| Message ID | 153565957352.35524.1005746906902065126.stgit@djiang5-desk3.ch.intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | mm: fix BUG_ON() in vmf_insert_pfn_pud() from VM_MIXEDMAP removal | expand |
Dave Jiang <dave.jiang@intel.com> writes: > 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. > > Fixes: e1fb4a08649 ("dax: remove VM_MIXEDMAP for fsdax and device dax") > > Reported-by: Vishal Verma <vishal.l.verma@intel.com> > Signed-off-by: Dave Jiang <dave.jiang@intel.com> Acked-by: Jeff Moyer <jmoyer@redhat.com> > --- > mm/huge_memory.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/mm/huge_memory.c b/mm/huge_memory.c > index c3bc7e9c9a2a..533f9b00147d 100644 > --- a/mm/huge_memory.c > +++ b/mm/huge_memory.c > @@ -821,11 +821,11 @@ vm_fault_t vmf_insert_pfn_pud(struct vm_area_struct *vma, unsigned long addr, > * 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; > > _______________________________________________ > Linux-nvdimm mailing list > Linux-nvdimm@lists.01.org > https://lists.01.org/mailman/listinfo/linux-nvdimm
On Thu, 2018-08-30 at 13:06 -0700, Dave Jiang wrote: > 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. > > Fixes: e1fb4a08649 ("dax: remove VM_MIXEDMAP for fsdax and device > dax") > > Reported-by: Vishal Verma <vishal.l.verma@intel.com> > Signed-off-by: Dave Jiang <dave.jiang@intel.com> > --- > mm/huge_memory.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) This fixes the unit test failure, feel free to add: Tested-by: Vishal Verma <vishal.l.verma@intel.com> > > diff --git a/mm/huge_memory.c b/mm/huge_memory.c > index c3bc7e9c9a2a..533f9b00147d 100644 > --- a/mm/huge_memory.c > +++ b/mm/huge_memory.c > @@ -821,11 +821,11 @@ vm_fault_t vmf_insert_pfn_pud(struct > vm_area_struct *vma, unsigned long addr, > * 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_MIXEDM > AP)); > 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; >
On Thu 30-08-18 13:06:13, Dave Jiang wrote: > 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. > > Fixes: e1fb4a08649 ("dax: remove VM_MIXEDMAP for fsdax and device dax") > > Reported-by: Vishal Verma <vishal.l.verma@intel.com> > Signed-off-by: Dave Jiang <dave.jiang@intel.com> Looks good. You can add: Reviewed-by: Jan Kara <jack@suse.cz> Honza > --- > mm/huge_memory.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/mm/huge_memory.c b/mm/huge_memory.c > index c3bc7e9c9a2a..533f9b00147d 100644 > --- a/mm/huge_memory.c > +++ b/mm/huge_memory.c > @@ -821,11 +821,11 @@ vm_fault_t vmf_insert_pfn_pud(struct vm_area_struct *vma, unsigned long addr, > * 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; > >
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index c3bc7e9c9a2a..533f9b00147d 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -821,11 +821,11 @@ vm_fault_t vmf_insert_pfn_pud(struct vm_area_struct *vma, unsigned long addr, * 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;
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. Fixes: e1fb4a08649 ("dax: remove VM_MIXEDMAP for fsdax and device dax") Reported-by: Vishal Verma <vishal.l.verma@intel.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> --- mm/huge_memory.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)