Aren/NetBSD
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Implement in-module ref-counting, and do not allow auto-unload if there

Browse Source 
are existing references.

Note that manual unloading is not prevented.

OK christos@

XXX Also note that there is still a small window where the ref-count can
XXX be decremented, and then the process/thread preempted.  If auto-unload
XXX happens before that thread can return from the module's code, bad
XXX things (tm) could happen.
This commit is contained in:
pgoyette 2014-01-21 20:33:01 +00:00
parent dd68def8c5
commit 1e5d7f9c10
1 changed files with 13 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

20
sys/opencrypto/cryptodev.c
View File

@ -1,4 +1,4 @@
/* $NetBSD: cryptodev.c,v 1.73 2014/01/21 18:54:28 pgoyette Exp $ */
/* $NetBSD: cryptodev.c,v 1.74 2014/01/21 20:33:01 pgoyette Exp $ */
/* $FreeBSD: src/sys/opencrypto/cryptodev.c,v 1.4.2.4 2003/06/03 00:09:02 sam Exp $ */
/* $OpenBSD: cryptodev.c,v 1.53 2002/07/10 22:21:30 mickey Exp $ */
@ -64,7 +64,7 @@
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: cryptodev.c,v 1.73 2014/01/21 18:54:28 pgoyette Exp $");
__KERNEL_RCSID(0, "$NetBSD: cryptodev.c,v 1.74 2014/01/21 20:33:01 pgoyette Exp $");
#include <sys/param.h>
#include <sys/systm.h>
@ -143,6 +143,8 @@ static int cryptoread(dev_t dev, struct uio *uio, int ioflag);
static int cryptowrite(dev_t dev, struct uio *uio, int ioflag);
static int cryptoselect(dev_t dev, int rw, struct lwp *l);
static int crypto_refcount = 0; /* Prevent detaching while in use */
/* Declaration of cloned-device (per-ctxt) entrypoints */
static int cryptof_read(struct file *, off_t *, struct uio *,
kauth_cred_t, int);
@ -262,6 +264,7 @@ cryptof_ioctl(struct file *fp, u_long cmd, void *data)
*/
criofcr->sesn = 1;
criofcr->requestid = 1;
crypto_refcount++;
mutex_exit(&crypto_mtx);
(void)fd_clone(criofp, criofd, (FREAD|FWRITE),
&cryptofops, criofcr);
@ -951,6 +954,7 @@ cryptof_close(struct file *fp)
}
seldestroy(&fcr->sinfo);
fp->f_data = NULL;
crypto_refcount--;
mutex_exit(&crypto_mtx);
pool_put(&fcrpl, fcr);
@ -1080,6 +1084,7 @@ cryptoopen(dev_t dev, int flag, int mode,
*/
fcr->sesn = 1;
fcr->requestid = 1;
crypto_refcount++;
mutex_exit(&crypto_mtx);
return fd_clone(fp, fd, flag, &cryptofops, fcr);
}
@ -2206,8 +2211,6 @@ crypto_modcmd(modcmd_t cmd, void *arg)
return error;
case MODULE_CMD_FINI:
#ifdef _MODULE
#ifdef notyet
/* We need to keep track of open instances before we do this */
error = config_cfdata_detach(crypto_cfdata);
if (error) {
return error;
@ -2216,12 +2219,15 @@ crypto_modcmd(modcmd_t cmd, void *arg)
config_cfattach_detach(crypto_cd.cd_name, &crypto_ca);
config_cfdriver_detach(&crypto_cd);
devsw_detach(NULL, &crypto_cdevsw);
#else
return EOPNOTSUPP;
#endif
#endif
return error;
#ifdef _MODULE
case MODULE_CMD_AUTOUNLOAD:
if (crypto_refcount != 0)
return EBUSY;
/* FALLTHROUGH */
#endif
default:
return ENOTTY;
}