From: Thomas Klein <tklein@de.ibm.com>
To: davem@davemloft.net
Cc: netdev@vger.kernel.org, linuxppc-dev@ozlabs.org,
linux-kernel@vger.kernel.org, themann@de.ibm.com
Subject: [PATCH 2/2][RESEND] ehea: fix possible DLPAR/mem deadlock
Date: Wed, 21 Apr 2010 11:11:31 +0200 [thread overview]
Message-ID: <201004211111.31298.tklein@de.ibm.com> (raw)
Force serialization of userspace-triggered DLPAR/mem operations
Signed-off-by: Thomas Klein <tklein@de.ibm.com>
---
Patch created against net-2.6
diff -Nurp net-2.6.orig/drivers/net/ehea/ehea.h net-2.6/drivers/net/ehea/ehea.h
--- net-2.6.orig/drivers/net/ehea/ehea.h 2010-04-21 10:23:21.000000000 +0200
+++ net-2.6/drivers/net/ehea/ehea.h 2010-04-21 10:42:14.000000000 +0200
@@ -40,7 +40,7 @@
#include <asm/io.h>
#define DRV_NAME "ehea"
-#define DRV_VERSION "EHEA_0102"
+#define DRV_VERSION "EHEA_0103"
/* eHEA capability flags */
#define DLPAR_PORT_ADD_REM 1
diff -Nurp net-2.6.orig/drivers/net/ehea/ehea_main.c net-2.6/drivers/net/ehea/ehea_main.c
--- net-2.6.orig/drivers/net/ehea/ehea_main.c 2010-04-21 10:43:14.000000000 +0200
+++ net-2.6/drivers/net/ehea/ehea_main.c 2010-04-21 10:42:14.000000000 +0200
@@ -2889,7 +2889,6 @@ static void ehea_rereg_mrs(struct work_s
int ret, i;
struct ehea_adapter *adapter;
- mutex_lock(&dlpar_mem_lock);
ehea_info("LPAR memory changed - re-initializing driver");
list_for_each_entry(adapter, &adapter_list, list)
@@ -2959,7 +2958,6 @@ static void ehea_rereg_mrs(struct work_s
}
ehea_info("re-initializing driver complete");
out:
- mutex_unlock(&dlpar_mem_lock);
return;
}
@@ -3542,7 +3540,14 @@ void ehea_crash_handler(void)
static int ehea_mem_notifier(struct notifier_block *nb,
unsigned long action, void *data)
{
+ int ret = NOTIFY_BAD;
struct memory_notify *arg = data;
+
+ if (!mutex_trylock(&dlpar_mem_lock)) {
+ ehea_info("ehea_mem_notifier must not be called parallelized");
+ goto out;
+ }
+
switch (action) {
case MEM_CANCEL_OFFLINE:
ehea_info("memory offlining canceled");
@@ -3551,14 +3556,14 @@ static int ehea_mem_notifier(struct noti
ehea_info("memory is going online");
set_bit(__EHEA_STOP_XFER, &ehea_driver_flags);
if (ehea_add_sect_bmap(arg->start_pfn, arg->nr_pages))
- return NOTIFY_BAD;
+ goto out_unlock;
ehea_rereg_mrs(NULL);
break;
case MEM_GOING_OFFLINE:
ehea_info("memory is going offline");
set_bit(__EHEA_STOP_XFER, &ehea_driver_flags);
if (ehea_rem_sect_bmap(arg->start_pfn, arg->nr_pages))
- return NOTIFY_BAD;
+ goto out_unlock;
ehea_rereg_mrs(NULL);
break;
default:
@@ -3566,8 +3571,12 @@ static int ehea_mem_notifier(struct noti
}
ehea_update_firmware_handles();
+ ret = NOTIFY_OK;
- return NOTIFY_OK;
+out_unlock:
+ mutex_unlock(&dlpar_mem_lock);
+out:
+ return ret;
}
static struct notifier_block ehea_mem_nb = {
reply other threads:[~2010-04-21 9:11 UTC|newest]
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