Provide binary compatibility for architectures that (erroneously) had

a larger MAXPARTITIONS value (and thus larger struct disklabel).
This commit is contained in:
martin 2013-04-04 12:51:39 +00:00
parent 35d9a96a44
commit 9d0957eba7

View File

@ -1,4 +1,4 @@
/* $NetBSD: sys_generic.c,v 1.128 2012/01/25 00:28:36 christos Exp $ */
/* $NetBSD: sys_generic.c,v 1.129 2013/04/04 12:51:39 martin Exp $ */
/*-
* Copyright (c) 2007, 2008, 2009 The NetBSD Foundation, Inc.
@ -70,7 +70,7 @@
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: sys_generic.c,v 1.128 2012/01/25 00:28:36 christos Exp $");
__KERNEL_RCSID(0, "$NetBSD: sys_generic.c,v 1.129 2013/04/04 12:51:39 martin Exp $");
#include <sys/param.h>
#include <sys/systm.h>
@ -526,6 +526,12 @@ sys_ioctl(struct lwp *l, const struct sys_ioctl_args *uap, register_t *retval)
void *data, *memp;
#define STK_PARAMS 128
u_long stkbuf[STK_PARAMS/sizeof(u_long)];
#if __TMPBIGMAXPARTITIONS > MAXPARTITIONS
size_t zero_last = 0;
#define zero_size(SZ) ((SZ)+zero_last)
#else
#define zero_size(SZ) (SZ)
#endif
memp = NULL;
alloc_size = 0;
@ -563,7 +569,34 @@ sys_ioctl(struct lwp *l, const struct sys_ioctl_args *uap, register_t *retval)
* but only copyin/out the smaller amount.
*/
if (IOCGROUP(com) == 'd') {
#if __TMPBIGMAXPARTITIONS > MAXPARTITIONS
u_long ocom = com;
#endif
u_long ncom = com ^ (DIOCGDINFO ^ DIOCGDINFO32);
#if __TMPBIGMAXPARTITIONS > MAXPARTITIONS
/*
* Userland might use struct disklabel that is bigger than the
* the kernel version (historic accident) - alloc userland
* size and zero unused part on copyout.
*/
#define DISKLABELLENDIFF (sizeof(struct partition) \
*(__TMPBIGMAXPARTITIONS-MAXPARTITIONS))
#define IOCFIXUP(NIOC) ((NIOC&~(IOCPARM_MASK<<IOCPARM_SHIFT)) | \
(IOCPARM_LEN(NIOC)-DISKLABELLENDIFF)<<IOCPARM_SHIFT)
switch (IOCFIXUP(ocom)) {
case DIOCGDINFO:
case DIOCWDINFO:
case DIOCSDINFO:
case DIOCGDEFLABEL:
com = ncom = IOCFIXUP(ocom);
zero_last = DISKLABELLENDIFF;
size -= DISKLABELLENDIFF;
goto done;
}
#endif
switch (ncom) {
case DIOCGDINFO:
case DIOCWDINFO:
@ -574,6 +607,9 @@ sys_ioctl(struct lwp *l, const struct sys_ioctl_args *uap, register_t *retval)
alloc_size = IOCPARM_LEN(DIOCGDINFO);
break;
}
#if __TMPBIGMAXPARTITIONS > MAXPARTITIONS
done: ;
#endif
}
if (size > IOCPARM_MAX) {
error = ENOTTY;
@ -615,7 +651,7 @@ sys_ioctl(struct lwp *l, const struct sys_ioctl_args *uap, register_t *retval)
* Zero the buffer so the user always
* gets back something deterministic.
*/
memset(data, 0, size);
memset(data, 0, zero_size(size));
} else if (com&IOC_VOID) {
*(void **)data = SCARG(uap, data);
}
@ -648,7 +684,8 @@ sys_ioctl(struct lwp *l, const struct sys_ioctl_args *uap, register_t *retval)
* already set and checked above.
*/
if (error == 0 && (com&IOC_OUT) && size) {
error = copyout(data, SCARG(uap, data), size);
error = copyout(data, SCARG(uap, data),
zero_size(size));
ktrgenio(SCARG(uap, fd), UIO_READ, SCARG(uap, data),
size, error);
}