cregit-Linux how code gets into the kernel

Release 4.10 drivers/xen/gntdev.c

Directory: drivers/xen
/******************************************************************************
 * gntdev.c
 *
 * Device for accessing (in user-space) pages that have been granted by other
 * domains.
 *
 * Copyright (c) 2006-2007, D G Murray.
 *           (c) 2009 Gerd Hoffmann <kraxel@redhat.com>
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */


#undef DEBUG


#define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/miscdevice.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/mman.h>
#include <linux/mmu_notifier.h>
#include <linux/types.h>
#include <linux/uaccess.h>
#include <linux/sched.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <linux/highmem.h>

#include <xen/xen.h>
#include <xen/grant_table.h>
#include <xen/balloon.h>
#include <xen/gntdev.h>
#include <xen/events.h>
#include <xen/page.h>
#include <asm/xen/hypervisor.h>
#include <asm/xen/hypercall.h>

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Derek G. Murray <Derek.Murray@cl.cam.ac.uk>, "
	      "Gerd Hoffmann <kraxel@redhat.com>");
MODULE_DESCRIPTION("User-space granted page access driver");


static int limit = 1024*1024;
module_param(limit, int, 0644);
MODULE_PARM_DESC(limit, "Maximum number of grants that may be mapped by "
		"the gntdev device");


static atomic_t pages_mapped = ATOMIC_INIT(0);


static int use_ptemod;

#define populate_freeable_maps use_ptemod


struct gntdev_priv {
	/* maps with visible offsets in the file descriptor */
	
struct list_head maps;
	/* maps that are not visible; will be freed on munmap.
         * Only populated if populate_freeable_maps == 1 */
	
struct list_head freeable_maps;
	/* lock protects maps and freeable_maps */
	
struct mutex lock;
	
struct mm_struct *mm;
	
struct mmu_notifier mn;
};


struct unmap_notify {
	
int flags;
	/* Address relative to the start of the grant_map */
	
int addr;
	
int event;
};


struct grant_map {
	
struct list_head next;
	
struct vm_area_struct *vma;
	
int index;
	
int count;
	
int flags;
	
atomic_t users;
	
struct unmap_notify notify;
	
struct ioctl_gntdev_grant_ref *grants;
	
struct gnttab_map_grant_ref   *map_ops;
	
struct gnttab_unmap_grant_ref *unmap_ops;
	
struct gnttab_map_grant_ref   *kmap_ops;
	
struct gnttab_unmap_grant_ref *kunmap_ops;
	
struct page **pages;
	
unsigned long pages_vm_start;
};

static int unmap_grant_pages(struct grant_map *map, int offset, int pages);

/* ------------------------------------------------------------------ */


static void gntdev_print_maps(struct gntdev_priv *priv, char *text, int text_index) { #ifdef DEBUG struct grant_map *map; pr_debug("%s: maps list (priv %p)\n", __func__, priv); list_for_each_entry(map, &priv->maps, next) pr_debug(" index %2d, count %2d %s\n", map->index, map->count, map->index == text_index && text ? text : ""); #endif }

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daniel de graafdaniel de graaf22.86%150.00%
Total70100.00%2100.00%


static void gntdev_free_map(struct grant_map *map) { if (map == NULL) return; if (map->pages) gnttab_free_pages(map->count, map->pages); kfree(map->pages); kfree(map->grants); kfree(map->map_ops); kfree(map->unmap_ops); kfree(map->kmap_ops); kfree(map->kunmap_ops); kfree(map); }

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static struct grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count) { struct grant_map *add; int i; add = kzalloc(sizeof(struct grant_map), GFP_KERNEL); if (NULL == add) return NULL; add->grants = kcalloc(count, sizeof(add->grants[0]), GFP_KERNEL); add->map_ops = kcalloc(count, sizeof(add->map_ops[0]), GFP_KERNEL); add->unmap_ops = kcalloc(count, sizeof(add->unmap_ops[0]), GFP_KERNEL); add->kmap_ops = kcalloc(count, sizeof(add->kmap_ops[0]), GFP_KERNEL); add->kunmap_ops = kcalloc(count, sizeof(add->kunmap_ops[0]), GFP_KERNEL); add->pages = kcalloc(count, sizeof(add->pages[0]), GFP_KERNEL); if (NULL == add->grants || NULL == add->map_ops || NULL == add->unmap_ops || NULL == add->kmap_ops || NULL == add->kunmap_ops || NULL == add->pages) goto err; if (gnttab_alloc_pages(count, add->pages)) goto err; for (i = 0; i < count; i++) { add->map_ops[i].handle = -1; add->unmap_ops[i].handle = -1; add->kmap_ops[i].handle = -1; add->kunmap_ops[i].handle = -1; } add->index = 0; add->count = count; atomic_set(&add->users, 1); return add; err: gntdev_free_map(add); return NULL; }

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gerd hoffmanngerd hoffmann14143.38%110.00%
stefano stabellinistefano stabellini8626.46%220.00%
daniel de graafdaniel de graaf4212.92%330.00%
david vrabeldavid vrabel4112.62%330.00%
dan carpenterdan carpenter154.62%110.00%
Total325100.00%10100.00%


static void gntdev_add_map(struct gntdev_priv *priv, struct grant_map *add) { struct grant_map *map; list_for_each_entry(map, &priv->maps, next) { if (add->index + add->count < map->index) { list_add_tail(&add->next, &map->next); goto done; } add->index = map->index + map->count; } list_add_tail(&add->next, &priv->maps); done: gntdev_print_maps(priv, "[new]", add->index); }

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static struct grant_map *gntdev_find_map_index(struct gntdev_priv *priv, int index, int count) { struct grant_map *map; list_for_each_entry(map, &priv->maps, next) { if (map->index != index) continue; if (count && map->count != count) continue; return map; } return NULL; }

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gerd hoffmanngerd hoffmann5896.67%150.00%
daniel de graafdaniel de graaf23.33%150.00%
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static void gntdev_put_map(struct gntdev_priv *priv, struct grant_map *map) { if (!map) return; if (!atomic_dec_and_test(&map->users)) return; atomic_sub(map->count, &pages_mapped); if (map->notify.flags & UNMAP_NOTIFY_SEND_EVENT) { notify_remote_via_evtchn(map->notify.event); evtchn_put(map->notify.event); } if (populate_freeable_maps && priv) { mutex_lock(&priv->lock); list_del(&map->next); mutex_unlock(&priv->lock); } if (map->pages && !use_ptemod) unmap_grant_pages(map, 0, map->count); gntdev_free_map(map); }

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daniel de graafdaniel de graaf9673.28%660.00%
gerd hoffmanngerd hoffmann2619.85%110.00%
stefano stabellinistefano stabellini53.82%110.00%
david vrabeldavid vrabel43.05%220.00%
Total131100.00%10100.00%

/* ------------------------------------------------------------------ */
static int find_grant_ptes(pte_t *pte, pgtable_t token, unsigned long addr, void *data) { struct grant_map *map = data; unsigned int pgnr = (addr - map->vma->vm_start) >> PAGE_SHIFT; int flags = map->flags | GNTMAP_application_map | GNTMAP_contains_pte; u64 pte_maddr; BUG_ON(pgnr >= map->count); pte_maddr = arbitrary_virt_to_machine(pte).maddr; /* * Set the PTE as special to force get_user_pages_fast() fall * back to the slow path. If this is not supported as part of * the grant map, it will be done afterwards. */ if (xen_feature(XENFEAT_gnttab_map_avail_bits)) flags |= (1 << _GNTMAP_guest_avail0); gnttab_set_map_op(&map->map_ops[pgnr], pte_maddr, flags, map->grants[pgnr].ref, map->grants[pgnr].domid); gnttab_set_unmap_op(&map->unmap_ops[pgnr], pte_maddr, flags, -1 /* handle */); return 0; }

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gerd hoffmanngerd hoffmann11477.55%120.00%
david vrabeldavid vrabel1610.88%120.00%
daniel de graafdaniel de graaf138.84%240.00%
jeremy fitzhardingejeremy fitzhardinge42.72%120.00%
Total147100.00%5100.00%

#ifdef CONFIG_X86
static int set_grant_ptes_as_special(pte_t *pte, pgtable_t token, unsigned long addr, void *data) { set_pte_at(current->mm, addr, pte, pte_mkspecial(*pte)); return 0; }

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#endif
static int map_grant_pages(struct grant_map *map) { int i, err = 0; if (!use_ptemod) { /* Note: it could already be mapped */ if (map->map_ops[0].handle != -1) return 0; for (i = 0; i < map->count; i++) { unsigned long addr = (unsigned long) pfn_to_kaddr(page_to_pfn(map->pages[i])); gnttab_set_map_op(&map->map_ops[i], addr, map->flags, map->grants[i].ref, map->grants[i].domid); gnttab_set_unmap_op(&map->unmap_ops[i], addr, map->flags, -1 /* handle */); } } else { /* * Setup the map_ops corresponding to the pte entries pointing * to the kernel linear addresses of the struct pages. * These ptes are completely different from the user ptes dealt * with find_grant_ptes. */ for (i = 0; i < map->count; i++) { unsigned long address = (unsigned long) pfn_to_kaddr(page_to_pfn(map->pages[i])); BUG_ON(PageHighMem(map->pages[i])); gnttab_set_map_op(&map->kmap_ops[i], address, map->flags | GNTMAP_host_map, map->grants[i].ref, map->grants[i].domid); gnttab_set_unmap_op(&map->kunmap_ops[i], address, map->flags | GNTMAP_host_map, -1); } } pr_debug("map %d+%d\n", map->index, map->count); err = gnttab_map_refs(map->map_ops, use_ptemod ? map->kmap_ops : NULL, map->pages, map->count); if (err) return err; for (i = 0; i < map->count; i++) { if (map->map_ops[i].status) { err = -EINVAL; continue; } map->unmap_ops[i].handle = map->map_ops[i].handle; if (use_ptemod) map->kunmap_ops[i].handle = map->kmap_ops[i].handle; } return err; }

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daniel de graafdaniel de graaf12934.40%330.00%
stefano stabellinistefano stabellini10427.73%330.00%
gerd hoffmanngerd hoffmann9926.40%110.00%
david vrabeldavid vrabel369.60%110.00%
ian campbellian campbell61.60%110.00%
konrad rzeszutek wilkkonrad rzeszutek wilk10.27%110.00%
Total375100.00%10100.00%


static int __unmap_grant_pages(struct grant_map *map, int offset, int pages) { int i, err = 0; struct gntab_unmap_queue_data unmap_data; if (map->notify.flags & UNMAP_NOTIFY_CLEAR_BYTE) { int pgno = (map->notify.addr >> PAGE_SHIFT); if (pgno >= offset && pgno < offset + pages) { /* No need for kmap, pages are in lowmem */ uint8_t *tmp = pfn_to_kaddr(page_to_pfn(map->pages[pgno])); tmp[map->notify.addr & (PAGE_SIZE-1)] = 0; map->notify.flags &= ~UNMAP_NOTIFY_CLEAR_BYTE; } } unmap_data.unmap_ops = map->unmap_ops + offset; unmap_data.kunmap_ops = use_ptemod ? map->kunmap_ops + offset : NULL; unmap_data.pages = map->pages + offset; unmap_data.count = pages; err = gnttab_unmap_refs_sync(&unmap_data); if (err) return err; for (i = 0; i < pages; i++) { if (map->unmap_ops[offset+i].status) err = -EINVAL; pr_debug("unmap handle=%d st=%d\n", map->unmap_ops[offset+i].handle, map->unmap_ops[offset+i].status); map->unmap_ops[offset+i].handle = -1; } return err; }

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daniel de graafdaniel de graaf11547.33%545.45%
gerd hoffmanngerd hoffmann8334.16%19.09%
jennifer herbertjennifer herbert2811.52%19.09%
stefano stabellinistefano stabellini114.53%218.18%
bob liubob liu52.06%19.09%
david vrabeldavid vrabel10.41%19.09%
Total243100.00%11100.00%


static int unmap_grant_pages(struct grant_map *map, int offset, int pages) { int range, err = 0; pr_debug("unmap %d+%d [%d+%d]\n", map->index, map->count, offset, pages); /* It is possible the requested range will have a "hole" where we * already unmapped some of the grants. Only unmap valid ranges. */ while (pages && !err) { while (pages && map->unmap_ops[offset].handle == -1) { offset++; pages--; } range = 0; while (range < pages) { if (map->unmap_ops[offset+range].handle == -1) { range--; break; } range++; } err = __unmap_grant_pages(map, offset, range); offset += range; pages -= range; } return err; }

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daniel de graafdaniel de graaf134100.00%2100.00%
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/* ------------------------------------------------------------------ */
static void gntdev_vma_open(struct vm_area_struct *vma) { struct grant_map *map = vma->vm_private_data; pr_debug("gntdev_vma_open %p\n", vma); atomic_inc(&map->users); }

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daniel de graafdaniel de graaf35100.00%1100.00%
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static void gntdev_vma_close(struct vm_area_struct *vma) { struct grant_map *map = vma->vm_private_data; struct file *file = vma->vm_file; struct gntdev_priv *priv = file->private_data; pr_debug("gntdev_vma_close %p\n", vma); if (use_ptemod) { /* It is possible that an mmu notifier could be running * concurrently, so take priv->lock to ensure that the vma won't * vanishing during the unmap_grant_pages call, since we will * spin here until that completes. Such a concurrent call will * not do any unmapping, since that has been done prior to * closing the vma, but it may still iterate the unmap_ops list. */ mutex_lock(&priv->lock); map->vma = NULL; mutex_unlock(&priv->lock); } vma->vm_private_data = NULL; gntdev_put_map(priv, map); }

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david vrabeldavid vrabel22.30%120.00%
Total87100.00%5100.00%


static struct page *gntdev_vma_find_special_page(struct vm_area_struct *vma, unsigned long addr) { struct grant_map *map = vma->vm_private_data; return map->pages[(addr - map->pages_vm_start) >> PAGE_SHIFT]; }

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static const struct vm_operations_struct gntdev_vmops = { .open = gntdev_vma_open, .close = gntdev_vma_close, .find_special_page = gntdev_vma_find_special_page, }; /* ------------------------------------------------------------------ */
static void unmap_if_in_range(struct grant_map *map, unsigned long start, unsigned long end) { unsigned long mstart, mend; int err; if (!map->vma) return; if (map->vma->vm_start >= end) return; if (map->vma->vm_end <= start) return; mstart = max(start, map->vma->vm_start); mend = min(end, map->vma->vm_end); pr_debug("map %d+%d (%lx %lx), range %lx %lx, mrange %lx %lx\n", map->index, map->count, map->vma->vm_start, map->vma->vm_end, start, end, mstart, mend); err = unmap_grant_pages(map, (mstart - map->vma->vm_start) >> PAGE_SHIFT, (mend - mstart) >> PAGE_SHIFT); WARN_ON(err); }

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gerd hoffmanngerd hoffmann14395.97%150.00%
daniel de graafdaniel de graaf64.03%150.00%
Total149100.00%2100.00%


static void mn_invl_range_start(struct mmu_notifier *mn, struct mm_struct *mm, unsigned long start, unsigned long end) { struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn); struct grant_map *map; mutex_lock(&priv->lock); list_for_each_entry(map, &priv->maps, next) { unmap_if_in_range(map, start, end); } list_for_each_entry(map, &priv->freeable_maps, next) { unmap_if_in_range(map, start, end); } mutex_unlock(&priv->lock); }

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daniel de graafdaniel de graaf8889.80%133.33%
gerd hoffmanngerd hoffmann88.16%133.33%
david vrabeldavid vrabel22.04%133.33%
Total98100.00%3100.00%


static void mn_invl_page(struct mmu_notifier *mn, struct mm_struct *mm, unsigned long address) { mn_invl_range_start(mn, mm, address, address + PAGE_SIZE); }

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static void mn_release(struct mmu_notifier *mn, struct mm_struct *mm) { struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn); struct grant_map *map; int err; mutex_lock(&priv->lock); list_for_each_entry(map, &priv->maps, next) { if (!map->vma) continue; pr_debug("map %d+%d (%lx %lx)\n", map->index, map->count, map->vma->vm_start, map->vma->vm_end); err = unmap_grant_pages(map, /* offset */ 0, map->count); WARN_ON(err); } list_for_each_entry(map, &priv->freeable_maps, next) { if (!map->vma) continue; pr_debug("map %d+%d (%lx %lx)\n", map->index, map->count, map->vma->vm_start, map->vma->vm_end); err = unmap_grant_pages(map, /* offset */ 0, map->count); WARN_ON(err); } mutex_unlock(&priv->lock); }

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gerd hoffmanngerd hoffmann11564.25%133.33%
daniel de graafdaniel de graaf6234.64%133.33%
david vrabeldavid vrabel21.12%133.33%
Total179100.00%3100.00%

static const struct mmu_notifier_ops gntdev_mmu_ops = { .release = mn_release, .invalidate_page = mn_invl_page, .invalidate_range_start = mn_invl_range_start, }; /* ------------------------------------------------------------------ */
static int gntdev_open(struct inode *inode, struct file *flip) { struct gntdev_priv *priv; int ret = 0; priv = kzalloc(sizeof(*priv), GFP_KERNEL); if (!priv) return -ENOMEM; INIT_LIST_HEAD(&priv->maps); INIT_LIST_HEAD(&priv->freeable_maps); mutex_init(&priv->lock); if (use_ptemod) { priv->mm = get_task_mm(current); if (!priv->mm) { kfree(priv); return -ENOMEM; } priv->mn.ops = &gntdev_mmu_ops; ret = mmu_notifier_register(&priv->mn, priv->mm); mmput(priv->mm); } if (ret) { kfree(priv); return ret; } flip->private_data = priv; pr_debug("priv %p\n", priv); return 0; }

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gerd hoffmanngerd hoffmann15090.91%125.00%
daniel de graafdaniel de graaf148.48%250.00%
david vrabeldavid vrabel10.61%125.00%
Total165100.00%4100.00%


static int gntdev_release(struct inode *inode, struct file *flip) { struct gntdev_priv *priv = flip->private_data; struct grant_map *map; pr_debug("priv %p\n", priv); mutex_lock(&priv->lock); while (!list_empty(&priv->maps)) { map = list_entry(priv->maps.next, struct grant_map, next); list_del(&map->next); gntdev_put_map(NULL /* already removed */, map); } WARN_ON(!list_empty(&priv->freeable_maps)); mutex_unlock(&priv->lock); if (use_ptemod) mmu_notifier_unregister(&priv->mn, priv->mm); kfree(priv); return 0; }

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gerd hoffmanngerd hoffmann9470.15%120.00%
daniel de graafdaniel de graaf2417.91%360.00%
marek marczykowskimarek marczykowski1611.94%120.00%
Total134100.00%5100.00%


static long gntdev_ioctl_map_grant_ref(struct gntdev_priv *priv, struct ioctl_gntdev_map_grant_ref __user *u) { struct ioctl_gntdev_map_grant_ref op; struct grant_map *map; int err; if (copy_from_user(&op, u, sizeof(op)) != 0) return -EFAULT; pr_debug("priv %p, add %d\n", priv, op.count); if (unlikely(op.count <= 0)) return -EINVAL; err = -ENOMEM; map = gntdev_alloc_map(priv, op.count); if (!map) return err; if (unlikely(atomic_add_return(op.count, &pages_mapped) > limit)) { pr_debug("can't map: over limit\n"); gntdev_put_map(NULL, map); return err; } if (copy_from_user(map->grants, &u->refs, sizeof(map->grants[0]) * op.count) != 0) { gntdev_put_map(NULL, map); return -EFAULT; } mutex_lock(&priv->lock); gntdev_add_map(priv, map); op.index = map->index << PAGE_SHIFT; mutex_unlock(&priv->lock); if (copy_to_user(u, &op, sizeof(op)) != 0) return -EFAULT; return 0; }

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gerd hoffmanngerd hoffmann18478.63%120.00%
daniel de graafdaniel de graaf4820.51%360.00%
david vrabeldavid vrabel20.85%120.00%
Total234100.00%5100.00%


static long gntdev_ioctl_unmap_grant_ref(struct gntdev_priv *priv, struct ioctl_gntdev_unmap_grant_ref __user *u) { struct ioctl_gntdev_unmap_grant_ref op; struct grant_map *map; int err = -ENOENT; if (copy_from_user(&op, u, sizeof(op)) != 0) return -EFAULT; pr_debug("priv %p, del %d+%d\n", priv, (int)op.index, (int)op.count); mutex_lock(&priv->lock); map = gntdev_find_map_index(priv, op.index >> PAGE_SHIFT, op.count); if (map) { list_del(&map->next); if (populate_freeable_maps) list_add_tail(&map->next, &priv->freeable_maps); err = 0; } mutex_unlock(&priv->lock); if (map) gntdev_put_map(priv, map); return err; }

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gerd hoffmanngerd hoffmann11271.79%120.00%
daniel de graafdaniel de graaf4226.92%360.00%
david vrabeldavid vrabel21.28%120.00%
Total156100.00%5100.00%


static long gntdev_ioctl_get_offset_for_vaddr(struct gntdev_priv *priv, struct ioctl_gntdev_get_offset_for_vaddr __user *u) { struct ioctl_gntdev_get_offset_for_vaddr op; struct vm_area_struct *vma; struct grant_map *map; int rv = -EINVAL; if (copy_from_user(&op, u, sizeof(op)) != 0) return -EFAULT; pr_debug("priv %p, offset for vaddr %lx\n", priv, (unsigned long)op.vaddr); down_read(&current->mm->mmap_sem); vma = find_vma(current->mm, op.vaddr); if (!vma || vma->vm_ops != &gntdev_vmops) goto out_unlock; map = vma->vm_private_data; if (!map) goto out_unlock; op.offset = map->index << PAGE_SHIFT; op.count = map->count; rv = 0; out_unlock: up_read(&current->mm->mmap_sem); if (rv == 0 && copy_to_user(u, &op, sizeof(op)) != 0) return -EFAULT; return rv; }

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gerd hoffmanngerd hoffmann12064.17%133.33%
daniel de graafdaniel de graaf6735.83%266.67%
Total187100.00%3100.00%


static long gntdev_ioctl_notify(struct gntdev_priv *priv, void __user *u) { struct ioctl_gntdev_unmap_notify op; struct grant_map *map; int rc; int out_flags; unsigned int out_event; if (copy_from_user(&op, u, sizeof(op))) return -EFAULT; if (op.action & ~(UNMAP_NOTIFY_CLEAR_BYTE|UNMAP_NOTIFY_SEND_EVENT)) return -EINVAL; /* We need to grab a reference to the event channel we are going to use * to send the notify before releasing the reference we may already have * (if someone has called this ioctl twice). This is required so that * it is possible to change the clear_byte part of the notification * without disturbing the event channel part, which may now be the last * reference to that event channel. */ if (op.action & UNMAP_NOTIFY_SEND_EVENT) { if (evtchn_get(op.event_channel_port)) return -EINVAL; } out_flags = op.action; out_event = op.event_channel_port; mutex_lock(&priv->lock); list_for_each_entry(map, &priv->maps, next) { uint64_t begin = map->index << PAGE_SHIFT; uint64_t end = (map->index + map->count) << PAGE_SHIFT; if (op.index >= begin && op.index < end) goto found; } rc = -ENOENT; goto unlock_out; found: if ((op.action & UNMAP_NOTIFY_CLEAR_BYTE) && (map->flags & GNTMAP_readonly)) { rc = -EINVAL; goto unlock_out; } out_flags = map->notify.flags; out_event = map->notify.event; map->notify.flags = op.action; map->notify.addr = op.index - (map->index << PAGE_SHIFT); map->notify.event = op.event_channel_port; rc = 0; unlock_out: mutex_unlock(&priv->lock); /* Drop the reference to the event channel we did not save in the map */ if (out_flags & UNMAP_NOTIFY_SEND_EVENT) evtchn_put(out_event); return rc; }

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PersonTokensPropCommitsCommitProp
daniel de graafdaniel de graaf28599.30%375.00%
david vrabeldavid vrabel20.70%125.00%
Total287100.00%4100.00%

#define GNTDEV_COPY_BATCH 16 struct gntdev_copy_batch { struct gnttab_copy ops[GNTDEV_COPY_BATCH]; struct page *pages[GNTDEV_COPY_BATCH]; s16 __user *status[GNTDEV_COPY_BATCH]; unsigned int nr_ops; unsigned int nr_pages; };
static int gntdev_get_page(struct gntdev_copy_batch *batch, void __user *virt, bool writeable, unsigned long *gfn) { unsigned long addr = (unsigned long)virt; struct page *page; unsigned long xen_pfn; int ret; ret = get_user_pages_fast(addr, 1, writeable, &page); if (ret < 0) return ret; batch->pages[batch->nr_pages++] = page; xen_pfn = page_to_xen_pfn(page) + XEN_PFN_DOWN(addr & ~PAGE_MASK); *gfn = pfn_to_gfn(xen_pfn); return 0; }

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PersonTokensPropCommitsCommitProp
david vrabeldavid vrabel107100.00%1100.00%
Total107100.00%1100.00%


static void gntdev_put_pages(struct gntdev_copy_batch *batch) { unsigned int i; for (i = 0; i < batch->nr_pages; i++) put_page(batch->pages[i]); batch->nr_pages = 0; }

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david vrabeldavid vrabel46100.00%1100.00%
Total46100.00%1100.00%


static int gntdev_copy(struct gntdev_copy_batch *batch) { unsigned int i; gnttab_batch_copy(batch->ops, batch->nr_ops); gntdev_put_pages(batch); /* * For each completed op, update the status if the op failed * and all previous ops for the segment were successful. */ for (i = 0; i < batch->nr_ops; i++) { s16 status = batch->ops[i].status; s16 old_status; if (status == GNTST_okay) continue; if (__get_user(old_status, batch->status[i])) return -EFAULT; if (old_status != GNTST_okay) continue; if (__put_user(status, batch->status[i])) return -EFAULT; } batch->nr_ops = 0; return 0; }

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PersonTokensPropCommitsCommitProp
david vrabeldavid vrabel123100.00%1100.00%
Total123100.00%1100.00%


static int gntdev_grant_copy_seg(struct gntdev_copy_batch *batch, struct gntdev_grant_copy_segment *seg, s16 __user *status) { uint16_t copied = 0; /* * Disallow local -> local copies since there is only space in * batch->pages for one page per-op and this would be a very * expensive memcpy(). */ if (!(seg->flags & (GNTCOPY_source_gref | GNTCOPY_dest_gref))) return -EINVAL; /* Can't cross page if source/dest is a grant ref. */ if (seg->flags & GNTCOPY_source_gref) { if (seg->source.foreign.offset + seg->len > XEN_PAGE_SIZE) return -EINVAL; } if (seg->flags & GNTCOPY_dest_gref) { if (seg->dest.foreign.offset + seg->len > XEN_PAGE_SIZE) return -EINVAL; } if (put_user(GNTST_okay, status)) return -EFAULT; while (copied < seg->len) { struct gnttab_copy *op; void __user *virt; size_t len, off; unsigned long gfn; int ret; if (batch->nr_ops >= GNTDEV_COPY_BATCH) { ret = gntdev_copy(batch); if (ret < 0) return ret; } len = seg->len - copied; op = &batch->ops[batch->nr_ops]; op->flags = 0; if (seg->flags & GNTCOPY_source_gref) { op->source.u.ref = seg->source.foreign.ref; op->source.domid = seg->source.foreign.domid; op->source.offset = seg->source.foreign.offset + copied; op->flags |= GNTCOPY_source_gref; } else { virt = seg->source.virt + copied; off = (unsigned long)virt & ~XEN_PAGE_MASK; len = min(len, (size_t)XEN_PAGE_SIZE - off); ret = gntdev_get_page(batch, virt, false, &gfn); if (ret < 0) return ret; op->source.u.gmfn = gfn; op->source.domid = DOMID_SELF; op->source.offset = off; } if (seg->flags & GNTCOPY_dest_gref) { op->dest.u.ref = seg->dest.foreign.ref; op->dest.domid = seg->dest.foreign.domid; op->dest.offset = seg->dest.foreign.offset + copied; op->flags |= GNTCOPY_dest_gref; } else { virt = seg->dest.virt + copied; off = (unsigned long)virt & ~XEN_PAGE_MASK; len = min(len, (size_t)XEN_PAGE_SIZE - off); ret = gntdev_get_page(batch, virt, true, &gfn); if (ret < 0) return ret; op->dest.u.gmfn = gfn; op->dest.domid = DOMID_SELF; op->dest.offset = off; } op->len = len; copied += len; batch->status[batch->nr_ops] = status; batch->nr_ops++; } return 0; }

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david vrabeldavid vrabel531100.00%1100.00%
Total531100.00%1100.00%


static long gntdev_ioctl_grant_copy(struct gntdev_priv *priv, void __user *u) { struct ioctl_gntdev_grant_copy copy; struct gntdev_copy_batch batch; unsigned int i; int ret = 0; if (copy_from_user(&copy, u, sizeof(copy))) return -EFAULT; batch.nr_ops = 0; batch.nr_pages = 0; for (i = 0; i < copy.count; i++) { struct gntdev_grant_copy_segment seg; if (copy_from_user(&seg, &copy.segments[i], sizeof(seg))) { ret = -EFAULT; goto out; } ret = gntdev_grant_copy_seg(&batch, &seg, &copy.segments[i].status); if (ret < 0) goto out; cond_resched(); } if (batch.nr_ops) ret = gntdev_copy(&batch); return ret; out: gntdev_put_pages(&batch); return ret; }

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david vrabeldavid vrabel177100.00%1100.00%
Total177100.00%1100.00%


static long gntdev_ioctl(struct file *flip, unsigned int cmd, unsigned long arg) { struct gntdev_priv *priv = flip->private_data; void __user *ptr = (void __user *)arg; switch (cmd) { case IOCTL_GNTDEV_MAP_GRANT_REF: return gntdev_ioctl_map_grant_ref(priv, ptr); case IOCTL_GNTDEV_UNMAP_GRANT_REF: return gntdev_ioctl_unmap_grant_ref(priv, ptr); case IOCTL_GNTDEV_GET_OFFSET_FOR_VADDR: return gntdev_ioctl_get_offset_for_vaddr(priv, ptr); case IOCTL_GNTDEV_SET_UNMAP_NOTIFY: return gntdev_ioctl_notify(priv, ptr); case IOCTL_GNTDEV_GRANT_COPY: return gntdev_ioctl_grant_copy(priv, ptr); default: pr_debug("priv %p, unknown cmd %x\n", priv, cmd); return -ENOIOCTLCMD; } return 0; }

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gerd hoffmanngerd hoffmann9681.36%133.33%
david vrabeldavid vrabel119.32%133.33%
daniel de graafdaniel de graaf119.32%133.33%
Total118100.00%3100.00%


static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma) { struct gntdev_priv *priv = flip->private_data; int index = vma->vm_pgoff; int count = vma_pages(vma); struct grant_map *map; int i, err = -EINVAL; if ((vma->vm_flags & VM_WRITE) && !(vma->vm_flags & VM_SHARED)) return -EINVAL; pr_debug("map %d+%d at %lx (pgoff %lx)\n", index, count, vma->vm_start, vma->vm_pgoff); mutex_lock(&priv->lock); map = gntdev_find_map_index(priv, index, count); if (!map) goto unlock_out; if (use_ptemod && map->vma) goto unlock_out; if (use_ptemod && priv->mm != vma->vm_mm) { pr_warn("Huh? Other mm?\n"); goto unlock_out; } atomic_inc(&map->users); vma->vm_ops = &gntdev_vmops; vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP | VM_MIXEDMAP; if (use_ptemod) vma->vm_flags |= VM_DONTCOPY; vma->vm_private_data = map; if (use_ptemod) map->vma = vma; if (map->flags) { if ((vma->vm_flags & VM_WRITE) && (map->flags & GNTMAP_readonly)) goto out_unlock_put; } else { map->flags = GNTMAP_host_map; if (!(vma->vm_flags & VM_WRITE)) map->flags |= GNTMAP_readonly; } mutex_unlock(&priv->lock); if (use_ptemod) { err = apply_to_page_range(vma->vm_mm, vma->vm_start, vma->vm_end - vma->vm_start, find_grant_ptes, map); if (err) { pr_warn("find_grant_ptes() failure.\n"); goto out_put_map; } } err = map_grant_pages(map); if (err) goto out_put_map; if (!use_ptemod) { for (i = 0; i < count; i++) { err = vm_insert_page(vma, vma->vm_start + i*PAGE_SIZE, map->pages[i]); if (err) goto out_put_map; } } else { #ifdef CONFIG_X86 /* * If the PTEs were not made special by the grant map * hypercall, do so here. * * This is racy since the mapping is already visible * to userspace but userspace should be well-behaved * enough to not touch it until the mmap() call * returns. */ if (!xen_feature(XENFEAT_gnttab_map_avail_bits)) { apply_to_page_range(vma->vm_mm, vma->vm_start, vma->vm_end - vma->vm_start, set_grant_ptes_as_special, NULL); } #endif map->pages_vm_start = vma->vm_start; } return 0; unlock_out: mutex_unlock(&priv->lock); return err; out_unlock_put: mutex_unlock(&priv->lock); out_put_map: if (use_ptemod) map->vma = NULL; gntdev_put_map(priv, map); return err; }

Contributors

PersonTokensPropCommitsCommitProp
gerd hoffmanngerd hoffmann24852.21%15.56%
daniel de graafdaniel de graaf15232.00%844.44%
david vrabeldavid vrabel5411.37%316.67%
dan carpenterdan carpenter122.53%15.56%
muhammad falak r wanimuhammad falak r wani30.63%15.56%
boris ostrovskyboris ostrovsky20.42%211.11%
joe perchesjoe perches20.42%15.56%
konstantin khlebnikovkonstantin khlebnikov20.42%15.56%
Total475100.00%18100.00%

static const struct file_operations gntdev_fops = { .owner = THIS_MODULE, .open = gntdev_open, .release = gntdev_release, .mmap = gntdev_mmap, .unlocked_ioctl = gntdev_ioctl }; static struct miscdevice gntdev_miscdev = { .minor = MISC_DYNAMIC_MINOR, .name = "xen/gntdev", .fops = &gntdev_fops, }; /* ------------------------------------------------------------------ */
static int __init gntdev_init(void) { int err; if (!xen_domain()) return -ENODEV; use_ptemod = !xen_feature(XENFEAT_auto_translated_physmap); err = misc_register(&gntdev_miscdev); if (err != 0) { pr_err("Could not register gntdev device\n"); return err; } return 0; }

Contributors

PersonTokensPropCommitsCommitProp
gerd hoffmanngerd hoffmann4884.21%125.00%
konrad rzeszutek wilkkonrad rzeszutek wilk58.77%125.00%
daniel de graafdaniel de graaf35.26%125.00%
joe perchesjoe perches11.75%125.00%
Total57100.00%4100.00%


static void __exit gntdev_exit(void) { misc_deregister(&gntdev_miscdev); }

Contributors

PersonTokensPropCommitsCommitProp
gerd hoffmanngerd hoffmann15100.00%1100.00%
Total15100.00%1100.00%

module_init(gntdev_init); module_exit(gntdev_exit); /* ------------------------------------------------------------------ */

Overall Contributors

PersonTokensPropCommitsCommitProp
gerd hoffmanngerd hoffmann234742.15%11.96%
daniel de graafdaniel de graaf150326.99%2039.22%
david vrabeldavid vrabel138624.89%815.69%
stefano stabellinistefano stabellini2173.90%47.84%
jennifer herbertjennifer herbert280.50%11.96%
dan carpenterdan carpenter270.48%23.92%
marek marczykowskimarek marczykowski160.29%11.96%
joe perchesjoe perches100.18%11.96%
konrad rzeszutek wilkkonrad rzeszutek wilk70.13%35.88%
ian campbellian campbell60.11%11.96%
bob liubob liu50.09%11.96%
jeremy fitzhardingejeremy fitzhardinge40.07%11.96%
julien gralljulien grall30.05%11.96%
muhammad falak r wanimuhammad falak r wani30.05%11.96%
boris ostrovskyboris ostrovsky20.04%23.92%
konstantin khlebnikovkonstantin khlebnikov20.04%11.96%
kirill a. shutemovkirill a. shutemov10.02%11.96%
julia lawalljulia lawall10.02%11.96%
Total5568100.00%51100.00%
Directory: drivers/xen
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