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| Current File : //sys/amd64/compile/hs32/modules/usr/src/sys/modules/geom/geom_sched/gsched_rr/@/kern/subr_uio.c |
/*-
* Copyright (c) 1982, 1986, 1991, 1993
* The Regents of the University of California. All rights reserved.
* (c) UNIX System Laboratories, Inc.
* All or some portions of this file are derived from material licensed
* to the University of California by American Telephone and Telegraph
* Co. or Unix System Laboratories, Inc. and are reproduced herein with
* the permission of UNIX System Laboratories, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)kern_subr.c 8.3 (Berkeley) 1/21/94
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD: release/9.1.0/sys/kern/subr_uio.c 233647 2012-03-29 04:54:34Z alc $");
#include "opt_zero.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/limits.h>
#include <sys/lock.h>
#include <sys/mman.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/resourcevar.h>
#include <sys/sched.h>
#include <sys/sysctl.h>
#include <sys/vnode.h>
#include <vm/vm.h>
#include <vm/vm_extern.h>
#include <vm/vm_page.h>
#include <vm/vm_map.h>
#ifdef ZERO_COPY_SOCKETS
#include <vm/vm_param.h>
#include <vm/vm_object.h>
#endif
SYSCTL_INT(_kern, KERN_IOV_MAX, iov_max, CTLFLAG_RD, NULL, UIO_MAXIOV,
"Maximum number of elements in an I/O vector; sysconf(_SC_IOV_MAX)");
static int uiomove_faultflag(void *cp, int n, struct uio *uio, int nofault);
#ifdef ZERO_COPY_SOCKETS
/* Declared in uipc_socket.c */
extern int so_zero_copy_receive;
/*
* Identify the physical page mapped at the given kernel virtual
* address. Insert this physical page into the given address space at
* the given virtual address, replacing the physical page, if any,
* that already exists there.
*/
static int
vm_pgmoveco(vm_map_t mapa, vm_offset_t kaddr, vm_offset_t uaddr)
{
vm_map_t map = mapa;
vm_page_t kern_pg, user_pg;
vm_object_t uobject;
vm_map_entry_t entry;
vm_pindex_t upindex;
vm_prot_t prot;
boolean_t wired;
KASSERT((uaddr & PAGE_MASK) == 0,
("vm_pgmoveco: uaddr is not page aligned"));
/*
* Herein the physical page is validated and dirtied. It is
* unwired in sf_buf_mext().
*/
kern_pg = PHYS_TO_VM_PAGE(vtophys(kaddr));
kern_pg->valid = VM_PAGE_BITS_ALL;
KASSERT(kern_pg->queue == PQ_NONE && kern_pg->wire_count == 1,
("vm_pgmoveco: kern_pg is not correctly wired"));
if ((vm_map_lookup(&map, uaddr,
VM_PROT_WRITE, &entry, &uobject,
&upindex, &prot, &wired)) != KERN_SUCCESS) {
return(EFAULT);
}
VM_OBJECT_LOCK(uobject);
retry:
if ((user_pg = vm_page_lookup(uobject, upindex)) != NULL) {
if (vm_page_sleep_if_busy(user_pg, TRUE, "vm_pgmoveco"))
goto retry;
vm_page_lock(user_pg);
pmap_remove_all(user_pg);
vm_page_free(user_pg);
vm_page_unlock(user_pg);
} else {
/*
* Even if a physical page does not exist in the
* object chain's first object, a physical page from a
* backing object may be mapped read only.
*/
if (uobject->backing_object != NULL)
pmap_remove(map->pmap, uaddr, uaddr + PAGE_SIZE);
}
vm_page_insert(kern_pg, uobject, upindex);
vm_page_dirty(kern_pg);
VM_OBJECT_UNLOCK(uobject);
vm_map_lookup_done(map, entry);
return(KERN_SUCCESS);
}
#endif /* ZERO_COPY_SOCKETS */
int
copyin_nofault(const void *udaddr, void *kaddr, size_t len)
{
int error, save;
save = vm_fault_disable_pagefaults();
error = copyin(udaddr, kaddr, len);
vm_fault_enable_pagefaults(save);
return (error);
}
int
copyout_nofault(const void *kaddr, void *udaddr, size_t len)
{
int error, save;
save = vm_fault_disable_pagefaults();
error = copyout(kaddr, udaddr, len);
vm_fault_enable_pagefaults(save);
return (error);
}
int
uiomove(void *cp, int n, struct uio *uio)
{
return (uiomove_faultflag(cp, n, uio, 0));
}
int
uiomove_nofault(void *cp, int n, struct uio *uio)
{
return (uiomove_faultflag(cp, n, uio, 1));
}
static int
uiomove_faultflag(void *cp, int n, struct uio *uio, int nofault)
{
struct thread *td;
struct iovec *iov;
size_t cnt;
int error, newflags, save;
td = curthread;
error = 0;
KASSERT(uio->uio_rw == UIO_READ || uio->uio_rw == UIO_WRITE,
("uiomove: mode"));
KASSERT(uio->uio_segflg != UIO_USERSPACE || uio->uio_td == td,
("uiomove proc"));
if (!nofault)
WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
"Calling uiomove()");
/* XXX does it make a sense to set TDP_DEADLKTREAT for UIO_SYSSPACE ? */
newflags = TDP_DEADLKTREAT;
if (uio->uio_segflg == UIO_USERSPACE && nofault) {
/*
* Fail if a non-spurious page fault occurs.
*/
newflags |= TDP_NOFAULTING | TDP_RESETSPUR;
}
save = curthread_pflags_set(newflags);
while (n > 0 && uio->uio_resid) {
iov = uio->uio_iov;
cnt = iov->iov_len;
if (cnt == 0) {
uio->uio_iov++;
uio->uio_iovcnt--;
continue;
}
if (cnt > n)
cnt = n;
switch (uio->uio_segflg) {
case UIO_USERSPACE:
maybe_yield();
if (uio->uio_rw == UIO_READ)
error = copyout(cp, iov->iov_base, cnt);
else
error = copyin(iov->iov_base, cp, cnt);
if (error)
goto out;
break;
case UIO_SYSSPACE:
if (uio->uio_rw == UIO_READ)
bcopy(cp, iov->iov_base, cnt);
else
bcopy(iov->iov_base, cp, cnt);
break;
case UIO_NOCOPY:
break;
}
iov->iov_base = (char *)iov->iov_base + cnt;
iov->iov_len -= cnt;
uio->uio_resid -= cnt;
uio->uio_offset += cnt;
cp = (char *)cp + cnt;
n -= cnt;
}
out:
curthread_pflags_restore(save);
return (error);
}
/*
* Wrapper for uiomove() that validates the arguments against a known-good
* kernel buffer. Currently, uiomove accepts a signed (n) argument, which
* is almost definitely a bad thing, so we catch that here as well. We
* return a runtime failure, but it might be desirable to generate a runtime
* assertion failure instead.
*/
int
uiomove_frombuf(void *buf, int buflen, struct uio *uio)
{
size_t offset, n;
if (uio->uio_offset < 0 || uio->uio_resid < 0 ||
(offset = uio->uio_offset) != uio->uio_offset)
return (EINVAL);
if (buflen <= 0 || offset >= buflen)
return (0);
if ((n = buflen - offset) > IOSIZE_MAX)
return (EINVAL);
return (uiomove((char *)buf + offset, n, uio));
}
#ifdef ZERO_COPY_SOCKETS
/*
* Experimental support for zero-copy I/O
*/
static int
userspaceco(void *cp, u_int cnt, struct uio *uio, int disposable)
{
struct iovec *iov;
int error;
iov = uio->uio_iov;
if (uio->uio_rw == UIO_READ) {
if ((so_zero_copy_receive != 0)
&& ((cnt & PAGE_MASK) == 0)
&& ((((intptr_t) iov->iov_base) & PAGE_MASK) == 0)
&& ((uio->uio_offset & PAGE_MASK) == 0)
&& ((((intptr_t) cp) & PAGE_MASK) == 0)
&& (disposable != 0)) {
/* SOCKET: use page-trading */
/*
* We only want to call vm_pgmoveco() on
* disposeable pages, since it gives the
* kernel page to the userland process.
*/
error = vm_pgmoveco(&curproc->p_vmspace->vm_map,
(vm_offset_t)cp, (vm_offset_t)iov->iov_base);
/*
* If we get an error back, attempt
* to use copyout() instead. The
* disposable page should be freed
* automatically if we weren't able to move
* it into userland.
*/
if (error != 0)
error = copyout(cp, iov->iov_base, cnt);
} else {
error = copyout(cp, iov->iov_base, cnt);
}
} else {
error = copyin(iov->iov_base, cp, cnt);
}
return (error);
}
int
uiomoveco(void *cp, int n, struct uio *uio, int disposable)
{
struct iovec *iov;
u_int cnt;
int error;
KASSERT(uio->uio_rw == UIO_READ || uio->uio_rw == UIO_WRITE,
("uiomoveco: mode"));
KASSERT(uio->uio_segflg != UIO_USERSPACE || uio->uio_td == curthread,
("uiomoveco proc"));
while (n > 0 && uio->uio_resid) {
iov = uio->uio_iov;
cnt = iov->iov_len;
if (cnt == 0) {
uio->uio_iov++;
uio->uio_iovcnt--;
continue;
}
if (cnt > n)
cnt = n;
switch (uio->uio_segflg) {
case UIO_USERSPACE:
maybe_yield();
error = userspaceco(cp, cnt, uio, disposable);
if (error)
return (error);
break;
case UIO_SYSSPACE:
if (uio->uio_rw == UIO_READ)
bcopy(cp, iov->iov_base, cnt);
else
bcopy(iov->iov_base, cp, cnt);
break;
case UIO_NOCOPY:
break;
}
iov->iov_base = (char *)iov->iov_base + cnt;
iov->iov_len -= cnt;
uio->uio_resid -= cnt;
uio->uio_offset += cnt;
cp = (char *)cp + cnt;
n -= cnt;
}
return (0);
}
#endif /* ZERO_COPY_SOCKETS */
/*
* Give next character to user as result of read.
*/
int
ureadc(int c, struct uio *uio)
{
struct iovec *iov;
char *iov_base;
WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
"Calling ureadc()");
again:
if (uio->uio_iovcnt == 0 || uio->uio_resid == 0)
panic("ureadc");
iov = uio->uio_iov;
if (iov->iov_len == 0) {
uio->uio_iovcnt--;
uio->uio_iov++;
goto again;
}
switch (uio->uio_segflg) {
case UIO_USERSPACE:
if (subyte(iov->iov_base, c) < 0)
return (EFAULT);
break;
case UIO_SYSSPACE:
iov_base = iov->iov_base;
*iov_base = c;
iov->iov_base = iov_base;
break;
case UIO_NOCOPY:
break;
}
iov->iov_base = (char *)iov->iov_base + 1;
iov->iov_len--;
uio->uio_resid--;
uio->uio_offset++;
return (0);
}
int
copyinfrom(const void * __restrict src, void * __restrict dst, size_t len,
int seg)
{
int error = 0;
switch (seg) {
case UIO_USERSPACE:
error = copyin(src, dst, len);
break;
case UIO_SYSSPACE:
bcopy(src, dst, len);
break;
default:
panic("copyinfrom: bad seg %d\n", seg);
}
return (error);
}
int
copyinstrfrom(const void * __restrict src, void * __restrict dst, size_t len,
size_t * __restrict copied, int seg)
{
int error = 0;
switch (seg) {
case UIO_USERSPACE:
error = copyinstr(src, dst, len, copied);
break;
case UIO_SYSSPACE:
error = copystr(src, dst, len, copied);
break;
default:
panic("copyinstrfrom: bad seg %d\n", seg);
}
return (error);
}
int
copyiniov(struct iovec *iovp, u_int iovcnt, struct iovec **iov, int error)
{
u_int iovlen;
*iov = NULL;
if (iovcnt > UIO_MAXIOV)
return (error);
iovlen = iovcnt * sizeof (struct iovec);
*iov = malloc(iovlen, M_IOV, M_WAITOK);
error = copyin(iovp, *iov, iovlen);
if (error) {
free(*iov, M_IOV);
*iov = NULL;
}
return (error);
}
int
copyinuio(struct iovec *iovp, u_int iovcnt, struct uio **uiop)
{
struct iovec *iov;
struct uio *uio;
u_int iovlen;
int error, i;
*uiop = NULL;
if (iovcnt > UIO_MAXIOV)
return (EINVAL);
iovlen = iovcnt * sizeof (struct iovec);
uio = malloc(iovlen + sizeof *uio, M_IOV, M_WAITOK);
iov = (struct iovec *)(uio + 1);
error = copyin(iovp, iov, iovlen);
if (error) {
free(uio, M_IOV);
return (error);
}
uio->uio_iov = iov;
uio->uio_iovcnt = iovcnt;
uio->uio_segflg = UIO_USERSPACE;
uio->uio_offset = -1;
uio->uio_resid = 0;
for (i = 0; i < iovcnt; i++) {
if (iov->iov_len > IOSIZE_MAX - uio->uio_resid) {
free(uio, M_IOV);
return (EINVAL);
}
uio->uio_resid += iov->iov_len;
iov++;
}
*uiop = uio;
return (0);
}
struct uio *
cloneuio(struct uio *uiop)
{
struct uio *uio;
int iovlen;
iovlen = uiop->uio_iovcnt * sizeof (struct iovec);
uio = malloc(iovlen + sizeof *uio, M_IOV, M_WAITOK);
*uio = *uiop;
uio->uio_iov = (struct iovec *)(uio + 1);
bcopy(uiop->uio_iov, uio->uio_iov, iovlen);
return (uio);
}
/*
* Map some anonymous memory in user space of size sz, rounded up to the page
* boundary.
*/
int
copyout_map(struct thread *td, vm_offset_t *addr, size_t sz)
{
struct vmspace *vms;
int error;
vm_size_t size;
vms = td->td_proc->p_vmspace;
/*
* Map somewhere after heap in process memory.
*/
PROC_LOCK(td->td_proc);
*addr = round_page((vm_offset_t)vms->vm_daddr +
lim_max(td->td_proc, RLIMIT_DATA));
PROC_UNLOCK(td->td_proc);
/* round size up to page boundry */
size = (vm_size_t)round_page(sz);
error = vm_mmap(&vms->vm_map, addr, size, PROT_READ | PROT_WRITE,
VM_PROT_ALL, MAP_PRIVATE | MAP_ANON, OBJT_DEFAULT, NULL, 0);
return (error);
}
/*
* Unmap memory in user space.
*/
int
copyout_unmap(struct thread *td, vm_offset_t addr, size_t sz)
{
vm_map_t map;
vm_size_t size;
if (sz == 0)
return (0);
map = &td->td_proc->p_vmspace->vm_map;
size = (vm_size_t)round_page(sz);
if (vm_map_remove(map, addr, addr + size) != KERN_SUCCESS)
return (EINVAL);
return (0);
}