mm/huge_memory: fix vmf_insert_pfn_{pmd, pud}() crash, handle unaligned addresses

BugLink: https://bugs.launchpad.net/bugs/1838576
commit fce86ff5802bac3a7b19db171aa1949ef9caac31 upstream.

Starting with 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

Link: http://lkml.kernel.org/r/155741946350.372037.11148198430068238140.stgit@dwillia2-desk3.amr.corp.intel.com
Fixes: c6f3c5ee40c1 ("mm/huge_memory.c: fix modifying of page protection by insert_pfn_pmd()")
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reported-by: Piotr Balcer <piotr.balcer@intel.com>
Tested-by: Yan Ma <yan.ma@intel.com>
Tested-by: Pankaj Gupta <pagupta@redhat.com>
Reviewed-by: Matthew Wilcox <willy@infradead.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Chandan Rajendra <chandan@linux.ibm.com>
Cc: Souptick Joarder <jrdr.linux@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

diff --git a/drivers/dax/device.c b/drivers/dax/device.c
index 1e9e22c2c827d9fca9331655e9e0dd123a12d93a..d14623c2778d226ff42ca9536367971d7ae6eb23 100644 (file)
--- a/drivers/dax/device.c
+++ b/drivers/dax/device.c
@@ -335,8 +335,7 @@ static int __dev_dax_pmd_fault(struct dev_dax *dev_dax, struct vm_fault *vmf)
 
        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
@@ -387,8 +386,7 @@ static int __dev_dax_pud_fault(struct dev_dax *dev_dax, struct vm_fault *vmf)
 
        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 int __dev_dax_pud_fault(struct dev_dax *dev_dax, struct vm_fault *vmf)

diff --git a/fs/dax.c b/fs/dax.c
index c2ebf10b70daf706fcf80a1ad2cab3468fe75170..7bcc84adc626a89d499c508004c7f54e6cf05ba6 100644 (file)
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1435,8 +1435,7 @@ static int 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:
@@ -1550,8 +1549,7 @@ static int dax_insert_pfn_mkwrite(struct vm_fault *vmf,
                break;
 #ifdef CONFIG_FS_DAX_PMD
        case PE_SIZE_PMD:
-               vmf_ret = vmf_insert_pfn_pmd(vmf->vma, vmf->address, vmf->pmd,
-                       pfn, true);
+               vmf_ret = vmf_insert_pfn_pmd(vmf, pfn, FAULT_FLAG_WRITE);
                break;
 #endif
        default:

diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index 0bec79ae4c2d224d5ba664d894f6c7130832fe29..fc3b020e32384d80373f58858312a2a247b0eb39 100644 (file)
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -46,10 +46,8 @@ 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);
-int vmf_insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr,
-                       pmd_t *pmd, pfn_t pfn, bool write);
-int vmf_insert_pfn_pud(struct vm_area_struct *vma, unsigned long addr,
-                       pud_t *pud, pfn_t pfn, bool write);
+int vmf_insert_pfn_pmd(struct vm_fault *vmf, pfn_t pfn, bool write);
+int 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 31e267aeb34161f82663827dbad6265f05fa9949..6351706804ecb2b272c48a142a02e06a942d4c82 100644 (file)
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -776,11 +776,13 @@ out_unlock:
                pte_free(mm, pgtable);
 }
 
-int vmf_insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr,
-                       pmd_t *pmd, pfn_t pfn, bool write)
+int 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
@@ -803,7 +805,7 @@ int 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);
@@ -852,10 +854,12 @@ out_unlock:
        spin_unlock(ptl);
 }
 
-int vmf_insert_pfn_pud(struct vm_area_struct *vma, unsigned long addr,
-                       pud_t *pud, pfn_t pfn, bool write)
+int 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
@@ -872,7 +876,7 @@ int 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);