linux-kernel - [PATCH 5/6] x86/mce: Provide an option to keep cmci

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Tue, 7 Aug 2012 13:46:56 -0700
From:	Tony Luck <tony.luck@...el.com>
To:	Chen Gong <gong.chen@...ux.intel.com>
Cc:	bp@...64.org, x86@...nel.org, linux-kernel@...r.kernel.org
Subject: [PATCH 5/6] x86/mce: Provide an option to keep cmci_reenable() quiet

cmci_reenable() calls cmci_discover() to look at which machine check
banks are shared between processors. It ensure that only one cpu takes
ownership of each shared bank. At boot time cmci_discover() is muted,
but during hot add events it provides some output which may be helpful
to ensure that all banks have an owner.

We want to use cmci_reenable() when a CMCI storm subsides. In this case
the topology has not changed, so we do not need any commentary as it
goes about its business.

Add a "quiet" argument to cmci_reenable() that it passes to cmci_discover().

Signed-off-by: Tony Luck <tony.luck@...el.com>
---

[Patches 1-4 remain as previously posted. This is a new patch to
 help tidy console messages. Old patch 5 becomes patch 6 (and has
 a few cleanups]

 arch/x86/include/asm/mce.h             |  4 ++--
 arch/x86/kernel/cpu/mcheck/mce.c       |  4 ++--
 arch/x86/kernel/cpu/mcheck/mce_intel.c | 10 +++++-----
 3 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h
index 441520e..bf79a0f 100644
--- a/arch/x86/include/asm/mce.h
+++ b/arch/x86/include/asm/mce.h
@@ -165,13 +165,13 @@ extern int mce_cmci_disabled;
 extern int mce_ignore_ce;
 void mce_intel_feature_init(struct cpuinfo_x86 *c);
 void cmci_clear(void);
-void cmci_reenable(void);
+void cmci_reenable(int quiet);
 void cmci_rediscover(int dying);
 void cmci_recheck(void);
 #else
 static inline void mce_intel_feature_init(struct cpuinfo_x86 *c) { }
 static inline void cmci_clear(void) {}
-static inline void cmci_reenable(void) {}
+static inline void cmci_reenable(int quiet) {}
 static inline void cmci_rediscover(int dying) {}
 static inline void cmci_recheck(void) {}
 #endif
diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index b4dde15..826dd21 100644
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -1994,7 +1994,7 @@ static void mce_enable_ce(void *all)
 {
 	if (!mce_available(__this_cpu_ptr(&cpu_info)))
 		return;
-	cmci_reenable();
+	cmci_reenable(0);
 	cmci_recheck();
 	if (all)
 		__mcheck_cpu_init_timer();
@@ -2246,7 +2246,7 @@ static void __cpuinit mce_reenable_cpu(void *h)
 		return;
 
 	if (!(action & CPU_TASKS_FROZEN))
-		cmci_reenable();
+		cmci_reenable(0);
 	for (i = 0; i < banks; i++) {
 		struct mce_bank *b = &mce_banks[i];
 
diff --git a/arch/x86/kernel/cpu/mcheck/mce_intel.c b/arch/x86/kernel/cpu/mcheck/mce_intel.c
index 38e49bc..e652cde 100644
--- a/arch/x86/kernel/cpu/mcheck/mce_intel.c
+++ b/arch/x86/kernel/cpu/mcheck/mce_intel.c
@@ -78,7 +78,7 @@ static void print_update(char *type, int *hdr, int num)
  * on this CPU. Use the algorithm recommended in the SDM to discover shared
  * banks.
  */
-static void cmci_discover(int banks, int boot)
+static void cmci_discover(int banks, int quiet)
 {
 	unsigned long *owned = (void *)&__get_cpu_var(mce_banks_owned);
 	unsigned long flags;
@@ -96,7 +96,7 @@ static void cmci_discover(int banks, int boot)
 
 		/* Already owned by someone else? */
 		if (val & MCI_CTL2_CMCI_EN) {
-			if (test_and_clear_bit(i, owned) && !boot)
+			if (test_and_clear_bit(i, owned) && !quiet)
 				print_update("SHD", &hdr, i);
 			__clear_bit(i, __get_cpu_var(mce_poll_banks));
 			continue;
@@ -109,7 +109,7 @@ static void cmci_discover(int banks, int boot)
 
 		/* Did the enable bit stick? -- the bank supports CMCI */
 		if (val & MCI_CTL2_CMCI_EN) {
-			if (!test_and_set_bit(i, owned) && !boot)
+			if (!test_and_set_bit(i, owned) && !quiet)
 				print_update("CMCI", &hdr, i);
 			__clear_bit(i, __get_cpu_var(mce_poll_banks));
 		} else {
@@ -196,11 +196,11 @@ void cmci_rediscover(int dying)
 /*
  * Reenable CMCI on this CPU in case a CPU down failed.
  */
-void cmci_reenable(void)
+void cmci_reenable(int quiet)
 {
 	int banks;
 	if (cmci_supported(&banks))
-		cmci_discover(banks, 0);
+		cmci_discover(banks, quiet);
 }
 
 static void intel_init_cmci(void)
-- 
1.7.10.2.552.gaa3bb87

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/