On Thu 09-05-19 09:31:41, Dan Williams wrote: > Starting with commit c6f3c5ee40c1 "mm/huge_memory.c: fix modifying of > page protection by insert_pfn_pmd()" vmf_insert_pfn_pmd() internally > calls pmdp_set_access_flags(). That helper enforces a pmd aligned > @address argument via VM_BUG_ON() assertion. > > Update the implementation to take a 'struct vm_fault' argument directly > and apply the address alignment fixup internally to fix crash signatures > like: > > kernel BUG at arch/x86/mm/pgtable.c:515! > invalid opcode: 0000 [#1] SMP NOPTI > CPU: 51 PID: 43713 Comm: java Tainted: G OE 4.19.35 #1 > [..] > RIP: 0010:pmdp_set_access_flags+0x48/0x50 > [..] > Call Trace: > vmf_insert_pfn_pmd+0x198/0x350 > dax_iomap_fault+0xe82/0x1190 > ext4_dax_huge_fault+0x103/0x1f0 > ? __switch_to_asm+0x40/0x70 > __handle_mm_fault+0x3f6/0x1370 > ? __switch_to_asm+0x34/0x70 > ? __switch_to_asm+0x40/0x70 > handle_mm_fault+0xda/0x200 > __do_page_fault+0x249/0x4f0 > do_page_fault+0x32/0x110 > ? page_fault+0x8/0x30 > page_fault+0x1e/0x30 > > Cc: <stable@xxxxxxxxxxxxxxx> > Fixes: c6f3c5ee40c1 ("mm/huge_memory.c: fix modifying of page protection by insert_pfn_pmd()") > Reported-by: Piotr Balcer <piotr.balcer@xxxxxxxxx> > Tested-by: Yan Ma <yan.ma@xxxxxxxxx> > Cc: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx> > Cc: Chandan Rajendra <chandan@xxxxxxxxxxxxx> > Cc: Jan Kara <jack@xxxxxxx> > Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx> > Cc: Souptick Joarder <jrdr.linux@xxxxxxxxx> > Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx> Looks good to me. You can add: Reviewed-by: Jan Kara <jack@xxxxxxx> Honza > --- > > drivers/dax/device.c | 6 ++---- > fs/dax.c | 6 ++---- > include/linux/huge_mm.h | 6 ++---- > mm/huge_memory.c | 16 ++++++++++------ > 4 files changed, 16 insertions(+), 18 deletions(-) > > diff --git a/drivers/dax/device.c b/drivers/dax/device.c > index e428468ab661..996d68ff992a 100644 > --- a/drivers/dax/device.c > +++ b/drivers/dax/device.c > @@ -184,8 +184,7 @@ static vm_fault_t __dev_dax_pmd_fault(struct dev_dax *dev_dax, > > *pfn = phys_to_pfn_t(phys, dax_region->pfn_flags); > > - return vmf_insert_pfn_pmd(vmf->vma, vmf->address, vmf->pmd, *pfn, > - vmf->flags & FAULT_FLAG_WRITE); > + return vmf_insert_pfn_pmd(vmf, *pfn, vmf->flags & FAULT_FLAG_WRITE); > } > > #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD > @@ -235,8 +234,7 @@ static vm_fault_t __dev_dax_pud_fault(struct dev_dax *dev_dax, > > *pfn = phys_to_pfn_t(phys, dax_region->pfn_flags); > > - return vmf_insert_pfn_pud(vmf->vma, vmf->address, vmf->pud, *pfn, > - vmf->flags & FAULT_FLAG_WRITE); > + return vmf_insert_pfn_pud(vmf, *pfn, vmf->flags & FAULT_FLAG_WRITE); > } > #else > static vm_fault_t __dev_dax_pud_fault(struct dev_dax *dev_dax, > diff --git a/fs/dax.c b/fs/dax.c > index e5e54da1715f..83009875308c 100644 > --- a/fs/dax.c > +++ b/fs/dax.c > @@ -1575,8 +1575,7 @@ static vm_fault_t dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp, > } > > trace_dax_pmd_insert_mapping(inode, vmf, PMD_SIZE, pfn, entry); > - result = vmf_insert_pfn_pmd(vma, vmf->address, vmf->pmd, pfn, > - write); > + result = vmf_insert_pfn_pmd(vmf, pfn, write); > break; > case IOMAP_UNWRITTEN: > case IOMAP_HOLE: > @@ -1686,8 +1685,7 @@ dax_insert_pfn_mkwrite(struct vm_fault *vmf, pfn_t pfn, unsigned int order) > ret = vmf_insert_mixed_mkwrite(vmf->vma, vmf->address, pfn); > #ifdef CONFIG_FS_DAX_PMD > else if (order == PMD_ORDER) > - ret = vmf_insert_pfn_pmd(vmf->vma, vmf->address, vmf->pmd, > - pfn, true); > + ret = vmf_insert_pfn_pmd(vmf, pfn, FAULT_FLAG_WRITE); > #endif > else > ret = VM_FAULT_FALLBACK; > diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h > index 381e872bfde0..7cd5c150c21d 100644 > --- a/include/linux/huge_mm.h > +++ b/include/linux/huge_mm.h > @@ -47,10 +47,8 @@ extern bool move_huge_pmd(struct vm_area_struct *vma, unsigned long old_addr, > extern int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd, > unsigned long addr, pgprot_t newprot, > int prot_numa); > -vm_fault_t vmf_insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr, > - pmd_t *pmd, pfn_t pfn, bool write); > -vm_fault_t vmf_insert_pfn_pud(struct vm_area_struct *vma, unsigned long addr, > - pud_t *pud, pfn_t pfn, bool write); > +vm_fault_t vmf_insert_pfn_pmd(struct vm_fault *vmf, pfn_t pfn, bool write); > +vm_fault_t vmf_insert_pfn_pud(struct vm_fault *vmf, pfn_t pfn, bool write); > enum transparent_hugepage_flag { > TRANSPARENT_HUGEPAGE_FLAG, > TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, > diff --git a/mm/huge_memory.c b/mm/huge_memory.c > index 165ea46bf149..4310c6e9e5a3 100644 > --- a/mm/huge_memory.c > +++ b/mm/huge_memory.c > @@ -793,11 +793,13 @@ static void insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr, > pte_free(mm, pgtable); > } > > -vm_fault_t vmf_insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr, > - pmd_t *pmd, pfn_t pfn, bool write) > +vm_fault_t vmf_insert_pfn_pmd(struct vm_fault *vmf, pfn_t pfn, bool write) > { > + unsigned long addr = vmf->address & PMD_MASK; > + struct vm_area_struct *vma = vmf->vma; > pgprot_t pgprot = vma->vm_page_prot; > pgtable_t pgtable = NULL; > + > /* > * If we had pmd_special, we could avoid all these restrictions, > * but we need to be consistent with PTEs and architectures that > @@ -820,7 +822,7 @@ vm_fault_t vmf_insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr, > > track_pfn_insert(vma, &pgprot, pfn); > > - insert_pfn_pmd(vma, addr, pmd, pfn, pgprot, write, pgtable); > + insert_pfn_pmd(vma, addr, vmf->pmd, pfn, pgprot, write, pgtable); > return VM_FAULT_NOPAGE; > } > EXPORT_SYMBOL_GPL(vmf_insert_pfn_pmd); > @@ -869,10 +871,12 @@ static void insert_pfn_pud(struct vm_area_struct *vma, unsigned long addr, > spin_unlock(ptl); > } > > -vm_fault_t vmf_insert_pfn_pud(struct vm_area_struct *vma, unsigned long addr, > - pud_t *pud, pfn_t pfn, bool write) > +vm_fault_t vmf_insert_pfn_pud(struct vm_fault *vmf, pfn_t pfn, bool write) > { > + unsigned long addr = vmf->address & PUD_MASK; > + struct vm_area_struct *vma = vmf->vma; > pgprot_t pgprot = vma->vm_page_prot; > + > /* > * If we had pud_special, we could avoid all these restrictions, > * but we need to be consistent with PTEs and architectures that > @@ -889,7 +893,7 @@ vm_fault_t vmf_insert_pfn_pud(struct vm_area_struct *vma, unsigned long addr, > > track_pfn_insert(vma, &pgprot, pfn); > > - insert_pfn_pud(vma, addr, pud, pfn, pgprot, write); > + insert_pfn_pud(vma, addr, vmf->pud, pfn, pgprot, write); > return VM_FAULT_NOPAGE; > } > EXPORT_SYMBOL_GPL(vmf_insert_pfn_pud); > -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR