diff options
Diffstat (limited to 'arch/x86/kernel/cpu/mcheck')
| -rw-r--r-- | arch/x86/kernel/cpu/mcheck/Makefile | 1 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/mcheck/dev-mcelog.c | 121 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/mcheck/mce-internal.h | 1 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/mcheck/mce_intel.c | 1 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/mcheck/p5.c | 1 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/mcheck/threshold.c | 1 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/mcheck/winchip.c | 1 |
7 files changed, 33 insertions, 94 deletions
diff --git a/arch/x86/kernel/cpu/mcheck/Makefile b/arch/x86/kernel/cpu/mcheck/Makefile index 43051f0777d4..bcc7c54c7041 100644 --- a/arch/x86/kernel/cpu/mcheck/Makefile +++ b/arch/x86/kernel/cpu/mcheck/Makefile @@ -1,3 +1,4 @@ +# SPDX-License-Identifier: GPL-2.0 obj-y = mce.o mce-severity.o mce-genpool.o obj-$(CONFIG_X86_ANCIENT_MCE) += winchip.o p5.o diff --git a/arch/x86/kernel/cpu/mcheck/dev-mcelog.c b/arch/x86/kernel/cpu/mcheck/dev-mcelog.c index 10cec43aac38..7f85b76f43bc 100644 --- a/arch/x86/kernel/cpu/mcheck/dev-mcelog.c +++ b/arch/x86/kernel/cpu/mcheck/dev-mcelog.c @@ -24,14 +24,6 @@ static DEFINE_MUTEX(mce_chrdev_read_mutex); static char mce_helper[128]; static char *mce_helper_argv[2] = { mce_helper, NULL }; -#define mce_log_get_idx_check(p) \ -({ \ - RCU_LOCKDEP_WARN(!rcu_read_lock_sched_held() && \ - !lockdep_is_held(&mce_chrdev_read_mutex), \ - "suspicious mce_log_get_idx_check() usage"); \ - smp_load_acquire(&(p)); \ -}) - /* * Lockless MCE logging infrastructure. * This avoids deadlocks on printk locks without having to break locks. Also @@ -53,43 +45,32 @@ static int dev_mce_log(struct notifier_block *nb, unsigned long val, void *data) { struct mce *mce = (struct mce *)data; - unsigned int next, entry; - - wmb(); - for (;;) { - entry = mce_log_get_idx_check(mcelog.next); - for (;;) { - - /* - * When the buffer fills up discard new entries. - * Assume that the earlier errors are the more - * interesting ones: - */ - if (entry >= MCE_LOG_LEN) { - set_bit(MCE_OVERFLOW, - (unsigned long *)&mcelog.flags); - return NOTIFY_OK; - } - /* Old left over entry. Skip: */ - if (mcelog.entry[entry].finished) { - entry++; - continue; - } - break; - } - smp_rmb(); - next = entry + 1; - if (cmpxchg(&mcelog.next, entry, next) == entry) - break; + unsigned int entry; + + mutex_lock(&mce_chrdev_read_mutex); + + entry = mcelog.next; + + /* + * When the buffer fills up discard new entries. Assume that the + * earlier errors are the more interesting ones: + */ + if (entry >= MCE_LOG_LEN) { + set_bit(MCE_OVERFLOW, (unsigned long *)&mcelog.flags); + goto unlock; } + + mcelog.next = entry + 1; + memcpy(mcelog.entry + entry, mce, sizeof(struct mce)); - wmb(); mcelog.entry[entry].finished = 1; - wmb(); /* wake processes polling /dev/mcelog */ wake_up_interruptible(&mce_chrdev_wait); +unlock: + mutex_unlock(&mce_chrdev_read_mutex); + return NOTIFY_OK; } @@ -177,13 +158,6 @@ static int mce_chrdev_release(struct inode *inode, struct file *file) return 0; } -static void collect_tscs(void *data) -{ - unsigned long *cpu_tsc = (unsigned long *)data; - - cpu_tsc[smp_processor_id()] = rdtsc(); -} - static int mce_apei_read_done; /* Collect MCE record of previous boot in persistent storage via APEI ERST. */ @@ -231,14 +205,9 @@ static ssize_t mce_chrdev_read(struct file *filp, char __user *ubuf, size_t usize, loff_t *off) { char __user *buf = ubuf; - unsigned long *cpu_tsc; - unsigned prev, next; + unsigned next; int i, err; - cpu_tsc = kmalloc(nr_cpu_ids * sizeof(long), GFP_KERNEL); - if (!cpu_tsc) - return -ENOMEM; - mutex_lock(&mce_chrdev_read_mutex); if (!mce_apei_read_done) { @@ -247,65 +216,29 @@ static ssize_t mce_chrdev_read(struct file *filp, char __user *ubuf, goto out; } - next = mce_log_get_idx_check(mcelog.next); - /* Only supports full reads right now */ err = -EINVAL; if (*off != 0 || usize < MCE_LOG_LEN*sizeof(struct mce)) goto out; + next = mcelog.next; err = 0; - prev = 0; - do { - for (i = prev; i < next; i++) { - unsigned long start = jiffies; - struct mce *m = &mcelog.entry[i]; - - while (!m->finished) { - if (time_after_eq(jiffies, start + 2)) { - memset(m, 0, sizeof(*m)); - goto timeout; - } - cpu_relax(); - } - smp_rmb(); - err |= copy_to_user(buf, m, sizeof(*m)); - buf += sizeof(*m); -timeout: - ; - } - - memset(mcelog.entry + prev, 0, - (next - prev) * sizeof(struct mce)); - prev = next; - next = cmpxchg(&mcelog.next, prev, 0); - } while (next != prev); - - synchronize_sched(); - /* - * Collect entries that were still getting written before the - * synchronize. - */ - on_each_cpu(collect_tscs, cpu_tsc, 1); - - for (i = next; i < MCE_LOG_LEN; i++) { + for (i = 0; i < next; i++) { struct mce *m = &mcelog.entry[i]; - if (m->finished && m->tsc < cpu_tsc[m->cpu]) { - err |= copy_to_user(buf, m, sizeof(*m)); - smp_rmb(); - buf += sizeof(*m); - memset(m, 0, sizeof(*m)); - } + err |= copy_to_user(buf, m, sizeof(*m)); + buf += sizeof(*m); } + memset(mcelog.entry, 0, next * sizeof(struct mce)); + mcelog.next = 0; + if (err) err = -EFAULT; out: mutex_unlock(&mce_chrdev_read_mutex); - kfree(cpu_tsc); return err ? err : buf - ubuf; } diff --git a/arch/x86/kernel/cpu/mcheck/mce-internal.h b/arch/x86/kernel/cpu/mcheck/mce-internal.h index debb974fd17d..aa0d5df9dc60 100644 --- a/arch/x86/kernel/cpu/mcheck/mce-internal.h +++ b/arch/x86/kernel/cpu/mcheck/mce-internal.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0 */ #ifndef __X86_MCE_INTERNAL_H__ #define __X86_MCE_INTERNAL_H__ diff --git a/arch/x86/kernel/cpu/mcheck/mce_intel.c b/arch/x86/kernel/cpu/mcheck/mce_intel.c index e84db79ef272..d05be307d081 100644 --- a/arch/x86/kernel/cpu/mcheck/mce_intel.c +++ b/arch/x86/kernel/cpu/mcheck/mce_intel.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * Intel specific MCE features. * Copyright 2004 Zwane Mwaikambo <zwane@linuxpower.ca> diff --git a/arch/x86/kernel/cpu/mcheck/p5.c b/arch/x86/kernel/cpu/mcheck/p5.c index 2a0717bf8033..5cddf831720f 100644 --- a/arch/x86/kernel/cpu/mcheck/p5.c +++ b/arch/x86/kernel/cpu/mcheck/p5.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * P5 specific Machine Check Exception Reporting * (C) Copyright 2002 Alan Cox <alan@lxorguk.ukuu.org.uk> diff --git a/arch/x86/kernel/cpu/mcheck/threshold.c b/arch/x86/kernel/cpu/mcheck/threshold.c index 5e7249e42f8f..2b584b319eff 100644 --- a/arch/x86/kernel/cpu/mcheck/threshold.c +++ b/arch/x86/kernel/cpu/mcheck/threshold.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * Common corrected MCE threshold handler code: */ diff --git a/arch/x86/kernel/cpu/mcheck/winchip.c b/arch/x86/kernel/cpu/mcheck/winchip.c index c6a722e1d011..3b45b270a865 100644 --- a/arch/x86/kernel/cpu/mcheck/winchip.c +++ b/arch/x86/kernel/cpu/mcheck/winchip.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * IDT Winchip specific Machine Check Exception Reporting * (C) Copyright 2002 Alan Cox <alan@lxorguk.ukuu.org.uk> |