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| author | Jan Kara <jack@suse.cz> | 2017-11-03 12:21:21 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-12-20 10:04:59 +0100 |
| commit | b59614cfd2d3619eedc1b711ac51efb7636efba6 (patch) | |
| tree | 91ad3bafc5d682f5b797fed51c5b76650ffb2a53 | |
| parent | 44de70ecec2d9aaf2a0f0c790ae4bba592c6ca3a (diff) | |
| download | linux-stable-b59614cfd2d3619eedc1b711ac51efb7636efba6.tar.gz linux-stable-b59614cfd2d3619eedc1b711ac51efb7636efba6.tar.bz2 linux-stable-b59614cfd2d3619eedc1b711ac51efb7636efba6.zip | |
mm: Handle 0 flags in _calc_vm_trans() macro
[ Upstream commit 592e254502041f953e84d091eae2c68cba04c10b ]
_calc_vm_trans() does not handle the situation when some of the passed
flags are 0 (which can happen if these VM flags do not make sense for
the architecture). Improve the _calc_vm_trans() macro to return 0 in
such situation. Since all passed flags are constant, this does not add
any runtime overhead.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | include/linux/mman.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/include/linux/mman.h b/include/linux/mman.h index 16373c8f5f57..369bc3405a6d 100644 --- a/include/linux/mman.h +++ b/include/linux/mman.h @@ -63,8 +63,9 @@ static inline int arch_validate_prot(unsigned long prot) * ("bit1" and "bit2" must be single bits) */ #define _calc_vm_trans(x, bit1, bit2) \ + ((!(bit1) || !(bit2)) ? 0 : \ ((bit1) <= (bit2) ? ((x) & (bit1)) * ((bit2) / (bit1)) \ - : ((x) & (bit1)) / ((bit1) / (bit2))) + : ((x) & (bit1)) / ((bit1) / (bit2)))) /* * Combine the mmap "prot" argument into "vm_flags" used internally. |