| Message ID | 161315649533.7249.11715726297751446001.stgit@gimli.home (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | vfio/type1: Use follow_pte() | expand |
On Fri, Feb 12, 2021 at 12:01:50PM -0700, Alex Williamson wrote: > follow_pfn() doesn't make sure that we're using the correct page > protections, get the pte with follow_pte() so that we can test > protections and get the pfn from the pte. > > Fixes: 5cbf3264bc71 ("vfio/type1: Fix VA->PA translation for PFNMAP VMAs in vaddr_get_pfn()") > Signed-off-by: Alex Williamson <alex.williamson@redhat.com> > --- > drivers/vfio/vfio_iommu_type1.c | 14 ++++++++++++-- > 1 file changed, 12 insertions(+), 2 deletions(-) > > diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c > index ec9fd95a138b..90715413c3d9 100644 > --- a/drivers/vfio/vfio_iommu_type1.c > +++ b/drivers/vfio/vfio_iommu_type1.c > @@ -463,9 +463,11 @@ static int follow_fault_pfn(struct vm_area_struct *vma, struct mm_struct *mm, > unsigned long vaddr, unsigned long *pfn, > bool write_fault) > { > + pte_t *ptep; > + spinlock_t *ptl; > int ret; > > - ret = follow_pfn(vma, vaddr, pfn); > + ret = follow_pte(vma->vm_mm, vaddr, NULL, &ptep, NULL, &ptl); > if (ret) { > bool unlocked = false; > > @@ -479,9 +481,17 @@ static int follow_fault_pfn(struct vm_area_struct *vma, struct mm_struct *mm, > if (ret) > return ret; > > - ret = follow_pfn(vma, vaddr, pfn); > + ret = follow_pte(vma->vm_mm, vaddr, NULL, &ptep, NULL, &ptl); commit 9fd6dad1261a541b3f5fa7dc5b152222306e6702 in linux-next is what export's follow_pte and it uses a different signature: +int follow_pte(struct mm_struct *mm, unsigned long address, + pte_t **ptepp, spinlock_t **ptlp) Recommend you send this patch for rc1 once the right stuff lands in Linus's tree Otherwise it looks OK Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Jason
On Fri, 12 Feb 2021 15:08:51 -0400 Jason Gunthorpe <jgg@nvidia.com> wrote: > On Fri, Feb 12, 2021 at 12:01:50PM -0700, Alex Williamson wrote: > > follow_pfn() doesn't make sure that we're using the correct page > > protections, get the pte with follow_pte() so that we can test > > protections and get the pfn from the pte. > > > > Fixes: 5cbf3264bc71 ("vfio/type1: Fix VA->PA translation for PFNMAP VMAs in vaddr_get_pfn()") > > Signed-off-by: Alex Williamson <alex.williamson@redhat.com> > > --- > > drivers/vfio/vfio_iommu_type1.c | 14 ++++++++++++-- > > 1 file changed, 12 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c > > index ec9fd95a138b..90715413c3d9 100644 > > --- a/drivers/vfio/vfio_iommu_type1.c > > +++ b/drivers/vfio/vfio_iommu_type1.c > > @@ -463,9 +463,11 @@ static int follow_fault_pfn(struct vm_area_struct *vma, struct mm_struct *mm, > > unsigned long vaddr, unsigned long *pfn, > > bool write_fault) > > { > > + pte_t *ptep; > > + spinlock_t *ptl; > > int ret; > > > > - ret = follow_pfn(vma, vaddr, pfn); > > + ret = follow_pte(vma->vm_mm, vaddr, NULL, &ptep, NULL, &ptl); > > if (ret) { > > bool unlocked = false; > > > > @@ -479,9 +481,17 @@ static int follow_fault_pfn(struct vm_area_struct *vma, struct mm_struct *mm, > > if (ret) > > return ret; > > > > - ret = follow_pfn(vma, vaddr, pfn); > > + ret = follow_pte(vma->vm_mm, vaddr, NULL, &ptep, NULL, &ptl); > > commit 9fd6dad1261a541b3f5fa7dc5b152222306e6702 in linux-next is what > export's follow_pte and it uses a different signature: > > +int follow_pte(struct mm_struct *mm, unsigned long address, > + pte_t **ptepp, spinlock_t **ptlp) Thanks, I stole it off the mailing list and hadn't noticed the change. > Recommend you send this patch for rc1 once the right stuff lands in > Linus's tree > > Otherwise it looks OK > > Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Thanks! Alex
Hi Alex,
I love your patch! Yet something to improve:
[auto build test ERROR on vfio/next]
[also build test ERROR on v5.11-rc7 next-20210211]
[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]
url: https://github.com/0day-ci/linux/commits/Alex-Williamson/vfio-type1-Use-follow_pte/20210213-030541
base: https://github.com/awilliam/linux-vfio.git next
config: i386-randconfig-a002-20210209 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-15) 9.3.0
reproduce (this is a W=1 build):
# https://github.com/0day-ci/linux/commit/d1aea3bcf226e5225e706acb7df2f4c68ea8858a
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Alex-Williamson/vfio-type1-Use-follow_pte/20210213-030541
git checkout d1aea3bcf226e5225e706acb7df2f4c68ea8858a
# save the attached .config to linux build tree
make W=1 ARCH=i386
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
All errors (new ones prefixed by >>):
In file included from include/linux/mm.h:33,
from include/linux/scatterlist.h:8,
from include/linux/iommu.h:10,
from drivers/vfio/vfio_iommu_type1.c:27:
drivers/vfio/vfio_iommu_type1.c: In function 'follow_fault_pfn':
>> include/linux/pgtable.h:81:24: error: implicit declaration of function 'kunmap_atomic'; did you mean 'iommu_map_atomic'? [-Werror=implicit-function-declaration]
81 | #define pte_unmap(pte) kunmap_atomic((pte))
| ^~~~~~~~~~~~~
include/linux/mm.h:2231:2: note: in expansion of macro 'pte_unmap'
2231 | pte_unmap(pte); \
| ^~~~~~~~~
drivers/vfio/vfio_iommu_type1.c:494:2: note: in expansion of macro 'pte_unmap_unlock'
494 | pte_unmap_unlock(ptep, ptl);
| ^~~~~~~~~~~~~~~~
cc1: some warnings being treated as errors
vim +81 include/linux/pgtable.h
974b9b2c68f3d3 Mike Rapoport 2020-06-08 76
974b9b2c68f3d3 Mike Rapoport 2020-06-08 77 #if defined(CONFIG_HIGHPTE)
974b9b2c68f3d3 Mike Rapoport 2020-06-08 78 #define pte_offset_map(dir, address) \
974b9b2c68f3d3 Mike Rapoport 2020-06-08 79 ((pte_t *)kmap_atomic(pmd_page(*(dir))) + \
974b9b2c68f3d3 Mike Rapoport 2020-06-08 80 pte_index((address)))
974b9b2c68f3d3 Mike Rapoport 2020-06-08 @81 #define pte_unmap(pte) kunmap_atomic((pte))
974b9b2c68f3d3 Mike Rapoport 2020-06-08 82 #else
974b9b2c68f3d3 Mike Rapoport 2020-06-08 83 #define pte_offset_map(dir, address) pte_offset_kernel((dir), (address))
974b9b2c68f3d3 Mike Rapoport 2020-06-08 84 #define pte_unmap(pte) ((void)(pte)) /* NOP */
974b9b2c68f3d3 Mike Rapoport 2020-06-08 85 #endif
974b9b2c68f3d3 Mike Rapoport 2020-06-08 86
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
Hi Alex,
I love your patch! Yet something to improve:
[auto build test ERROR on vfio/next]
[also build test ERROR on v5.11-rc7]
[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]
url: https://github.com/0day-ci/linux/commits/Alex-Williamson/vfio-type1-Use-follow_pte/20210213-030541
base: https://github.com/awilliam/linux-vfio.git next
config: x86_64-rhel (attached as .config)
compiler: gcc-9 (Debian 9.3.0-15) 9.3.0
reproduce (this is a W=1 build):
# https://github.com/0day-ci/linux/commit/d1aea3bcf226e5225e706acb7df2f4c68ea8858a
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Alex-Williamson/vfio-type1-Use-follow_pte/20210213-030541
git checkout d1aea3bcf226e5225e706acb7df2f4c68ea8858a
# save the attached .config to linux build tree
make W=1 ARCH=x86_64
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
All errors (new ones prefixed by >>, old ones prefixed by <<):
>> ERROR: modpost: "follow_pte" [drivers/vfio/vfio_iommu_type1.ko] undefined!
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
On Fri, 12 Feb 2021 12:01:50 -0700 Alex Williamson <alex.williamson@redhat.com> wrote: > follow_pfn() doesn't make sure that we're using the correct page > protections, get the pte with follow_pte() so that we can test > protections and get the pfn from the pte. > > Fixes: 5cbf3264bc71 ("vfio/type1: Fix VA->PA translation for PFNMAP VMAs in vaddr_get_pfn()") > Signed-off-by: Alex Williamson <alex.williamson@redhat.com> > --- > drivers/vfio/vfio_iommu_type1.c | 14 ++++++++++++-- > 1 file changed, 12 insertions(+), 2 deletions(-) > With the function signature adapted: Reviewed-by: Cornelia Huck <cohuck@redhat.com>
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index ec9fd95a138b..90715413c3d9 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -463,9 +463,11 @@ static int follow_fault_pfn(struct vm_area_struct *vma, struct mm_struct *mm, unsigned long vaddr, unsigned long *pfn, bool write_fault) { + pte_t *ptep; + spinlock_t *ptl; int ret; - ret = follow_pfn(vma, vaddr, pfn); + ret = follow_pte(vma->vm_mm, vaddr, NULL, &ptep, NULL, &ptl); if (ret) { bool unlocked = false; @@ -479,9 +481,17 @@ static int follow_fault_pfn(struct vm_area_struct *vma, struct mm_struct *mm, if (ret) return ret; - ret = follow_pfn(vma, vaddr, pfn); + ret = follow_pte(vma->vm_mm, vaddr, NULL, &ptep, NULL, &ptl); + if (ret) + return ret; } + if (write_fault && !pte_write(*ptep)) + ret = -EFAULT; + else + *pfn = pte_pfn(*ptep); + + pte_unmap_unlock(ptep, ptl); return ret; }
follow_pfn() doesn't make sure that we're using the correct page protections, get the pte with follow_pte() so that we can test protections and get the pfn from the pte. Fixes: 5cbf3264bc71 ("vfio/type1: Fix VA->PA translation for PFNMAP VMAs in vaddr_get_pfn()") Signed-off-by: Alex Williamson <alex.williamson@redhat.com> --- drivers/vfio/vfio_iommu_type1.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-)