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author | Jan Kara <jack@suse.cz> | 2017-11-03 12:21:21 +0100 |
---|---|---|
committer | Sasha Levin <alexander.levin@microsoft.com> | 2018-01-17 12:55:38 -0500 |
commit | a5579ec0173222b49e104e17aab63cd664d14024 (patch) | |
tree | 85269720a5241e9b6e4604697e53c9feea3150cb | |
parent | 7103f7e1bcc4f3387c371d7ad3f102597e84da0c (diff) | |
download | linux-rt-a5579ec0173222b49e104e17aab63cd664d14024.tar.gz |
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@microsoft.com>
-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. |