This is a note to let you know that I've just added the patch titled
virt: acrn: stop using follow_pfn
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
virt-acrn-stop-using-follow_pfn.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 3573ef75e001e95fdc0b0cc28e69267f6abc26d7
Author: Christoph Hellwig <hch@xxxxxx>
Date: Mon Mar 25 07:45:40 2024 +0800
virt: acrn: stop using follow_pfn
[ Upstream commit 1b265da7ea1e1ae997fa119c2846bb389eb39c6b ]
Patch series "remove follow_pfn".
This series open codes follow_pfn in the only remaining caller, although
the code there remains questionable. It then also moves follow_phys into
the only user and simplifies it a bit.
This patch (of 3):
Switch from follow_pfn to follow_pte so that we can get rid of follow_pfn.
Note that this doesn't fix any of the pre-existing raciness and lack of
permission checking in the code.
Link: https://lkml.kernel.org/r/20240324234542.2038726-1-hch@xxxxxx
Link: https://lkml.kernel.org/r/20240324234542.2038726-2-hch@xxxxxx
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: Fei Li <fei1.li@xxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Stable-dep-of: 3d6586008f7b ("drivers/virt/acrn: fix PFNMAP PTE checks in acrn_vm_ram_map()")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/virt/acrn/mm.c b/drivers/virt/acrn/mm.c
index b4ad8d452e9a1..ffc1d1136f765 100644
--- a/drivers/virt/acrn/mm.c
+++ b/drivers/virt/acrn/mm.c
@@ -171,18 +171,24 @@ int acrn_vm_ram_map(struct acrn_vm *vm, struct acrn_vm_memmap *memmap)
mmap_read_lock(current->mm);
vma = vma_lookup(current->mm, memmap->vma_base);
if (vma && ((vma->vm_flags & VM_PFNMAP) != 0)) {
+ spinlock_t *ptl;
+ pte_t *ptep;
+
if ((memmap->vma_base + memmap->len) > vma->vm_end) {
mmap_read_unlock(current->mm);
return -EINVAL;
}
- ret = follow_pfn(vma, memmap->vma_base, &pfn);
- mmap_read_unlock(current->mm);
+ ret = follow_pte(vma->vm_mm, memmap->vma_base, &ptep, &ptl);
if (ret < 0) {
+ mmap_read_unlock(current->mm);
dev_dbg(acrn_dev.this_device,
"Failed to lookup PFN at VMA:%pK.\n", (void *)memmap->vma_base);
return ret;
}
+ pfn = pte_pfn(ptep_get(ptep));
+ pte_unmap_unlock(ptep, ptl);
+ mmap_read_unlock(current->mm);
return acrn_mm_region_add(vm, memmap->user_vm_pa,
PFN_PHYS(pfn), memmap->len,
