dahdi: Experimentally remove dependency on the Big Kernel Lock.

With the release of Linux 2.6.37, the Big Kernel Lock is now a compile
time option.  This change adds a mutex around the one place in the code
that we already knew was dependent on the lock_kernel/unlock_kernel
calls for serialization and drops the other calls to
lock_kernel/unlock_kernel if CONFIG_BKL is not defined.

This is *mostly* the dahdi-no-bkl.patch with a few minor whitespace
changes, the global_dialparmslock made static, and a warning added to
let people know they are running an experimental configuration.

(issue #18604)
Reported by: jkroon
Patches:
      dahdi-no-bkl.patch uploaded by jkroon (license 714)

Signed-off-by: Jaco Kroon <jaco@uls.co.za>
Signed-off-by: Shaun Ruffell <sruffell@digium.com>

Origin: http://svnview.digium.com/svn/dahdi?view=rev&rev=9721

git-svn-id: http://svn.asterisk.org/svn/dahdi/linux/branches/2.4@9725 a0bf4364-ded3-4de4-8d8a-66a801d63aff
This commit is contained in:
Jaco Kroon
2011-01-31 17:59:01 +00:00
committed by Shaun Ruffell
parent 97130b1841
commit a9d7147a60

View File

@@ -48,8 +48,9 @@
#include <linux/sched.h>
#include <linux/list.h>
#include <linux/delay.h>
#include <linux/mutex.h>
#ifdef HAVE_UNLOCKED_IOCTL
#if defined(HAVE_UNLOCKED_IOCTL) && defined(CONFIG_BKL)
#include <linux/smp_lock.h>
#endif
@@ -91,7 +92,7 @@
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 37)
#ifndef CONFIG_BKL
#error You must have CONFIG_BKL lock defined to build DAHDI
#warning "No CONFIG_BKL is an experimental configuration."
#endif
#endif
@@ -317,6 +318,8 @@ static struct dahdi_dialparams global_dialparams = {
.mfr2_tonelen = DEFAULT_MFR2_LENGTH,
};
static DEFINE_MUTEX(global_dialparamslock);
static int dahdi_chan_ioctl(struct file *file, unsigned int cmd, unsigned long data, int unit);
#if defined(CONFIG_DAHDI_MMX) || defined(ECHO_CAN_FP)
@@ -3069,7 +3072,7 @@ static int ioctl_load_zone(unsigned long data)
size_t size;
int res;
int x;
void *slab, *ptr;
void *slab = NULL, *ptr;
struct dahdi_zone *z;
struct dahdi_tone *t;
void __user * user_data = (void __user *)data;
@@ -3087,21 +3090,21 @@ static int ioctl_load_zone(unsigned long data)
if ((work->th.count < 0) || (work->th.count > MAX_TONES)) {
module_printk(KERN_NOTICE, "Too many tones included\n");
kfree(work);
return -EINVAL;
res = -EINVAL;
goto error_exit;
}
space = size = sizeof(*z) + work->th.count * sizeof(*t);
if (size > MAX_SIZE) {
kfree(work);
return -E2BIG;
res = -E2BIG;
goto error_exit;
}
z = ptr = slab = kzalloc(size, GFP_KERNEL);
if (!z) {
kfree(work);
return -ENOMEM;
res = -ENOMEM;
goto error_exit;
}
ptr = (char *) ptr + sizeof(*z);
@@ -3112,8 +3115,8 @@ static int ioctl_load_zone(unsigned long data)
for (x = 0; x < DAHDI_MAX_CADENCE; x++)
z->ringcadence[x] = work->th.ringcadence[x];
mutex_lock(&global_dialparamslock);
atomic_set(&z->refcount, 0);
for (x = 0; x < work->th.count; x++) {
enum {
REGULAR_TONE,
@@ -3124,18 +3127,16 @@ static int ioctl_load_zone(unsigned long data)
} tone_type;
if (space < sizeof(*t)) {
kfree(slab);
kfree(work);
module_printk(KERN_NOTICE, "Insufficient tone zone space\n");
return -EINVAL;
res = -EINVAL;
goto unlock_error_exit;
}
res = copy_from_user(&work->td, user_data,
sizeof(work->td));
if (res) {
kfree(slab);
kfree(work);
return -EFAULT;
res = -EFAULT;
goto unlock_error_exit;
}
user_data += sizeof(work->td);
@@ -3157,9 +3158,8 @@ static int ioctl_load_zone(unsigned long data)
module_printk(KERN_NOTICE,
"Invalid 'next' pointer: %d\n",
work->next[x]);
kfree(slab);
kfree(work);
return -EINVAL;
res = -EINVAL;
goto unlock_error_exit;
}
} else if ((work->td.tone >= DAHDI_TONE_DTMF_BASE) &&
(work->td.tone <= DAHDI_TONE_DTMF_MAX)) {
@@ -3185,9 +3185,8 @@ static int ioctl_load_zone(unsigned long data)
module_printk(KERN_NOTICE,
"Invalid tone (%d) defined\n",
work->td.tone);
kfree(slab);
kfree(work);
return -EINVAL;
res = -EINVAL;
goto unlock_error_exit;
}
t->fac1 = work->td.fac1;
@@ -3243,6 +3242,7 @@ static int ioctl_load_zone(unsigned long data)
break;
}
}
mutex_unlock(&global_dialparamslock);
for (x = 0; x < work->th.count; x++) {
if (work->samples[x])
@@ -3259,6 +3259,14 @@ static int ioctl_load_zone(unsigned long data)
}
kfree(work);
return 0;
unlock_error_exit:
mutex_unlock(&global_dialparamslock);
error_exit:
kfree(work);
kfree(slab);
return res;
}
@@ -4542,6 +4550,8 @@ static int dahdi_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long da
if (copy_from_user(&tdp, user_data, sizeof(tdp)))
return -EFAULT;
mutex_lock(&global_dialparamslock);
if ((tdp.dtmf_tonelen >= 10) && (tdp.dtmf_tonelen <= 4000)) {
global_dialparams.dtmf_tonelen = tdp.dtmf_tonelen;
}
@@ -4583,13 +4593,17 @@ static int dahdi_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long da
mfr1_silence.tonesamples = global_dialparams.mfv1_tonelen * DAHDI_CHUNKSIZE;
mfr2_silence.tonesamples = global_dialparams.mfr2_tonelen * DAHDI_CHUNKSIZE;
mutex_unlock(&global_dialparamslock);
break;
}
case DAHDI_GET_DIALPARAMS:
{
struct dahdi_dialparams tdp;
mutex_lock(&global_dialparamslock);
tdp = global_dialparams;
mutex_unlock(&global_dialparamslock);
if (copy_to_user(user_data, &tdp, sizeof(tdp)))
return -EFAULT;
break;
@@ -5904,19 +5918,15 @@ static int dahdi_prechan_ioctl(struct file *file, unsigned int cmd, unsigned lon
return 0;
}
#ifdef HAVE_UNLOCKED_IOCTL
static long dahdi_ioctl(struct file *file, unsigned int cmd, unsigned long data)
#else
static int dahdi_ioctl(struct inode *inode, struct file *file,
unsigned int cmd, unsigned long data)
#endif
static long
dahdi_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long data)
{
int unit = UNIT(file);
struct dahdi_chan *chan;
struct dahdi_timer *timer;
int ret;
#ifdef HAVE_UNLOCKED_IOCTL
#if defined(HAVE_UNLOCKED_IOCTL) && defined(CONFIG_BKL)
lock_kernel();
#endif
@@ -5968,12 +5978,20 @@ static int dahdi_ioctl(struct inode *inode, struct file *file,
ret = dahdi_chan_ioctl(file, cmd, data, unit);
unlock_exit:
#ifdef HAVE_UNLOCKED_IOCTL
#if defined(HAVE_UNLOCKED_IOCTL) && defined(CONFIG_BKL)
unlock_kernel();
#endif
return ret;
}
#ifndef HAVE_UNLOCKED_IOCTL
static int dahdi_ioctl(struct inode *inode, struct file *file,
unsigned int cmd, unsigned long data)
{
return dahdi_unlocked_ioctl(file, cmd, data);
}
#endif
#ifdef HAVE_COMPAT_IOCTL
static long dahdi_ioctl_compat(struct file *file, unsigned int cmd,
unsigned long data)
@@ -5981,7 +5999,7 @@ static long dahdi_ioctl_compat(struct file *file, unsigned int cmd,
if (cmd == DAHDI_SFCONFIG)
return -ENOTTY; /* Not supported yet */
return dahdi_ioctl(file, cmd, data);
return dahdi_unlocked_ioctl(file, cmd, data);
}
#endif
@@ -8678,7 +8696,7 @@ static struct file_operations dahdi_fops = {
.open = dahdi_open,
.release = dahdi_release,
#ifdef HAVE_UNLOCKED_IOCTL
.unlocked_ioctl = dahdi_ioctl,
.unlocked_ioctl = dahdi_unlocked_ioctl,
#ifdef HAVE_COMPAT_IOCTL
.compat_ioctl = dahdi_ioctl_compat,
#endif