Re: [PATCH 2/2] thp, shmem: Fix conflict of above-47bit hint address and PMD alignment
From: kbuild test robot
Date: Fri Dec 27 2019 - 19:17:50 EST
Hi "Kirill,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on linus/master]
[also build test WARNING on v5.5-rc3 next-20191220]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system. BTW, we also suggest to use '--base' option to specify the
base tree in git format-patch, please see https://stackoverflow.com/a/37406982]
url: https://github.com/0day-ci/linux/commits/Kirill-A-Shutemov/Fix-two-above-47bit-hint-address-vs-THP-bugs/20191223-221713
base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 46cf053efec6a3a5f343fead837777efe8252a46
reproduce:
# apt-get install sparse
# sparse version: v0.6.1-129-g341daf20-dirty
make ARCH=x86_64 allmodconfig
make C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__'
If you fix the issue, kindly add following tag
Reported-by: kbuild test robot <lkp@xxxxxxxxx>
sparse warnings: (new ones prefixed by >>)
>> mm/shmem.c:2147:34: sparse: sparse: incorrect type in argument 1 (different base types)
>> mm/shmem.c:2147:34: sparse: expected struct file *
>> mm/shmem.c:2147:34: sparse: got unsigned long uaddr
vim +2147 mm/shmem.c
2073
2074 unsigned long shmem_get_unmapped_area(struct file *file,
2075 unsigned long uaddr, unsigned long len,
2076 unsigned long pgoff, unsigned long flags)
2077 {
2078 unsigned long (*get_area)(struct file *,
2079 unsigned long, unsigned long, unsigned long, unsigned long);
2080 unsigned long addr;
2081 unsigned long offset;
2082 unsigned long inflated_len;
2083 unsigned long inflated_addr;
2084 unsigned long inflated_offset;
2085
2086 if (len > TASK_SIZE)
2087 return -ENOMEM;
2088
2089 get_area = current->mm->get_unmapped_area;
2090 addr = get_area(file, uaddr, len, pgoff, flags);
2091
2092 if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGE_PAGECACHE))
2093 return addr;
2094 if (IS_ERR_VALUE(addr))
2095 return addr;
2096 if (addr & ~PAGE_MASK)
2097 return addr;
2098 if (addr > TASK_SIZE - len)
2099 return addr;
2100
2101 if (shmem_huge == SHMEM_HUGE_DENY)
2102 return addr;
2103 if (len < HPAGE_PMD_SIZE)
2104 return addr;
2105 if (flags & MAP_FIXED)
2106 return addr;
2107 /*
2108 * Our priority is to support MAP_SHARED mapped hugely;
2109 * and support MAP_PRIVATE mapped hugely too, until it is COWed.
2110 * But if caller specified an address hint and we allocated area there
2111 * successfully, respect that as before.
2112 */
2113 if (uaddr == addr)
2114 return addr;
2115
2116 if (shmem_huge != SHMEM_HUGE_FORCE) {
2117 struct super_block *sb;
2118
2119 if (file) {
2120 VM_BUG_ON(file->f_op != &shmem_file_operations);
2121 sb = file_inode(file)->i_sb;
2122 } else {
2123 /*
2124 * Called directly from mm/mmap.c, or drivers/char/mem.c
2125 * for "/dev/zero", to create a shared anonymous object.
2126 */
2127 if (IS_ERR(shm_mnt))
2128 return addr;
2129 sb = shm_mnt->mnt_sb;
2130 }
2131 if (SHMEM_SB(sb)->huge == SHMEM_HUGE_NEVER)
2132 return addr;
2133 }
2134
2135 offset = (pgoff << PAGE_SHIFT) & (HPAGE_PMD_SIZE-1);
2136 if (offset && offset + len < 2 * HPAGE_PMD_SIZE)
2137 return addr;
2138 if ((addr & (HPAGE_PMD_SIZE-1)) == offset)
2139 return addr;
2140
2141 inflated_len = len + HPAGE_PMD_SIZE - PAGE_SIZE;
2142 if (inflated_len > TASK_SIZE)
2143 return addr;
2144 if (inflated_len < len)
2145 return addr;
2146
> 2147 inflated_addr = get_area(uaddr, 0, inflated_len, 0, flags);
2148 if (IS_ERR_VALUE(inflated_addr))
2149 return addr;
2150 if (inflated_addr & ~PAGE_MASK)
2151 return addr;
2152
2153 inflated_offset = inflated_addr & (HPAGE_PMD_SIZE-1);
2154 inflated_addr += offset - inflated_offset;
2155 if (inflated_offset > offset)
2156 inflated_addr += HPAGE_PMD_SIZE;
2157
2158 if (inflated_addr > TASK_SIZE - len)
2159 return addr;
2160 return inflated_addr;
2161 }
2162
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