3.18-stable review patch. If anyone has any objections, please let me know.
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From: Jan Kara jack@suse.cz
[ 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 --- include/linux/mman.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/include/linux/mman.h +++ b/include/linux/mman.h @@ -63,8 +63,9 @@ static inline int arch_validate_prot(uns * ("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.