Skip to content

[BOLT] Add ORC validation for the Linux kernel #90660

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 1 commit into from
Apr 30, 2024
Merged

[BOLT] Add ORC validation for the Linux kernel #90660

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
31 changes: 31 additions & 0 deletions bolt/lib/Rewrite/LinuxKernelRewriter.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -248,6 +248,9 @@ class LinuxKernelRewriter final : public MetadataRewriter {
/// Update ORC data in the binary.
Error rewriteORCTables();

/// Validate written ORC tables after binary emission.
Error validateORCTables();

/// Static call table handling.
Error readStaticCalls();
Error rewriteStaticCalls();
Expand Down Expand Up @@ -358,6 +361,9 @@ class LinuxKernelRewriter final : public MetadataRewriter {
if (Error E = updateStaticKeysJumpTablePostEmit())
return E;

if (Error E = validateORCTables())
return E;

return Error::success();
}
};
Expand Down Expand Up @@ -837,6 +843,31 @@ Error LinuxKernelRewriter::rewriteORCTables() {
return Error::success();
}

Error LinuxKernelRewriter::validateORCTables() {
if (!ORCUnwindIPSection)
return Error::success();

const uint64_t IPSectionAddress = ORCUnwindIPSection->getAddress();
DataExtractor IPDE = DataExtractor(ORCUnwindIPSection->getOutputContents(),
BC.AsmInfo->isLittleEndian(),
BC.AsmInfo->getCodePointerSize());
DataExtractor::Cursor IPCursor(0);
uint64_t PrevIP = 0;
for (uint32_t Index = 0; Index < NumORCEntries; ++Index) {
const uint64_t IP =
IPSectionAddress + IPCursor.tell() + (int32_t)IPDE.getU32(IPCursor);
if (!IPCursor)
return createStringError(errc::executable_format_error,
"out of bounds while reading ORC IP table: %s",
toString(IPCursor.takeError()).c_str());

assert(IP >= PrevIP && "Unsorted ORC table detected");
PrevIP = IP;
}

return Error::success();
}

/// The static call site table is created by objtool and contains entries in the
/// following format:
///
Expand Down