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Merge c3d0e3fd41 ("Merge tag 'fs.idmapped.mount_setattr.v5.13-rc3' of gitolite.kernel.org:pub/scm/linux/kernel/git/brauner/linux") into android-mainline

Browse Source 
Steps on the way to 5.13-rc3

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I1240b18093d92f7efa6eaa20096491589ad5d58b
This commit is contained in:
Greg Kroah-Hartman
2021-05-25 11:04:05 +02:00
parent 531d377ab8 c3d0e3fd41
commit 5e9b6fa9a4
2 changed files with 54 additions and 23 deletions
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71
drivers/gpu/drm/i915/i915_mm.c
View File

@@ -28,10 +28,46 @@
#include "i915_drv.h"
#define EXPECTED_FLAGS (VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP)
struct remap_pfn {
struct mm_struct *mm;
unsigned long pfn;
pgprot_t prot;
struct sgt_iter sgt;
resource_size_t iobase;
};
#define use_dma(io) ((io) != -1)
static inline unsigned long sgt_pfn(const struct remap_pfn *r)
{
if (use_dma(r->iobase))
return (r->sgt.dma + r->sgt.curr + r->iobase) >> PAGE_SHIFT;
else
return r->sgt.pfn + (r->sgt.curr >> PAGE_SHIFT);
}
static int remap_sg(pte_t *pte, unsigned long addr, void *data)
{
struct remap_pfn *r = data;
if (GEM_WARN_ON(!r->sgt.sgp))
return -EINVAL;
/* Special PTE are not associated with any struct page */
set_pte_at(r->mm, addr, pte,
pte_mkspecial(pfn_pte(sgt_pfn(r), r->prot)));
r->pfn++; /* track insertions in case we need to unwind later */
r->sgt.curr += PAGE_SIZE;
if (r->sgt.curr >= r->sgt.max)
r->sgt = __sgt_iter(__sg_next(r->sgt.sgp), use_dma(r->iobase));
return 0;
}
#define EXPECTED_FLAGS (VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP)
/**
* remap_io_sg - remap an IO mapping to userspace
* @vma: user vma to map to
@@ -46,7 +82,12 @@ int remap_io_sg(struct vm_area_struct *vma,
unsigned long addr, unsigned long size,
struct scatterlist *sgl, resource_size_t iobase)
{
unsigned long pfn, len, remapped = 0;
struct remap_pfn r = {
.mm = vma->vm_mm,
.prot = vma->vm_page_prot,
.sgt = __sgt_iter(sgl, use_dma(iobase)),
.iobase = iobase,
};
int err;
/* We rely on prevalidation of the io-mapping to skip track_pfn(). */
@@ -55,25 +96,11 @@ int remap_io_sg(struct vm_area_struct *vma,
if (!use_dma(iobase))
flush_cache_range(vma, addr, size);
do {
if (use_dma(iobase)) {
if (!sg_dma_len(sgl))
break;
pfn = (sg_dma_address(sgl) + iobase) >> PAGE_SHIFT;
len = sg_dma_len(sgl);
} else {
pfn = page_to_pfn(sg_page(sgl));
len = sgl->length;
}
err = apply_to_page_range(r.mm, addr, size, remap_sg, &r);
if (unlikely(err)) {
zap_vma_ptes(vma, addr, r.pfn << PAGE_SHIFT);
return err;
}
err = remap_pfn_range(vma, addr + remapped, pfn, len,
vma->vm_page_prot);
if (err)
break;
remapped += len;
} while ((sgl = __sg_next(sgl)));
if (err)
zap_vma_ptes(vma, addr, remapped);
return err;
return 0;
}

6
fs/namespace.c
View File

@@ -3855,8 +3855,12 @@ static int can_idmap_mount(const struct mount_kattr *kattr, struct mount *mnt)
if (!(m->mnt_sb->s_type->fs_flags & FS_ALLOW_IDMAP))
return -EINVAL;
/* Don't yet support filesystem mountable in user namespaces. */
if (m->mnt_sb->s_user_ns != &init_user_ns)
return -EINVAL;
/* We're not controlling the superblock. */
if (!ns_capable(m->mnt_sb->s_user_ns, CAP_SYS_ADMIN))
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
/* Mount has already been visible in the filesystem hierarchy. */