diff options
author | Vishal Verma <vishal.l.verma@intel.com> | 2017-04-18 20:42:35 +0200 |
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committer | Thomas Gleixner <tglx@linutronix.de> | 2017-04-18 22:23:48 +0200 |
commit | 0dc9c639e6553e39c13b2c0d54c8a1b098cb95e2 (patch) | |
tree | 688b31f3512c24a518bc2df0659afde8bb64b21e /arch/x86/kernel/cpu | |
parent | 4f7d029b9bf009fbee76bb10c0c4351a1870d2f3 (diff) | |
download | op-kernel-dev-0dc9c639e6553e39c13b2c0d54c8a1b098cb95e2.zip op-kernel-dev-0dc9c639e6553e39c13b2c0d54c8a1b098cb95e2.tar.gz |
x86/mce: Make the MCE notifier a blocking one
The NFIT MCE handler callback (for handling media errors on NVDIMMs)
takes a mutex to add the location of a memory error to a list. But since
the notifier call chain for machine checks (x86_mce_decoder_chain) is
atomic, we get a lockdep splat like:
BUG: sleeping function called from invalid context at kernel/locking/mutex.c:620
in_atomic(): 1, irqs_disabled(): 0, pid: 4, name: kworker/0:0
[..]
Call Trace:
dump_stack
___might_sleep
__might_sleep
mutex_lock_nested
? __lock_acquire
nfit_handle_mce
notifier_call_chain
atomic_notifier_call_chain
? atomic_notifier_call_chain
mce_gen_pool_process
Convert the notifier to a blocking one which gets to run only in process
context.
Boris: remove the notifier call in atomic context in print_mce(). For
now, let's print the MCE on the atomic path so that we can make sure
they go out and get logged at least.
Fixes: 6839a6d96f4e ("nfit: do an ARS scrub on hitting a latent media error")
Reported-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
Acked-by: Tony Luck <tony.luck@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Cc: x86-ml <x86@kernel.org>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/20170411224457.24777-1-vishal.l.verma@intel.com
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'arch/x86/kernel/cpu')
-rw-r--r-- | arch/x86/kernel/cpu/mcheck/mce-genpool.c | 2 | ||||
-rw-r--r-- | arch/x86/kernel/cpu/mcheck/mce-internal.h | 2 | ||||
-rw-r--r-- | arch/x86/kernel/cpu/mcheck/mce.c | 17 |
3 files changed, 5 insertions, 16 deletions
diff --git a/arch/x86/kernel/cpu/mcheck/mce-genpool.c b/arch/x86/kernel/cpu/mcheck/mce-genpool.c index 1e5a50c..217cd44 100644 --- a/arch/x86/kernel/cpu/mcheck/mce-genpool.c +++ b/arch/x86/kernel/cpu/mcheck/mce-genpool.c @@ -85,7 +85,7 @@ void mce_gen_pool_process(struct work_struct *__unused) head = llist_reverse_order(head); llist_for_each_entry_safe(node, tmp, head, llnode) { mce = &node->mce; - atomic_notifier_call_chain(&x86_mce_decoder_chain, 0, mce); + blocking_notifier_call_chain(&x86_mce_decoder_chain, 0, mce); gen_pool_free(mce_evt_pool, (unsigned long)node, sizeof(*node)); } } diff --git a/arch/x86/kernel/cpu/mcheck/mce-internal.h b/arch/x86/kernel/cpu/mcheck/mce-internal.h index 903043e..19592ba 100644 --- a/arch/x86/kernel/cpu/mcheck/mce-internal.h +++ b/arch/x86/kernel/cpu/mcheck/mce-internal.h @@ -13,7 +13,7 @@ enum severity_level { MCE_PANIC_SEVERITY, }; -extern struct atomic_notifier_head x86_mce_decoder_chain; +extern struct blocking_notifier_head x86_mce_decoder_chain; #define ATTR_LEN 16 #define INITIAL_CHECK_INTERVAL 5 * 60 /* 5 minutes */ diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c index 5accfbd..af44ebe 100644 --- a/arch/x86/kernel/cpu/mcheck/mce.c +++ b/arch/x86/kernel/cpu/mcheck/mce.c @@ -123,7 +123,7 @@ static void (*quirk_no_way_out)(int bank, struct mce *m, struct pt_regs *regs); * CPU/chipset specific EDAC code can register a notifier call here to print * MCE errors in a human-readable form. */ -ATOMIC_NOTIFIER_HEAD(x86_mce_decoder_chain); +BLOCKING_NOTIFIER_HEAD(x86_mce_decoder_chain); /* Do initial initialization of a struct mce */ void mce_setup(struct mce *m) @@ -220,7 +220,7 @@ void mce_register_decode_chain(struct notifier_block *nb) WARN_ON(nb->priority > MCE_PRIO_LOWEST && nb->priority < MCE_PRIO_EDAC); - atomic_notifier_chain_register(&x86_mce_decoder_chain, nb); + blocking_notifier_chain_register(&x86_mce_decoder_chain, nb); } EXPORT_SYMBOL_GPL(mce_register_decode_chain); @@ -228,7 +228,7 @@ void mce_unregister_decode_chain(struct notifier_block *nb) { atomic_dec(&num_notifiers); - atomic_notifier_chain_unregister(&x86_mce_decoder_chain, nb); + blocking_notifier_chain_unregister(&x86_mce_decoder_chain, nb); } EXPORT_SYMBOL_GPL(mce_unregister_decode_chain); @@ -321,18 +321,7 @@ static void __print_mce(struct mce *m) static void print_mce(struct mce *m) { - int ret = 0; - __print_mce(m); - - /* - * Print out human-readable details about the MCE error, - * (if the CPU has an implementation for that) - */ - ret = atomic_notifier_call_chain(&x86_mce_decoder_chain, 0, m); - if (ret == NOTIFY_STOP) - return; - pr_emerg_ratelimited(HW_ERR "Run the above through 'mcelog --ascii'\n"); } |