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| author | Nick Mathewson <nickm@torproject.org> | 2017-12-20 09:34:25 -0500 |
|---|---|---|
| committer | Nick Mathewson <nickm@torproject.org> | 2017-12-20 09:37:18 -0500 |
| commit | accd0ea65bb817ad8f2361c5ca06c40ac9a9a11f (patch) | |
| tree | e8f11a2682cc219fcda06a792aa883e9620a616c | |
| parent | eecfed0cd2c8c92175106e211d1662fa43fc60bc (diff) | |
| download | tor-accd0ea65bb817ad8f2361c5ca06c40ac9a9a11f.tar.gz tor-accd0ea65bb817ad8f2361c5ca06c40ac9a9a11f.zip | |
Fix the clz32 and clz64 settings on MSVC.
Fixes bug 24633; bugfix on 0.2.9.1-alpha.
| -rw-r--r-- | changes/bug24633 | 5 | ||||
| -rw-r--r-- | src/ext/timeouts/timeout-bitops.c | 4 |
2 files changed, 7 insertions, 2 deletions
diff --git a/changes/bug24633 b/changes/bug24633 new file mode 100644 index 0000000000..028c7cc143 --- /dev/null +++ b/changes/bug24633 @@ -0,0 +1,5 @@ + o Minor bugfixes (portability, msvc): + - Fix a bug in the bit-counting parts of our timing-wheel code on + MSVC. (Note that MSVC is still not a supported build platform, + due to cyptographic timing channel risks.) Fixes bug 24633; + bugfix on 0.2.9.1-alpha. diff --git a/src/ext/timeouts/timeout-bitops.c b/src/ext/timeouts/timeout-bitops.c index a018f33b95..45466f6cb3 100644 --- a/src/ext/timeouts/timeout-bitops.c +++ b/src/ext/timeouts/timeout-bitops.c @@ -40,7 +40,7 @@ static __inline int clz32(unsigned long val) { DWORD zeros = 0; _BitScanReverse(&zeros, val); - return zeros; + return 31 - zeros; } #ifdef _WIN64 /* According to the documentation, these only exist on Win64. */ @@ -54,7 +54,7 @@ static __inline int clz64(uint64_t val) { DWORD zeros = 0; _BitScanReverse64(&zeros, val); - return zeros; + return 63 - zeros; } #else static __inline int ctz64(uint64_t val) |