kernel-ark/drivers/isdn/capi/kcapi_proc.c
Jan Kiszka 88c896ef87 CAPI: Rework application locking
Drop the application rw-lock in favour of RCU. This synchronizes
capi20_release against capi_ctr_handle_message which may dereference an
application from (soft-)IRQ context. Any other access to the application
list is now protected by the capi_controller_lock as well. This also
allows to safely inspect applications for /proc dumping by holding
capi_controller_lock.

At this chance, drop some useless release_in_progress checks where we
obtained the application pointer from the list (which becomes NULL on
release_in_progress).

Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-16 16:01:22 -08:00

322 lines
7.4 KiB
C

/*
* Kernel CAPI 2.0 Module - /proc/capi handling
*
* Copyright 1999 by Carsten Paeth <calle@calle.de>
* Copyright 2002 by Kai Germaschewski <kai@germaschewski.name>
*
* This software may be used and distributed according to the terms
* of the GNU General Public License, incorporated herein by reference.
*
*/
#include "kcapi.h"
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/init.h>
static char *state2str(unsigned short state)
{
switch (state) {
case CAPI_CTR_DETECTED: return "detected";
case CAPI_CTR_LOADING: return "loading";
case CAPI_CTR_RUNNING: return "running";
default: return "???";
}
}
// /proc/capi
// ===========================================================================
// /proc/capi/controller:
// cnr driver cardstate name driverinfo
// /proc/capi/contrstats:
// cnr nrecvctlpkt nrecvdatapkt nsentctlpkt nsentdatapkt
// ---------------------------------------------------------------------------
static void *controller_start(struct seq_file *seq, loff_t *pos)
__acquires(capi_controller_lock)
{
mutex_lock(&capi_controller_lock);
if (*pos < CAPI_MAXCONTR)
return &capi_controller[*pos];
return NULL;
}
static void *controller_next(struct seq_file *seq, void *v, loff_t *pos)
{
++*pos;
if (*pos < CAPI_MAXCONTR)
return &capi_controller[*pos];
return NULL;
}
static void controller_stop(struct seq_file *seq, void *v)
__releases(capi_controller_lock)
{
mutex_unlock(&capi_controller_lock);
}
static int controller_show(struct seq_file *seq, void *v)
{
struct capi_ctr *ctr = *(struct capi_ctr **) v;
if (!ctr)
return 0;
seq_printf(seq, "%d %-10s %-8s %-16s %s\n",
ctr->cnr, ctr->driver_name,
state2str(ctr->state),
ctr->name,
ctr->procinfo ? ctr->procinfo(ctr) : "");
return 0;
}
static int contrstats_show(struct seq_file *seq, void *v)
{
struct capi_ctr *ctr = *(struct capi_ctr **) v;
if (!ctr)
return 0;
seq_printf(seq, "%d %lu %lu %lu %lu\n",
ctr->cnr,
ctr->nrecvctlpkt,
ctr->nrecvdatapkt,
ctr->nsentctlpkt,
ctr->nsentdatapkt);
return 0;
}
static const struct seq_operations seq_controller_ops = {
.start = controller_start,
.next = controller_next,
.stop = controller_stop,
.show = controller_show,
};
static const struct seq_operations seq_contrstats_ops = {
.start = controller_start,
.next = controller_next,
.stop = controller_stop,
.show = contrstats_show,
};
static int seq_controller_open(struct inode *inode, struct file *file)
{
return seq_open(file, &seq_controller_ops);
}
static int seq_contrstats_open(struct inode *inode, struct file *file)
{
return seq_open(file, &seq_contrstats_ops);
}
static const struct file_operations proc_controller_ops = {
.owner = THIS_MODULE,
.open = seq_controller_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
};
static const struct file_operations proc_contrstats_ops = {
.owner = THIS_MODULE,
.open = seq_contrstats_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
};
// /proc/capi/applications:
// applid l3cnt dblkcnt dblklen #ncci recvqueuelen
// /proc/capi/applstats:
// applid nrecvctlpkt nrecvdatapkt nsentctlpkt nsentdatapkt
// ---------------------------------------------------------------------------
static void *applications_start(struct seq_file *seq, loff_t *pos)
__acquires(capi_controller_lock)
{
mutex_lock(&capi_controller_lock);
if (*pos < CAPI_MAXAPPL)
return &capi_applications[*pos];
return NULL;
}
static void *
applications_next(struct seq_file *seq, void *v, loff_t *pos)
{
++*pos;
if (*pos < CAPI_MAXAPPL)
return &capi_applications[*pos];
return NULL;
}
static void applications_stop(struct seq_file *seq, void *v)
__releases(capi_controller_lock)
{
mutex_unlock(&capi_controller_lock);
}
static int
applications_show(struct seq_file *seq, void *v)
{
struct capi20_appl *ap = *(struct capi20_appl **) v;
if (!ap)
return 0;
seq_printf(seq, "%u %d %d %d\n",
ap->applid,
ap->rparam.level3cnt,
ap->rparam.datablkcnt,
ap->rparam.datablklen);
return 0;
}
static int
applstats_show(struct seq_file *seq, void *v)
{
struct capi20_appl *ap = *(struct capi20_appl **) v;
if (!ap)
return 0;
seq_printf(seq, "%u %lu %lu %lu %lu\n",
ap->applid,
ap->nrecvctlpkt,
ap->nrecvdatapkt,
ap->nsentctlpkt,
ap->nsentdatapkt);
return 0;
}
static const struct seq_operations seq_applications_ops = {
.start = applications_start,
.next = applications_next,
.stop = applications_stop,
.show = applications_show,
};
static const struct seq_operations seq_applstats_ops = {
.start = applications_start,
.next = applications_next,
.stop = applications_stop,
.show = applstats_show,
};
static int
seq_applications_open(struct inode *inode, struct file *file)
{
return seq_open(file, &seq_applications_ops);
}
static int
seq_applstats_open(struct inode *inode, struct file *file)
{
return seq_open(file, &seq_applstats_ops);
}
static const struct file_operations proc_applications_ops = {
.owner = THIS_MODULE,
.open = seq_applications_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
};
static const struct file_operations proc_applstats_ops = {
.owner = THIS_MODULE,
.open = seq_applstats_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
};
// ---------------------------------------------------------------------------
static void *capi_driver_start(struct seq_file *seq, loff_t *pos)
__acquires(&capi_drivers_lock)
{
mutex_lock(&capi_drivers_lock);
return seq_list_start(&capi_drivers, *pos);
}
static void *capi_driver_next(struct seq_file *seq, void *v, loff_t *pos)
{
return seq_list_next(v, &capi_drivers, pos);
}
static void capi_driver_stop(struct seq_file *seq, void *v)
__releases(&capi_drivers_lock)
{
mutex_unlock(&capi_drivers_lock);
}
static int capi_driver_show(struct seq_file *seq, void *v)
{
struct capi_driver *drv = list_entry(v, struct capi_driver, list);
seq_printf(seq, "%-32s %s\n", drv->name, drv->revision);
return 0;
}
static const struct seq_operations seq_capi_driver_ops = {
.start = capi_driver_start,
.next = capi_driver_next,
.stop = capi_driver_stop,
.show = capi_driver_show,
};
static int
seq_capi_driver_open(struct inode *inode, struct file *file)
{
int err;
err = seq_open(file, &seq_capi_driver_ops);
return err;
}
static const struct file_operations proc_driver_ops = {
.owner = THIS_MODULE,
.open = seq_capi_driver_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
};
// ---------------------------------------------------------------------------
void __init
kcapi_proc_init(void)
{
proc_mkdir("capi", NULL);
proc_mkdir("capi/controllers", NULL);
proc_create("capi/controller", 0, NULL, &proc_controller_ops);
proc_create("capi/contrstats", 0, NULL, &proc_contrstats_ops);
proc_create("capi/applications", 0, NULL, &proc_applications_ops);
proc_create("capi/applstats", 0, NULL, &proc_applstats_ops);
proc_create("capi/driver", 0, NULL, &proc_driver_ops);
}
void __exit
kcapi_proc_exit(void)
{
remove_proc_entry("capi/driver", NULL);
remove_proc_entry("capi/controller", NULL);
remove_proc_entry("capi/contrstats", NULL);
remove_proc_entry("capi/applications", NULL);
remove_proc_entry("capi/applstats", NULL);
remove_proc_entry("capi/controllers", NULL);
remove_proc_entry("capi", NULL);
}