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authorCorey Minyard <minyard@acm.org>2006-03-31 05:30:39 -0500
committerLinus Torvalds <torvalds@g5.osdl.org>2006-03-31 15:18:54 -0500
commit453823ba08ba762b3d58934b6dce75edce37169e (patch)
tree80170bf784145621467ba83ea44d25dc3e5e5964 /drivers/char
parentee37df7877eeaa16d7761cce64854110a7c17ad9 (diff)
[PATCH] IPMI: fix startup race condition
Matt Domsch noticed a startup race with the IPMI kernel thread, it was possible (though extraordinarly unlikely) that a message could come in before the upper layer was ready to handle it. This patch splits the startup processing of an IPMI interface into two parts, one to get ready and one to actually start the processes to receive messages from the interface. [akpm@osdl.org: cleanups] Signed-off-by: Corey Minyard <minyard@acm.org> Cc: Matt Domsch <Matt_Domsch@dell.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'drivers/char')
-rw-r--r--drivers/char/ipmi/ipmi_msghandler.c9
-rw-r--r--drivers/char/ipmi/ipmi_si_intf.c59
2 files changed, 41 insertions, 27 deletions
diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c
index 40eb005b9d77..a0b6f797d97d 100644
--- a/drivers/char/ipmi/ipmi_msghandler.c
+++ b/drivers/char/ipmi/ipmi_msghandler.c
@@ -2305,8 +2305,7 @@ int ipmi_register_smi(struct ipmi_smi_handlers *handlers,
2305 void *send_info, 2305 void *send_info,
2306 struct ipmi_device_id *device_id, 2306 struct ipmi_device_id *device_id,
2307 struct device *si_dev, 2307 struct device *si_dev,
2308 unsigned char slave_addr, 2308 unsigned char slave_addr)
2309 ipmi_smi_t *new_intf)
2310{ 2309{
2311 int i, j; 2310 int i, j;
2312 int rv; 2311 int rv;
@@ -2388,9 +2387,9 @@ int ipmi_register_smi(struct ipmi_smi_handlers *handlers,
2388 if (rv) 2387 if (rv)
2389 goto out; 2388 goto out;
2390 2389
2391 /* FIXME - this is an ugly kludge, this sets the intf for the 2390 rv = handlers->start_processing(send_info, intf);
2392 caller before sending any messages with it. */ 2391 if (rv)
2393 *new_intf = intf; 2392 goto out;
2394 2393
2395 get_guid(intf); 2394 get_guid(intf);
2396 2395
diff --git a/drivers/char/ipmi/ipmi_si_intf.c b/drivers/char/ipmi/ipmi_si_intf.c
index 35fbd4d8ed4b..d48d86bd2c2b 100644
--- a/drivers/char/ipmi/ipmi_si_intf.c
+++ b/drivers/char/ipmi/ipmi_si_intf.c
@@ -972,10 +972,37 @@ static irqreturn_t si_bt_irq_handler(int irq, void *data, struct pt_regs *regs)
972 return si_irq_handler(irq, data, regs); 972 return si_irq_handler(irq, data, regs);
973} 973}
974 974
975static int smi_start_processing(void *send_info,
976 ipmi_smi_t intf)
977{
978 struct smi_info *new_smi = send_info;
979
980 new_smi->intf = intf;
981
982 /* Set up the timer that drives the interface. */
983 setup_timer(&new_smi->si_timer, smi_timeout, (long)new_smi);
984 new_smi->last_timeout_jiffies = jiffies;
985 mod_timer(&new_smi->si_timer, jiffies + SI_TIMEOUT_JIFFIES);
986
987 if (new_smi->si_type != SI_BT) {
988 new_smi->thread = kthread_run(ipmi_thread, new_smi,
989 "kipmi%d", new_smi->intf_num);
990 if (IS_ERR(new_smi->thread)) {
991 printk(KERN_NOTICE "ipmi_si_intf: Could not start"
992 " kernel thread due to error %ld, only using"
993 " timers to drive the interface\n",
994 PTR_ERR(new_smi->thread));
995 new_smi->thread = NULL;
996 }
997 }
998
999 return 0;
1000}
975 1001
976static struct ipmi_smi_handlers handlers = 1002static struct ipmi_smi_handlers handlers =
977{ 1003{
978 .owner = THIS_MODULE, 1004 .owner = THIS_MODULE,
1005 .start_processing = smi_start_processing,
979 .sender = sender, 1006 .sender = sender,
980 .request_events = request_events, 1007 .request_events = request_events,
981 .set_run_to_completion = set_run_to_completion, 1008 .set_run_to_completion = set_run_to_completion,
@@ -2162,9 +2189,13 @@ static void setup_xaction_handlers(struct smi_info *smi_info)
2162 2189
2163static inline void wait_for_timer_and_thread(struct smi_info *smi_info) 2190static inline void wait_for_timer_and_thread(struct smi_info *smi_info)
2164{ 2191{
2165 if (smi_info->thread != NULL && smi_info->thread != ERR_PTR(-ENOMEM)) 2192 if (smi_info->intf) {
2166 kthread_stop(smi_info->thread); 2193 /* The timer and thread are only running if the
2167 del_timer_sync(&smi_info->si_timer); 2194 interface has been started up and registered. */
2195 if (smi_info->thread != NULL)
2196 kthread_stop(smi_info->thread);
2197 del_timer_sync(&smi_info->si_timer);
2198 }
2168} 2199}
2169 2200
2170static struct ipmi_default_vals 2201static struct ipmi_default_vals
@@ -2341,21 +2372,6 @@ static int try_smi_init(struct smi_info *new_smi)
2341 if (new_smi->irq) 2372 if (new_smi->irq)
2342 new_smi->si_state = SI_CLEARING_FLAGS_THEN_SET_IRQ; 2373 new_smi->si_state = SI_CLEARING_FLAGS_THEN_SET_IRQ;
2343 2374
2344 /* The ipmi_register_smi() code does some operations to
2345 determine the channel information, so we must be ready to
2346 handle operations before it is called. This means we have
2347 to stop the timer if we get an error after this point. */
2348 init_timer(&(new_smi->si_timer));
2349 new_smi->si_timer.data = (long) new_smi;
2350 new_smi->si_timer.function = smi_timeout;
2351 new_smi->last_timeout_jiffies = jiffies;
2352 new_smi->si_timer.expires = jiffies + SI_TIMEOUT_JIFFIES;
2353
2354 add_timer(&(new_smi->si_timer));
2355 if (new_smi->si_type != SI_BT)
2356 new_smi->thread = kthread_run(ipmi_thread, new_smi,
2357 "kipmi%d", new_smi->intf_num);
2358
2359 if (!new_smi->dev) { 2375 if (!new_smi->dev) {
2360 /* If we don't already have a device from something 2376 /* If we don't already have a device from something
2361 * else (like PCI), then register a new one. */ 2377 * else (like PCI), then register a new one. */
@@ -2365,7 +2381,7 @@ static int try_smi_init(struct smi_info *new_smi)
2365 printk(KERN_ERR 2381 printk(KERN_ERR
2366 "ipmi_si_intf:" 2382 "ipmi_si_intf:"
2367 " Unable to allocate platform device\n"); 2383 " Unable to allocate platform device\n");
2368 goto out_err_stop_timer; 2384 goto out_err;
2369 } 2385 }
2370 new_smi->dev = &new_smi->pdev->dev; 2386 new_smi->dev = &new_smi->pdev->dev;
2371 new_smi->dev->driver = &ipmi_driver; 2387 new_smi->dev->driver = &ipmi_driver;
@@ -2377,7 +2393,7 @@ static int try_smi_init(struct smi_info *new_smi)
2377 " Unable to register system interface device:" 2393 " Unable to register system interface device:"
2378 " %d\n", 2394 " %d\n",
2379 rv); 2395 rv);
2380 goto out_err_stop_timer; 2396 goto out_err;
2381 } 2397 }
2382 new_smi->dev_registered = 1; 2398 new_smi->dev_registered = 1;
2383 } 2399 }
@@ -2386,8 +2402,7 @@ static int try_smi_init(struct smi_info *new_smi)
2386 new_smi, 2402 new_smi,
2387 &new_smi->device_id, 2403 &new_smi->device_id,
2388 new_smi->dev, 2404 new_smi->dev,
2389 new_smi->slave_addr, 2405 new_smi->slave_addr);
2390 &(new_smi->intf));
2391 if (rv) { 2406 if (rv) {
2392 printk(KERN_ERR 2407 printk(KERN_ERR
2393 "ipmi_si: Unable to register device: error %d\n", 2408 "ipmi_si: Unable to register device: error %d\n",