diff mbox series

[v3,1/2] udmabuf: Use vmf_insert_pfn and VM_PFNMAP for handling mmap

Message ID 20230817064623.3424348-2-vivek.kasireddy@intel.com (mailing list archive)
State New, archived
Headers show
Series udmabuf: Add back support for mapping hugetlb pages (v3) | expand

Commit Message

Kasireddy, Vivek Aug. 17, 2023, 6:46 a.m. UTC 
Add VM_PFNMAP to vm_flags in the mmap handler to ensure that
the mappings would be managed without using struct page.

And, in the vm_fault handler, use vmf_insert_pfn to share the
page's pfn to userspace instead of directly sharing the page
(via struct page *).

Cc: David Hildenbrand <david@redhat.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Dongwon Kim <dongwon.kim@intel.com>
Cc: Junxiao Chang <junxiao.chang@intel.com>
Suggested-by: David Hildenbrand <david@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Vivek Kasireddy <vivek.kasireddy@intel.com>
---
 drivers/dma-buf/udmabuf.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

Comments

kernel test robot Aug. 17, 2023, 10:48 p.m. UTC | #1 
Hi Vivek,

kernel test robot noticed the following build errors:

[auto build test ERROR on drm-misc/drm-misc-next]
[also build test ERROR on drm-tip/drm-tip linus/master v6.5-rc6 next-20230817]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Vivek-Kasireddy/udmabuf-Use-vmf_insert_pfn-and-VM_PFNMAP-for-handling-mmap/20230817-150922
base:   git://anongit.freedesktop.org/drm/drm-misc drm-misc-next
patch link:    https://lore.kernel.org/r/20230817064623.3424348-2-vivek.kasireddy%40intel.com
patch subject: [PATCH v3 1/2] udmabuf: Use vmf_insert_pfn and VM_PFNMAP for handling mmap
config: sh-randconfig-r004-20230818 (https://download.01.org/0day-ci/archive/20230818/202308180617.Rl3Qsrnt-lkp@intel.com/config)
compiler: sh4-linux-gcc (GCC) 12.3.0
reproduce: (https://download.01.org/0day-ci/archive/20230818/202308180617.Rl3Qsrnt-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202308180617.Rl3Qsrnt-lkp@intel.com/

All errors (new ones prefixed by >>):

   sh4-linux-ld: drivers/dma-buf/udmabuf.o: in function `udmabuf_vm_fault':
>> udmabuf.c:(.text+0xd8): undefined reference to `vmf_insert_pfn'
kernel test robot Aug. 18, 2023, 6:54 a.m. UTC | #2 
Hi Vivek,

kernel test robot noticed the following build errors:

[auto build test ERROR on drm-misc/drm-misc-next]
[also build test ERROR on drm-tip/drm-tip linus/master v6.5-rc6 next-20230817]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Vivek-Kasireddy/udmabuf-Use-vmf_insert_pfn-and-VM_PFNMAP-for-handling-mmap/20230817-150922
base:   git://anongit.freedesktop.org/drm/drm-misc drm-misc-next
patch link:    https://lore.kernel.org/r/20230817064623.3424348-2-vivek.kasireddy%40intel.com
patch subject: [PATCH v3 1/2] udmabuf: Use vmf_insert_pfn and VM_PFNMAP for handling mmap
config: arm-randconfig-r035-20230818 (https://download.01.org/0day-ci/archive/20230818/202308181405.UwIsWuMi-lkp@intel.com/config)
compiler: clang version 17.0.0 (https://github.com/llvm/llvm-project.git 4a5ac14ee968ff0ad5d2cc1ffa0299048db4c88a)
reproduce: (https://download.01.org/0day-ci/archive/20230818/202308181405.UwIsWuMi-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202308181405.UwIsWuMi-lkp@intel.com/

All errors (new ones prefixed by >>):

>> ld.lld: error: undefined symbol: vmf_insert_pfn
   >>> referenced by udmabuf.c:44 (drivers/dma-buf/udmabuf.c:44)
   >>>               drivers/dma-buf/udmabuf.o:(udmabuf_vm_fault) in archive vmlinux.a
diff mbox series

Patch

diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c
index c40645999648..820c993c8659 100644
--- a/drivers/dma-buf/udmabuf.c
+++ b/drivers/dma-buf/udmabuf.c
@@ -35,12 +35,13 @@  static vm_fault_t udmabuf_vm_fault(struct vm_fault *vmf)
 	struct vm_area_struct *vma = vmf->vma;
 	struct udmabuf *ubuf = vma->vm_private_data;
 	pgoff_t pgoff = vmf->pgoff;
+	unsigned long pfn;
 
 	if (pgoff >= ubuf->pagecount)
 		return VM_FAULT_SIGBUS;
-	vmf->page = ubuf->pages[pgoff];
-	get_page(vmf->page);
-	return 0;
+
+	pfn = page_to_pfn(ubuf->pages[pgoff]);
+	return vmf_insert_pfn(vma, vmf->address, pfn);
 }
 
 static const struct vm_operations_struct udmabuf_vm_ops = {
@@ -56,6 +57,7 @@  static int mmap_udmabuf(struct dma_buf *buf, struct vm_area_struct *vma)
 
 	vma->vm_ops = &udmabuf_vm_ops;
 	vma->vm_private_data = ubuf;
+	vm_flags_set(vma, VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP);
 	return 0;
 }