, unsigned long *validp,
                          struct pt_regs *regs)
 {
        int i, ret = 0;
+       char *tmp;
 
        for (i = 0; i < mca_cfg.banks; i++) {
                m->status = mce_rdmsrl(MSR_IA32_MCx_STATUS(i));
@@ -716,9 +720,11 @@ static int mce_no_way_out(struct mce *m, char **msg, unsigned long *validp,
                        if (quirk_no_way_out)
                                quirk_no_way_out(i, m, regs);
                }
-               if (mce_severity(m, mca_cfg.tolerant, msg, true) >=
-                   MCE_PANIC_SEVERITY)
+
+               if (mce_severity(m, mca_cfg.tolerant, &tmp, true) >= MCE_PANIC_SEVERITY) {
+                       *msg = tmp;
                        ret = 1;
+               }
        }
        return ret;
 }
@@ -1884,7 +1890,7 @@ out:
 static unsigned int mce_chrdev_poll(struct file *file, poll_table *wait)
 {
        poll_wait(file, &mce_chrdev_wait, wait);
-       if (rcu_access_index(mcelog.next))
+       if (READ_ONCE(mcelog.next))
                return POLLIN | POLLRDNORM;
        if (!mce_apei_read_done && apei_check_mce())
                return POLLIN | POLLRDNORM;
@@ -1929,8 +1935,8 @@ void register_mce_write_callback(ssize_t (*fn)(struct file *filp,
 }
 EXPORT_SYMBOL_GPL(register_mce_write_callback);
 
-ssize_t mce_chrdev_write(struct file *filp, const char __user *ubuf,
-                        size_t usize, loff_t *off)
+static ssize_t mce_chrdev_write(struct file *filp, const char __user *ubuf,
+                               size_t usize, loff_t *off)
 {
        if (mce_write)
                return mce_write(filp, ubuf, usize, off);