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* Protection against stack-based memory corruption errors using SafeStackPeter Collingbourne2015-06-152-1/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds the safe stack instrumentation pass to LLVM, which separates the program stack into a safe stack, which stores return addresses, register spills, and local variables that are statically verified to be accessed in a safe way, and the unsafe stack, which stores everything else. Such separation makes it much harder for an attacker to corrupt objects on the safe stack, including function pointers stored in spilled registers and return addresses. You can find more information about the safe stack, as well as other parts of or control-flow hijack protection technique in our OSDI paper on code-pointer integrity (http://dslab.epfl.ch/pubs/cpi.pdf) and our project website (http://levee.epfl.ch). The overhead of our implementation of the safe stack is very close to zero (0.01% on the Phoronix benchmarks). This is lower than the overhead of stack cookies, which are supported by LLVM and are commonly used today, yet the security guarantees of the safe stack are strictly stronger than stack cookies. In some cases, the safe stack improves performance due to better cache locality. Our current implementation of the safe stack is stable and robust, we used it to recompile multiple projects on Linux including Chromium, and we also recompiled the entire FreeBSD user-space system and more than 100 packages. We ran unit tests on the FreeBSD system and many of the packages and observed no errors caused by the safe stack. The safe stack is also fully binary compatible with non-instrumented code and can be applied to parts of a program selectively. This patch is our implementation of the safe stack on top of LLVM. The patches make the following changes: - Add the safestack function attribute, similar to the ssp, sspstrong and sspreq attributes. - Add the SafeStack instrumentation pass that applies the safe stack to all functions that have the safestack attribute. This pass moves all unsafe local variables to the unsafe stack with a separate stack pointer, whereas all safe variables remain on the regular stack that is managed by LLVM as usual. - Invoke the pass as the last stage before code generation (at the same time the existing cookie-based stack protector pass is invoked). - Add unit tests for the safe stack. Original patch by Volodymyr Kuznetsov and others at the Dependable Systems Lab at EPFL; updates and upstreaming by myself. Differential Revision: http://reviews.llvm.org/D6094 llvm-svn: 239761
* MIR Serialization: Connect the machine function analysis pass to the MIR parser.Alex Lorenz2015-06-154-33/+102
| | | | | | | | | | | | | | | | | | | | | This commit connects the machine function analysis pass (which creates machine functions) to the MIR parser, which will initialize the machine functions with the state from the MIR file and reconstruct the machine IR. This commit introduces a new interface called 'MachineFunctionInitializer', which can be used to provide custom initialization for the machine functions. This commit also introduces a new diagnostic class called 'DiagnosticInfoMIRParser' which is used for MIR parsing errors. This commit modifies the default diagnostic handling in LLVMContext - now the the diagnostics are printed directly into llvm::errs() so that the MIR parsing errors can be printed with colours. Reviewers: Justin Bogner Differential Revision: http://reviews.llvm.org/D9928 llvm-svn: 239753
* Unbreak the build from r239740.Sanjoy Das2015-06-151-4/+4
| | | | | | Do not re-use an enum name as a field name. Some bots don't like this. llvm-svn: 239746
* [CodeGen] Add a pass to fold null checks into nearby memory operations.Sanjoy Das2015-06-154-0/+270
| | | | | | | | | | | | | | | | | | | | | Summary: This change adds an "ImplicitNullChecks" target dependent pass. This pass folds null checks into memory operation using the FAULTING_LOAD pseudo-op introduced in previous patches. Depends on D10197 Depends on D10199 Depends on D10200 Reviewers: reames, rnk, pgavlin, JosephTremoulet, atrick Reviewed By: atrick Subscribers: ab, JosephTremoulet, llvm-commits Differential Revision: http://reviews.llvm.org/D10201 llvm-svn: 239743
* [TargetInstrInfo] Rename getLdStBaseRegImmOfs and implement for x86.Sanjoy Das2015-06-151-1/+1
| | | | | | | | | | | | | | | | | | | | | | | Summary: TargetInstrInfo::getLdStBaseRegImmOfs to TargetInstrInfo::getMemOpBaseRegImmOfs and implement for x86. The implementation only handles a few easy cases now and will be made more sophisticated in the future. This is NFCI: the only user of `getLdStBaseRegImmOfs` (now `getmemOpBaseRegImmOfs`) is `LoadClusterMotion` and `LoadClusterMotion` is disabled for x86. Reviewers: reames, ab, MatzeB, atrick Reviewed By: MatzeB, atrick Subscribers: llvm-commits Differential Revision: http://reviews.llvm.org/D10199 llvm-svn: 239741
* [CodeGen] Introduce a FAULTING_LOAD_OP pseudo-op.Sanjoy Das2015-06-152-0/+115
| | | | | | | | | | | | | | | | | | | | | | | | | | Summary: This instruction encodes a loading operation that may fault, and a label to branch to if the load page-faults. The locations of potentially faulting loads and their "handler" destinations are recorded in a FaultMap section, meant to be consumed by LLVM's clients. Nothing generates FAULTING_LOAD_OP instructions yet, but they will be used in a future change. The documentation (FaultMaps.rst) needs improvement and I will update this diff with a more expanded version shortly. Depends on D10196 Reviewers: rnk, reames, AndyAyers, ab, atrick, pgavlin Reviewed By: atrick, pgavlin Subscribers: llvm-commits Differential Revision: http://reviews.llvm.org/D10197 llvm-svn: 239740
* [MachineSink] Improve runtime performance. NFC.Arnaud A. de Grandmaison2015-06-151-35/+59
| | | | | | | | | | | | This patch fixes a compilation time issue, when MachineSink faces PHIs with a huge number of operands. This can happen for example in goto table based interpreters, where some basic blocks can have several of those PHIs, each one with several hundreds operands. MachineSink was spending a significant time re-building and re-sorting the list of successors of the current MachineBasicBlock. The computing and sorting of the current MachineBasicBlock successors is now cached. llvm-svn: 239720
* AsmPrinter.cpp: Avoid crashes for targeting like "arm-mingw32". CurrentFnSym ↵NAKAMURA Takumi2015-06-141-1/+2
| | | | | | might not be <MCSymbolELF> here. llvm-svn: 239692
* Reformat.NAKAMURA Takumi2015-06-141-5/+3
| | | | llvm-svn: 239691
* [DAGCombiner] Added BSWAP(BSWAP(x)) -> x combine pattern.Simon Pilgrim2015-06-131-0/+3
| | | | llvm-svn: 239682
* hoist loop-invariant; NFCISanjay Patel2015-06-131-3/+2
| | | | llvm-svn: 239681
* remove function names from comments and clean up; NFCSanjay Patel2015-06-131-58/+40
| | | | llvm-svn: 239680
* [SelectionDAG] Added assertions + UNDEF handling for BSWAP node creation.Simon Pilgrim2015-06-131-0/+8
| | | | llvm-svn: 239679
* remove unnecessary casts; NFCISanjay Patel2015-06-131-3/+2
| | | | llvm-svn: 239678
* [DAGCombiner] Added BSWAP vector constant folding support.Simon Pilgrim2015-06-132-0/+13
| | | | llvm-svn: 239675
* Stripped trailing whitespace. NFC.Simon Pilgrim2015-06-131-5/+5
| | | | llvm-svn: 239674
* Rename TargetSubtargetInfo::enablePostMachineScheduler() to ↵Matthias Braun2015-06-132-2/+2
| | | | | | | | | | | | | | enablePostRAScheduler() r213101 changed the behaviour of this method to not only affect the PostMachineScheduler scheduler but also the PostRAScheduler scheduler, renaming should make this fact clear. Also document that the preferred way is to specify this in the scheduling model instead of overriding this method. Differential Revision: http://reviews.llvm.org/D10427 llvm-svn: 239659
* MachineLICM: Use TargetSchedModel instead of just itinerariesMatthias Braun2015-06-132-12/+13
| | | | | | | | | This will use Itinieraries if available, but will also work if just a MCSchedModel is available. Differential Revision: http://reviews.llvm.org/D10428 llvm-svn: 239658
* [WinEH] Put finally pointers in the handler scope table fieldReid Kleckner2015-06-111-14/+13
| | | | | | | | | | We were putting them in the filter field, which is correct for 64-bit but wrong for 32-bit. Also switch the order of scope table entry emission so outermost entries are emitted first, and fix an obvious state assignment bug. llvm-svn: 239574
* [WinEH] Create an llvm.x86.seh.exceptioninfo intrinsicReid Kleckner2015-06-111-3/+18
| | | | | | | | | | | | | | This intrinsic is like framerecover plus a load. It recovers the EH registration stack allocation from the parent frame and loads the exception information field out of it, giving back a pointer to an EXCEPTION_POINTERS struct. It's designed for clang to use in SEH filter expressions instead of accessing the EXCEPTION_POINTERS parameter that is available on x64. This required a minor change to MC to allow defining a label variable to another absolute framerecover label variable. llvm-svn: 239567
* Replace string GNU Triples with llvm::Triple in TargetMachine. NFC.Daniel Sanders2015-06-111-3/+3
| | | | | | | | | | | | | | | | | | Summary: For the moment, TargetMachine::getTargetTriple() still returns a StringRef. This continues the patch series to eliminate StringRef forms of GNU triples from the internals of LLVM that began in r239036. Reviewers: rengolin Reviewed By: rengolin Subscribers: ted, llvm-commits, rengolin, jholewinski Differential Revision: http://reviews.llvm.org/D10362 llvm-svn: 239554
* [CodeGen] ArrayRef'ize cond/pred in various TII APIs. NFC.Ahmed Bougacha2015-06-111-3/+2
| | | | llvm-svn: 239553
* Generalize emitAbsoluteSymbolDiff.Rafael Espindola2015-06-111-19/+1
| | | | | | | | | | This makes emitAbsoluteSymbolDiff always succeed and moves logic from the asm printer to it. The object one now also works on ELF. If two symbols are in the same fragment, we will never move them apart. llvm-svn: 239552
* Revert "Fix merges of non-zero vector stores"Reid Kleckner2015-06-111-19/+6
| | | | | | | | This reverts commit r239539. It was causing SDAG assertions while building freetype. llvm-svn: 239543
* Fix merges of non-zero vector storesMatt Arsenault2015-06-111-6/+19
| | | | | | | | | | Now actually stores the non-zero constant instead of 0. I somehow forgot to include this part of r238108. The test change was just an independent instruction order swap, so just add another check line to satisfy CHECK-NEXT. llvm-svn: 239539
* remove function names from comments; NFCSanjay Patel2015-06-111-15/+13
| | | | llvm-svn: 239532
* [LiveVariables] Improve isLiveOut runtime performances. NFC.Arnaud A. de Grandmaison2015-06-111-31/+8
| | | | | | | | | | | | On large goto table based interpreters, where phi nodes can have (very) large fan-ins, isLiveOut exhibited poor performances: about 40% of the full codegen time was spent in PHIElim, sorting MachineBasicBlock addresses. This patch improve the performances for such cases, and does not show compile time regressions on the LNT, at bootstrap (llvm+clang+lldb) or any other benchmarks we have in-house. llvm-svn: 239510
* [PHIElim] Use ranges and const-ify, NFC.Arnaud A. de Grandmaison2015-06-111-12/+11
| | | | llvm-svn: 239508
* Remove MachineModuleInfo::UsedFunctions as it has no users.Pete Cooper2015-06-112-18/+0
| | | | | | | | | | It hasn't been used since r130964. This also removes MachineModuleInfo::isUsedFunction and MachineModuleInfo::AnalyzeModule, both of which were only there to support UsedFunctions. llvm-svn: 239501
* punctuation policing; NFCSanjay Patel2015-06-101-5/+5
| | | | llvm-svn: 239484
* [WinEH] _except_handlerN uses 0 instead of 1 to indicate catch-allReid Kleckner2015-06-101-6/+4
| | | | | | Our usage of 1 was a holdover from __C_specific_handler. llvm-svn: 239482
* fix typo in comment; NFCSanjay Patel2015-06-101-1/+1
| | | | llvm-svn: 239478
* [StatepointLowering] Reuse stack slots across basic blocksIgor Laevsky2015-06-101-66/+115
| | | | | | | | | | | During statepoint lowering we can sometimes avoid spilling of the value if we know that it was already spilled for previous statepoint. We were doing this by checking if incoming statepoint value was lowered into load from stack slot. This was working only in boundaries of one basic block. But instead of looking at the lowered node we can look directly at the llvm-ir value and if it was gc.relocate (or some simple modification of it) look up stack slot for it's derived pointer and reuse stack slot from it. This allows us to look across basic block boundaries. Differential Revision: http://reviews.llvm.org/D10251 llvm-svn: 239472
* Remove safeseh debug print and remove extra bracesReid Kleckner2015-06-101-5/+2
| | | | llvm-svn: 239449
* [WinEH] Emit .safeseh directives for all 32-bit exception handlersReid Kleckner2015-06-101-0/+8
| | | | | | | | | | Use a "safeseh" string attribute to do this. You would think we chould just accumulate the set of personalities like we do on dwarf, but this fails to account for the LSDA-loading thunks we use for __CxxFrameHandler3. Each of those needs to make it into .sxdata as well. The string attribute seemed like the most straightforward approach. llvm-svn: 239448
* Fix -Wsign-compare warning in WinException.cppReid Kleckner2015-06-101-1/+2
| | | | llvm-svn: 239445
* [RegisterScavenger] Fix handling of predicated instructionsTobias Edler von Koch2015-06-091-7/+3
| | | | | | | | | | | | | | | | | | | | | | | | | Summary: The RegisterScavenger explicitly ignores <kill> flags on operands of predicated instructions and therefore assumes that such registers remain live. When it then scavenges such a register, it inserts a spill of this (killed) register. This is invalid code and gets flagged up by the verifier. Nowadays kill flags are set correctly on predicated instructions. This patch makes the Scavenger respect them. The bug has so far only been triggered by an internal pass, so I don't have a test case unfortunately. Fixes PR23119. Reviewers: hfinkel, tobiasvk_caf Subscribers: llvm-commits Differential Revision: http://reviews.llvm.org/D9039 llvm-svn: 239439
* [WinEH] Add 32-bit SEH state table emission prototypeReid Kleckner2015-06-095-11/+125
| | | | | | | | | | | | This gets all the handler info through to the asm printer and we can look at the .xdata tables now. I've convinced one small catch-all test case to work, but other than that, it would be a stretch to say this is functional. The state numbering algorithm avoids doing any scope reconstruction as we do for C++ to simplify the implementation. llvm-svn: 239433
* Revert "[DWARF] Fix a few corner cases in expression emission"David Blaikie2015-06-093-33/+9
| | | | | | | This reverts commit r239380 due to apparently GDB regressions: http://lab.llvm.org:8011/builders/clang-x86_64-ubuntu-gdb-75/builds/22562 llvm-svn: 239420
* [DWARF] Fix a few corner cases in expression emissionKeno Fischer2015-06-093-9/+33
| | | | | | | | | | | | | | | | | | | Summary: I noticed an object file with `DW_OP_reg4 DW_OP_breg4 0` as a DWARF expression, which I traced to a missing break (and `++I`) in this code snippet. While I was at it, I also added support for a few other corner cases along the same lines that I could think of. Test Plan: Hand-crafted test case to exercises these cases is included. Reviewers: echristo, dblaikie, aprantl Reviewed By: aprantl Subscribers: llvm-commits Differential Revision: http://reviews.llvm.org/D10302 llvm-svn: 239380
* Implement computeKnownBits for min/max nodesMatt Arsenault2015-06-091-1/+22
| | | | llvm-svn: 239378
* MC: Add target hook to control symbol quotingMatt Arsenault2015-06-091-3/+4
| | | | llvm-svn: 239370
* [InstrInfo] Refactor foldOperandImpl to thread through InsertPt. NFCKeno Fischer2015-06-081-7/+8
| | | | | | | | | | | | | | | | | | Summary: This was a longstanding FIXME and is a necessary precursor to cases where foldOperandImpl may have to create more than one instruction (e.g. to constrain a register class). This is the split out NFC changes from D6262. Reviewers: pete, ributzka, uweigand, mcrosier Reviewed By: mcrosier Subscribers: mcrosier, ted, llvm-commits Differential Revision: http://reviews.llvm.org/D10174 llvm-svn: 239336
* [ARM] Pass a callback to FunctionPass constructors to enable skipping executionAkira Hatanaka2015-06-082-2/+24
| | | | | | | | | | | | | | | | on a per-function basis. Previously some of the passes were conditionally added to ARM's pass pipeline based on the target machine's subtarget. This patch makes changes to add those passes unconditionally and execute them conditonally based on the predicate functor passed to the pass constructors. This enables running different sets of passes for different functions in the module. rdar://problem/20542263 Differential Revision: http://reviews.llvm.org/D8717 llvm-svn: 239325
* Fix assertion failure in global-merge with unused ConstantExprOliver Stannard2015-06-081-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | The global-merge pass was crashing because it assumes that all ConstantExprs (reached via the global variables that they use) have at least one user. I haven't worked out a way to test this, as an unused ConstantExpr cannot be represented by serialised IR, and global-merge can only be run in llc, which does not run any passes which can make a ConstantExpr dead. This (reduced to the point of silliness) C code triggers this bug when compiled for arm-none-eabi at -O1: static a = 7; static volatile b[10] = {&a}; c; main() { c = 0; for (; c < 10;) printf(b[c]); } Differential Revision: http://reviews.llvm.org/D10314 llvm-svn: 239308
* [DAGCombiner] Added CTLZ vector constant folding support.Simon Pilgrim2015-06-082-2/+4
| | | | llvm-svn: 239305
* [DAGCombiner] Added CTTZ vector constant folding support.Simon Pilgrim2015-06-082-2/+4
| | | | llvm-svn: 239293
* [DAGCombiner] Added CTPOP vector constant folding support.Simon Pilgrim2015-06-072-2/+3
| | | | | | Added tests to the existing SSE/AVX test files. llvm-svn: 239252
* Move the code in TargetPassConfig::addPass that inserts machine printer pass toAkira Hatanaka2015-06-051-16/+18
| | | | | | | | | | | the overloaded version of addPass which takes Pass*. This change enables inserting the machine printer pass when the overloaded version of addPass that takes Pass* is called to add a pass, instead of the one which takes AnalysisID. I need this to prevent make-check tests from failing when I commit another patch later. llvm-svn: 239192
* DAGCombiner: don't duplicate (fmul x, c) in visitFNEG if fneg is freeFiona Glaser2015-06-051-1/+2
| | | | | | | | | | For targets with a free fneg, this fold is always a net loss if it ends up duplicating the multiply, so definitely avoid it. This might be true for some targets without a free fneg too, but I'll leave that for future investigation. llvm-svn: 239167
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