diff options
| author | Matthew Auld <matthew.auld@intel.com> | 2026-09-08 17:50:54 +0100 |
|---|---|---|
| committer | Matthew Auld <matthew.auld@intel.com> | 2026-09-09 10:57:10 +0100 |
| commit | 7cf85c190814c209cb182eaba39e184c1655faa9 (patch) | |
| tree | f20bb7181e6512f76406ba071473ccf1e2c1d7d8 | |
| parent | fb2ee38bab8025ad6a7a9cbb4635c5a178e4a7bc (diff) | |
| download | linux-next-7cf85c190814c209cb182eaba39e184c1655faa9.tar.gz linux-next-7cf85c190814c209cb182eaba39e184c1655faa9.zip | |
drm/xe/mmio_gem: reject VM_EXEC and drop VM_DONTCOPY
Hardware MMIO registers should never be executable; reject VM_EXEC
at mmap time and clear VM_MAYEXEC to prevent later mprotect attempts.
Also drop VM_DONTCOPY so that child processes across fork() can
inherit the mapping and lazily fault in the PFNs, matching standard
DRM GEM semantics and making the existing drm_gem_vm_open() callback
functional.
This aligns with existing PCI_BARRIER, which will use this in the next
patch. We don't want any noticeable behaviour change there, since this
will be user visible. This will also be the first user.
Assisted-by: LLM
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Tejas Upadhyay <tejas.upadhyay@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Ilia Levi <ilia.levi@intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Link: https://patch.msgid.link/20260908165046.1393557-17-matthew.auld@intel.com
| -rw-r--r-- | drivers/gpu/drm/xe/xe_mmio_gem.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/drivers/gpu/drm/xe/xe_mmio_gem.c b/drivers/gpu/drm/xe/xe_mmio_gem.c index 5ffe03d36190..3cdc9538957d 100644 --- a/drivers/gpu/drm/xe/xe_mmio_gem.c +++ b/drivers/gpu/drm/xe/xe_mmio_gem.c @@ -177,9 +177,12 @@ static int xe_mmio_gem_mmap(struct drm_gem_object *base, struct vm_area_struct * if ((vma->vm_flags & VM_SHARED) == 0) return -EINVAL; + if (vma->vm_flags & VM_EXEC) + return -EINVAL; + vma->vm_page_prot = pgprot_noncached(vma_get_page_prot(vma)); - vm_flags_set(vma, VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP | - VM_DONTCOPY | VM_NORESERVE); + vm_flags_mod(vma, VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP | + VM_NORESERVE, VM_MAYEXEC); /* Defer actual mapping to the fault handler. */ return 0; |