From 2fcaf60ca07b0db5f8824a368bf890122c3db86a Mon Sep 17 00:00:00 2001 From: Corey Minyard Date: Wed, 17 Dec 2014 07:11:54 -0600 Subject: ipmi: Remove a FIXME for slab conversion There can't be more than a few IPMI messages allocated at any one time, so converting the messages to slabs would be a waste. So just remove the FIXME. Suggested-by: Nicholas Krause Signed-off-by: Corey Minyard diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c index 6b65fa4..ab59541 100644 --- a/drivers/char/ipmi/ipmi_msghandler.c +++ b/drivers/char/ipmi/ipmi_msghandler.c @@ -4212,7 +4212,6 @@ static void need_waiter(ipmi_smi_t intf) static atomic_t smi_msg_inuse_count = ATOMIC_INIT(0); static atomic_t recv_msg_inuse_count = ATOMIC_INIT(0); -/* FIXME - convert these to slabs. */ static void free_smi_msg(struct ipmi_smi_msg *msg) { atomic_dec(&smi_msg_inuse_count); -- cgit v0.10.2 From bb82d90e748660a5386cc8f9fc8300bff163ce5f Mon Sep 17 00:00:00 2001 From: Wolfram Sang Date: Mon, 22 Dec 2014 23:18:28 +0100 Subject: char: ipmi: Remove obsolete cleanup for clientdata A few new i2c-drivers came into the kernel which clear the clientdata-pointer on exit or error. This is obsolete meanwhile, the core will do it. Signed-off-by: Wolfram Sang Signed-off-by: Corey Minyard diff --git a/drivers/char/ipmi/ipmi_ssif.c b/drivers/char/ipmi/ipmi_ssif.c index 982b963..74128e6 100644 --- a/drivers/char/ipmi/ipmi_ssif.c +++ b/drivers/char/ipmi/ipmi_ssif.c @@ -1097,8 +1097,6 @@ static int ssif_remove(struct i2c_client *client) if (!ssif_info) return 0; - i2c_set_clientdata(client, NULL); - /* * After this point, we won't deliver anything asychronously * to the message handler. We can unregister ourself. -- cgit v0.10.2 From 31013fa92c3a334f45dc13f4fffd5a7f0d5edca6 Mon Sep 17 00:00:00 2001 From: Nicholas Krause Date: Mon, 29 Dec 2014 21:54:27 -0500 Subject: drivers:char:ipmi: Remove unneeded FIXME comment in the file,ipmi_si_intf.c Removes a no longer needed FIXME comment in the function,acpi_gpe_irq_setup for the file,ipmi_si_intf.c. This comment is no longer needed as clearly we are passing the correct level of ACPI_GPE_LEVEL_TRIGGERED to the installer function,acpi_install_gpe_handler due to no breakage after years of using this ACPI level in the function,acpi_install_gpe_handler. Signed-off-by: Nicholas Krause Signed-off-by: Corey Minyard diff --git a/drivers/char/ipmi/ipmi_si_intf.c b/drivers/char/ipmi/ipmi_si_intf.c index 967b73a..2969c3f 100644 --- a/drivers/char/ipmi/ipmi_si_intf.c +++ b/drivers/char/ipmi/ipmi_si_intf.c @@ -2071,7 +2071,6 @@ static int acpi_gpe_irq_setup(struct smi_info *info) if (!info->irq) return 0; - /* FIXME - is level triggered right? */ status = acpi_install_gpe_handler(NULL, info->irq, ACPI_GPE_LEVEL_TRIGGERED, -- cgit v0.10.2 From f93aae9f8d30fc96fc57740f5e9260cf719c39d9 Mon Sep 17 00:00:00 2001 From: John Stultz Date: Wed, 7 Jan 2015 14:24:28 -0800 Subject: ipmi: Cleanup DEBUG_TIMING ifdef usage The driver uses #ifdef DEBUG_TIMING in order to conditionally print out timestamped debug messages. Unfortunately it adds the ifdefs all over the usage sites. This patch cleans it up by adding a debug_timestamp() function which is compiled out if DEBUG_TIMING isn't present. This cleans up all the ugly ifdefs in the function logic. Cc: openipmi-developer@lists.sourceforge.net Cc: Arnd Bergmann Signed-off-by: John Stultz Signed-off-by: Corey Minyard diff --git a/drivers/char/ipmi/ipmi_si_intf.c b/drivers/char/ipmi/ipmi_si_intf.c index 2969c3f..5116f76 100644 --- a/drivers/char/ipmi/ipmi_si_intf.c +++ b/drivers/char/ipmi/ipmi_si_intf.c @@ -321,6 +321,18 @@ static int try_smi_init(struct smi_info *smi); static void cleanup_one_si(struct smi_info *to_clean); static void cleanup_ipmi_si(void); +#ifdef DEBUG_TIMING +void debug_timestamp(char *msg) +{ + struct timeval t; + + do_gettimeofday(&t); + pr_debug("**%s: %d.%9.9d\n", msg, t.tv_sec, t.tv_usec); +} +#else +#define debug_timestamp(x) +#endif + static ATOMIC_NOTIFIER_HEAD(xaction_notifier_list); static int register_xaction_notifier(struct notifier_block *nb) { @@ -358,9 +370,6 @@ static void return_hosed_msg(struct smi_info *smi_info, int cCode) static enum si_sm_result start_next_msg(struct smi_info *smi_info) { int rv; -#ifdef DEBUG_TIMING - struct timeval t; -#endif if (!smi_info->waiting_msg) { smi_info->curr_msg = NULL; @@ -370,10 +379,7 @@ static enum si_sm_result start_next_msg(struct smi_info *smi_info) smi_info->curr_msg = smi_info->waiting_msg; smi_info->waiting_msg = NULL; -#ifdef DEBUG_TIMING - do_gettimeofday(&t); - printk(KERN_DEBUG "**Start2: %d.%9.9d\n", t.tv_sec, t.tv_usec); -#endif + debug_timestamp("Start2"); err = atomic_notifier_call_chain(&xaction_notifier_list, 0, smi_info); if (err & NOTIFY_STOP_MASK) { @@ -582,12 +588,8 @@ static void check_bt_irq(struct smi_info *smi_info, bool irq_on) static void handle_transaction_done(struct smi_info *smi_info) { struct ipmi_smi_msg *msg; -#ifdef DEBUG_TIMING - struct timeval t; - do_gettimeofday(&t); - printk(KERN_DEBUG "**Done: %d.%9.9d\n", t.tv_sec, t.tv_usec); -#endif + debug_timestamp("Done"); switch (smi_info->si_state) { case SI_NORMAL: if (!smi_info->curr_msg) @@ -929,17 +931,11 @@ static void sender(void *send_info, struct smi_info *smi_info = send_info; enum si_sm_result result; unsigned long flags; -#ifdef DEBUG_TIMING - struct timeval t; -#endif BUG_ON(smi_info->waiting_msg); smi_info->waiting_msg = msg; -#ifdef DEBUG_TIMING - do_gettimeofday(&t); - printk("**Enqueue: %d.%9.9d\n", t.tv_sec, t.tv_usec); -#endif + debug_timestamp("Enqueue"); if (smi_info->run_to_completion) { /* @@ -1128,15 +1124,10 @@ static void smi_timeout(unsigned long data) unsigned long jiffies_now; long time_diff; long timeout; -#ifdef DEBUG_TIMING - struct timeval t; -#endif spin_lock_irqsave(&(smi_info->si_lock), flags); -#ifdef DEBUG_TIMING - do_gettimeofday(&t); - printk(KERN_DEBUG "**Timer: %d.%9.9d\n", t.tv_sec, t.tv_usec); -#endif + debug_timestamp("Timer"); + jiffies_now = jiffies; time_diff = (((long)jiffies_now - (long)smi_info->last_timeout_jiffies) * SI_USEC_PER_JIFFY); @@ -1173,18 +1164,13 @@ static irqreturn_t si_irq_handler(int irq, void *data) { struct smi_info *smi_info = data; unsigned long flags; -#ifdef DEBUG_TIMING - struct timeval t; -#endif spin_lock_irqsave(&(smi_info->si_lock), flags); smi_inc_stat(smi_info, interrupts); -#ifdef DEBUG_TIMING - do_gettimeofday(&t); - printk(KERN_DEBUG "**Interrupt: %d.%9.9d\n", t.tv_sec, t.tv_usec); -#endif + debug_timestamp("Interrupt"); + smi_event_handler(smi_info, 0); spin_unlock_irqrestore(&(smi_info->si_lock), flags); return IRQ_HANDLED; @@ -2038,18 +2024,13 @@ static u32 ipmi_acpi_gpe(acpi_handle gpe_device, { struct smi_info *smi_info = context; unsigned long flags; -#ifdef DEBUG_TIMING - struct timeval t; -#endif spin_lock_irqsave(&(smi_info->si_lock), flags); smi_inc_stat(smi_info, interrupts); -#ifdef DEBUG_TIMING - do_gettimeofday(&t); - printk("**ACPI_GPE: %d.%9.9d\n", t.tv_sec, t.tv_usec); -#endif + debug_timestamp("ACPI_GPE"); + smi_event_handler(smi_info, 0); spin_unlock_irqrestore(&(smi_info->si_lock), flags); -- cgit v0.10.2 From 48862ea2ce86370b708614506d93f07ed09b066f Mon Sep 17 00:00:00 2001 From: John Stultz Date: Wed, 7 Jan 2015 14:24:29 -0800 Subject: ipmi: Update timespec usage to timespec64 As part of the internal y2038 cleanup, this patch removes timespec usage in the ipmi driver, replacing it timespec64 Cc: openipmi-developer@lists.sourceforge.net Cc: Arnd Bergmann Signed-off-by: John Stultz Signed-off-by: Corey Minyard diff --git a/drivers/char/ipmi/ipmi_si_intf.c b/drivers/char/ipmi/ipmi_si_intf.c index 5116f76..fd6110f 100644 --- a/drivers/char/ipmi/ipmi_si_intf.c +++ b/drivers/char/ipmi/ipmi_si_intf.c @@ -324,10 +324,10 @@ static void cleanup_ipmi_si(void); #ifdef DEBUG_TIMING void debug_timestamp(char *msg) { - struct timeval t; + struct timespec64 t; - do_gettimeofday(&t); - pr_debug("**%s: %d.%9.9d\n", msg, t.tv_sec, t.tv_usec); + getnstimeofday64(&t); + pr_debug("**%s: %lld.%9.9ld\n", msg, (long long) t.tv_sec, t.tv_nsec); } #else #define debug_timestamp(x) @@ -985,18 +985,18 @@ static void set_run_to_completion(void *send_info, bool i_run_to_completion) * we are spinning in kipmid looking for something and not delaying * between checks */ -static inline void ipmi_si_set_not_busy(struct timespec *ts) +static inline void ipmi_si_set_not_busy(struct timespec64 *ts) { ts->tv_nsec = -1; } -static inline int ipmi_si_is_busy(struct timespec *ts) +static inline int ipmi_si_is_busy(struct timespec64 *ts) { return ts->tv_nsec != -1; } static inline int ipmi_thread_busy_wait(enum si_sm_result smi_result, const struct smi_info *smi_info, - struct timespec *busy_until) + struct timespec64 *busy_until) { unsigned int max_busy_us = 0; @@ -1005,12 +1005,13 @@ static inline int ipmi_thread_busy_wait(enum si_sm_result smi_result, if (max_busy_us == 0 || smi_result != SI_SM_CALL_WITH_DELAY) ipmi_si_set_not_busy(busy_until); else if (!ipmi_si_is_busy(busy_until)) { - getnstimeofday(busy_until); - timespec_add_ns(busy_until, max_busy_us*NSEC_PER_USEC); + getnstimeofday64(busy_until); + timespec64_add_ns(busy_until, max_busy_us*NSEC_PER_USEC); } else { - struct timespec now; - getnstimeofday(&now); - if (unlikely(timespec_compare(&now, busy_until) > 0)) { + struct timespec64 now; + + getnstimeofday64(&now); + if (unlikely(timespec64_compare(&now, busy_until) > 0)) { ipmi_si_set_not_busy(busy_until); return 0; } @@ -1033,7 +1034,7 @@ static int ipmi_thread(void *data) struct smi_info *smi_info = data; unsigned long flags; enum si_sm_result smi_result; - struct timespec busy_until; + struct timespec64 busy_until; ipmi_si_set_not_busy(&busy_until); set_user_nice(current, MAX_NICE); -- cgit v0.10.2 From 191cc41405188780e5f8f3c90d84a1e747d962e9 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Wed, 28 Jan 2015 16:00:11 +0100 Subject: ipmi: avoid gcc warning A new harmless warning has come up on ARM builds with gcc-4.9: drivers/char/ipmi/ipmi_msghandler.c: In function 'smi_send.isra.11': include/linux/spinlock.h:372:95: warning: 'flags' may be used uninitialized in this function [-Wmaybe-uninitialized] raw_spin_unlock_irqrestore(&lock->rlock, flags); ^ drivers/char/ipmi/ipmi_msghandler.c:1490:16: note: 'flags' was declared here unsigned long flags; ^ This could be worked around by initializing the 'flags' variable, but it seems better to rework the code to avoid this. Signed-off-by: Arnd Bergmann Fixes: 7ea0ed2b5be81 ("ipmi: Make the message handler easier to use for SMI interfaces") Signed-off-by: Corey Minyard diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c index ab59541..4891c39 100644 --- a/drivers/char/ipmi/ipmi_msghandler.c +++ b/drivers/char/ipmi/ipmi_msghandler.c @@ -1483,14 +1483,10 @@ static inline void format_lan_msg(struct ipmi_smi_msg *smi_msg, smi_msg->msgid = msgid; } -static void smi_send(ipmi_smi_t intf, struct ipmi_smi_handlers *handlers, - struct ipmi_smi_msg *smi_msg, int priority) +static struct ipmi_smi_msg *smi_add_send_msg(ipmi_smi_t intf, + struct ipmi_smi_msg *smi_msg, + int priority) { - int run_to_completion = intf->run_to_completion; - unsigned long flags; - - if (!run_to_completion) - spin_lock_irqsave(&intf->xmit_msgs_lock, flags); if (intf->curr_msg) { if (priority > 0) list_add_tail(&smi_msg->link, &intf->hp_xmit_msgs); @@ -1500,8 +1496,25 @@ static void smi_send(ipmi_smi_t intf, struct ipmi_smi_handlers *handlers, } else { intf->curr_msg = smi_msg; } - if (!run_to_completion) + + return smi_msg; +} + + +static void smi_send(ipmi_smi_t intf, struct ipmi_smi_handlers *handlers, + struct ipmi_smi_msg *smi_msg, int priority) +{ + int run_to_completion = intf->run_to_completion; + + if (run_to_completion) { + smi_msg = smi_add_send_msg(intf, smi_msg, priority); + } else { + unsigned long flags; + + spin_lock_irqsave(&intf->xmit_msgs_lock, flags); + smi_msg = smi_add_send_msg(intf, smi_msg, priority); spin_unlock_irqrestore(&intf->xmit_msgs_lock, flags); + } if (smi_msg) handlers->sender(intf->send_info, smi_msg); -- cgit v0.10.2 From bdf2829cb673afc3aeb4f04531546c7605e8d94e Mon Sep 17 00:00:00 2001 From: Nicholas Krause Date: Sat, 31 Jan 2015 00:17:54 -0500 Subject: ipmi: Free ipmi_recv_msg messages from the linked list on close This adds a loop through the elements in the linked list, recv_msgs using list_for_entry_safe in order to free messages in this list. In addition we are using the safe version of this marco in order to prevent use after bugs related to deleting the element we are on currently by holding a pointer to the next element after the current one we are on and freeing with the function, ipmi_free_recv_msg internally in this loop. Signed-off-by: Nicholas Krause Signed-off-by: Corey Minyard diff --git a/drivers/char/ipmi/ipmi_devintf.c b/drivers/char/ipmi/ipmi_devintf.c index ec318bf..1786574 100644 --- a/drivers/char/ipmi/ipmi_devintf.c +++ b/drivers/char/ipmi/ipmi_devintf.c @@ -157,12 +157,16 @@ static int ipmi_release(struct inode *inode, struct file *file) { struct ipmi_file_private *priv = file->private_data; int rv; + struct ipmi_recv_msg *msg, *next; rv = ipmi_destroy_user(priv->user); if (rv) return rv; - /* FIXME - free the messages in the list. */ + list_for_each_entry_safe(msg, next, &priv->recv_msgs, link) + ipmi_free_recv_msg(msg); + + kfree(priv); return 0; -- cgit v0.10.2 From 2d06a0c9b3756404e141cafcd62b29ce05238007 Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Wed, 4 Feb 2015 15:36:14 +0100 Subject: ipmi: Use is_visible callback for conditional sysfs entries Instead of manual calls of device_create_file() and device_remove_file(), implement the condition in is_visible callback for the attribute group and put these entries to the group, too. This simplifies the code and avoids the possible races. Signed-off-by: Takashi Iwai Signed-off-by: Corey Minyard diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c index 4891c39..d5a2bd7 100644 --- a/drivers/char/ipmi/ipmi_msghandler.c +++ b/drivers/char/ipmi/ipmi_msghandler.c @@ -2366,11 +2366,28 @@ static struct attribute *bmc_dev_attrs[] = { &dev_attr_additional_device_support.attr, &dev_attr_manufacturer_id.attr, &dev_attr_product_id.attr, + &dev_attr_aux_firmware_revision.attr, + &dev_attr_guid.attr, NULL }; +static umode_t bmc_dev_attr_is_visible(struct kobject *kobj, + struct attribute *attr, int idx) +{ + struct device *dev = kobj_to_dev(kobj); + struct bmc_device *bmc = to_bmc_device(dev); + umode_t mode = attr->mode; + + if (attr == &dev_attr_aux_firmware_revision.attr) + return bmc->id.aux_firmware_revision_set ? mode : 0; + if (attr == &dev_attr_guid.attr) + return bmc->guid_set ? mode : 0; + return mode; +} + static struct attribute_group bmc_dev_attr_group = { .attrs = bmc_dev_attrs, + .is_visible = bmc_dev_attr_is_visible, }; static const struct attribute_group *bmc_dev_attr_groups[] = { @@ -2393,13 +2410,6 @@ cleanup_bmc_device(struct kref *ref) { struct bmc_device *bmc = container_of(ref, struct bmc_device, usecount); - if (bmc->id.aux_firmware_revision_set) - device_remove_file(&bmc->pdev.dev, - &dev_attr_aux_firmware_revision); - if (bmc->guid_set) - device_remove_file(&bmc->pdev.dev, - &dev_attr_guid); - platform_device_unregister(&bmc->pdev); } @@ -2420,33 +2430,6 @@ static void ipmi_bmc_unregister(ipmi_smi_t intf) mutex_unlock(&ipmidriver_mutex); } -static int create_bmc_files(struct bmc_device *bmc) -{ - int err; - - if (bmc->id.aux_firmware_revision_set) { - err = device_create_file(&bmc->pdev.dev, - &dev_attr_aux_firmware_revision); - if (err) - goto out; - } - if (bmc->guid_set) { - err = device_create_file(&bmc->pdev.dev, - &dev_attr_guid); - if (err) - goto out_aux_firm; - } - - return 0; - -out_aux_firm: - if (bmc->id.aux_firmware_revision_set) - device_remove_file(&bmc->pdev.dev, - &dev_attr_aux_firmware_revision); -out: - return err; -} - static int ipmi_bmc_register(ipmi_smi_t intf, int ifnum) { int rv; @@ -2535,15 +2518,6 @@ static int ipmi_bmc_register(ipmi_smi_t intf, int ifnum) return rv; } - rv = create_bmc_files(bmc); - if (rv) { - mutex_lock(&ipmidriver_mutex); - platform_device_unregister(&bmc->pdev); - mutex_unlock(&ipmidriver_mutex); - - return rv; - } - dev_info(intf->si_dev, "Found new BMC (man_id: 0x%6.6x, " "prod_id: 0x%4.4x, dev_id: 0x%2.2x)\n", bmc->id.manufacturer_id, -- cgit v0.10.2 From d6c5dc18d863338528f4e89e8dba9449c6e30f4e Mon Sep 17 00:00:00 2001 From: Joe Perches Date: Tue, 17 Feb 2015 11:10:56 -0800 Subject: ipmi: Remove uses of return value of seq_printf The seq_printf like functions will soon be changed to return void. Convert these uses to check seq_has_overflowed instead. Signed-off-by: Joe Perches Signed-off-by: Corey Minyard diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c index d5a2bd7..9bb5928 100644 --- a/drivers/char/ipmi/ipmi_msghandler.c +++ b/drivers/char/ipmi/ipmi_msghandler.c @@ -1998,7 +1998,9 @@ static int smi_ipmb_proc_show(struct seq_file *m, void *v) seq_printf(m, "%x", intf->channels[0].address); for (i = 1; i < IPMI_MAX_CHANNELS; i++) seq_printf(m, " %x", intf->channels[i].address); - return seq_putc(m, '\n'); + seq_putc(m, '\n'); + + return seq_has_overflowed(m); } static int smi_ipmb_proc_open(struct inode *inode, struct file *file) @@ -2017,9 +2019,11 @@ static int smi_version_proc_show(struct seq_file *m, void *v) { ipmi_smi_t intf = m->private; - return seq_printf(m, "%u.%u\n", - ipmi_version_major(&intf->bmc->id), - ipmi_version_minor(&intf->bmc->id)); + seq_printf(m, "%u.%u\n", + ipmi_version_major(&intf->bmc->id), + ipmi_version_minor(&intf->bmc->id)); + + return seq_has_overflowed(m); } static int smi_version_proc_open(struct inode *inode, struct file *file) diff --git a/drivers/char/ipmi/ipmi_si_intf.c b/drivers/char/ipmi/ipmi_si_intf.c index fd6110f..321ecb2 100644 --- a/drivers/char/ipmi/ipmi_si_intf.c +++ b/drivers/char/ipmi/ipmi_si_intf.c @@ -2979,7 +2979,9 @@ static int smi_type_proc_show(struct seq_file *m, void *v) { struct smi_info *smi = m->private; - return seq_printf(m, "%s\n", si_to_str[smi->si_type]); + seq_printf(m, "%s\n", si_to_str[smi->si_type]); + + return seq_has_overflowed(m); } static int smi_type_proc_open(struct inode *inode, struct file *file) @@ -3041,16 +3043,18 @@ static int smi_params_proc_show(struct seq_file *m, void *v) { struct smi_info *smi = m->private; - return seq_printf(m, - "%s,%s,0x%lx,rsp=%d,rsi=%d,rsh=%d,irq=%d,ipmb=%d\n", - si_to_str[smi->si_type], - addr_space_to_str[smi->io.addr_type], - smi->io.addr_data, - smi->io.regspacing, - smi->io.regsize, - smi->io.regshift, - smi->irq, - smi->slave_addr); + seq_printf(m, + "%s,%s,0x%lx,rsp=%d,rsi=%d,rsh=%d,irq=%d,ipmb=%d\n", + si_to_str[smi->si_type], + addr_space_to_str[smi->io.addr_type], + smi->io.addr_data, + smi->io.regspacing, + smi->io.regsize, + smi->io.regshift, + smi->irq, + smi->slave_addr); + + return seq_has_overflowed(m); } static int smi_params_proc_open(struct inode *inode, struct file *file) diff --git a/drivers/char/ipmi/ipmi_ssif.c b/drivers/char/ipmi/ipmi_ssif.c index 74128e6..f6e378d 100644 --- a/drivers/char/ipmi/ipmi_ssif.c +++ b/drivers/char/ipmi/ipmi_ssif.c @@ -1196,7 +1196,9 @@ static int ssif_detect(struct i2c_client *client, struct i2c_board_info *info) static int smi_type_proc_show(struct seq_file *m, void *v) { - return seq_puts(m, "ssif\n"); + seq_puts(m, "ssif\n"); + + return seq_has_overflowed(m); } static int smi_type_proc_open(struct inode *inode, struct file *file) -- cgit v0.10.2 From 1d86e29b4a612eb01c39daa48749ab7964e77e03 Mon Sep 17 00:00:00 2001 From: Corey Minyard Date: Thu, 19 Feb 2015 08:25:49 -0600 Subject: ipmi: Fix a memory ordering issue From a locking point of view it is safe to check waiting_msg without a lock, but there is a memory ordering issue that causes it to possibly not be set right when viewed from another processor. We are already claiming a lock right after that, move the check to inside the lock to enforce the memory ordering. Signed-off-by: Corey Minyard diff --git a/drivers/char/ipmi/ipmi_si_intf.c b/drivers/char/ipmi/ipmi_si_intf.c index 321ecb2..f6646ed 100644 --- a/drivers/char/ipmi/ipmi_si_intf.c +++ b/drivers/char/ipmi/ipmi_si_intf.c @@ -932,9 +932,6 @@ static void sender(void *send_info, enum si_sm_result result; unsigned long flags; - BUG_ON(smi_info->waiting_msg); - smi_info->waiting_msg = msg; - debug_timestamp("Enqueue"); if (smi_info->run_to_completion) { @@ -942,7 +939,7 @@ static void sender(void *send_info, * If we are running to completion, start it and run * transactions until everything is clear. */ - smi_info->curr_msg = smi_info->waiting_msg; + smi_info->curr_msg = msg; smi_info->waiting_msg = NULL; /* @@ -960,6 +957,15 @@ static void sender(void *send_info, } spin_lock_irqsave(&smi_info->si_lock, flags); + /* + * The following two lines don't need to be under the lock for + * the lock's sake, but they do need SMP memory barriers to + * avoid getting things out of order. We are already claiming + * the lock, anyway, so just do it under the lock to avoid the + * ordering problem. + */ + BUG_ON(smi_info->waiting_msg); + smi_info->waiting_msg = msg; check_start_timer_thread(smi_info); spin_unlock_irqrestore(&smi_info->si_lock, flags); } -- cgit v0.10.2