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9ff59ff11997ff22cbccfcffd00a6a35d012d38d
xen/tools/libxc/xc_linux_osdep.c
T
Daniel De Graaf dc52d92824 libxc: Fix checks on grant notify arguments 
The notify offset and event channels are both unsigned variables, so
testing for >= 0 will not correctly detect the use of -1 to indicate
the field is unused. Remove the useless comparison and replace with
correct range checks or comparisons to -1.

Reported-by: Anil Madhavapeddy <anil@recoil.org>
Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Committed-by: Ian Jackson <ian.jackson@eu.citrix.com>
2011-12-01 18:20:12 +00:00

790 lines
21 KiB
C
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/******************************************************************************
*
* Copyright 2006 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*
* xc_gnttab functions:
* Copyright (c) 2007-2008, D G Murray <Derek.Murray@cl.cam.ac.uk>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <errno.h>
#include <fcntl.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/mman.h>
#include <sys/ioctl.h>
#include <xen/memory.h>
#include <xen/sys/evtchn.h>
#include <xen/sys/gntdev.h>
#include <xen/sys/gntalloc.h>
#include "xenctrl.h"
#include "xenctrlosdep.h"
#define ERROR(_m, _a...) xc_osdep_log(xch,XTL_ERROR,XC_INTERNAL_ERROR,_m , ## _a )
#define PERROR(_m, _a...) xc_osdep_log(xch,XTL_ERROR,XC_INTERNAL_ERROR,_m \
" (%d = %s)", ## _a , errno, xc_strerror(xch, errno))
static xc_osdep_handle linux_privcmd_open(xc_interface *xch)
{
int flags, saved_errno;
int fd = open("/proc/xen/privcmd", O_RDWR);
if ( fd == -1 )
{
PERROR("Could not obtain handle on privileged command interface");
return XC_OSDEP_OPEN_ERROR;
}
/* Although we return the file handle as the 'xc handle' the API
does not specify / guarentee that this integer is in fact
a file handle. Thus we must take responsiblity to ensure
it doesn't propagate (ie leak) outside the process */
if ( (flags = fcntl(fd, F_GETFD)) < 0 )
{
PERROR("Could not get file handle flags");
goto error;
}
flags |= FD_CLOEXEC;
if ( fcntl(fd, F_SETFD, flags) < 0 )
{
PERROR("Could not set file handle flags");
goto error;
}
return (xc_osdep_handle)fd;
error:
saved_errno = errno;
close(fd);
errno = saved_errno;
return XC_OSDEP_OPEN_ERROR;
}
static int linux_privcmd_close(xc_interface *xch, xc_osdep_handle h)
{
int fd = (int)h;
return close(fd);
}
static void *linux_privcmd_alloc_hypercall_buffer(xc_interface *xch, xc_osdep_handle h, int npages)
{
size_t size = npages * XC_PAGE_SIZE;
void *p;
p = xc_memalign(xch, XC_PAGE_SIZE, size);
if (!p)
return NULL;
if ( mlock(p, size) < 0 )
{
free(p);
return NULL;
}
return p;
}
static void linux_privcmd_free_hypercall_buffer(xc_interface *xch, xc_osdep_handle h, void *ptr, int npages)
{
(void) munlock(ptr, npages * XC_PAGE_SIZE);
free(ptr);
}
static int linux_privcmd_hypercall(xc_interface *xch, xc_osdep_handle h, privcmd_hypercall_t *hypercall)
{
int fd = (int)h;
return ioctl(fd, IOCTL_PRIVCMD_HYPERCALL, hypercall);
}
static int xc_map_foreign_batch_single(int fd, uint32_t dom,
xen_pfn_t *mfn, unsigned long addr)
{
privcmd_mmapbatch_t ioctlx;
int rc;
ioctlx.num = 1;
ioctlx.dom = dom;
ioctlx.addr = addr;
ioctlx.arr = mfn;
do
{
*mfn ^= XEN_DOMCTL_PFINFO_PAGEDTAB;
usleep(100);
rc = ioctl(fd, IOCTL_PRIVCMD_MMAPBATCH, &ioctlx);
}
while ( (rc < 0) && (errno == ENOENT) );
return rc;
}
static void *linux_privcmd_map_foreign_batch(xc_interface *xch, xc_osdep_handle h,
uint32_t dom, int prot,
xen_pfn_t *arr, int num)
{
int fd = (int)h;
privcmd_mmapbatch_t ioctlx;
void *addr;
int rc;
addr = mmap(NULL, num << XC_PAGE_SHIFT, prot, MAP_SHARED, fd, 0);
if ( addr == MAP_FAILED )
{
PERROR("xc_map_foreign_batch: mmap failed");
return NULL;
}
ioctlx.num = num;
ioctlx.dom = dom;
ioctlx.addr = (unsigned long)addr;
ioctlx.arr = arr;
rc = ioctl(fd, IOCTL_PRIVCMD_MMAPBATCH, &ioctlx);
if ( (rc < 0) && (errno == ENOENT) )
{
int i;
for ( i = 0; i < num; i++ )
{
if ( (arr[i] & XEN_DOMCTL_PFINFO_LTAB_MASK) ==
XEN_DOMCTL_PFINFO_PAGEDTAB )
{
unsigned long paged_addr = (unsigned long)addr + (i << XC_PAGE_SHIFT);
rc = xc_map_foreign_batch_single(fd, dom, &arr[i],
paged_addr);
if ( rc < 0 )
goto out;
}
}
}
out:
if ( rc < 0 )
{
int saved_errno = errno;
PERROR("xc_map_foreign_batch: ioctl failed");
(void)munmap(addr, num << XC_PAGE_SHIFT);
errno = saved_errno;
return NULL;
}
return addr;
}
static void *linux_privcmd_map_foreign_bulk(xc_interface *xch, xc_osdep_handle h,
uint32_t dom, int prot,
const xen_pfn_t *arr, int *err, unsigned int num)
{
int fd = (int)h;
privcmd_mmapbatch_v2_t ioctlx;
void *addr;
unsigned int i;
int rc;
addr = mmap(NULL, (unsigned long)num << XC_PAGE_SHIFT, prot, MAP_SHARED,
fd, 0);
if ( addr == MAP_FAILED )
{
PERROR("xc_map_foreign_batch: mmap failed");
return NULL;
}
ioctlx.num = num;
ioctlx.dom = dom;
ioctlx.addr = (unsigned long)addr;
ioctlx.arr = arr;
ioctlx.err = err;
rc = ioctl(fd, IOCTL_PRIVCMD_MMAPBATCH_V2, &ioctlx);
if ( rc < 0 && errno == ENOENT )
{
for ( i = rc = 0; rc == 0 && i < num; i++ )
{
if ( err[i] != -ENOENT )
continue;
ioctlx.num = 1;
ioctlx.dom = dom;
ioctlx.addr = (unsigned long)addr + ((unsigned long)i<<XC_PAGE_SHIFT);
ioctlx.arr = arr + i;
ioctlx.err = err + i;
do {
usleep(100);
rc = ioctl(fd, IOCTL_PRIVCMD_MMAPBATCH_V2, &ioctlx);
} while ( rc < 0 && err[i] == -ENOENT );
}
}
if ( rc < 0 && errno == EINVAL && (int)num > 0 )
{
/*
* IOCTL_PRIVCMD_MMAPBATCH_V2 is not supported - fall back to
* IOCTL_PRIVCMD_MMAPBATCH.
*/
xen_pfn_t *pfn = malloc(num * sizeof(*pfn));
if ( pfn )
{
privcmd_mmapbatch_t ioctlx;
memcpy(pfn, arr, num * sizeof(*arr));
ioctlx.num = num;
ioctlx.dom = dom;
ioctlx.addr = (unsigned long)addr;
ioctlx.arr = pfn;
rc = ioctl(fd, IOCTL_PRIVCMD_MMAPBATCH, &ioctlx);
rc = rc < 0 ? -errno : 0;
for ( i = 0; i < num; ++i )
{
switch ( pfn[i] ^ arr[i] )
{
case 0:
err[i] = rc != -ENOENT ? rc : 0;
continue;
default:
err[i] = -EINVAL;
continue;
case XEN_DOMCTL_PFINFO_PAGEDTAB:
if ( rc != -ENOENT )
{
err[i] = rc ?: -EINVAL;
continue;
}
rc = xc_map_foreign_batch_single(fd, dom, pfn + i,
(unsigned long)addr + ((unsigned long)i<<XC_PAGE_SHIFT));
if ( rc < 0 )
{
rc = -errno;
break;
}
rc = -ENOENT;
continue;
}
break;
}
free(pfn);
if ( rc == -ENOENT && i == num )
rc = 0;
else if ( rc )
{
errno = -rc;
rc = -1;
}
}
else
{
errno = -ENOMEM;
rc = -1;
}
}
if ( rc < 0 )
{
int saved_errno = errno;
PERROR("xc_map_foreign_bulk: ioctl failed");
(void)munmap(addr, (unsigned long)num << XC_PAGE_SHIFT);
errno = saved_errno;
return NULL;
}
return addr;
}
static void *linux_privcmd_map_foreign_range(xc_interface *xch, xc_osdep_handle h,
uint32_t dom, int size, int prot,
unsigned long mfn)
{
xen_pfn_t *arr;
int num;
int i;
void *ret;
num = (size + XC_PAGE_SIZE - 1) >> XC_PAGE_SHIFT;
arr = calloc(num, sizeof(xen_pfn_t));
for ( i = 0; i < num; i++ )
arr[i] = mfn + i;
ret = xc_map_foreign_pages(xch, dom, prot, arr, num);
free(arr);
return ret;
}
static void *linux_privcmd_map_foreign_ranges(xc_interface *xch, xc_osdep_handle h,
uint32_t dom, size_t size, int prot,
size_t chunksize, privcmd_mmap_entry_t entries[],
int nentries)
{
xen_pfn_t *arr;
int num_per_entry;
int num;
int i;
int j;
void *ret;
num_per_entry = chunksize >> XC_PAGE_SHIFT;
num = num_per_entry * nentries;
arr = calloc(num, sizeof(xen_pfn_t));
for ( i = 0; i < nentries; i++ )
for ( j = 0; j < num_per_entry; j++ )
arr[i * num_per_entry + j] = entries[i].mfn + j;
ret = xc_map_foreign_pages(xch, dom, prot, arr, num);
free(arr);
return ret;
}
static struct xc_osdep_ops linux_privcmd_ops = {
.open = &linux_privcmd_open,
.close = &linux_privcmd_close,
.u.privcmd = {
.alloc_hypercall_buffer = &linux_privcmd_alloc_hypercall_buffer,
.free_hypercall_buffer = &linux_privcmd_free_hypercall_buffer,
.hypercall = &linux_privcmd_hypercall,
.map_foreign_batch = &linux_privcmd_map_foreign_batch,
.map_foreign_bulk = &linux_privcmd_map_foreign_bulk,
.map_foreign_range = &linux_privcmd_map_foreign_range,
.map_foreign_ranges = &linux_privcmd_map_foreign_ranges,
},
};
#define DEVXEN "/dev/xen/"
static xc_osdep_handle linux_evtchn_open(xc_evtchn *xce)
{
int fd = open(DEVXEN "evtchn", O_RDWR);
if ( fd == -1 )
return XC_OSDEP_OPEN_ERROR;
return (xc_osdep_handle)fd;
}
static int linux_evtchn_close(xc_evtchn *xce, xc_osdep_handle h)
{
int fd = (int)h;
return close(fd);
}
static int linux_evtchn_fd(xc_evtchn *xce, xc_osdep_handle h)
{
return (int)h;
}
static int linux_evtchn_notify(xc_evtchn *xce, xc_osdep_handle h, evtchn_port_t port)
{
int fd = (int)h;
struct ioctl_evtchn_notify notify;
notify.port = port;
return ioctl(fd, IOCTL_EVTCHN_NOTIFY, &notify);
}
static evtchn_port_or_error_t
linux_evtchn_bind_unbound_port(xc_evtchn *xce, xc_osdep_handle h, int domid)
{
int fd = (int)h;
struct ioctl_evtchn_bind_unbound_port bind;
bind.remote_domain = domid;
return ioctl(fd, IOCTL_EVTCHN_BIND_UNBOUND_PORT, &bind);
}
static evtchn_port_or_error_t
linux_evtchn_bind_interdomain(xc_evtchn *xce, xc_osdep_handle h, int domid,
evtchn_port_t remote_port)
{
int fd = (int)h;
struct ioctl_evtchn_bind_interdomain bind;
bind.remote_domain = domid;
bind.remote_port = remote_port;
return ioctl(fd, IOCTL_EVTCHN_BIND_INTERDOMAIN, &bind);
}
static evtchn_port_or_error_t
linux_evtchn_bind_virq(xc_evtchn *xce, xc_osdep_handle h, unsigned int virq)
{
int fd = (int)h;
struct ioctl_evtchn_bind_virq bind;
bind.virq = virq;
return ioctl(fd, IOCTL_EVTCHN_BIND_VIRQ, &bind);
}
static int linux_evtchn_unbind(xc_evtchn *xce, xc_osdep_handle h, evtchn_port_t port)
{
int fd = (int)h;
struct ioctl_evtchn_unbind unbind;
unbind.port = port;
return ioctl(fd, IOCTL_EVTCHN_UNBIND, &unbind);
}
static evtchn_port_or_error_t linux_evtchn_pending(xc_evtchn *xce, xc_osdep_handle h)
{
int fd = (int)h;
evtchn_port_t port;
if ( read(fd, &port, sizeof(port)) != sizeof(port) )
return -1;
return port;
}
static int linux_evtchn_unmask(xc_evtchn *xce, xc_osdep_handle h, evtchn_port_t port)
{
int fd = (int)h;
if ( write(fd, &port, sizeof(port)) != sizeof(port) )
return -1;
return 0;
}
static struct xc_osdep_ops linux_evtchn_ops = {
.open = &linux_evtchn_open,
.close = &linux_evtchn_close,
.u.evtchn = {
.fd = &linux_evtchn_fd,
.notify = &linux_evtchn_notify,
.bind_unbound_port = &linux_evtchn_bind_unbound_port,
.bind_interdomain = &linux_evtchn_bind_interdomain,
.bind_virq = &linux_evtchn_bind_virq,
.unbind = &linux_evtchn_unbind,
.pending = &linux_evtchn_pending,
.unmask = &linux_evtchn_unmask,
},
};
static xc_osdep_handle linux_gnttab_open(xc_gnttab *xcg)
{
int fd = open(DEVXEN "gntdev", O_RDWR);
if ( fd == -1 )
return XC_OSDEP_OPEN_ERROR;
return (xc_osdep_handle)fd;
}
static int linux_gnttab_close(xc_gnttab *xcg, xc_osdep_handle h)
{
int fd = (int)h;
return close(fd);
}
static void *linux_gnttab_grant_map(xc_gnttab *xch, xc_osdep_handle h,
uint32_t count, int flags, int prot,
uint32_t *domids, uint32_t *refs,
uint32_t notify_offset,
evtchn_port_t notify_port)
{
int fd = (int)h;
struct ioctl_gntdev_map_grant_ref *map;
void *addr = NULL;
int domids_stride = 1;
int i;
if (flags & XC_GRANT_MAP_SINGLE_DOMAIN)
domids_stride = 0;
map = malloc(sizeof(*map) +
(count - 1) * sizeof(struct ioctl_gntdev_map_grant_ref));
if ( map == NULL )
return NULL;
for ( i = 0; i < count; i++ )
{
map->refs[i].domid = domids[i * domids_stride];
map->refs[i].ref = refs[i];
}
map->count = count;
if ( ioctl(fd, IOCTL_GNTDEV_MAP_GRANT_REF, map) ) {
PERROR("linux_gnttab_grant_map: ioctl MAP_GRANT_REF failed");
goto out;
}
retry:
addr = mmap(NULL, XC_PAGE_SIZE * count, prot, MAP_SHARED, fd,
map->index);
if (addr == MAP_FAILED && errno == EAGAIN)
{
/*
* The grant hypercall can return EAGAIN if the granted page is
* swapped out. Since the paging daemon may be in the same domain, the
* hypercall cannot block without causing a deadlock.
*
* Because there are no notificaitons when the page is swapped in, wait
* a bit before retrying, and hope that the page will arrive eventually.
*/
usleep(1000);
goto retry;
}
if (addr != MAP_FAILED)
{
int rv = 0;
struct ioctl_gntdev_unmap_notify notify;
notify.index = map->index;
notify.action = 0;
if (notify_offset < XC_PAGE_SIZE * count) {
notify.index += notify_offset;
notify.action |= UNMAP_NOTIFY_CLEAR_BYTE;
}
if (notify_port != -1) {
notify.event_channel_port = notify_port;
notify.action |= UNMAP_NOTIFY_SEND_EVENT;
}
if (notify.action)
rv = ioctl(fd, IOCTL_GNTDEV_SET_UNMAP_NOTIFY, &notify);
if (rv) {
PERROR("linux_gnttab_grant_map: ioctl SET_UNMAP_NOTIFY failed");
munmap(addr, count * XC_PAGE_SIZE);
addr = MAP_FAILED;
}
}
if (addr == MAP_FAILED)
{
int saved_errno = errno;
struct ioctl_gntdev_unmap_grant_ref unmap_grant;
/* Unmap the driver slots used to store the grant information. */
PERROR("xc_gnttab_map_grant_refs: mmap failed");
unmap_grant.index = map->index;
unmap_grant.count = count;
ioctl(fd, IOCTL_GNTDEV_UNMAP_GRANT_REF, &unmap_grant);
errno = saved_errno;
addr = NULL;
}
out:
free(map);
return addr;
}
static int linux_gnttab_munmap(xc_gnttab *xcg, xc_osdep_handle h,
void *start_address, uint32_t count)
{
int fd = (int)h;
struct ioctl_gntdev_get_offset_for_vaddr get_offset;
struct ioctl_gntdev_unmap_grant_ref unmap_grant;
int rc;
if ( start_address == NULL )
{
errno = EINVAL;
return -1;
}
/* First, it is necessary to get the offset which was initially used to
* mmap() the pages.
*/
get_offset.vaddr = (unsigned long)start_address;
if ( (rc = ioctl(fd, IOCTL_GNTDEV_GET_OFFSET_FOR_VADDR,
&get_offset)) )
return rc;
if ( get_offset.count != count )
{
errno = EINVAL;
return -1;
}
/* Next, unmap the memory. */
if ( (rc = munmap(start_address, count * getpagesize())) )
return rc;
/* Finally, unmap the driver slots used to store the grant information. */
unmap_grant.index = get_offset.offset;
unmap_grant.count = count;
if ( (rc = ioctl(fd, IOCTL_GNTDEV_UNMAP_GRANT_REF, &unmap_grant)) )
return rc;
return 0;
}
static struct xc_osdep_ops linux_gnttab_ops = {
.open = &linux_gnttab_open,
.close = &linux_gnttab_close,
.u.gnttab = {
.grant_map = &linux_gnttab_grant_map,
.munmap = &linux_gnttab_munmap,
},
};
static xc_osdep_handle linux_gntshr_open(xc_gntshr *xcg)
{
int fd = open(DEVXEN "gntalloc", O_RDWR);
if ( fd == -1 )
return XC_OSDEP_OPEN_ERROR;
return (xc_osdep_handle)fd;
}
static int linux_gntshr_close(xc_gntshr *xcg, xc_osdep_handle h)
{
int fd = (int)h;
return close(fd);
}
static void *linux_gntshr_share_pages(xc_gntshr *xch, xc_osdep_handle h,
uint32_t domid, int count,
uint32_t *refs, int writable,
uint32_t notify_offset,
evtchn_port_t notify_port)
{
struct ioctl_gntalloc_alloc_gref *gref_info = NULL;
struct ioctl_gntalloc_unmap_notify notify;
struct ioctl_gntalloc_dealloc_gref gref_drop;
int fd = (int)h;
int err;
void *area = NULL;
gref_info = malloc(sizeof(*gref_info) + count * sizeof(uint32_t));
if (!gref_info)
return NULL;
gref_info->domid = domid;
gref_info->flags = writable ? GNTALLOC_FLAG_WRITABLE : 0;
gref_info->count = count;
err = ioctl(fd, IOCTL_GNTALLOC_ALLOC_GREF, gref_info);
if (err) {
PERROR("linux_gntshr_share_pages: ioctl failed");
goto out;
}
area = mmap(NULL, count * XC_PAGE_SIZE, PROT_READ | PROT_WRITE,
MAP_SHARED, fd, gref_info->index);
if (area == MAP_FAILED) {
area = NULL;
PERROR("linux_gntshr_share_pages: mmap failed");
goto out_remove_fdmap;
}
notify.index = gref_info->index;
notify.action = 0;
if (notify_offset < XC_PAGE_SIZE * count) {
notify.index += notify_offset;
notify.action |= UNMAP_NOTIFY_CLEAR_BYTE;
}
if (notify_port != -1) {
notify.event_channel_port = notify_port;
notify.action |= UNMAP_NOTIFY_SEND_EVENT;
}
if (notify.action)
err = ioctl(fd, IOCTL_GNTALLOC_SET_UNMAP_NOTIFY, &notify);
if (err) {
PERROR("linux_gntshr_share_page_notify: ioctl SET_UNMAP_NOTIFY failed");
munmap(area, count * XC_PAGE_SIZE);
area = NULL;
}
memcpy(refs, gref_info->gref_ids, count * sizeof(uint32_t));
out_remove_fdmap:
/* Removing the mapping from the file descriptor does not cause the pages to
* be deallocated until the mapping is removed.
*/
gref_drop.index = gref_info->index;
gref_drop.count = count;
ioctl(fd, IOCTL_GNTALLOC_DEALLOC_GREF, &gref_drop);
out:
free(gref_info);
return area;
}
static int linux_gntshr_munmap(xc_gntshr *xcg, xc_osdep_handle h,
void *start_address, uint32_t count)
{
return munmap(start_address, count);
}
static struct xc_osdep_ops linux_gntshr_ops = {
.open = &linux_gntshr_open,
.close = &linux_gntshr_close,
.u.gntshr = {
.share_pages = &linux_gntshr_share_pages,
.munmap = &linux_gntshr_munmap,
},
};
static struct xc_osdep_ops *linux_osdep_init(xc_interface *xch, enum xc_osdep_type type)
{
switch ( type )
{
case XC_OSDEP_PRIVCMD:
return &linux_privcmd_ops;
case XC_OSDEP_EVTCHN:
return &linux_evtchn_ops;
case XC_OSDEP_GNTTAB:
return &linux_gnttab_ops;
case XC_OSDEP_GNTSHR:
return &linux_gntshr_ops;
default:
return NULL;
}
}
xc_osdep_info_t xc_osdep_info = {
.name = "Linux Native OS interface",
.init = &linux_osdep_init,
.fake = 0,
};
/*
* Local variables:
* mode: C
* c-set-style: "BSD"
* c-basic-offset: 4
* tab-width: 4
* indent-tabs-mode: nil
* End:
*/
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