Module Name: src
Committed By: riastradh
Date: Mon Jun 14 10:14:58 UTC 2021
Modified Files:
src/sys/dev/pad: pad.c
Log Message:
pad(4): Make this exclusively a cloning device.
padN numbering never corresponded with audioM numbering except by
accident, so the non-cloning device never worked reliably for
scripting. This simplifies the logic substantially.
While here, fix drvctl detach race.
To generate a diff of this commit:
cvs rdiff -u -r1.70 -r1.71 src/sys/dev/pad/pad.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/dev/pad/pad.c
diff -u src/sys/dev/pad/pad.c:1.70 src/sys/dev/pad/pad.c:1.71
--- src/sys/dev/pad/pad.c:1.70 Mon Jun 14 10:14:46 2021
+++ src/sys/dev/pad/pad.c Mon Jun 14 10:14:58 2021
@@ -1,4 +1,4 @@
-/* $NetBSD: pad.c,v 1.70 2021/06/14 10:14:46 riastradh Exp $ */
+/* $NetBSD: pad.c,v 1.71 2021/06/14 10:14:58 riastradh Exp $ */
/*-
* Copyright (c) 2007 Jared D. McNeill <jmcne...@invisible.ca>
@@ -27,7 +27,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: pad.c,v 1.70 2021/06/14 10:14:46 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: pad.c,v 1.71 2021/06/14 10:14:58 riastradh Exp $");
#include <sys/param.h>
#include <sys/types.h>
@@ -54,6 +54,8 @@ __KERNEL_RCSID(0, "$NetBSD: pad.c,v 1.70
#include <dev/pad/padvar.h>
+#include "ioconf.h"
+
/* #define PAD_DEBUG */
#ifdef PAD_DEBUG
#define DPRINTF(fmt...) printf(fmt)
@@ -61,17 +63,10 @@ __KERNEL_RCSID(0, "$NetBSD: pad.c,v 1.70
#define DPRINTF(fmt...) /**/
#endif
-#define MAXDEVS 128
-#define PADCLONER 254
-#define PADUNIT(x) minor(x)
-
#define PADFREQ 44100
#define PADCHAN 2
#define PADPREC 16
-extern struct cfdriver pad_cd;
-kmutex_t padconfig;
-
typedef struct pad_block {
uint8_t *pb_ptr;
int pb_len;
@@ -107,7 +102,7 @@ static void pad_get_locks(void *, kmutex
static void pad_done_output(void *);
static void pad_swvol_codec(audio_filter_arg_t *);
-static int pad_close(struct pad_softc *);
+static void pad_close(struct pad_softc *);
static int pad_read(struct pad_softc *, off_t *, struct uio *,
kauth_cred_t, int);
@@ -155,14 +150,12 @@ extern void padattach(int);
static int pad_add_block(struct pad_softc *, uint8_t *, int);
static int pad_get_block(struct pad_softc *, pad_block_t *, int);
-dev_type_open(cdev_pad_open);
-dev_type_close(cdev_pad_close);
-dev_type_read(cdev_pad_read);
+static dev_type_open(pad_open);
const struct cdevsw pad_cdevsw = {
- .d_open = cdev_pad_open,
- .d_close = cdev_pad_close,
- .d_read = cdev_pad_read,
+ .d_open = pad_open,
+ .d_close = noclose,
+ .d_read = noread,
.d_write = nowrite,
.d_ioctl = noioctl,
.d_stop = nostop,
@@ -204,9 +197,6 @@ padattach(int n)
config_cfdriver_detach(&pad_cd);
return;
}
- mutex_init(&padconfig, MUTEX_DEFAULT, IPL_NONE);
-
- return;
}
static int
@@ -221,6 +211,8 @@ pad_attach(device_t parent, device_t sel
{
struct pad_softc *sc = device_private(self);
+ KASSERT(KERNEL_LOCKED_P());
+
aprint_normal_dev(self, "outputs: 44100Hz, 16-bit, stereo\n");
sc->sc_dev = self;
@@ -239,6 +231,8 @@ pad_attach(device_t parent, device_t sel
if (!pmf_device_register(sc->sc_dev, NULL, NULL))
aprint_error_dev(sc->sc_dev,
"couldn't establish power handler\n");
+
+ sc->sc_open = 1;
}
static int
@@ -248,6 +242,12 @@ pad_detach(device_t self, int flags)
int cmaj, mn;
int error;
+ KASSERT(KERNEL_LOCKED_P());
+
+ /* Prevent detach without going through close -- e.g., drvctl. */
+ if (sc->sc_open)
+ return EBUSY;
+
error = config_detach_children(self, flags);
if (error)
return error;
@@ -320,85 +320,61 @@ pad_get_block(struct pad_softc *sc, pad_
return 0;
}
-int
-cdev_pad_open(dev_t dev, int flags, int fmt, struct lwp *l)
+static int
+pad_open(dev_t dev, int flags, int fmt, struct lwp *l)
{
- struct pad_softc *sc;
- struct file *fp;
- device_t paddev;
- cfdata_t cf;
- int error, fd, i;
-
- error = 0;
-
- mutex_enter(&padconfig);
- if (PADUNIT(dev) == PADCLONER) {
- for (i = 0; i < MAXDEVS; i++) {
- if (device_lookup(&pad_cd, i) == NULL)
- break;
- }
- if (i == MAXDEVS)
- goto bad;
- } else {
- if (PADUNIT(dev) >= MAXDEVS)
- goto bad;
- i = PADUNIT(dev);
- }
+ struct file *fp = NULL;
+ device_t self;
+ struct pad_softc *sc = NULL;
+ cfdata_t cf = NULL;
+ int error, fd;
+
+ error = fd_allocfile(&fp, &fd);
+ if (error)
+ goto out;
- cf = kmem_alloc(sizeof(struct cfdata), KM_SLEEP);
+ cf = kmem_alloc(sizeof(*cf), KM_SLEEP);
cf->cf_name = pad_cd.cd_name;
cf->cf_atname = pad_cd.cd_name;
- cf->cf_unit = i;
+ cf->cf_unit = 0;
cf->cf_fstate = FSTATE_STAR;
- bool existing = false;
- paddev = device_lookup(&pad_cd, minor(dev));
- if (paddev == NULL)
- paddev = config_attach_pseudo(cf);
- else
- existing = true;
- if (paddev == NULL)
- goto bad;
-
- sc = device_private(paddev);
- if (sc == NULL)
- goto bad;
-
- if (sc->sc_open == 1) {
- mutex_exit(&padconfig);
- return EBUSY;
- }
-
- if (PADUNIT(dev) == PADCLONER) {
- error = fd_allocfile(&fp, &fd);
- if (error) {
- if (existing == false)
- config_detach(paddev, 0);
- mutex_exit(&padconfig);
- return error;
- }
- error = fd_clone(fp, fd, flags, &pad_fileops, sc);
- KASSERT(error == EMOVEFD);
- }
- sc->sc_open = 1;
- mutex_exit(&padconfig);
-
+ self = config_attach_pseudo(cf);
+ if (self == NULL) {
+ error = ENXIO;
+ goto out;
+ }
+ sc = device_private(self);
+ KASSERT(sc->sc_dev == self);
+ cf = NULL;
+
+ error = fd_clone(fp, fd, flags, &pad_fileops, sc);
+ KASSERT(error == EMOVEFD);
+ fp = NULL;
+ sc = NULL;
+
+out: if (sc)
+ pad_close(sc);
+ if (cf)
+ kmem_free(cf, sizeof(*cf));
+ if (fp)
+ fd_abort(curproc, fp, fd);
return error;
-bad:
- mutex_exit(&padconfig);
- return ENXIO;
}
-static int
+static void
pad_close(struct pad_softc *sc)
{
- int rc __diagused;
+ device_t self = sc->sc_dev;
+ cfdata_t cf = device_cfdata(self);
- /* XXX Defend against concurrent drvctl detach. */
- rc = config_detach(sc->sc_dev, DETACH_FORCE);
- KASSERT(rc == 0);
+ KERNEL_LOCK(1, NULL);
+ KASSERT(sc->sc_open);
+ sc->sc_open = 0;
+ (void)config_detach(self, DETACH_FORCE);
+ KERNEL_UNLOCK_ONE(NULL);
- return 0;
+ kmem_free(cf, sizeof(*cf));
}
static int
@@ -407,25 +383,6 @@ fops_pad_close(struct file *fp)
struct pad_softc *sc = fp->f_pad;
pad_close(sc);
- fp->f_pad = NULL;
-
- return 0;
-}
-
-int
-cdev_pad_close(dev_t dev, int flags, int ifmt, struct lwp *l)
-{
- struct pad_softc *sc;
-
- /*
- * XXX Defend against concurrent drvctl detach. Simply testing
- * sc == NULL here is not enough -- it could be detached after
- * we look it up but before we've issued our own config_detach.
- */
- sc = device_lookup_private(&pad_cd, PADUNIT(dev));
- if (sc == NULL)
- return 0;
- pad_close(sc);
return 0;
}
@@ -481,18 +438,6 @@ fops_pad_mmap(struct file *fp, off_t *of
return 1;
}
-int
-cdev_pad_read(dev_t dev, struct uio *uio, int ioflag)
-{
- struct pad_softc *sc;
-
- sc = device_private(device_lookup(&pad_cd, PADUNIT(dev)));
- if (sc == NULL)
- return ENXIO;
-
- return pad_read(sc, NULL, uio, NULL, ioflag);
-}
-
static int
fops_pad_read(struct file *fp, off_t *offp, struct uio *uio, kauth_cred_t cred,
int ioflag)
@@ -795,7 +740,6 @@ pad_modcmd(modcmd_t cmd, void *arg)
pad_cfattach, cfdata_ioconf_pad);
break;
}
- mutex_init(&padconfig, MUTEX_DEFAULT, IPL_NONE);
#endif
break;
@@ -813,7 +757,6 @@ pad_modcmd(modcmd_t cmd, void *arg)
&pad_cdevsw, &cmajor);
break;
}
- mutex_destroy(&padconfig);
#endif
break;
