From 9090589d87506c578ea1523ffd7ae7fd9424fb28 Mon Sep 17 00:00:00 2001 From: Shaohua Li Date: Tue, 7 Apr 2009 10:24:29 +0800 Subject: 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 ++++--------- 1 file changed, 4 insertions(+), 9 deletions(-) (limited to 'drivers/acpi/proc.c') 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; } -- cgit v1.2.3