summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorJan Kara <jack@suse.cz>2017-11-03 12:21:21 +0100
committerSasha Levin <alexander.levin@microsoft.com>2018-01-17 12:55:38 -0500
commita5579ec0173222b49e104e17aab63cd664d14024 (patch)
tree85269720a5241e9b6e4604697e53c9feea3150cb
parent7103f7e1bcc4f3387c371d7ad3f102597e84da0c (diff)
downloadlinux-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.h3
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.