[PATCH] ibmasm driver: fix race in command refcount logic
This patch fixes a race in the command reference counting logic by putting
spinlocks around kobject_put() in the command_put function.
- Also added debug messages.
- Changed a memcpy to memcpy_fromio since we are reading from io space.
Signed-off-by: Max Asbock <masbock@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/misc/ibmasm/heartbeat.c b/drivers/misc/ibmasm/heartbeat.c
index ce09309..f295401 100644
--- a/drivers/misc/ibmasm/heartbeat.c
+++ b/drivers/misc/ibmasm/heartbeat.c
@@ -25,6 +25,7 @@
#include <linux/notifier.h>
#include "ibmasm.h"
#include "dot_command.h"
+#include "lowlevel.h"
static int suspend_heartbeats = 0;
@@ -62,7 +63,7 @@
int ibmasm_heartbeat_init(struct service_processor *sp)
{
- sp->heartbeat = ibmasm_new_command(HEARTBEAT_BUFFER_SIZE);
+ sp->heartbeat = ibmasm_new_command(sp, HEARTBEAT_BUFFER_SIZE);
if (sp->heartbeat == NULL)
return -ENOMEM;
@@ -71,6 +72,12 @@
void ibmasm_heartbeat_exit(struct service_processor *sp)
{
+ char tsbuf[32];
+
+ dbg("%s:%d at %s\n", __FUNCTION__, __LINE__, get_timestamp(tsbuf));
+ ibmasm_wait_for_response(sp->heartbeat, IBMASM_CMD_TIMEOUT_NORMAL);
+ dbg("%s:%d at %s\n", __FUNCTION__, __LINE__, get_timestamp(tsbuf));
+ suspend_heartbeats = 1;
command_put(sp->heartbeat);
}
@@ -78,14 +85,16 @@
{
struct command *cmd = sp->heartbeat;
struct dot_command_header *header = (struct dot_command_header *)cmd->buffer;
+ char tsbuf[32];
+ dbg("%s:%d at %s\n", __FUNCTION__, __LINE__, get_timestamp(tsbuf));
if (suspend_heartbeats)
return;
/* return the received dot command to sender */
cmd->status = IBMASM_CMD_PENDING;
size = min(size, cmd->buffer_size);
- memcpy(cmd->buffer, message, size);
+ memcpy_fromio(cmd->buffer, message, size);
header->type = sp_write;
ibmasm_exec_command(sp, cmd);
}