Re: [PATCH v7 17/17] mm: add mmu_notifier argument to follow_pfn

kernel test robot
2020-11-27T19:12:41Z

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Hi Daniel,

I love your patch! Yet something to improve:

[auto build test ERROR on linuxtv-media/master]
[also build test ERROR on char-misc/char-misc-testing v5.10-rc5]
[cannot apply to hnaz-linux-mm/master next-20201127]
[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/Daniel-Vetter/follow_pfn-and-other-iomap-races/20201128-004421
base: git://linuxtv.org/media_tree.git master
config: s390-randconfig-r032-20201127 (attached as .config)
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project f095ac11a9550530a4a54298debb8b04b36422be)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# install s390 cross compiling tool for clang build
# apt-get install binutils-s390x-linux-gnu
# https://github.com/0day-ci/linux/commit/d76a3489433ce67d45da86aa12953385427f0ac9
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Daniel-Vetter/follow_pfn-and-other-iomap-races/20201128-004421
git checkout d76a3489433ce67d45da86aa12953385427f0ac9
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=s390

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 arch/s390/include/asm/kvm_para.h:25:
In file included from arch/s390/include/asm/diag.h:12:
In file included from include/linux/if_ether.h:19:
In file included from include/linux/skbuff.h:31:
In file included from include/linux/dma-mapping.h:10:
In file included from include/linux/scatterlist.h:9:
In file included from arch/s390/include/asm/io.h:80:
include/asm-generic/io.h:490:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr));
~~~~~~~~~~ ^
include/uapi/linux/byteorder/big_endian.h:34:59: note: expanded from macro '__le32_to_cpu'
#define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x))
^
include/uapi/linux/swab.h:119:21: note: expanded from macro '__swab32'
___constant_swab32(x) : \
^
include/uapi/linux/swab.h:21:12: note: expanded from macro '___constant_swab32'
(((__u32)(x) & (__u32)0x00ff0000UL) >> 8) | \
^
In file included from arch/s390/kvm/../../../virt/kvm/kvm_main.c:18:
In file included from include/linux/kvm_host.h:32:
In file included from include/linux/kvm_para.h:5:
In file included from include/uapi/linux/kvm_para.h:36:
In file included from arch/s390/include/asm/kvm_para.h:25:
In file included from arch/s390/include/asm/diag.h:12:
In file included from include/linux/if_ether.h:19:
In file included from include/linux/skbuff.h:31:
In file included from include/linux/dma-mapping.h:10:
In file included from include/linux/scatterlist.h:9:
In file included from arch/s390/include/asm/io.h:80:
include/asm-generic/io.h:490:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr));
~~~~~~~~~~ ^
include/uapi/linux/byteorder/big_endian.h:34:59: note: expanded from macro '__le32_to_cpu'
#define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x))
^
include/uapi/linux/swab.h:119:21: note: expanded from macro '__swab32'
___constant_swab32(x) : \
^
include/uapi/linux/swab.h:22:12: note: expanded from macro '___constant_swab32'
(((__u32)(x) & (__u32)0xff000000UL) >> 24)))
^
In file included from arch/s390/kvm/../../../virt/kvm/kvm_main.c:18:
In file included from include/linux/kvm_host.h:32:
In file included from include/linux/kvm_para.h:5:
In file included from include/uapi/linux/kvm_para.h:36:
In file included from arch/s390/include/asm/kvm_para.h:25:
In file included from arch/s390/include/asm/diag.h:12:
In file included from include/linux/if_ether.h:19:
In file included from include/linux/skbuff.h:31:
In file included from include/linux/dma-mapping.h:10:
In file included from include/linux/scatterlist.h:9:
In file included from arch/s390/include/asm/io.h:80:
include/asm-generic/io.h:490:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr));
~~~~~~~~~~ ^
include/uapi/linux/byteorder/big_endian.h:34:59: note: expanded from macro '__le32_to_cpu'
#define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x))
^
include/uapi/linux/swab.h:120:12: note: expanded from macro '__swab32'
__fswab32(x))
^
In file included from arch/s390/kvm/../../../virt/kvm/kvm_main.c:18:
In file included from include/linux/kvm_host.h:32:
In file included from include/linux/kvm_para.h:5:
In file included from include/uapi/linux/kvm_para.h:36:
In file included from arch/s390/include/asm/kvm_para.h:25:
In file included from arch/s390/include/asm/diag.h:12:
In file included from include/linux/if_ether.h:19:
In file included from include/linux/skbuff.h:31:
In file included from include/linux/dma-mapping.h:10:
In file included from include/linux/scatterlist.h:9:
In file included from arch/s390/include/asm/io.h:80:
include/asm-generic/io.h:501:33: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writeb(value, PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:511:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writew((u16 __force)cpu_to_le16(value), PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:521:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writel((u32 __force)cpu_to_le32(value), PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:609:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
readsb(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:617:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
readsw(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:625:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
readsl(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:634:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
writesb(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:643:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
writesw(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:652:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
writesl(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
>> arch/s390/kvm/../../../virt/kvm/kvm_main.c:1894:40: error: no member named 'mmu_notifier' in 'struct kvm'
r = follow_pfn(vma, addr, &pfn, &kvm->mmu_notifier);
~~~ ^
arch/s390/kvm/../../../virt/kvm/kvm_main.c:1909:41: error: no member named 'mmu_notifier' in 'struct kvm'
r = follow_pfn(vma, addr, &pfn, &kvm->mmu_notifier);
~~~ ^
20 warnings and 2 errors generated.

vim +1894 arch/s390/kvm/../../../virt/kvm/kvm_main.c

1885
1886 static int hva_to_pfn_remapped(struct kvm *kvm, struct vm_area_struct *vma,
1887 unsigned long addr, bool *async,
1888 bool write_fault, bool *writable,
1889 kvm_pfn_t *p_pfn)
1890 {
1891 unsigned long pfn;
1892 int r;
1893
> 1894 r = follow_pfn(vma, addr, &pfn, &kvm->mmu_notifier);
1895 if (r) {
1896 /*
1897 * get_user_pages fails for VM_IO and VM_PFNMAP vmas and does
1898 * not call the fault handler, so do it here.
1899 */
1900 bool unlocked = false;
1901 r = fixup_user_fault(current->mm, addr,
1902 (write_fault ? FAULT_FLAG_WRITE : 0),
1903 &unlocked);
1904 if (unlocked)
1905 return -EAGAIN;
1906 if (r)
1907 return r;
1908
1909 r = follow_pfn(vma, addr, &pfn, &kvm->mmu_notifier);
1910 if (r)
1911 return r;
1912
1913 }
1914
1915 if (writable)
1916 *writable = true;
1917
1918 /*
1919 * Get a reference here because callers of *hva_to_pfn* and
1920 * *gfn_to_pfn* ultimately call kvm_release_pfn_clean on the
1921 * returned pfn. This is only needed if the VMA has VM_MIXEDMAP
1922 * set, but the kvm_get_pfn/kvm_release_pfn_clean pair will
1923 * simply do nothing for reserved pfns.
1924 *
1925 * Whoever called remap_pfn_range is also going to call e.g.
1926 * unmap_mapping_range before the underlying pages are freed,
1927 * causing a call to our MMU notifier.
1928 */
1929 kvm_get_pfn(pfn);
1930
1931 *p_pfn = pfn;
1932 return 0;
1933 }
1934

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

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