The patch titled
Subject: mm: fix BUG_ON() in vmf_insert_pfn_pud() from VM_MIXEDMAP removal
has been added to the -mm tree. Its filename is
mm-fix-bug_on-in-vmf_insert_pfn_pud-from-vm_mixedmap-removal.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-fix-bug_on-in-vmf_insert_pfn_pud-from-vm_mixedmap-removal.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-fix-bug_on-in-vmf_insert_pfn_pud-from-vm_mixedmap-removal.patch
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------------------------------------------------------
From: Dave Jiang <dave.jiang@xxxxxxxxx>
Subject: mm: fix BUG_ON() in vmf_insert_pfn_pud() from VM_MIXEDMAP removal
It looks like I missed the PUD path when doing VM_MIXEDMAP removal.
This can be triggered by:
1. Boot with memmap=4G!8G
2. build ndctl with destructive flag on
3. make TESTS=device-dax check
[ +0.000675] kernel BUG at mm/huge_memory.c:824!
Applying the same change that was applied to vmf_insert_pfn_pmd() in the
original patch.
Link: http://lkml.kernel.org/r/153565957352.35524.1005746906902065126.stgit@xxxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: e1fb4a08649 ("dax: remove VM_MIXEDMAP for fsdax and device dax")
Signed-off-by: Dave Jiang <dave.jiang@xxxxxxxxx>
Reported-by: Vishal Verma <vishal.l.verma@xxxxxxxxx>
Tested-by: Vishal Verma <vishal.l.verma@xxxxxxxxx>
Acked-by: Jeff Moyer <jmoyer@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
diff -puN mm/huge_memory.c~mm-fix-bug_on-in-vmf_insert_pfn_pud-from-vm_mixedmap-removal mm/huge_memory.c
--- a/mm/huge_memory.c~mm-fix-bug_on-in-vmf_insert_pfn_pud-from-vm_mixedmap-removal
+++ a/mm/huge_memory.c
@@ -821,11 +821,11 @@ vm_fault_t vmf_insert_pfn_pud(struct vm_
* but we need to be consistent with PTEs and architectures that
* can't support a 'special' bit.
*/
- BUG_ON(!(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)));
+ BUG_ON(!(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)) &&
+ !pfn_t_devmap(pfn));
BUG_ON((vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)) ==
(VM_PFNMAP|VM_MIXEDMAP));
BUG_ON((vma->vm_flags & VM_PFNMAP) && is_cow_mapping(vma->vm_flags));
- BUG_ON(!pfn_t_devmap(pfn));
if (addr < vma->vm_start || addr >= vma->vm_end)
return VM_FAULT_SIGBUS;
_
Patches currently in -mm which might be from dave.jiang@xxxxxxxxx are
mm-fix-bug_on-in-vmf_insert_pfn_pud-from-vm_mixedmap-removal.patch
