Hi Mike, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on linus/master] [also build test WARNING on v4.16-rc7 next-20180329] [if your patch is applied to the wrong git tree, please drop us a note to help improve the system] url: https://github.com/0day-ci/linux/commits/Mike-Kravetz/hugetlbfs-fix-bug-in-pgoff-overflow-checking/20180329-231724 config: i386-randconfig-x000-201812 (attached as .config) compiler: gcc-7 (Debian 7.3.0-1) 7.3.0 reproduce: # save the attached .config to linux build tree make ARCH=i386 All warnings (new ones prefixed by >>): fs/hugetlbfs/inode.c: In function 'hugetlbfs_file_mmap': >> fs/hugetlbfs/inode.c:119:35: warning: left shift count >= width of type [-Wshift-count-overflow] (((1UL << (PAGE_SHIFT + 1)) - 1) << \ ^ fs/hugetlbfs/inode.c:144:38: note: in expansion of macro 'PGOFF_LOFFT_MAX' if ((loff_t)vma->vm_pgoff & (loff_t)PGOFF_LOFFT_MAX) ^~~~~~~~~~~~~~~ vim +119 fs/hugetlbfs/inode.c 110 111 /* 112 * Mask used when checking the page offset value passed in via system 113 * calls. This value will be converted to a loff_t which is signed. 114 * Therefore, we want to check the upper PAGE_SHIFT + 1 bits of the 115 * value. The extra bit (- 1 in the shift value) is to take the sign 116 * bit into account. 117 */ 118 #define PGOFF_LOFFT_MAX \ > 119 (((1UL << (PAGE_SHIFT + 1)) - 1) << \ 120 ((sizeof(loff_t) * BITS_PER_BYTE) - (PAGE_SHIFT + 1))) 121 --- 0-DAY kernel test infrastructure Open Source Technology Center https://lists.01.org/pipermail/kbuild-all Intel Corporation
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