From 9090589d87506c578ea1523ffd7ae7fd9424fb28 Mon Sep 17 00:00:00 2001 From: Shaohua Li Date: Tue, 7 Apr 2009 10:24:29 +0800 Subject: [PATCH] ACPI: convert acpi_device_lock spinlock to mutex Convert acpi_device_lock to a mutex to avoid a potential race upon access to /proc/acpi/wakeup Delete the lock entirely in wakeup.c since it is not necessary (and can not sleep) Found-by: Linus Torvalds Signed-off-by: Shaohua Li Signed-off-by: Len Brown --- drivers/acpi/proc.c | 13 ++++--------- drivers/acpi/scan.c | 14 +++++++------- drivers/acpi/sleep.h | 3 +++ drivers/acpi/wakeup.c | 30 +++++++----------------------- 4 files changed, 21 insertions(+), 39 deletions(-) diff --git a/drivers/acpi/proc.c b/drivers/acpi/proc.c index 05dfdc96802..d0d550d22a6 100644 --- a/drivers/acpi/proc.c +++ b/drivers/acpi/proc.c @@ -343,9 +343,6 @@ acpi_system_write_alarm(struct file *file, } #endif /* HAVE_ACPI_LEGACY_ALARM */ -extern struct list_head acpi_wakeup_device_list; -extern spinlock_t acpi_device_lock; - static int acpi_system_wakeup_device_seq_show(struct seq_file *seq, void *offset) { @@ -353,7 +350,7 @@ acpi_system_wakeup_device_seq_show(struct seq_file *seq, void *offset) seq_printf(seq, "Device\tS-state\t Status Sysfs node\n"); - spin_lock(&acpi_device_lock); + mutex_lock(&acpi_device_lock); list_for_each_safe(node, next, &acpi_wakeup_device_list) { struct acpi_device *dev = container_of(node, struct acpi_device, wakeup_list); @@ -361,7 +358,6 @@ acpi_system_wakeup_device_seq_show(struct seq_file *seq, void *offset) if (!dev->wakeup.flags.valid) continue; - spin_unlock(&acpi_device_lock); ldev = acpi_get_physical_device(dev->handle); seq_printf(seq, "%s\t S%d\t%c%-8s ", @@ -376,9 +372,8 @@ acpi_system_wakeup_device_seq_show(struct seq_file *seq, void *offset) seq_printf(seq, "\n"); put_device(ldev); - spin_lock(&acpi_device_lock); } - spin_unlock(&acpi_device_lock); + mutex_unlock(&acpi_device_lock); return 0; } @@ -409,7 +404,7 @@ acpi_system_write_wakeup_device(struct file *file, strbuf[len] = '\0'; sscanf(strbuf, "%s", str); - spin_lock(&acpi_device_lock); + mutex_lock(&acpi_device_lock); list_for_each_safe(node, next, &acpi_wakeup_device_list) { struct acpi_device *dev = container_of(node, struct acpi_device, wakeup_list); @@ -446,7 +441,7 @@ acpi_system_write_wakeup_device(struct file *file, } } } - spin_unlock(&acpi_device_lock); + mutex_unlock(&acpi_device_lock); return count; } diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index 20c23c04920..e63f2febad8 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -24,7 +24,7 @@ extern struct acpi_device *acpi_root; static LIST_HEAD(acpi_device_list); static LIST_HEAD(acpi_bus_id_list); -DEFINE_SPINLOCK(acpi_device_lock); +DEFINE_MUTEX(acpi_device_lock); LIST_HEAD(acpi_wakeup_device_list); struct acpi_device_bus_id{ @@ -500,7 +500,7 @@ static int acpi_device_register(struct acpi_device *device, return -ENOMEM; } - spin_lock(&acpi_device_lock); + mutex_lock(&acpi_device_lock); /* * Find suitable bus_id and instance number in acpi_bus_id_list * If failed, create one and link it into acpi_bus_id_list @@ -528,7 +528,7 @@ static int acpi_device_register(struct acpi_device *device, list_add_tail(&device->g_list, &acpi_device_list); if (device->wakeup.flags.valid) list_add_tail(&device->wakeup_list, &acpi_wakeup_device_list); - spin_unlock(&acpi_device_lock); + mutex_unlock(&acpi_device_lock); if (device->parent) device->dev.parent = &parent->dev; @@ -549,20 +549,20 @@ static int acpi_device_register(struct acpi_device *device, device->removal_type = ACPI_BUS_REMOVAL_NORMAL; return 0; end: - spin_lock(&acpi_device_lock); + mutex_lock(&acpi_device_lock); if (device->parent) { list_del(&device->node); list_del(&device->g_list); } else list_del(&device->g_list); list_del(&device->wakeup_list); - spin_unlock(&acpi_device_lock); + mutex_unlock(&acpi_device_lock); return result; } static void acpi_device_unregister(struct acpi_device *device, int type) { - spin_lock(&acpi_device_lock); + mutex_lock(&acpi_device_lock); if (device->parent) { list_del(&device->node); list_del(&device->g_list); @@ -570,7 +570,7 @@ static void acpi_device_unregister(struct acpi_device *device, int type) list_del(&device->g_list); list_del(&device->wakeup_list); - spin_unlock(&acpi_device_lock); + mutex_unlock(&acpi_device_lock); acpi_detach_data(device->handle, acpi_bus_data_handler); diff --git a/drivers/acpi/sleep.h b/drivers/acpi/sleep.h index cfaf8f5b0a1..8a8f3b3382a 100644 --- a/drivers/acpi/sleep.h +++ b/drivers/acpi/sleep.h @@ -5,3 +5,6 @@ extern int acpi_suspend (u32 state); extern void acpi_enable_wakeup_device_prep(u8 sleep_state); extern void acpi_enable_wakeup_device(u8 sleep_state); extern void acpi_disable_wakeup_device(u8 sleep_state); + +extern struct list_head acpi_wakeup_device_list; +extern struct mutex acpi_device_lock; diff --git a/drivers/acpi/wakeup.c b/drivers/acpi/wakeup.c index 5aee8c26cc9..88725dcdf8b 100644 --- a/drivers/acpi/wakeup.c +++ b/drivers/acpi/wakeup.c @@ -12,12 +12,14 @@ #include "internal.h" #include "sleep.h" +/* + * We didn't lock acpi_device_lock in the file, because it invokes oops in + * suspend/resume and isn't really required as this is called in S-state. At + * that time, there is no device hotplug + **/ #define _COMPONENT ACPI_SYSTEM_COMPONENT ACPI_MODULE_NAME("wakeup_devices") -extern struct list_head acpi_wakeup_device_list; -extern spinlock_t acpi_device_lock; - /** * acpi_enable_wakeup_device_prep - prepare wakeup devices * @sleep_state: ACPI state @@ -29,7 +31,6 @@ void acpi_enable_wakeup_device_prep(u8 sleep_state) { struct list_head *node, *next; - spin_lock(&acpi_device_lock); list_for_each_safe(node, next, &acpi_wakeup_device_list) { struct acpi_device *dev = container_of(node, struct acpi_device, @@ -40,11 +41,8 @@ void acpi_enable_wakeup_device_prep(u8 sleep_state) (sleep_state > (u32) dev->wakeup.sleep_state)) continue; - spin_unlock(&acpi_device_lock); acpi_enable_wakeup_device_power(dev, sleep_state); - spin_lock(&acpi_device_lock); } - spin_unlock(&acpi_device_lock); } /** @@ -60,7 +58,6 @@ void acpi_enable_wakeup_device(u8 sleep_state) * Caution: this routine must be invoked when interrupt is disabled * Refer ACPI2.0: P212 */ - spin_lock(&acpi_device_lock); list_for_each_safe(node, next, &acpi_wakeup_device_list) { struct acpi_device *dev = container_of(node, struct acpi_device, wakeup_list); @@ -74,22 +71,17 @@ void acpi_enable_wakeup_device(u8 sleep_state) if ((!dev->wakeup.state.enabled && !dev->wakeup.flags.prepared) || sleep_state > (u32) dev->wakeup.sleep_state) { if (dev->wakeup.flags.run_wake) { - spin_unlock(&acpi_device_lock); /* set_gpe_type will disable GPE, leave it like that */ acpi_set_gpe_type(dev->wakeup.gpe_device, dev->wakeup.gpe_number, ACPI_GPE_TYPE_RUNTIME); - spin_lock(&acpi_device_lock); } continue; } - spin_unlock(&acpi_device_lock); if (!dev->wakeup.flags.run_wake) acpi_enable_gpe(dev->wakeup.gpe_device, dev->wakeup.gpe_number); - spin_lock(&acpi_device_lock); } - spin_unlock(&acpi_device_lock); } /** @@ -101,7 +93,6 @@ void acpi_disable_wakeup_device(u8 sleep_state) { struct list_head *node, *next; - spin_lock(&acpi_device_lock); list_for_each_safe(node, next, &acpi_wakeup_device_list) { struct acpi_device *dev = container_of(node, struct acpi_device, wakeup_list); @@ -112,19 +103,16 @@ void acpi_disable_wakeup_device(u8 sleep_state) if ((!dev->wakeup.state.enabled && !dev->wakeup.flags.prepared) || sleep_state > (u32) dev->wakeup.sleep_state) { if (dev->wakeup.flags.run_wake) { - spin_unlock(&acpi_device_lock); acpi_set_gpe_type(dev->wakeup.gpe_device, dev->wakeup.gpe_number, ACPI_GPE_TYPE_WAKE_RUN); /* Re-enable it, since set_gpe_type will disable it */ acpi_enable_gpe(dev->wakeup.gpe_device, dev->wakeup.gpe_number); - spin_lock(&acpi_device_lock); } continue; } - spin_unlock(&acpi_device_lock); acpi_disable_wakeup_device_power(dev); /* Never disable run-wake GPE */ if (!dev->wakeup.flags.run_wake) { @@ -133,16 +121,14 @@ void acpi_disable_wakeup_device(u8 sleep_state) acpi_clear_gpe(dev->wakeup.gpe_device, dev->wakeup.gpe_number, ACPI_NOT_ISR); } - spin_lock(&acpi_device_lock); } - spin_unlock(&acpi_device_lock); } int __init acpi_wakeup_device_init(void) { struct list_head *node, *next; - spin_lock(&acpi_device_lock); + mutex_lock(&acpi_device_lock); list_for_each_safe(node, next, &acpi_wakeup_device_list) { struct acpi_device *dev = container_of(node, struct acpi_device, @@ -150,15 +136,13 @@ int __init acpi_wakeup_device_init(void) /* In case user doesn't load button driver */ if (!dev->wakeup.flags.run_wake || dev->wakeup.state.enabled) continue; - spin_unlock(&acpi_device_lock); acpi_set_gpe_type(dev->wakeup.gpe_device, dev->wakeup.gpe_number, ACPI_GPE_TYPE_WAKE_RUN); acpi_enable_gpe(dev->wakeup.gpe_device, dev->wakeup.gpe_number); dev->wakeup.state.enabled = 1; - spin_lock(&acpi_device_lock); } - spin_unlock(&acpi_device_lock); + mutex_unlock(&acpi_device_lock); return 0; }