r360876 didn't fix 2 call sites in clang.
Expected<ArrayRef<uint8_t>> may be better but use Expected<StringRef> for now.
Follow-up of D61781.
llvm-svn: 360892
It broke the Clang build, see llvm-commits thread.
> Expected<ArrayRef<uint8_t>> may be better but use Expected<StringRef> for now.
>
> Follow-up of D61781.
llvm-svn: 360878
That patch is the fix for https://bugs.llvm.org/show_bug.cgi?id=40703
"wrong line number info for obj file compiled with -ffunction-sections"
bug. The problem happened with only .o files. If object file contains
several .text sections then line number information showed incorrectly.
The reason for this is that DwarfLineTable could not detect section which
corresponds to specified address(because address is the local to the
section). And as the result it could not select proper sequence in the
line table. The fix is to pass SectionIndex with the address. So that it
would be possible to differentiate addresses from various sections. With
this fix llvm-objdump shows correct line numbers for disassembled code.
Differential review: https://reviews.llvm.org/D58194
llvm-svn: 354972
to reflect the new license.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351636
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
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
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
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
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
