netdev - [PATCH v2 25/45] staging/octeon: Use get/put_online_cpus

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: <20130625203003.16593.38565.stgit@srivatsabhat.in.ibm.com>
Date:	Wed, 26 Jun 2013 02:00:04 +0530
From:	"Srivatsa S. Bhat" <srivatsa.bhat@...ux.vnet.ibm.com>
To:	tglx@...utronix.de, peterz@...radead.org, tj@...nel.org,
	oleg@...hat.com, paulmck@...ux.vnet.ibm.com, rusty@...tcorp.com.au,
	mingo@...nel.org, akpm@...ux-foundation.org, namhyung@...nel.org,
	walken@...gle.com, vincent.guittot@...aro.org, laijs@...fujitsu.com
Cc:	rostedt@...dmis.org, wangyun@...ux.vnet.ibm.com,
	xiaoguangrong@...ux.vnet.ibm.com, sbw@....edu, fweisbec@...il.com,
	zhong@...ux.vnet.ibm.com, nikunj@...ux.vnet.ibm.com,
	srivatsa.bhat@...ux.vnet.ibm.com, linux-pm@...r.kernel.org,
	linux-arch@...r.kernel.org, linuxppc-dev@...ts.ozlabs.org,
	netdev@...r.kernel.org, linux-kernel@...r.kernel.org,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	devel@...verdev.osuosl.org, David Daney <david.daney@...ium.com>,
	"Srivatsa S. Bhat" <srivatsa.bhat@...ux.vnet.ibm.com>
Subject: [PATCH v2 25/45] staging/octeon: Use get/put_online_cpus_atomic() to
 prevent CPU offline

Once stop_machine() is gone from the CPU offline path, we won't be able
to depend on disabling preemption to prevent CPUs from going offline
from under us.

Use the get/put_online_cpus_atomic() APIs to prevent CPUs from going
offline, while invoking from atomic context.

Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc: devel@...verdev.osuosl.org
Acked-by: David Daney <david.daney@...ium.com>
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@...ux.vnet.ibm.com>
---

 drivers/staging/octeon/ethernet-rx.c |    3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/staging/octeon/ethernet-rx.c b/drivers/staging/octeon/ethernet-rx.c
index 34afc16..8588b4d 100644
--- a/drivers/staging/octeon/ethernet-rx.c
+++ b/drivers/staging/octeon/ethernet-rx.c
@@ -36,6 +36,7 @@
 #include <linux/prefetch.h>
 #include <linux/ratelimit.h>
 #include <linux/smp.h>
+#include <linux/cpu.h>
 #include <linux/interrupt.h>
 #include <net/dst.h>
 #ifdef CONFIG_XFRM
@@ -97,6 +98,7 @@ static void cvm_oct_enable_one_cpu(void)
 		return;
 
 	/* ... if a CPU is available, Turn on NAPI polling for that CPU.  */
+	get_online_cpus_atomic();
 	for_each_online_cpu(cpu) {
 		if (!cpu_test_and_set(cpu, core_state.cpu_state)) {
 			v = smp_call_function_single(cpu, cvm_oct_enable_napi,
@@ -106,6 +108,7 @@ static void cvm_oct_enable_one_cpu(void)
 			break;
 		}
 	}
+	put_online_cpus_atomic();
 }
 
 static void cvm_oct_no_more_work(void)

--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html