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author | Filipe Cabecinhas <me@filcab.net> | 2018-07-16 13:41:54 +0000 |
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committer | Filipe Cabecinhas <me@filcab.net> | 2018-07-16 13:41:54 +0000 |
commit | f0786cf087d6740f281b7b8093066a47a706d29a (patch) | |
tree | 7c36c7078e24a4412cdc7b9f25c2d8c8a5009ff6 | |
parent | 18d98c75375cfbb4a4cffbdf6e21ec2f1458abaa (diff) |
[cfi] Don't pass a uint16_t to memset. Make sure the 16-bit constant is appropriate for us.
Reviewers: eugenis, pcc, kcc
Subscribers: delcypher, #sanitizers, llvm-commits
Differential Revision: https://reviews.llvm.org/D49252
git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@337170 91177308-0d34-0410-b5e6-96231b3b80d8
-rw-r--r-- | lib/cfi/cfi.cc | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/lib/cfi/cfi.cc b/lib/cfi/cfi.cc index 52f504bd2..5ee836569 100644 --- a/lib/cfi/cfi.cc +++ b/lib/cfi/cfi.cc @@ -132,7 +132,10 @@ void ShadowBuilder::Start() { void ShadowBuilder::AddUnchecked(uptr begin, uptr end) { uint16_t *shadow_begin = MemToShadow(begin, shadow_); uint16_t *shadow_end = MemToShadow(end - 1, shadow_) + 1; - memset(shadow_begin, kUncheckedShadow, + // memset takes a byte, so our unchecked shadow value requires both bytes to + // be the same. Make sure we're ok during compilation. + static_assert(kUncheckedShadow & 0xff == ((kUncheckedShadow >> 8) & 0xff)); + memset(shadow_begin, kUncheckedShadow & 0xff, (shadow_end - shadow_begin) * sizeof(*shadow_begin)); } |