From 0937195715713b37ec843f28d99930dd7b1e8fbe Mon Sep 17 00:00:00 2001 From: Borislav Petkov Date: Thu, 8 Dec 2011 12:28:33 +0100 Subject: [PATCH] x86, MCE: Drain mcelog buffer Add a function which drains whatever MCEs were logged in already during boot and before the decoder chains were registered. Signed-off-by: Borislav Petkov --- arch/x86/kernel/cpu/mcheck/mce.c | 39 ++++++++++++++++++++++++++++++++ 1 file changed, 39 insertions(+) diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c index c3c66ac6ef74..5be2464cce6a 100644 --- a/arch/x86/kernel/cpu/mcheck/mce.c +++ b/arch/x86/kernel/cpu/mcheck/mce.c @@ -189,9 +189,48 @@ void mce_log(struct mce *mce) set_bit(0, &mce_need_notify); } +static void drain_mcelog_buffer(void) +{ + unsigned int next, i, prev = 0; + + next = rcu_dereference_check_mce(mcelog.next); + + do { + struct mce *m; + + /* drain what was logged during boot */ + for (i = prev; i < next; i++) { + unsigned long start = jiffies; + unsigned retries = 1; + + m = &mcelog.entry[i]; + + while (!m->finished) { + if (time_after_eq(jiffies, start + 2*retries)) + retries++; + + cpu_relax(); + + if (!m->finished && retries >= 4) { + pr_err("MCE: skipping error being logged currently!\n"); + break; + } + } + smp_rmb(); + atomic_notifier_call_chain(&x86_mce_decoder_chain, 0, m); + } + + memset(mcelog.entry + prev, 0, (next - prev) * sizeof(*m)); + prev = next; + next = cmpxchg(&mcelog.next, prev, 0); + } while (next != prev); +} + + void mce_register_decode_chain(struct notifier_block *nb) { atomic_notifier_chain_register(&x86_mce_decoder_chain, nb); + drain_mcelog_buffer(); } EXPORT_SYMBOL_GPL(mce_register_decode_chain); -- 2.45.2