Many bots buildling with make have been broken for several days, e.g.
http://lab.llvm.org:8011/builders/lld-x86_64-darwin13

llvm-svn: 342336

llvm-svn: 342148

When used in cross-DSO mode, CFI will generate calls to special functions rather than trap instructions.  For example, instead of generating

if (!InlinedFastCheck(f))
  abort();
call *f

CFI generates

if (!InlinedFastCheck(f))
  __cfi_slowpath(CallSiteTypeId, f);
call *f

This patch teaches cfi-verify to recognize calls to __cfi_slowpath and abort and treat them as trap functions.

In addition to normal symbols, we also parse the dynamic relocations to handle cross-DSO calls in libraries.

We also extend cfi-verify to recognize other patterns that occur using cross-DSO.  For example, some indirect calls are not guarded by a branch to a trap but instead follow a call to __cfi_slowpath.  For example:

if (!InlinedFastCheck(f))
  call *f
else {
  __cfi_slowpath(CallSiteTypeId, f);
  call *f
}

In this case, the second call to f is not marked as protected by the current code.  We thus recognize if indirect calls directly follow a call to a function that will trap on CFI violations and treat them as protected.

We also ignore indirect calls in the PLT, since on AArch64 each entry contains an indirect call that should not be protected by CFI, and these are labeled incorrectly when debug information is not present.

Differential Revision: https://reviews.llvm.org/D49383

llvm-svn: 340612

As suggested in the review for r337007, this makes cfi-verify abort on unsupported targets instead of producing incorrect results.  It also updates the design document to reflect this.

Differential Revision: https://reviews.llvm.org/D49304

llvm-svn: 337181

This patch adds support for AArch64 to cfi-verify.

This required three changes to cfi-verify.  First, it generalizes checking if an instruction is a trap by adding a new isTrap flag to TableGen (and defining it for x86 and AArch64).  Second, the code that ensures that the operand register is not clobbered between the CFI check and the indirect call needs to allow a single dereference (in x86 this happens as part of the jump instruction).  Third, we needed to ensure that return instructions are not counted as indirect branches.  Technically, returns are indirect branches and can be covered by CFI, but LLVM's forward-edge CFI does not protect them, and x86 does not consider them, so we keep that behavior.

In addition, we had to improve AArch64's code to evaluate the branch target of a MCInst to handle calls where the destination is not the first operand (which it often is not).

Differential Revision: https://reviews.llvm.org/D48836

llvm-svn: 337007

llvm-svn: 331835

llvm-svn: 324038

Summary:
This update now allows users to specify `--blame-context` and `--blame-context-all` to print source file blame information for the source of the blame.

Also updates the inline printing to correctly identify the top of the inlining stack for blame information.

Patch by Mitch Phillips!

Reviewers: vlad.tsyrklevich

Subscribers: llvm-commits, kcc, pcc

Differential Revision: https://reviews.llvm.org/D40111

llvm-svn: 324035

llvm-svn: 320631

We currently use target_link_libraries without an explicit scope
specifier (INTERFACE, PRIVATE or PUBLIC) when linking executables.
Dependencies added in this way apply to both the target and its
dependencies, i.e. they become part of the executable's link interface
and are transitive.

Transitive dependencies generally don't make sense for executables,
since you wouldn't normally be linking against an executable. This also
causes issues for generating install export files when using
LLVM_DISTRIBUTION_COMPONENTS. For example, clang has a lot of LLVM
library dependencies, which are currently added as interface
dependencies. If clang is in the distribution components but the LLVM
libraries it depends on aren't (which is a perfectly legitimate use case
if the LLVM libraries are being built static and there are therefore no
run-time dependencies on them), CMake will complain about the LLVM
libraries not being in export set when attempting to generate the
install export file for clang. This is reasonable behavior on CMake's
part, and the right thing is for LLVM's build system to explicitly use
PRIVATE dependencies for executables.

Unfortunately, CMake doesn't allow you to mix and match the keyword and
non-keyword target_link_libraries signatures for a single target; i.e.,
if a single call to target_link_libraries for a particular target uses
one of the INTERFACE, PRIVATE, or PUBLIC keywords, all other calls must
also be updated to use those keywords. This means we must do this change
in a single shot. I also fully expect to have missed some instances; I
tested by enabling all the projects in the monorepo (except dragonegg),
and configuring both with and without shared libraries, on both Darwin
and Linux, but I'm planning to rely on the buildbots for other
configurations (since it should be pretty easy to fix those).

Even after this change, we still have a lot of target_link_libraries
calls that don't specify a scope keyword, mostly for shared libraries.
I'm thinking about addressing those in a follow-up, but that's a
separate change IMO.

Differential Revision: https://reviews.llvm.org/D40823

llvm-svn: 319840

Summary:
This patch adds another failure mode for `validateCFIProtection(..)`, wherein any register that affects the indirect control flow instruction is clobbered to between the CFI-check and the instruction's execution.

Also includes a modification to make MCInstrDesc::hasDefOfPhysReg public.

Reviewers: vlad.tsyrklevich

Reviewed By: vlad.tsyrklevich

Subscribers: llvm-commits, pcc, kcc

Differential Revision: https://reviews.llvm.org/D39820

llvm-svn: 318238

Allows users to view GraphResult objects in a DOT directed-graph format. This feature can be turned on through the --print-graphs flag.

Also enabled pretty-printing of instructions in output. Together these features make analysis of unprotected CF instructions much easier by providing a visual control flow graph.

Reviewers: pcc

Subscribers: llvm-commits, kcc, vlad.tsyrklevich

Differential Revision: https://reviews.llvm.org/D39819

llvm-svn: 318211

Refactors the behaviour of building graphs out of FileAnalysis, allowing for analysis of the GraphResult by the callee without having to rebuild the graph. Means when we want to analyse the constructed graph (planned for later revisions), we don't do repeated work.

Also makes CFI verification in FileAnalysis now return an enum that allows us to differentiate why something failed, not just that it did/didn't fail.

Reviewers: vlad.tsyrklevich

Subscribers: kcc, pcc, llvm-commits

Differential Revision: https://reviews.llvm.org/D39764

llvm-svn: 317927

Adds the blacklist behaviour to llvm-cfi-verify. Now will calculate which lines caused expected failures in the blacklist and reports the number of affected indirect CF instructions for each blacklist entry.

Also moved DWARF checking after instruction analysis to improve performance significantly - unrolling the inlining stack is expensive.

Reviewers: vlad.tsyrklevich

Subscribers: aprantl, pcc, kcc, llvm-commits

Differential Revision: https://reviews.llvm.org/D39750

llvm-svn: 317743

[cfi-verify] Added a simple check that stops division-by-zero error when no indirect CF instructions are found in the provided file.

llvm-svn: 317500

Move the LLVMCFIVerify project into the Libraries folder on IDEs like Visual Studio rather than leave it in the root directory. NFC.

llvm-svn: 317415

Adds blacklist parsing behaviour for filtering results into four categories:

 - Expected Protected: Things that are not in the blacklist and are protected.
 - Unexpected Protected: Things that are in the blacklist and are protected.
 - Expected Unprotected: Things that are in the blacklist and are unprotected.
 - Unexpected Unprotected: Things that are not in the blacklist and are unprotected.

 now can optionally be invoked with a second command line argument, which specifies the blacklist file that the binary was built with.

Current  statistics for chromium:

Reviewers: vlad.tsyrklevich

Subscribers: mgorny, llvm-commits, pcc, kcc

Differential Revision: https://reviews.llvm.org/D39525

llvm-svn: 317364

cl::opt<uint64_t> fails when parsing command line arguments.

See https://bugs.llvm.org/show_bug.cgi?id=19665.

Reviewers: pcc

Subscribers: mgorny, llvm-commits, kcc

Differential Revision: https://reviews.llvm.org/D38657

llvm-svn: 317141

Summary: Help differentiate code and data by parsing DWARF information. This will reduce false positive rates where data is placed in executable sections and is mistakenly parsed as code, resulting in an inflation in the number of indirect CF instructions (and hence an inflation of the number of unprotected).

Also prints the DWARF line data around the region of each indirect CF instruction.

Reviewers: pcc

Subscribers: probinson, llvm-commits, vlad.tsyrklevich, mgorny, aprantl, kcc

Differential Revision: https://reviews.llvm.org/D38654

llvm-svn: 317050

Add a CFI protection check that is implemented by building a graph and inspecting the output to deduce if the indirect CF instruction is CFI protected. Also added the output of this instruction to printIndirectInstructions().

Reviewers: vlad.tsyrklevich

Subscribers: llvm-commits, kcc, pcc, mgorny

Differential Revision: https://reviews.llvm.org/D38428

llvm-svn: 316610

Subscribers: mgorny, aheejin

Differential Revision: https://reviews.llvm.org/D39250

llvm-svn: 316493

Patched out from D38427.

Reviewers: vlad.tsyrklevich

Reviewed By: vlad.tsyrklevich

Subscribers: llvm-commits, kcc, pcc, mgorny

Differential Revision: https://reviews.llvm.org/D39197

llvm-svn: 316375

Implement a localised graph builder for indirect control flow
instructions. Main interface is through GraphBuilder::buildFlowGraph,
which will build a flow graph around an indirect CF instruction. Various
modifications to FileVerifier are also made to const-expose some members
needed for machine code analysis done by the graph builder.

Reviewers: vlad.tsyrklevich

Reviewed By: vlad.tsyrklevich

Subscribers: llvm-commits, kcc, pcc

Differential Revision: https://reviews.llvm.org/D38427

llvm-svn: 316372

Accidently merged an incomplete upstream patch in 10e6ee563a6b5ca498f27972ca6dbe6c308f1ac2 - reverting the changes.

llvm-svn: 316359

llvm-svn: 316358

Summary:
llvm-cfi-verify (D38379) introduced a potential build failure when compiling with `-DLLVM_BUILD_LLVM_DYLIB=ON -DLLVM_LINK_LLVM_DYLIB=ON`. Specific versions of cmake seem to treat the `add_subdirectory()` rule differently. It seems as if old versions of cmake BFS these rules, adding them to the fringe for expansion later. Newer versions of cmake seem to immediately execute CMakeFiles that are present in this subdirectory.

If the subdirectory is expanded through the fringe, the globbing resultant from `llvm_add_implicit_projects()` from `cmake/modules/AddLLVM.cmake:1012` means that `tools/llvm-shlib/CMakeFile.txt` gets executed before `tools/llvm-cfi-verify/lib/CMakeFile.txt`. As the latter CMakeFile adds a new library, this expansion order means that the library files required the unit tests in `unittests/tools/llvm-cfi-verify/` are not present in the dynamic library. This causes unit tests to fail as the required functions can't be found.

This change now ensures that the libraries created by `llvm-cfi-verify` are statically linked into the unit tests. As `tools/llvm-cfi-verify/lib` no longer adds anything to `llvm-shlib`, there should be no concern about the order-of-compilation.

Reviewers: skatkov, pcc

Reviewed By: skatkov, pcc

Subscribers: llvm-commits, kcc, pcc, aheejin, vlad.tsyrklevich, mgorny

Differential Revision: https://reviews.llvm.org/D39020

llvm-svn: 316059

Add instruction analysis and machinecode traversal helpers in
preparation for control flow graph generation implementation.

Reviewers: vlad.tsyrklevich

Reviewed By: vlad.tsyrklevich

Subscribers: mgorny, llvm-commits, pcc, kcc

Differential Revision: https://reviews.llvm.org/D38424

llvm-svn: 315528

Summary: Move llvm-cfi-verify into a class in preparation for CFI analysis to come.

Reviewers: vlad.tsyrklevich

Reviewed By: vlad.tsyrklevich

Subscribers: mgorny, llvm-commits, pcc, kcc

Differential Revision: https://reviews.llvm.org/D38379

llvm-svn: 315504

This reverts commit r315363. It has a simple build failure, but more
importantly I want to confirm that unit tests run in check-all to make
sure that they don't silently break in the future.

llvm-svn: 315370

Summary: Move llvm-cfi-verify into a class in preparation for CFI analysis to come.

Reviewers: vlad.tsyrklevich

Reviewed By: vlad.tsyrklevich

Subscribers: mgorny, llvm-commits, pcc, kcc

Differential Revision: https://reviews.llvm.org/D38379

llvm-svn: 315363

Differential Revision: https://reviews.llvm.org/D38096

llvm-svn: 313817

Summary: Resubmission of D37937. Fixed i386 target building (conversion from std::size_t& to uint64_t& failed). Fixed documentation warning failure about docs/CFIVerify.rst not being in the tree.

Reviewers: vlad.tsyrklevich

Reviewed By: vlad.tsyrklevich

Patch by Mitch Phillips

Subscribers: sbc100, mgorny, pcc, llvm-commits, kcc

Differential Revision: https://reviews.llvm.org/D38089

llvm-svn: 313809

This reverts commit r313798, it's causing buildbot failures.

llvm-svn: 313804

Summary: Resubmission of D37937. Fixed i386 target building (conversion from std::size_t& to uint64_t& failed). Fixed documentation warning failure about docs/CFIVerify.rst not being in the tree.

Reviewers: vlad.tsyrklevich

Reviewed By: vlad.tsyrklevich

Patch by Mitch Phillips

Subscribers: mgorny, pcc, llvm-commits, kcc

Differential Revision: https://reviews.llvm.org/D38089

llvm-svn: 313798

This reverts commit r313688, it caused build failures for
llvm-i686-linux-RA

llvm-svn: 313689

Summary: Introduces the llvm-cfi-verify tool to llvm. Includes the design document (docs/CFIVerify.rst). Current implementation of the tool is simply a disassembler that identifies and prints the indirect control flow instructions.

Reviewers: vlad.tsyrklevich

Reviewed By: vlad.tsyrklevich

Patch by Mitch Phillips

Subscribers: llvm-commits, kcc, pcc, mgorny

Differential Revision: https://reviews.llvm.org/D37937

llvm-svn: 313688