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| author | Reid Kleckner <rnk@google.com> | 2017-11-30 22:41:21 +0000 |
|---|---|---|
| committer | Reid Kleckner <rnk@google.com> | 2017-11-30 22:41:21 +0000 |
| commit | ba4014e9dce96618ab4d8f820447df2a86023b74 (patch) | |
| tree | 378fd33b9c4ff2742645fa7f05fb1f2f8da439a3 /llvm/lib/CodeGen/StackProtector.cpp | |
| parent | 669cae1f28fee3b02ca536181279cf4bbf2314d2 (diff) | |
| download | bcm5719-llvm-ba4014e9dce96618ab4d8f820447df2a86023b74.tar.gz bcm5719-llvm-ba4014e9dce96618ab4d8f820447df2a86023b74.zip | |
XOR the frame pointer with the stack cookie when protecting the stack
Summary: This strengthens the guard and matches MSVC.
Reviewers: hans, etienneb
Subscribers: hiraditya, JDevlieghere, vlad.tsyrklevich, llvm-commits
Differential Revision: https://reviews.llvm.org/D40622
llvm-svn: 319490
Diffstat (limited to 'llvm/lib/CodeGen/StackProtector.cpp')
| -rw-r--r-- | llvm/lib/CodeGen/StackProtector.cpp | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/llvm/lib/CodeGen/StackProtector.cpp b/llvm/lib/CodeGen/StackProtector.cpp index e3340028863..62cef95a4af 100644 --- a/llvm/lib/CodeGen/StackProtector.cpp +++ b/llvm/lib/CodeGen/StackProtector.cpp @@ -385,8 +385,12 @@ static bool CreatePrologue(Function *F, Module *M, ReturnInst *RI, /// - The epilogue checks the value stored in the prologue against the original /// value. It calls __stack_chk_fail if they differ. bool StackProtector::InsertStackProtectors() { + // If the target wants to XOR the frame pointer into the guard value, it's + // impossible to emit the check in IR, so the target *must* support stack + // protection in SDAG. bool SupportsSelectionDAGSP = - EnableSelectionDAGSP && !TM->Options.EnableFastISel; + TLI->useStackGuardXorFP() || + (EnableSelectionDAGSP && !TM->Options.EnableFastISel); AllocaInst *AI = nullptr; // Place on stack that stores the stack guard. for (Function::iterator I = F->begin(), E = F->end(); I != E;) { |
