releases/upstream/2.6.24-rc4/0006-ACPI-thinkpad-acpi-allow-for-syscall-restart-in-sy.patch

   1 From fc589a3ce5f38db6239c147da4f9172a25575ecc Mon Sep 17 00:00:00 2001
   2 From: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
   3 Date: Tue, 30 Oct 2007 17:46:24 -0200
   4 Subject: [PATCH 21/23] ACPI: thinkpad-acpi: allow for syscall restart in sysfs handlers
   5
   6 Map an mutex_lock_interruptible() error return into ERESTARTSYS, as the
   7 only possible error from mutex_lock_interruptible is EINTR, and that will
   8 only happen if signal_pending() causes the mutex lock attempt to abort.
   9
  10 This still allows signals to be delivered ASAP, which is much nicer than
  11 just doing mutex_lock, and still shadows userspace from EINTR when
  12 SA_RESTART is active.
  13
  14 Problem reported by Peter Jordan.
  15
  16 Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
  17 Cc: Jean Delvare <khali@linux-fr.org>
  18 Cc: Peter Jordan <usernetwork@gmx.info>
  19 Cc: Richard Neill <rn214@hermes.cam.ac.uk>
  20 Signed-off-by: Len Brown <len.brown@intel.com>
  21 ---
  22  drivers/misc/thinkpad_acpi.c |   40 ++++++++++++++++------------------------
  23  1 files changed, 16 insertions(+), 24 deletions(-)
  24
  25 diff --git a/drivers/misc/thinkpad_acpi.c b/drivers/misc/thinkpad_acpi.c
  26 index 251110d..306daa5 100644
  27 --- a/drivers/misc/thinkpad_acpi.c
  28 +++ b/drivers/misc/thinkpad_acpi.c
  29 @@ -1342,9 +1342,8 @@ static int hotkey_read(char *p)
  30                 return len;
  31         }
  32
  33 -       res = mutex_lock_interruptible(&hotkey_mutex);
  34 -       if (res < 0)
  35 -               return res;
  36 +       if (mutex_lock_interruptible(&hotkey_mutex))
  37 +               return -ERESTARTSYS;
  38         res = hotkey_get(&status, &mask);
  39         mutex_unlock(&hotkey_mutex);
  40         if (res)
  41 @@ -1373,9 +1372,8 @@ static int hotkey_write(char *buf)
  42         if (!tp_features.hotkey)
  43                 return -ENODEV;
  44
  45 -       res = mutex_lock_interruptible(&hotkey_mutex);
  46 -       if (res < 0)
  47 -               return res;
  48 +       if (mutex_lock_interruptible(&hotkey_mutex))
  49 +               return -ERESTARTSYS;
  50
  51         res = hotkey_get(&status, &mask);
  52         if (res)
  53 @@ -3768,9 +3766,8 @@ static ssize_t fan_pwm1_store(struct device *dev,
  54         /* scale down from 0-255 to 0-7 */
  55         newlevel = (s >> 5) & 0x07;
  56
  57 -       rc = mutex_lock_interruptible(&fan_mutex);
  58 -       if (rc < 0)
  59 -               return rc;
  60 +       if (mutex_lock_interruptible(&fan_mutex))
  61 +               return -ERESTARTSYS;
  62
  63         rc = fan_get_status(&status);
  64         if (!rc && (status &
  65 @@ -4020,9 +4017,8 @@ static int fan_get_status_safe(u8 *status)
  66         int rc;
  67         u8 s;
  68
  69 -       rc = mutex_lock_interruptible(&fan_mutex);
  70 -       if (rc < 0)
  71 -               return rc;
  72 +       if (mutex_lock_interruptible(&fan_mutex))
  73 +               return -ERESTARTSYS;
  74         rc = fan_get_status(&s);
  75         if (!rc)
  76                 fan_update_desired_level(s);
  77 @@ -4156,9 +4152,8 @@ static int fan_set_level_safe(int level)
  78         if (!fan_control_allowed)
  79                 return -EPERM;
  80
  81 -       rc = mutex_lock_interruptible(&fan_mutex);
  82 -       if (rc < 0)
  83 -               return rc;
  84 +       if (mutex_lock_interruptible(&fan_mutex))
  85 +               return -ERESTARTSYS;
  86
  87         if (level == TPACPI_FAN_LAST_LEVEL)
  88                 level = fan_control_desired_level;
  89 @@ -4179,9 +4174,8 @@ static int fan_set_enable(void)
  90         if (!fan_control_allowed)
  91                 return -EPERM;
  92
  93 -       rc = mutex_lock_interruptible(&fan_mutex);
  94 -       if (rc < 0)
  95 -               return rc;
  96 +       if (mutex_lock_interruptible(&fan_mutex))
  97 +               return -ERESTARTSYS;
  98
  99         switch (fan_control_access_mode) {
 100         case TPACPI_FAN_WR_ACPI_FANS:
 101 @@ -4235,9 +4229,8 @@ static int fan_set_disable(void)
 102         if (!fan_control_allowed)
 103                 return -EPERM;
 104
 105 -       rc = mutex_lock_interruptible(&fan_mutex);
 106 -       if (rc < 0)
 107 -               return rc;
 108 +       if (mutex_lock_interruptible(&fan_mutex))
 109 +               return -ERESTARTSYS;
 110
 111         rc = 0;
 112         switch (fan_control_access_mode) {
 113 @@ -4274,9 +4267,8 @@ static int fan_set_speed(int speed)
 114         if (!fan_control_allowed)
 115                 return -EPERM;
 116
 117 -       rc = mutex_lock_interruptible(&fan_mutex);
 118 -       if (rc < 0)
 119 -               return rc;
 120 +       if (mutex_lock_interruptible(&fan_mutex))
 121 +               return -ERESTARTSYS;
 122
 123         rc = 0;
 124         switch (fan_control_access_mode) {
 125 --
 126 1.5.3.4
 127