Recommit [Object] Change object::SectionRef::getContents() to return Expected<StringRef>

r360876 didn't fix 2 call sites in clang.

Expected<ArrayRef<uint8_t>> may be better but use Expected<StringR

Recommit [Object] Change object::SectionRef::getContents() to return Expected<StringRef>

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

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Revert r360876 "[Object] Change object::SectionRef::getContents() to return Expected<StringRef>"

It broke the Clang build, see llvm-commits thread.

> Expected<ArrayRef<uint8_t>> may be better but u

Revert r360876 "[Object] Change object::SectionRef::getContents() to return Expected<StringRef>"

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

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[Object] Change object::SectionRef::getContents() to return Expected<StringRef>

Expected<ArrayRef<uint8_t>> may be better but use Expected<StringRef> for now.

Follow-up of D61781.

llvm-svn: 360876

[DebugInfo] add SectionedAddress to DebugInfo interfaces.

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

[DebugInfo] add SectionedAddress to DebugInfo interfaces.

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

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Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the ne

Update the file headers across all of the LLVM projects in the monorepo
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

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[cfi-verify] Support cross-DSO

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))

[cfi-verify] Support cross-DSO

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

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[cfi-verify] Abort on unsupported targets

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

[cfi-verify] Abort on unsupported targets

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

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[cfi-verify] Support AArch64.

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 n

[cfi-verify] Support AArch64.

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

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Remove redundant includes from tools.

llvm-svn: 320631

[cfi-verify] Validate there are no register clobbers between CFI-check and instruction execution.

Summary:
This patch adds another failure mode for `validateCFIProtection(..)`, wherein any register

[cfi-verify] Validate there are no register clobbers between CFI-check and instruction execution.

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

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[cfi-verify] Add DOT graph printing for GraphResult objects.

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

[cfi-verify] Add DOT graph printing for GraphResult objects.

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

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[cfi-verify] Made FileAnalysis operate on a GraphResult rather than build one and validate it.

Refactors the behaviour of building graphs out of FileAnalysis, allowing for analysis of the GraphResul

[cfi-verify] Made FileAnalysis operate on a GraphResult rather than build one and validate it.

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

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[cfi-verify] Adds blacklist blame behaviour to cfi-verify.

Adds the blacklist behaviour to llvm-cfi-verify. Now will calculate which lines caused expected failures in the blacklist and reports the n

[cfi-verify] Adds blacklist blame behaviour to cfi-verify.

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

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[cfi-verify] Add blacklist parsing for result filtering.

Adds blacklist parsing behaviour for filtering results into four categories:

- Expected Protected: Things that are not in the blacklist and

[cfi-verify] Add blacklist parsing for result filtering.

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

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Parse DWARF information to reduce false positives.

Summary: Help differentiate code and data by parsing DWARF information. This will reduce false positive rates where data is placed in executable se

Parse DWARF information to reduce false positives.

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

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Add FileVerifier::isCFIProtected().

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

Add FileVerifier::isCFIProtected().

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

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Made llvm-cfi-verify not execute unit tests on non-x86 builds.

Patched out from D38427.

Reviewers: vlad.tsyrklevich

Reviewed By: vlad.tsyrklevich

Subscribers: llvm-commits, kcc, pcc, mgorny

Diff

Made llvm-cfi-verify not execute unit tests on non-x86 builds.

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

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MC Helpers for llvm-cfi-verify.

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

Reviewers: vlad.tsyrklevich

Reviewed By:

MC Helpers for llvm-cfi-verify.

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

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Reland 'Classify llvm-cfi-verify.'

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

Reviewers: vlad.tsyrklevich

Reviewed By: vlad.tsyrklevich

Subscribers: mgorn

Reland 'Classify llvm-cfi-verify.'

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

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