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| author | David Gibson <david@gibson.dropbear.id.au> | 2015-09-03 10:08:23 +1000 |
|---|---|---|
| committer | David Gibson <david@gibson.dropbear.id.au> | 2015-09-23 10:51:09 +1000 |
| commit | 627c2ef7898794a28d706ecdf094491bebbb083a (patch) | |
| tree | 0d53ae00210a3b7dd6451a799bbcfea25bf433b2 | |
| parent | ad440b4ae0727dbef5cace419d94d774de96886c (diff) | |
spapr_drc: Fix potential undefined behaviour
The DRC_INDEX_ID_MASK macro does a left shift on ~0, which is a signed
quantity, and therefore undefined behaviour according to the C spec. In
particular this causes warnings from the clang sanitizer.
This fixes it by calculating the same mask without using ~0 (I think the
new method is a more common idiom for generating masks anyway). For good
measure I also use 1ULL to force the expression's type to unsigned long
long, which should be good for assigning to anything we're going to want
to.
Reported-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
| -rw-r--r-- | hw/ppc/spapr_drc.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/hw/ppc/spapr_drc.c b/hw/ppc/spapr_drc.c index ee874326ee..8cbcf4d346 100644 --- a/hw/ppc/spapr_drc.c +++ b/hw/ppc/spapr_drc.c @@ -32,7 +32,7 @@ #define DRC_CONTAINER_PATH "/dr-connector" #define DRC_INDEX_TYPE_SHIFT 28 -#define DRC_INDEX_ID_MASK (~(~0 << DRC_INDEX_TYPE_SHIFT)) +#define DRC_INDEX_ID_MASK ((1ULL << DRC_INDEX_TYPE_SHIFT) - 1) static sPAPRDRConnectorTypeShift get_type_shift(sPAPRDRConnectorType type) { |