From: kernel test robot <lkp@intel.com>
To: kbuild@lists.01.org
Subject: mm/nommu.c:1010:12: warning: The result of the left shift is undefined due to shifting by '32', which is greater or equal to the width of type 'int' [clang-analyzer-core.UndefinedBinaryOperatorResult]
Date: Mon, 08 Nov 2021 22:00:42 +0800 [thread overview]
Message-ID: <202111082226.T4frnUNL-lkp@intel.com> (raw)
[-- Attachment #1: Type: text/plain, Size: 37136 bytes --]
CC: llvm(a)lists.linux.dev
CC: kbuild-all(a)lists.01.org
CC: linux-kernel(a)vger.kernel.org
TO: Jakub Jelinek <jakub@redhat.com>
CC: "Peter Zijlstra (Intel)" <peterz@infradead.org>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Linux Memory Management List <linux-mm@kvack.org>
tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: 6b75d88fa81b122cce37ebf17428a849ccd3d0f1
commit: 2f78788b55baa3410b1ec91a576286abe1ad4d6a ilog2: improve ilog2 for constant arguments
date: 11 months ago
:::::: branch date: 19 hours ago
:::::: commit date: 11 months ago
config: riscv-randconfig-c006-20211003 (attached as .config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project 962e503cc8bc411f7523cc393acae8aae425b1c4)
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 riscv cross compiling tool for clang build
# apt-get install binutils-riscv64-linux-gnu
# https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=2f78788b55baa3410b1ec91a576286abe1ad4d6a
git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
git fetch --no-tags linus master
git checkout 2f78788b55baa3410b1ec91a576286abe1ad4d6a
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=riscv clang-analyzer
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
clang-analyzer warnings: (new ones prefixed by >>)
if (unlikely(!bh))
^
include/linux/compiler.h:78:42: note: expanded from macro 'unlikely'
# define unlikely(x) __builtin_expect(!!(x), 0)
^
fs/nilfs2/mdt.c:122:2: note: Taking false branch
if (unlikely(!bh))
^
fs/nilfs2/mdt.c:126:6: note: Assuming the condition is false
if (buffer_uptodate(bh))
^~~~~~~~~~~~~~~~~~~
fs/nilfs2/mdt.c:126:2: note: Taking false branch
if (buffer_uptodate(bh))
^
fs/nilfs2/mdt.c:129:2: note: Taking false branch
if (mode_flags & REQ_RAHEAD) {
^
fs/nilfs2/mdt.c:137:6: note: Assuming the condition is false
if (buffer_uptodate(bh)) {
^~~~~~~~~~~~~~~~~~~
fs/nilfs2/mdt.c:137:2: note: Taking false branch
if (buffer_uptodate(bh)) {
^
fs/nilfs2/mdt.c:143:6: note: Assuming 'ret' is not equal to 0
if (unlikely(ret)) {
^
include/linux/compiler.h:78:40: note: expanded from macro 'unlikely'
# define unlikely(x) __builtin_expect(!!(x), 0)
^~~~
fs/nilfs2/mdt.c:143:2: note: Taking true branch
if (unlikely(ret)) {
^
fs/nilfs2/mdt.c:145:3: note: Control jumps to line 160
goto failed_bh;
^
fs/nilfs2/mdt.c:164:2: note: Returning without writing to '*out_bh'
return ret;
^
fs/nilfs2/mdt.c:175:8: note: Returning from 'nilfs_mdt_submit_block'
err = nilfs_mdt_submit_block(inode, block, REQ_OP_READ, 0, &first_bh);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
fs/nilfs2/mdt.c:176:6: note: Assuming the condition is true
if (err == -EEXIST) /* internal code */
^~~~~~~~~~~~~~
fs/nilfs2/mdt.c:176:2: note: Taking true branch
if (err == -EEXIST) /* internal code */
^
fs/nilfs2/mdt.c:177:3: note: Control jumps to line 208
goto out;
^
fs/nilfs2/mdt.c:208:10: note: Assigned value is garbage or undefined
*out_bh = first_bh;
^ ~~~~~~~~
Suppressed 10 warnings (3 in non-user code, 7 with check filters).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
10 warnings generated.
Suppressed 10 warnings (3 in non-user code, 7 with check filters).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
2 warnings generated.
Suppressed 2 warnings (2 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
10 warnings generated.
Suppressed 10 warnings (3 in non-user code, 7 with check filters).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
10 warnings generated.
Suppressed 10 warnings (3 in non-user code, 7 with check filters).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
12 warnings generated.
mm/workingset.c:206:2: warning: Value stored to 'nid' is never read [clang-analyzer-deadcode.DeadStores]
nid = entry & ((1UL << NODES_SHIFT) - 1);
^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
mm/workingset.c:206:2: note: Value stored to 'nid' is never read
nid = entry & ((1UL << NODES_SHIFT) - 1);
^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Suppressed 11 warnings (3 in non-user code, 8 with check filters).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
10 warnings generated.
Suppressed 10 warnings (3 in non-user code, 7 with check filters).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
10 warnings generated.
Suppressed 10 warnings (3 in non-user code, 7 with check filters).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
13 warnings generated.
Suppressed 13 warnings (3 in non-user code, 10 with check filters).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
47 warnings generated.
mm/nommu.c:423:2: warning: Value stored to 'ret' is never read [clang-analyzer-deadcode.DeadStores]
ret = percpu_counter_init(&vm_committed_as, 0, GFP_KERNEL);
^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
mm/nommu.c:423:2: note: Value stored to 'ret' is never read
ret = percpu_counter_init(&vm_committed_as, 0, GFP_KERNEL);
^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
mm/nommu.c:881:6: warning: Value stored to 'prot' is never read [clang-analyzer-deadcode.DeadStores]
prot |= PROT_EXEC;
^
mm/nommu.c:881:6: note: Value stored to 'prot' is never read
mm/nommu.c:899:4: warning: Value stored to 'prot' is never read [clang-analyzer-deadcode.DeadStores]
prot |= PROT_EXEC;
^
mm/nommu.c:899:4: note: Value stored to 'prot' is never read
>> mm/nommu.c:1010:12: warning: The result of the left shift is undefined due to shifting by '32', which is greater or equal to the width of type 'int' [clang-analyzer-core.UndefinedBinaryOperatorResult]
total = 1 << order;
^
mm/nommu.c:1091:6: note: 'ret' is >= 0
if (ret < 0)
^~~
mm/nommu.c:1091:2: note: Taking false branch
if (ret < 0)
^
mm/nommu.c:1104:6: note: Assuming 'region' is non-null
if (!region)
^~~~~~~
mm/nommu.c:1104:2: note: Taking false branch
if (!region)
^
mm/nommu.c:1108:6: note: Assuming 'vma' is non-null
if (!vma)
^~~~
mm/nommu.c:1108:2: note: Taking false branch
if (!vma)
^
mm/nommu.c:1118:6: note: 'file' is null
if (file) {
^~~~
mm/nommu.c:1118:2: note: Taking false branch
if (file) {
^
mm/nommu.c:1133:6: note: Assuming the condition is false
if (vm_flags & VM_MAYSHARE) {
^~~~~~~~~~~~~~~~~~~~~~
mm/nommu.c:1133:2: note: Taking false branch
if (vm_flags & VM_MAYSHARE) {
^
mm/nommu.c:1230:6: note: 'file' is null
if (file && vma->vm_flags & VM_SHARED)
^~~~
mm/nommu.c:1230:11: note: Left side of '&&' is false
if (file && vma->vm_flags & VM_SHARED)
^
mm/nommu.c:1233:9: note: Calling 'do_mmap_private'
ret = do_mmap_private(vma, region, len, capabilities);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
mm/nommu.c:988:2: note: Taking false branch
if (capabilities & NOMMU_MAP_DIRECT) {
^
mm/nommu.c:1009:10: note: Calling 'get_order'
order = get_order(len);
^~~~~~~~~~~~~~
include/asm-generic/getorder.h:31:2: note: Taking false branch
if (__builtin_constant_p(size)) {
^
include/asm-generic/getorder.h:46:9: note: Calling 'fls64'
return fls64(size);
^~~~~~~~~~~
include/asm-generic/bitops/fls64.h:29:6: note: Assuming 'x' is not equal to 0
if (x == 0)
^~~~~~
include/asm-generic/bitops/fls64.h:29:2: note: Taking false branch
if (x == 0)
^
include/asm-generic/bitops/fls64.h:31:2: note: Returning the value 32
return __fls(x) + 1;
^~~~~~~~~~~~~~~~~~~
include/asm-generic/getorder.h:46:9: note: Returning from 'fls64'
return fls64(size);
^~~~~~~~~~~
include/asm-generic/getorder.h:46:2: note: Returning the value 32
return fls64(size);
^~~~~~~~~~~~~~~~~~
mm/nommu.c:1009:10: note: Returning from 'get_order'
order = get_order(len);
^~~~~~~~~~~~~~
mm/nommu.c:1009:2: note: The value 32 is assigned to 'order'
order = get_order(len);
^~~~~~~~~~~~~~~~~~~~~~
mm/nommu.c:1010:12: note: The result of the left shift is undefined due to shifting by '32', which is greater or equal to the width of type 'int'
total = 1 << order;
^ ~~~~~
mm/nommu.c:1010:12: warning: The result of the left shift is undefined due to shifting by '33', which is greater or equal to the width of type 'int' [clang-analyzer-core.UndefinedBinaryOperatorResult]
total = 1 << order;
^
mm/nommu.c:1091:6: note: 'ret' is >= 0
if (ret < 0)
^~~
mm/nommu.c:1091:2: note: Taking false branch
if (ret < 0)
^
mm/nommu.c:1104:6: note: Assuming 'region' is non-null
if (!region)
^~~~~~~
mm/nommu.c:1104:2: note: Taking false branch
if (!region)
^
mm/nommu.c:1108:6: note: Assuming 'vma' is non-null
if (!vma)
^~~~
mm/nommu.c:1108:2: note: Taking false branch
if (!vma)
^
mm/nommu.c:1118:6: note: 'file' is null
if (file) {
vim +1010 mm/nommu.c
^1da177e4c3f41 Linus Torvalds 2005-04-16 750
^1da177e4c3f41 Linus Torvalds 2005-04-16 751 /*
^1da177e4c3f41 Linus Torvalds 2005-04-16 752 * determine whether a mapping should be permitted and, if so, what sort of
^1da177e4c3f41 Linus Torvalds 2005-04-16 753 * mapping we're capable of supporting
^1da177e4c3f41 Linus Torvalds 2005-04-16 754 */
^1da177e4c3f41 Linus Torvalds 2005-04-16 755 static int validate_mmap_request(struct file *file,
^1da177e4c3f41 Linus Torvalds 2005-04-16 756 unsigned long addr,
^1da177e4c3f41 Linus Torvalds 2005-04-16 757 unsigned long len,
^1da177e4c3f41 Linus Torvalds 2005-04-16 758 unsigned long prot,
^1da177e4c3f41 Linus Torvalds 2005-04-16 759 unsigned long flags,
^1da177e4c3f41 Linus Torvalds 2005-04-16 760 unsigned long pgoff,
^1da177e4c3f41 Linus Torvalds 2005-04-16 761 unsigned long *_capabilities)
^1da177e4c3f41 Linus Torvalds 2005-04-16 762 {
8feae13110d60c David Howells 2009-01-08 763 unsigned long capabilities, rlen;
^1da177e4c3f41 Linus Torvalds 2005-04-16 764 int ret;
^1da177e4c3f41 Linus Torvalds 2005-04-16 765
^1da177e4c3f41 Linus Torvalds 2005-04-16 766 /* do the simple checks first */
22cc877b32202b Leon Romanovsky 2015-06-24 767 if (flags & MAP_FIXED)
^1da177e4c3f41 Linus Torvalds 2005-04-16 768 return -EINVAL;
^1da177e4c3f41 Linus Torvalds 2005-04-16 769
^1da177e4c3f41 Linus Torvalds 2005-04-16 770 if ((flags & MAP_TYPE) != MAP_PRIVATE &&
^1da177e4c3f41 Linus Torvalds 2005-04-16 771 (flags & MAP_TYPE) != MAP_SHARED)
^1da177e4c3f41 Linus Torvalds 2005-04-16 772 return -EINVAL;
^1da177e4c3f41 Linus Torvalds 2005-04-16 773
f81cff0d4067e4 Mike Frysinger 2006-12-06 774 if (!len)
^1da177e4c3f41 Linus Torvalds 2005-04-16 775 return -EINVAL;
^1da177e4c3f41 Linus Torvalds 2005-04-16 776
f81cff0d4067e4 Mike Frysinger 2006-12-06 777 /* Careful about overflows.. */
8feae13110d60c David Howells 2009-01-08 778 rlen = PAGE_ALIGN(len);
8feae13110d60c David Howells 2009-01-08 779 if (!rlen || rlen > TASK_SIZE)
f81cff0d4067e4 Mike Frysinger 2006-12-06 780 return -ENOMEM;
f81cff0d4067e4 Mike Frysinger 2006-12-06 781
^1da177e4c3f41 Linus Torvalds 2005-04-16 782 /* offset overflow? */
8feae13110d60c David Howells 2009-01-08 783 if ((pgoff + (rlen >> PAGE_SHIFT)) < pgoff)
f81cff0d4067e4 Mike Frysinger 2006-12-06 784 return -EOVERFLOW;
^1da177e4c3f41 Linus Torvalds 2005-04-16 785
^1da177e4c3f41 Linus Torvalds 2005-04-16 786 if (file) {
^1da177e4c3f41 Linus Torvalds 2005-04-16 787 /* files must support mmap */
72c2d531920048 Al Viro 2013-09-22 788 if (!file->f_op->mmap)
^1da177e4c3f41 Linus Torvalds 2005-04-16 789 return -ENODEV;
^1da177e4c3f41 Linus Torvalds 2005-04-16 790
^1da177e4c3f41 Linus Torvalds 2005-04-16 791 /* work out if what we've got could possibly be shared
^1da177e4c3f41 Linus Torvalds 2005-04-16 792 * - we support chardevs that provide their own "memory"
^1da177e4c3f41 Linus Torvalds 2005-04-16 793 * - we support files/blockdevs that are memory backed
^1da177e4c3f41 Linus Torvalds 2005-04-16 794 */
b4caecd48005fb Christoph Hellwig 2015-01-14 795 if (file->f_op->mmap_capabilities) {
b4caecd48005fb Christoph Hellwig 2015-01-14 796 capabilities = file->f_op->mmap_capabilities(file);
b4caecd48005fb Christoph Hellwig 2015-01-14 797 } else {
^1da177e4c3f41 Linus Torvalds 2005-04-16 798 /* no explicit capabilities set, so assume some
^1da177e4c3f41 Linus Torvalds 2005-04-16 799 * defaults */
496ad9aa8ef448 Al Viro 2013-01-23 800 switch (file_inode(file)->i_mode & S_IFMT) {
^1da177e4c3f41 Linus Torvalds 2005-04-16 801 case S_IFREG:
^1da177e4c3f41 Linus Torvalds 2005-04-16 802 case S_IFBLK:
b4caecd48005fb Christoph Hellwig 2015-01-14 803 capabilities = NOMMU_MAP_COPY;
^1da177e4c3f41 Linus Torvalds 2005-04-16 804 break;
^1da177e4c3f41 Linus Torvalds 2005-04-16 805
^1da177e4c3f41 Linus Torvalds 2005-04-16 806 case S_IFCHR:
^1da177e4c3f41 Linus Torvalds 2005-04-16 807 capabilities =
b4caecd48005fb Christoph Hellwig 2015-01-14 808 NOMMU_MAP_DIRECT |
b4caecd48005fb Christoph Hellwig 2015-01-14 809 NOMMU_MAP_READ |
b4caecd48005fb Christoph Hellwig 2015-01-14 810 NOMMU_MAP_WRITE;
^1da177e4c3f41 Linus Torvalds 2005-04-16 811 break;
^1da177e4c3f41 Linus Torvalds 2005-04-16 812
^1da177e4c3f41 Linus Torvalds 2005-04-16 813 default:
^1da177e4c3f41 Linus Torvalds 2005-04-16 814 return -EINVAL;
^1da177e4c3f41 Linus Torvalds 2005-04-16 815 }
^1da177e4c3f41 Linus Torvalds 2005-04-16 816 }
^1da177e4c3f41 Linus Torvalds 2005-04-16 817
^1da177e4c3f41 Linus Torvalds 2005-04-16 818 /* eliminate any capabilities that we can't support on this
^1da177e4c3f41 Linus Torvalds 2005-04-16 819 * device */
^1da177e4c3f41 Linus Torvalds 2005-04-16 820 if (!file->f_op->get_unmapped_area)
b4caecd48005fb Christoph Hellwig 2015-01-14 821 capabilities &= ~NOMMU_MAP_DIRECT;
6e242a1ceeb1bc Al Viro 2015-03-31 822 if (!(file->f_mode & FMODE_CAN_READ))
b4caecd48005fb Christoph Hellwig 2015-01-14 823 capabilities &= ~NOMMU_MAP_COPY;
^1da177e4c3f41 Linus Torvalds 2005-04-16 824
28d7a6ae92c099 Graff Yang 2009-08-18 825 /* The file shall have been opened with read permission. */
28d7a6ae92c099 Graff Yang 2009-08-18 826 if (!(file->f_mode & FMODE_READ))
28d7a6ae92c099 Graff Yang 2009-08-18 827 return -EACCES;
28d7a6ae92c099 Graff Yang 2009-08-18 828
^1da177e4c3f41 Linus Torvalds 2005-04-16 829 if (flags & MAP_SHARED) {
^1da177e4c3f41 Linus Torvalds 2005-04-16 830 /* do checks for writing, appending and locking */
^1da177e4c3f41 Linus Torvalds 2005-04-16 831 if ((prot & PROT_WRITE) &&
^1da177e4c3f41 Linus Torvalds 2005-04-16 832 !(file->f_mode & FMODE_WRITE))
^1da177e4c3f41 Linus Torvalds 2005-04-16 833 return -EACCES;
^1da177e4c3f41 Linus Torvalds 2005-04-16 834
496ad9aa8ef448 Al Viro 2013-01-23 835 if (IS_APPEND(file_inode(file)) &&
^1da177e4c3f41 Linus Torvalds 2005-04-16 836 (file->f_mode & FMODE_WRITE))
^1da177e4c3f41 Linus Torvalds 2005-04-16 837 return -EACCES;
^1da177e4c3f41 Linus Torvalds 2005-04-16 838
d7a06983a01a33 Jeff Layton 2014-03-10 839 if (locks_verify_locked(file))
^1da177e4c3f41 Linus Torvalds 2005-04-16 840 return -EAGAIN;
^1da177e4c3f41 Linus Torvalds 2005-04-16 841
b4caecd48005fb Christoph Hellwig 2015-01-14 842 if (!(capabilities & NOMMU_MAP_DIRECT))
^1da177e4c3f41 Linus Torvalds 2005-04-16 843 return -ENODEV;
^1da177e4c3f41 Linus Torvalds 2005-04-16 844
^1da177e4c3f41 Linus Torvalds 2005-04-16 845 /* we mustn't privatise shared mappings */
b4caecd48005fb Christoph Hellwig 2015-01-14 846 capabilities &= ~NOMMU_MAP_COPY;
ac7149045d9fcc Choi Gi-yong 2014-04-07 847 } else {
^1da177e4c3f41 Linus Torvalds 2005-04-16 848 /* we're going to read the file into private memory we
^1da177e4c3f41 Linus Torvalds 2005-04-16 849 * allocate */
b4caecd48005fb Christoph Hellwig 2015-01-14 850 if (!(capabilities & NOMMU_MAP_COPY))
^1da177e4c3f41 Linus Torvalds 2005-04-16 851 return -ENODEV;
^1da177e4c3f41 Linus Torvalds 2005-04-16 852
^1da177e4c3f41 Linus Torvalds 2005-04-16 853 /* we don't permit a private writable mapping to be
^1da177e4c3f41 Linus Torvalds 2005-04-16 854 * shared with the backing device */
^1da177e4c3f41 Linus Torvalds 2005-04-16 855 if (prot & PROT_WRITE)
b4caecd48005fb Christoph Hellwig 2015-01-14 856 capabilities &= ~NOMMU_MAP_DIRECT;
^1da177e4c3f41 Linus Torvalds 2005-04-16 857 }
^1da177e4c3f41 Linus Torvalds 2005-04-16 858
b4caecd48005fb Christoph Hellwig 2015-01-14 859 if (capabilities & NOMMU_MAP_DIRECT) {
b4caecd48005fb Christoph Hellwig 2015-01-14 860 if (((prot & PROT_READ) && !(capabilities & NOMMU_MAP_READ)) ||
b4caecd48005fb Christoph Hellwig 2015-01-14 861 ((prot & PROT_WRITE) && !(capabilities & NOMMU_MAP_WRITE)) ||
b4caecd48005fb Christoph Hellwig 2015-01-14 862 ((prot & PROT_EXEC) && !(capabilities & NOMMU_MAP_EXEC))
3c7b204547bc3d Bernd Schmidt 2010-05-25 863 ) {
b4caecd48005fb Christoph Hellwig 2015-01-14 864 capabilities &= ~NOMMU_MAP_DIRECT;
3c7b204547bc3d Bernd Schmidt 2010-05-25 865 if (flags & MAP_SHARED) {
22cc877b32202b Leon Romanovsky 2015-06-24 866 pr_warn("MAP_SHARED not completely supported on !MMU\n");
3c7b204547bc3d Bernd Schmidt 2010-05-25 867 return -EINVAL;
3c7b204547bc3d Bernd Schmidt 2010-05-25 868 }
3c7b204547bc3d Bernd Schmidt 2010-05-25 869 }
3c7b204547bc3d Bernd Schmidt 2010-05-25 870 }
3c7b204547bc3d Bernd Schmidt 2010-05-25 871
^1da177e4c3f41 Linus Torvalds 2005-04-16 872 /* handle executable mappings and implied executable
^1da177e4c3f41 Linus Torvalds 2005-04-16 873 * mappings */
90f8572b0f021f Eric W. Biederman 2015-06-29 874 if (path_noexec(&file->f_path)) {
^1da177e4c3f41 Linus Torvalds 2005-04-16 875 if (prot & PROT_EXEC)
^1da177e4c3f41 Linus Torvalds 2005-04-16 876 return -EPERM;
ac7149045d9fcc Choi Gi-yong 2014-04-07 877 } else if ((prot & PROT_READ) && !(prot & PROT_EXEC)) {
^1da177e4c3f41 Linus Torvalds 2005-04-16 878 /* handle implication of PROT_EXEC by PROT_READ */
^1da177e4c3f41 Linus Torvalds 2005-04-16 879 if (current->personality & READ_IMPLIES_EXEC) {
b4caecd48005fb Christoph Hellwig 2015-01-14 880 if (capabilities & NOMMU_MAP_EXEC)
^1da177e4c3f41 Linus Torvalds 2005-04-16 @881 prot |= PROT_EXEC;
^1da177e4c3f41 Linus Torvalds 2005-04-16 882 }
ac7149045d9fcc Choi Gi-yong 2014-04-07 883 } else if ((prot & PROT_READ) &&
^1da177e4c3f41 Linus Torvalds 2005-04-16 884 (prot & PROT_EXEC) &&
b4caecd48005fb Christoph Hellwig 2015-01-14 885 !(capabilities & NOMMU_MAP_EXEC)
^1da177e4c3f41 Linus Torvalds 2005-04-16 886 ) {
^1da177e4c3f41 Linus Torvalds 2005-04-16 887 /* backing file is not executable, try to copy */
b4caecd48005fb Christoph Hellwig 2015-01-14 888 capabilities &= ~NOMMU_MAP_DIRECT;
^1da177e4c3f41 Linus Torvalds 2005-04-16 889 }
ac7149045d9fcc Choi Gi-yong 2014-04-07 890 } else {
^1da177e4c3f41 Linus Torvalds 2005-04-16 891 /* anonymous mappings are always memory backed and can be
^1da177e4c3f41 Linus Torvalds 2005-04-16 892 * privately mapped
^1da177e4c3f41 Linus Torvalds 2005-04-16 893 */
b4caecd48005fb Christoph Hellwig 2015-01-14 894 capabilities = NOMMU_MAP_COPY;
^1da177e4c3f41 Linus Torvalds 2005-04-16 895
^1da177e4c3f41 Linus Torvalds 2005-04-16 896 /* handle PROT_EXEC implication by PROT_READ */
^1da177e4c3f41 Linus Torvalds 2005-04-16 897 if ((prot & PROT_READ) &&
^1da177e4c3f41 Linus Torvalds 2005-04-16 898 (current->personality & READ_IMPLIES_EXEC))
^1da177e4c3f41 Linus Torvalds 2005-04-16 899 prot |= PROT_EXEC;
^1da177e4c3f41 Linus Torvalds 2005-04-16 900 }
^1da177e4c3f41 Linus Torvalds 2005-04-16 901
^1da177e4c3f41 Linus Torvalds 2005-04-16 902 /* allow the security API to have its say */
e5467859f7f79b Al Viro 2012-05-30 903 ret = security_mmap_addr(addr);
^1da177e4c3f41 Linus Torvalds 2005-04-16 904 if (ret < 0)
^1da177e4c3f41 Linus Torvalds 2005-04-16 905 return ret;
^1da177e4c3f41 Linus Torvalds 2005-04-16 906
^1da177e4c3f41 Linus Torvalds 2005-04-16 907 /* looks okay */
^1da177e4c3f41 Linus Torvalds 2005-04-16 908 *_capabilities = capabilities;
^1da177e4c3f41 Linus Torvalds 2005-04-16 909 return 0;
^1da177e4c3f41 Linus Torvalds 2005-04-16 910 }
^1da177e4c3f41 Linus Torvalds 2005-04-16 911
^1da177e4c3f41 Linus Torvalds 2005-04-16 912 /*
^1da177e4c3f41 Linus Torvalds 2005-04-16 913 * we've determined that we can make the mapping, now translate what we
^1da177e4c3f41 Linus Torvalds 2005-04-16 914 * now know into VMA flags
^1da177e4c3f41 Linus Torvalds 2005-04-16 915 */
^1da177e4c3f41 Linus Torvalds 2005-04-16 916 static unsigned long determine_vm_flags(struct file *file,
^1da177e4c3f41 Linus Torvalds 2005-04-16 917 unsigned long prot,
^1da177e4c3f41 Linus Torvalds 2005-04-16 918 unsigned long flags,
^1da177e4c3f41 Linus Torvalds 2005-04-16 919 unsigned long capabilities)
^1da177e4c3f41 Linus Torvalds 2005-04-16 920 {
^1da177e4c3f41 Linus Torvalds 2005-04-16 921 unsigned long vm_flags;
^1da177e4c3f41 Linus Torvalds 2005-04-16 922
e6bfb70959a0ca Dave Hansen 2016-02-12 923 vm_flags = calc_vm_prot_bits(prot, 0) | calc_vm_flag_bits(flags);
^1da177e4c3f41 Linus Torvalds 2005-04-16 924 /* vm_flags |= mm->def_flags; */
^1da177e4c3f41 Linus Torvalds 2005-04-16 925
b4caecd48005fb Christoph Hellwig 2015-01-14 926 if (!(capabilities & NOMMU_MAP_DIRECT)) {
^1da177e4c3f41 Linus Torvalds 2005-04-16 927 /* attempt to share read-only copies of mapped file chunks */
3c7b204547bc3d Bernd Schmidt 2010-05-25 928 vm_flags |= VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC;
^1da177e4c3f41 Linus Torvalds 2005-04-16 929 if (file && !(prot & PROT_WRITE))
^1da177e4c3f41 Linus Torvalds 2005-04-16 930 vm_flags |= VM_MAYSHARE;
3c7b204547bc3d Bernd Schmidt 2010-05-25 931 } else {
^1da177e4c3f41 Linus Torvalds 2005-04-16 932 /* overlay a shareable mapping on the backing device or inode
^1da177e4c3f41 Linus Torvalds 2005-04-16 933 * if possible - used for chardevs, ramfs/tmpfs/shmfs and
^1da177e4c3f41 Linus Torvalds 2005-04-16 934 * romfs/cramfs */
b4caecd48005fb Christoph Hellwig 2015-01-14 935 vm_flags |= VM_MAYSHARE | (capabilities & NOMMU_VMFLAGS);
^1da177e4c3f41 Linus Torvalds 2005-04-16 936 if (flags & MAP_SHARED)
3c7b204547bc3d Bernd Schmidt 2010-05-25 937 vm_flags |= VM_SHARED;
^1da177e4c3f41 Linus Torvalds 2005-04-16 938 }
^1da177e4c3f41 Linus Torvalds 2005-04-16 939
^1da177e4c3f41 Linus Torvalds 2005-04-16 940 /* refuse to let anyone share private mappings with this process if
^1da177e4c3f41 Linus Torvalds 2005-04-16 941 * it's being traced - otherwise breakpoints set in it may interfere
^1da177e4c3f41 Linus Torvalds 2005-04-16 942 * with another untraced process
^1da177e4c3f41 Linus Torvalds 2005-04-16 943 */
a288eecce5253c Tejun Heo 2011-06-17 944 if ((flags & MAP_PRIVATE) && current->ptrace)
^1da177e4c3f41 Linus Torvalds 2005-04-16 945 vm_flags &= ~VM_MAYSHARE;
^1da177e4c3f41 Linus Torvalds 2005-04-16 946
^1da177e4c3f41 Linus Torvalds 2005-04-16 947 return vm_flags;
^1da177e4c3f41 Linus Torvalds 2005-04-16 948 }
^1da177e4c3f41 Linus Torvalds 2005-04-16 949
^1da177e4c3f41 Linus Torvalds 2005-04-16 950 /*
8feae13110d60c David Howells 2009-01-08 951 * set up a shared mapping on a file (the driver or filesystem provides and
8feae13110d60c David Howells 2009-01-08 952 * pins the storage)
^1da177e4c3f41 Linus Torvalds 2005-04-16 953 */
8feae13110d60c David Howells 2009-01-08 954 static int do_mmap_shared_file(struct vm_area_struct *vma)
^1da177e4c3f41 Linus Torvalds 2005-04-16 955 {
^1da177e4c3f41 Linus Torvalds 2005-04-16 956 int ret;
^1da177e4c3f41 Linus Torvalds 2005-04-16 957
f74ac01520c9f6 Miklos Szeredi 2017-02-20 958 ret = call_mmap(vma->vm_file, vma);
dd8632a12e500a Paul Mundt 2009-01-08 959 if (ret == 0) {
dd8632a12e500a Paul Mundt 2009-01-08 960 vma->vm_region->vm_top = vma->vm_region->vm_end;
645d83c5db970a David Howells 2009-09-24 961 return 0;
dd8632a12e500a Paul Mundt 2009-01-08 962 }
^1da177e4c3f41 Linus Torvalds 2005-04-16 963 if (ret != -ENOSYS)
^1da177e4c3f41 Linus Torvalds 2005-04-16 964 return ret;
^1da177e4c3f41 Linus Torvalds 2005-04-16 965
3fa30460ea5021 David Howells 2010-03-23 966 /* getting -ENOSYS indicates that direct mmap isn't possible (as
3fa30460ea5021 David Howells 2010-03-23 967 * opposed to tried but failed) so we can only give a suitable error as
3fa30460ea5021 David Howells 2010-03-23 968 * it's not possible to make a private copy if MAP_SHARED was given */
^1da177e4c3f41 Linus Torvalds 2005-04-16 969 return -ENODEV;
^1da177e4c3f41 Linus Torvalds 2005-04-16 970 }
^1da177e4c3f41 Linus Torvalds 2005-04-16 971
^1da177e4c3f41 Linus Torvalds 2005-04-16 972 /*
^1da177e4c3f41 Linus Torvalds 2005-04-16 973 * set up a private mapping or an anonymous shared mapping
^1da177e4c3f41 Linus Torvalds 2005-04-16 974 */
8feae13110d60c David Howells 2009-01-08 975 static int do_mmap_private(struct vm_area_struct *vma,
8feae13110d60c David Howells 2009-01-08 976 struct vm_region *region,
645d83c5db970a David Howells 2009-09-24 977 unsigned long len,
645d83c5db970a David Howells 2009-09-24 978 unsigned long capabilities)
^1da177e4c3f41 Linus Torvalds 2005-04-16 979 {
dbc8358c72373d Joonsoo Kim 2014-12-12 980 unsigned long total, point;
^1da177e4c3f41 Linus Torvalds 2005-04-16 981 void *base;
8feae13110d60c David Howells 2009-01-08 982 int ret, order;
^1da177e4c3f41 Linus Torvalds 2005-04-16 983
^1da177e4c3f41 Linus Torvalds 2005-04-16 984 /* invoke the file's mapping function so that it can keep track of
^1da177e4c3f41 Linus Torvalds 2005-04-16 985 * shared mappings on devices or memory
^1da177e4c3f41 Linus Torvalds 2005-04-16 986 * - VM_MAYSHARE will be set if it may attempt to share
^1da177e4c3f41 Linus Torvalds 2005-04-16 987 */
b4caecd48005fb Christoph Hellwig 2015-01-14 988 if (capabilities & NOMMU_MAP_DIRECT) {
f74ac01520c9f6 Miklos Szeredi 2017-02-20 989 ret = call_mmap(vma->vm_file, vma);
dd8632a12e500a Paul Mundt 2009-01-08 990 if (ret == 0) {
^1da177e4c3f41 Linus Torvalds 2005-04-16 991 /* shouldn't return success if we're not sharing */
dd8632a12e500a Paul Mundt 2009-01-08 992 BUG_ON(!(vma->vm_flags & VM_MAYSHARE));
dd8632a12e500a Paul Mundt 2009-01-08 993 vma->vm_region->vm_top = vma->vm_region->vm_end;
645d83c5db970a David Howells 2009-09-24 994 return 0;
^1da177e4c3f41 Linus Torvalds 2005-04-16 995 }
dd8632a12e500a Paul Mundt 2009-01-08 996 if (ret != -ENOSYS)
dd8632a12e500a Paul Mundt 2009-01-08 997 return ret;
^1da177e4c3f41 Linus Torvalds 2005-04-16 998
^1da177e4c3f41 Linus Torvalds 2005-04-16 999 /* getting an ENOSYS error indicates that direct mmap isn't
^1da177e4c3f41 Linus Torvalds 2005-04-16 1000 * possible (as opposed to tried but failed) so we'll try to
^1da177e4c3f41 Linus Torvalds 2005-04-16 1001 * make a private copy of the data and map that instead */
^1da177e4c3f41 Linus Torvalds 2005-04-16 1002 }
^1da177e4c3f41 Linus Torvalds 2005-04-16 1003
8feae13110d60c David Howells 2009-01-08 1004
^1da177e4c3f41 Linus Torvalds 2005-04-16 1005 /* allocate some memory to hold the mapping
^1da177e4c3f41 Linus Torvalds 2005-04-16 1006 * - note that this may not return a page-aligned address if the object
^1da177e4c3f41 Linus Torvalds 2005-04-16 1007 * we're allocating is smaller than a page
^1da177e4c3f41 Linus Torvalds 2005-04-16 1008 */
f67d9b1576c1c6 Bob Liu 2011-05-24 1009 order = get_order(len);
8feae13110d60c David Howells 2009-01-08 @1010 total = 1 << order;
f67d9b1576c1c6 Bob Liu 2011-05-24 1011 point = len >> PAGE_SHIFT;
dd8632a12e500a Paul Mundt 2009-01-08 1012
dbc8358c72373d Joonsoo Kim 2014-12-12 1013 /* we don't want to allocate a power-of-2 sized page set */
22cc877b32202b Leon Romanovsky 2015-06-24 1014 if (sysctl_nr_trim_pages && total - point >= sysctl_nr_trim_pages)
dbc8358c72373d Joonsoo Kim 2014-12-12 1015 total = point;
8feae13110d60c David Howells 2009-01-08 1016
da616534ed7f6e Joonsoo Kim 2015-02-27 1017 base = alloc_pages_exact(total << PAGE_SHIFT, GFP_KERNEL);
dbc8358c72373d Joonsoo Kim 2014-12-12 1018 if (!base)
dbc8358c72373d Joonsoo Kim 2014-12-12 1019 goto enomem;
dbc8358c72373d Joonsoo Kim 2014-12-12 1020
dbc8358c72373d Joonsoo Kim 2014-12-12 1021 atomic_long_add(total, &mmap_pages_allocated);
8feae13110d60c David Howells 2009-01-08 1022
8feae13110d60c David Howells 2009-01-08 1023 region->vm_flags = vma->vm_flags |= VM_MAPPED_COPY;
8feae13110d60c David Howells 2009-01-08 1024 region->vm_start = (unsigned long) base;
f67d9b1576c1c6 Bob Liu 2011-05-24 1025 region->vm_end = region->vm_start + len;
dd8632a12e500a Paul Mundt 2009-01-08 1026 region->vm_top = region->vm_start + (total << PAGE_SHIFT);
8feae13110d60c David Howells 2009-01-08 1027
8feae13110d60c David Howells 2009-01-08 1028 vma->vm_start = region->vm_start;
8feae13110d60c David Howells 2009-01-08 1029 vma->vm_end = region->vm_start + len;
^1da177e4c3f41 Linus Torvalds 2005-04-16 1030
^1da177e4c3f41 Linus Torvalds 2005-04-16 1031 if (vma->vm_file) {
^1da177e4c3f41 Linus Torvalds 2005-04-16 1032 /* read the contents of a file into the copy */
^1da177e4c3f41 Linus Torvalds 2005-04-16 1033 loff_t fpos;
^1da177e4c3f41 Linus Torvalds 2005-04-16 1034
^1da177e4c3f41 Linus Torvalds 2005-04-16 1035 fpos = vma->vm_pgoff;
^1da177e4c3f41 Linus Torvalds 2005-04-16 1036 fpos <<= PAGE_SHIFT;
^1da177e4c3f41 Linus Torvalds 2005-04-16 1037
b4bf802a5a6563 Christoph Hellwig 2017-09-01 1038 ret = kernel_read(vma->vm_file, base, len, &fpos);
^1da177e4c3f41 Linus Torvalds 2005-04-16 1039 if (ret < 0)
^1da177e4c3f41 Linus Torvalds 2005-04-16 1040 goto error_free;
^1da177e4c3f41 Linus Torvalds 2005-04-16 1041
^1da177e4c3f41 Linus Torvalds 2005-04-16 1042 /* clear the last little bit */
f67d9b1576c1c6 Bob Liu 2011-05-24 1043 if (ret < len)
f67d9b1576c1c6 Bob Liu 2011-05-24 1044 memset(base + ret, 0, len - ret);
^1da177e4c3f41 Linus Torvalds 2005-04-16 1045
bfd40eaff5abb9 Kirill A. Shutemov 2018-07-26 1046 } else {
bfd40eaff5abb9 Kirill A. Shutemov 2018-07-26 1047 vma_set_anonymous(vma);
^1da177e4c3f41 Linus Torvalds 2005-04-16 1048 }
^1da177e4c3f41 Linus Torvalds 2005-04-16 1049
^1da177e4c3f41 Linus Torvalds 2005-04-16 1050 return 0;
^1da177e4c3f41 Linus Torvalds 2005-04-16 1051
^1da177e4c3f41 Linus Torvalds 2005-04-16 1052 error_free:
7223bb4a829628 Namhyung Kim 2011-05-24 1053 free_page_series(region->vm_start, region->vm_top);
8feae13110d60c David Howells 2009-01-08 1054 region->vm_start = vma->vm_start = 0;
8feae13110d60c David Howells 2009-01-08 1055 region->vm_end = vma->vm_end = 0;
dd8632a12e500a Paul Mundt 2009-01-08 1056 region->vm_top = 0;
^1da177e4c3f41 Linus Torvalds 2005-04-16 1057 return ret;
^1da177e4c3f41 Linus Torvalds 2005-04-16 1058
^1da177e4c3f41 Linus Torvalds 2005-04-16 1059 enomem:
b1de0d139c97a6 Mitchel Humpherys 2014-06-06 1060 pr_err("Allocation of length %lu from process %d (%s) failed\n",
05ae6fa31874ed Greg Ungerer 2009-01-13 1061 len, current->pid, current->comm);
9af744d743170b Michal Hocko 2017-02-22 1062 show_free_areas(0, NULL);
^1da177e4c3f41 Linus Torvalds 2005-04-16 1063 return -ENOMEM;
^1da177e4c3f41 Linus Torvalds 2005-04-16 1064 }
^1da177e4c3f41 Linus Torvalds 2005-04-16 1065
:::::: The code at line 1010 was first introduced by commit
:::::: 8feae13110d60cc6287afabc2887366b0eb226c2 NOMMU: Make VMAs per MM as for MMU-mode linux
:::::: TO: David Howells <dhowells@redhat.com>
:::::: CC: David Howells <dhowells@redhat.com>
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org
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2021-11-08 14:00 kernel test robot [this message]
-- strict thread matches above, loose matches on Subject: below --
2021-11-13 13:49 mm/nommu.c:1010:12: warning: The result of the left shift is undefined due to shifting by '32', which is greater or equal to the width of type 'int' [clang-analyzer-core.UndefinedBinaryOperatorResult] kernel test robot
2021-08-23 4:10 kernel test robot
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