linux-kernel - [V6][PATCH 5/6] x86, nmi: track NMI usage stats

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: Windows password security audit tool. GUI, reports in PDF.

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

Message-Id: <1316805435-14832-6-git-send-email-dzickus@redhat.com>
Date:	Fri, 23 Sep 2011 15:17:14 -0400
From:	Don Zickus <dzickus@...hat.com>
To:	<x86@...nel.org>, Andi Kleen <andi@...stfloor.org>,
	Robert Richter <robert.richter@....com>,
	Peter Zijlstra <peterz@...radead.org>, ying.huang@...el.com
Cc:	LKML <linux-kernel@...r.kernel.org>, paulmck@...ux.vnet.ibm.com,
	avi@...hat.com, jeremy@...p.org, Don Zickus <dzickus@...hat.com>
Subject: [V6][PATCH 5/6] x86, nmi: track NMI usage stats

Now that the NMI handler are broken into lists, increment the appropriate
stats for each list.  This allows us to see what is going on when they
get printed out in the next patch.

Signed-off-by: Don Zickus <dzickus@...hat.com>
---
 arch/x86/kernel/nmi.c |   20 ++++++++++++++++++--
 1 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/nmi.c b/arch/x86/kernel/nmi.c
index 673e7a5..f0450da 100644
--- a/arch/x86/kernel/nmi.c
+++ b/arch/x86/kernel/nmi.c
@@ -53,6 +53,15 @@ static struct nmi_desc nmi_desc[NMI_MAX] =
 
 };
 
+struct nmi_stats {
+	unsigned int normal;
+	unsigned int unknown;
+	unsigned int external;
+	unsigned int swallow;
+};
+
+static DEFINE_PER_CPU(struct nmi_stats, nmi_stats);
+
 static int ignore_nmis;
 
 int unknown_nmi_panic;
@@ -267,8 +276,13 @@ unknown_nmi_error(unsigned char reason, struct pt_regs *regs)
 	 * if it caused the NMI)
 	 */
 	handled = nmi_handle(NMI_UNKNOWN, regs, false);
-	if (handled) 
+	if (handled) {
+		__this_cpu_add(nmi_stats.unknown, handled);
 		return;
+	}
+
+	__this_cpu_add(nmi_stats.unknown, 1);
+
 #ifdef CONFIG_MCA
 	/*
 	 * Might actually be able to figure out what the guilty party
@@ -319,6 +333,7 @@ static notrace __kprobes void default_do_nmi(struct pt_regs *regs)
 	__this_cpu_write(last_nmi_rip, regs->ip);
 
 	handled = nmi_handle(NMI_LOCAL, regs, b2b);
+	__this_cpu_add(nmi_stats.normal, handled);
 	if (handled) {
 		/*
 		 * There are cases when a NMI handler handles multiple
@@ -349,6 +364,7 @@ static notrace __kprobes void default_do_nmi(struct pt_regs *regs)
 		 */
 		reassert_nmi();
 #endif
+		__this_cpu_add(nmi_stats.external, 1);
 		raw_spin_unlock(&nmi_reason_lock);
 		return;
 	}
@@ -385,7 +401,7 @@ static notrace __kprobes void default_do_nmi(struct pt_regs *regs)
 	 * for now.
 	 */
 	if (b2b && __this_cpu_read(swallow_nmi))
-		;
+		__this_cpu_add(nmi_stats.swallow, 1);
 	else
 		unknown_nmi_error(reason, regs);
 }
-- 
1.7.6

--
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/