llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-clang Author: Paul Kirth (ilovepi) <details> <summary>Changes</summary> We want to support CFI instrumentation for the bitcode section, without miscompiling the object code portion of a FatLTO object. We can reuse the existing mechanisms in the LowerTypeTestsPass to do that, by just adding the pass to the FatLTO pipeline after the EmbedBitcodePass with the correct options set. Fixes #<!-- -->112053 --- Full diff: https://github.com/llvm/llvm-project/pull/112788.diff 2 Files Affected: - (added) clang/test/CodeGen/fat-lto-objects-cfi.cpp (+46) - (modified) llvm/lib/Passes/PassBuilderPipelines.cpp (+4) ``````````diff diff --git a/clang/test/CodeGen/fat-lto-objects-cfi.cpp b/clang/test/CodeGen/fat-lto-objects-cfi.cpp new file mode 100644 index 00000000000000..022e74fd9b6f22 --- /dev/null +++ b/clang/test/CodeGen/fat-lto-objects-cfi.cpp @@ -0,0 +1,46 @@ +// REQUIRES: x86-registered-target + +// RUN: %clangxx --target=x86_64-unknown-fuchsia -O2 -flto -ffat-lto-objects \ +// RUN: -fsanitize=cfi -fvisibility=hidden -S -emit-llvm -o - %s \ +// RUN: | FileCheck %s + +// CHECK: llvm.embedded.object +// CHECK-SAME: section ".llvm.lto" + +// CHECK-LABEL: define hidden void @foo +// CHECK: entry: +// CHECK-NEXT: %cmp14.not = icmp eq i64 %len, 0 +// CHECK-NEXT: br i1 %cmp14.not, label %for.end7, label %for.cond1.preheader.preheader +// CHECK: for.cond1.preheader.preheader: ; preds = %entry +// CHECK-NEXT: %arrayidx.1 = getelementptr inbounds nuw i8, ptr %ptr, i64 4 +// CHECK-NEXT: br label %for.cond1.preheader + +// CHECK-NOT: @llvm.type.test + +// The code below is a reduced case from https://github.com/llvm/llvm-project/issues/112053 +#define __PRINTFLIKE(__fmt, __varargs) __attribute__((__format__(__printf__, __fmt, __varargs))) +typedef void func(void* arg, const char* fmt, ...) __PRINTFLIKE(2, 3); +typedef __SIZE_TYPE__ size_t; +typedef unsigned long uintptr_t; + +extern "C" +void foo(const void* ptr, size_t len, long disp_addr, + func* printf_func, void* printf_arg) { + uintptr_t address = (uintptr_t)ptr; + size_t count; + + for (count = 0; count < len; count += 16) { + union { + unsigned int buf[4]; + unsigned char cbuf[16]; + } u; + size_t s = 10; + size_t i; + + for (i = 0; i < s / 4; i++) { + u.buf[i] = ((const unsigned int*)address)[i]; + printf_func(printf_arg, "%08x ", static_cast<unsigned int>(u.buf[i])); + } + } +} + diff --git a/llvm/lib/Passes/PassBuilderPipelines.cpp b/llvm/lib/Passes/PassBuilderPipelines.cpp index 17710eb94b6ded..81ea6ac7dcdf18 100644 --- a/llvm/lib/Passes/PassBuilderPipelines.cpp +++ b/llvm/lib/Passes/PassBuilderPipelines.cpp @@ -1629,6 +1629,10 @@ PassBuilder::buildFatLTODefaultPipeline(OptimizationLevel Level, bool ThinLTO, MPM.addPass(buildLTOPreLinkDefaultPipeline(Level)); MPM.addPass(EmbedBitcodePass(ThinLTO, EmitSummary)); + // If we're doing FatLTO w/ CFI enabled, we don't want the type tests in the + // object file. + MPM.addPass(LowerTypeTestsPass(nullptr, nullptr, true, true)); + // Use the ThinLTO post-link pipeline with sample profiling if (ThinLTO && PGOOpt && PGOOpt->Action == PGOOptions::SampleUse) MPM.addPass(buildThinLTODefaultPipeline(Level, /*ImportSummary=*/nullptr)); `````````` </details> https://github.com/llvm/llvm-project/pull/112788 _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
