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| author | Shaohua Li <shaohua.li@intel.com> | 2009-04-07 10:24:29 +0800 |
|---|---|---|
| committer | Len Brown <len.brown@intel.com> | 2009-04-07 00:02:40 -0400 |
| commit | 9090589d87506c578ea1523ffd7ae7fd9424fb28 (patch) | |
| tree | 215163d13dbfa514a4121594cd4c6e27fde9b911 /drivers/acpi/proc.c | |
| parent | d508afb437daee7cf07da085b635c44a4ebf9b38 (diff) | |
| download | lwn-9090589d87506c578ea1523ffd7ae7fd9424fb28.tar.gz lwn-9090589d87506c578ea1523ffd7ae7fd9424fb28.zip | |
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 <torvalds@linux-foundation.org>
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'drivers/acpi/proc.c')
| -rw-r--r-- | drivers/acpi/proc.c | 13 |
1 files changed, 4 insertions, 9 deletions
diff --git a/drivers/acpi/proc.c b/drivers/acpi/proc.c index 05dfdc96802e..d0d550d22a6d 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; } |