Hi Adam, (2014/06/14 6:18), Adam Buchbinder wrote: > When running with UndefinedBehaviorSanitizer, the tests produce the following > error: > > radix-tree.c:836:30: runtime error: shift exponent 18446744073709551613 > is too large for 64-bit type 'unsigned long' > > (That's a negative shift exponent represented as an unsigned long.) > > Even though the value is discarded in those cases, it's still undefined > behavior; see the C99 standard, section 6.5.7, paragraph three: "If the > value of the right operand is negative [...] the behavior is undefined." > > Signed-off-by: Adam Buchbinder <[email protected]>
It looks good to me. Reviewed-by: Satoru Takeuchi <[email protected]> Thanks, Satoru > --- > radix-tree.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/radix-tree.c b/radix-tree.c > index 4f295fc..7457944 100644 > --- a/radix-tree.c > +++ b/radix-tree.c > @@ -833,10 +833,10 @@ int radix_tree_tagged(struct radix_tree_root *root, > unsigned int tag) > static unsigned long __maxindex(unsigned int height) > { > unsigned int tmp = height * RADIX_TREE_MAP_SHIFT; > - unsigned long index = (~0UL >> (RADIX_TREE_INDEX_BITS - tmp - 1)) >> 1; > + unsigned long index = ~0UL; > > - if (tmp >= RADIX_TREE_INDEX_BITS) > - index = ~0UL; > + if (tmp < RADIX_TREE_INDEX_BITS) > + index = (index >> (RADIX_TREE_INDEX_BITS - tmp - 1)) >> 1; > return index; > } > > -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
