From 5d469ec0f40d65b2a0a704402990a43b2dafe197 Mon Sep 17 00:00:00 2001 From: Neil Horman Date: Wed, 6 Dec 2006 20:37:08 -0800 Subject: [PATCH] [PATCH] Correct misc_register return code handling in several drivers Clean up several code points in which the return code from misc_register is not handled properly. Several modules failed to deregister various hooks when misc_register fails, and this patch cleans them up. Also there are a few modules that legitimately don't care about the failure status of misc register. These drivers however unilaterally call misc_deregister on module unload. Since misc_register doesn't initialize the list_head in the init_routine if it fails, the deregister operation is at risk for oopsing when list_del is called. The initial solution was to manually init the list in the miscdev structure in each of those modules, but the consensus in this thread was to consolodate and do that universally inside misc_register. Signed-off-by: Neil Horman Cc: Bjorn Helgaas Cc: Kylene Jo Hall Cc: Dmitry Torokhov Cc: Olaf Hering Cc: Benjamin Herrenschmidt Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/char/misc.c | 2 ++ drivers/char/mmtimer.c | 23 ++++++++++++++++++----- drivers/char/tpm/tpm.c | 1 + drivers/input/misc/hp_sdc_rtc.c | 4 +++- drivers/macintosh/apm_emu.c | 3 ++- 5 files changed, 26 insertions(+), 7 deletions(-) diff --git a/drivers/char/misc.c b/drivers/char/misc.c index 7a484fc7cb9..7e975f60692 100644 --- a/drivers/char/misc.c +++ b/drivers/char/misc.c @@ -199,6 +199,8 @@ int misc_register(struct miscdevice * misc) dev_t dev; int err = 0; + INIT_LIST_HEAD(&misc->list); + down(&misc_sem); list_for_each_entry(c, &misc_list, list) { if (c->minor == misc->minor) { diff --git a/drivers/char/mmtimer.c b/drivers/char/mmtimer.c index 22b9905c1e5..c09160383a5 100644 --- a/drivers/char/mmtimer.c +++ b/drivers/char/mmtimer.c @@ -680,7 +680,7 @@ static int __init mmtimer_init(void) if (sn_rtc_cycles_per_second < 100000) { printk(KERN_ERR "%s: unable to determine clock frequency\n", MMTIMER_NAME); - return -1; + goto out1; } mmtimer_femtoperiod = ((unsigned long)1E15 + sn_rtc_cycles_per_second / @@ -689,13 +689,13 @@ static int __init mmtimer_init(void) if (request_irq(SGI_MMTIMER_VECTOR, mmtimer_interrupt, IRQF_PERCPU, MMTIMER_NAME, NULL)) { printk(KERN_WARNING "%s: unable to allocate interrupt.", MMTIMER_NAME); - return -1; + goto out1; } if (misc_register(&mmtimer_miscdev)) { printk(KERN_ERR "%s: failed to register device\n", MMTIMER_NAME); - return -1; + goto out2; } /* Get max numbered node, calculate slots needed */ @@ -709,16 +709,18 @@ static int __init mmtimer_init(void) if (timers == NULL) { printk(KERN_ERR "%s: failed to allocate memory for device\n", MMTIMER_NAME); - return -1; + goto out3; } + memset(timers,0,(sizeof(mmtimer_t *)*maxn)); + /* Allocate mmtimer_t's for each online node */ for_each_online_node(node) { timers[node] = kmalloc_node(sizeof(mmtimer_t)*NUM_COMPARATORS, GFP_KERNEL, node); if (timers[node] == NULL) { printk(KERN_ERR "%s: failed to allocate memory for device\n", MMTIMER_NAME); - return -1; + goto out4; } for (i=0; i< NUM_COMPARATORS; i++) { mmtimer_t * base = timers[node] + i; @@ -739,6 +741,17 @@ static int __init mmtimer_init(void) sn_rtc_cycles_per_second/(unsigned long)1E6); return 0; + +out4: + for_each_online_node(node) { + kfree(timers[node]); + } +out3: + misc_deregister(&mmtimer_miscdev); +out2: + free_irq(SGI_MMTIMER_VECTOR, NULL); +out1: + return -1; } module_init(mmtimer_init); diff --git a/drivers/char/tpm/tpm.c b/drivers/char/tpm/tpm.c index 774fa861169..33e1f66e39c 100644 --- a/drivers/char/tpm/tpm.c +++ b/drivers/char/tpm/tpm.c @@ -1155,6 +1155,7 @@ struct tpm_chip *tpm_register_hardware(struct device *dev, const struct tpm_vend if (sysfs_create_group(&dev->kobj, chip->vendor.attr_group)) { list_del(&chip->list); + misc_deregister(&chip->vendor.miscdev); put_device(dev); clear_bit(chip->dev_num, dev_mask); kfree(chip); diff --git a/drivers/input/misc/hp_sdc_rtc.c b/drivers/input/misc/hp_sdc_rtc.c index ab4da79ee56..31d5a13bfd6 100644 --- a/drivers/input/misc/hp_sdc_rtc.c +++ b/drivers/input/misc/hp_sdc_rtc.c @@ -695,7 +695,9 @@ static int __init hp_sdc_rtc_init(void) if ((ret = hp_sdc_request_timer_irq(&hp_sdc_rtc_isr))) return ret; - misc_register(&hp_sdc_rtc_dev); + if (misc_register(&hp_sdc_rtc_dev) != 0) + printk(KERN_INFO "Could not register misc. dev for i8042 rtc\n"); + create_proc_read_entry ("driver/rtc", 0, NULL, hp_sdc_rtc_read_proc, NULL); diff --git a/drivers/macintosh/apm_emu.c b/drivers/macintosh/apm_emu.c index 1293876a2eb..8862a83b8d8 100644 --- a/drivers/macintosh/apm_emu.c +++ b/drivers/macintosh/apm_emu.c @@ -529,7 +529,8 @@ static int __init apm_emu_init(void) if (apm_proc) apm_proc->owner = THIS_MODULE; - misc_register(&apm_device); + if (misc_register(&apm_device) != 0) + printk(KERN_INFO "Could not create misc. device for apm\n"); pmu_register_sleep_notifier(&apm_sleep_notifier); -- 2.41.1