Dan Williams dan.j.williams@intel.com writes:
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
Reviewed-by: Aneesh Kumar K.V aneesh.kumar@linux.ibm.com
Cc: stable@vger.kernel.org Fixes: c6f3c5ee40c1 ("mm/huge_memory.c: fix modifying of page protection by insert_pfn_pmd()") Reported-by: Piotr Balcer piotr.balcer@intel.com Tested-by: Yan Ma yan.ma@intel.com Cc: Aneesh Kumar K.V aneesh.kumar@linux.ibm.com Cc: Chandan Rajendra chandan@linux.ibm.com Cc: Jan Kara jack@suse.cz Cc: Andrew Morton akpm@linux-foundation.org Cc: Matthew Wilcox willy@infradead.org Cc: Souptick Joarder jrdr.linux@gmail.com Signed-off-by: Dan Williams dan.j.williams@intel.com
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);@@ -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);