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authorShaohua Li <shaohua.li@intel.com>2009-04-07 10:24:29 +0800
committerLen Brown <len.brown@intel.com>2009-04-07 00:02:40 -0400
commit9090589d87506c578ea1523ffd7ae7fd9424fb28 (patch)
tree215163d13dbfa514a4121594cd4c6e27fde9b911 /drivers/acpi/proc.c
parentd508afb437daee7cf07da085b635c44a4ebf9b38 (diff)
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.c13
1 files changed, 4 insertions, 9 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;
}