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author | Owen Anderson <resistor@mac.com> | 2008-02-05 04:34:03 +0000 |
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committer | Owen Anderson <resistor@mac.com> | 2008-02-05 04:34:03 +0000 |
commit | a8701a6c62158b2b84cc24ed2149e4107d03409a (patch) | |
tree | fdd1166f57014a81508e62ea46d424b3f1d4a21e /lib/Analysis/MemoryDependenceAnalysis.cpp | |
parent | 131d5c9f4a33a86464432ac194459217cca73c6e (diff) | |
download | external_llvm-a8701a6c62158b2b84cc24ed2149e4107d03409a.zip external_llvm-a8701a6c62158b2b84cc24ed2149e4107d03409a.tar.gz external_llvm-a8701a6c62158b2b84cc24ed2149e4107d03409a.tar.bz2 |
Fix an obscure read-after-free bug that Duncan found.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46738 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Analysis/MemoryDependenceAnalysis.cpp')
-rw-r--r-- | lib/Analysis/MemoryDependenceAnalysis.cpp | 30 |
1 files changed, 20 insertions, 10 deletions
diff --git a/lib/Analysis/MemoryDependenceAnalysis.cpp b/lib/Analysis/MemoryDependenceAnalysis.cpp index 445e16d..60e9e6b 100644 --- a/lib/Analysis/MemoryDependenceAnalysis.cpp +++ b/lib/Analysis/MemoryDependenceAnalysis.cpp @@ -463,15 +463,17 @@ void MemoryDependenceAnalysis::removeInstruction(Instruction* rem) { reverseDep[depGraphLocal[rem].first].erase(rem); if (depGraphEntry->second.first != NonLocal && + depGraphEntry->second.first != None && depGraphEntry->second.second) { // If we have dep info for rem, set them to it BasicBlock::iterator RI = depGraphEntry->second.first; RI++; newDep = RI; - } else if (depGraphEntry->second.first == NonLocal && + } else if ( (depGraphEntry->second.first == NonLocal || + depGraphEntry->second.first == None ) && depGraphEntry->second.second ) { // If we have a confirmed non-local flag, use it - newDep = NonLocal; + newDep = depGraphEntry->second.first; } else { // Otherwise, use the immediate successor of rem // NOTE: This is because, when getDependence is called, it will first @@ -480,14 +482,22 @@ void MemoryDependenceAnalysis::removeInstruction(Instruction* rem) { RI++; newDep = RI; } - - SmallPtrSet<Instruction*, 4>& set = reverseDep[rem]; - for (SmallPtrSet<Instruction*, 4>::iterator I = set.begin(), E = set.end(); - I != E; ++I) { - // Insert the new dependencies - // Mark it as unconfirmed as long as it is not the non-local flag - depGraphLocal[*I] = std::make_pair(newDep, !newDep); - } + } else { + // Otherwise, use the immediate successor of rem + // NOTE: This is because, when getDependence is called, it will first + // check the immediate predecessor of what is in the cache. + BasicBlock::iterator RI = rem; + RI++; + newDep = RI; + } + + SmallPtrSet<Instruction*, 4>& set = reverseDep[rem]; + for (SmallPtrSet<Instruction*, 4>::iterator I = set.begin(), E = set.end(); + I != E; ++I) { + // Insert the new dependencies + // Mark it as unconfirmed as long as it is not the non-local flag + depGraphLocal[*I] = std::make_pair(newDep, (newDep == NonLocal || + newDep == None)); } depGraphLocal.erase(rem); |