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| author | Hans Wennborg <hans@hanshq.net> | 2017-12-05 20:22:20 +0000 |
|---|---|---|
| committer | Hans Wennborg <hans@hanshq.net> | 2017-12-05 20:22:20 +0000 |
| commit | 5df9f0878be86ccff734eeaf51b20432787d655b (patch) | |
| tree | 1e31afc511a86357bce8c87df411e96374d5e7f3 /llvm/lib/CodeGen/StackProtector.cpp | |
| parent | 9d30c313f1d8d441cdc50e229ceb68d5fdbee38a (diff) | |
| download | llvm-5df9f0878be86ccff734eeaf51b20432787d655b.zip llvm-5df9f0878be86ccff734eeaf51b20432787d655b.tar.gz llvm-5df9f0878be86ccff734eeaf51b20432787d655b.tar.bz2 | |
Re-commit r319490 "XOR the frame pointer with the stack cookie when protecting the stack"
The patch originally broke Chromium (crbug.com/791714) due to its failing to
specify that the new pseudo instructions clobber EFLAGS. This commit fixes
that.
> 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: 319824
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 e334002..62cef95 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;) { |