https://github.com/bgergely0 updated https://github.com/llvm/llvm-project/pull/165227
From 080eaf921417c6fd2241e0578e0890b1aafa1bfa Mon Sep 17 00:00:00 2001 From: Gergely Balint <[email protected]> Date: Mon, 27 Oct 2025 09:29:54 +0000 Subject: [PATCH 1/2] [BOLT][PAC] Warn about synchronous unwind tables BOLT currently ignores functions with synchronous PAuth DWARF info. When more than 10% of functions get ignored for inconsistencies, we should emit a warning to only use asynchronous unwind tables. See also: #165215 --- bolt/lib/Passes/PointerAuthCFIAnalyzer.cpp | 8 ++++- .../AArch64/pacret-synchronous-unwind.cpp | 32 +++++++++++++++++++ 2 files changed, 39 insertions(+), 1 deletion(-) create mode 100644 bolt/test/runtime/AArch64/pacret-synchronous-unwind.cpp diff --git a/bolt/lib/Passes/PointerAuthCFIAnalyzer.cpp b/bolt/lib/Passes/PointerAuthCFIAnalyzer.cpp index 91030544d2b88..cc28ca47c26b1 100644 --- a/bolt/lib/Passes/PointerAuthCFIAnalyzer.cpp +++ b/bolt/lib/Passes/PointerAuthCFIAnalyzer.cpp @@ -133,11 +133,17 @@ Error PointerAuthCFIAnalyzer::runOnFunctions(BinaryContext &BC) { ParallelUtilities::runOnEachFunction( BC, ParallelUtilities::SchedulingPolicy::SP_INST_LINEAR, WorkFun, SkipPredicate, "PointerAuthCFIAnalyzer"); + + float IgnoredPercent = (100.0 * FunctionsIgnored) / Total; BC.outs() << "BOLT-INFO: PointerAuthCFIAnalyzer ran on " << Total << " functions. Ignored " << FunctionsIgnored << " functions " - << format("(%.2lf%%)", (100.0 * FunctionsIgnored) / Total) + << format("(%.2lf%%)", IgnoredPercent) << " because of CFI inconsistencies\n"; + if (IgnoredPercent >= 10.0) + BC.outs() << "BOLT-WARNING: PointerAuthCFIAnalyzer only supports " + "asynchronous unwind tables.\n"; + return Error::success(); } diff --git a/bolt/test/runtime/AArch64/pacret-synchronous-unwind.cpp b/bolt/test/runtime/AArch64/pacret-synchronous-unwind.cpp new file mode 100644 index 0000000000000..e90882833323d --- /dev/null +++ b/bolt/test/runtime/AArch64/pacret-synchronous-unwind.cpp @@ -0,0 +1,32 @@ +// Test to demonstrate that functions compiled with synchronous unwind tables +// are ignored by the PointerAuthCFIAnalyzer. +// Exception handling is needed to have _any_ unwind tables, otherwise the +// PointerAuthCFIAnalyzer does not run on these functions, so it does not ignore +// any function. +// +// REQUIRES: system-linux,bolt-runtime +// +// RUN: %clangxx --target=aarch64-unknown-linux-gnu \ +// RUN: -mbranch-protection=pac-ret \ +// RUN: -fno-asynchronous-unwind-tables \ +// RUN: %s -o %t.exe -Wl,-q +// RUN: llvm-bolt %t.exe -o %t.bolt | FileCheck %s --check-prefix=CHECK +// +// CHECK: PointerAuthCFIAnalyzer ran on 3 functions. Ignored +// CHECK-NOT: 0 functions (0.00%) because of CFI inconsistencies +// CHECK-SAME: 1 functions (33.33%) because of CFI inconsistencies +// CHECK-NEXT: PointerAuthCFIAnalyzer only supports asynchronous unwind tables + +#include <cstdio> +#include <stdexcept> + +void foo() { throw std::runtime_error("Exception from foo()."); } + +int main() { + try { + foo(); + } catch (const std::exception &e) { + printf("Exception caught: %s\n", e.what()); + } + return 0; +} From bd53804b5f88809e44377d03d0a484b2fbefb220 Mon Sep 17 00:00:00 2001 From: Gergely Balint <[email protected]> Date: Tue, 28 Oct 2025 09:23:08 +0000 Subject: [PATCH 2/2] [BOLT] Use opts::Verbosity in PointerAuthCFIAnalyzer --- bolt/lib/Passes/PointerAuthCFIAnalyzer.cpp | 27 ++++++++++++------- bolt/test/AArch64/negate-ra-state-incorrect.s | 2 +- 2 files changed, 18 insertions(+), 11 deletions(-) diff --git a/bolt/lib/Passes/PointerAuthCFIAnalyzer.cpp b/bolt/lib/Passes/PointerAuthCFIAnalyzer.cpp index cc28ca47c26b1..e4efb11356a3d 100644 --- a/bolt/lib/Passes/PointerAuthCFIAnalyzer.cpp +++ b/bolt/lib/Passes/PointerAuthCFIAnalyzer.cpp @@ -28,6 +28,10 @@ using namespace llvm; +namespace opts { +extern llvm::cl::opt<unsigned> Verbosity; +} // namespace opts + namespace llvm { namespace bolt { @@ -43,9 +47,10 @@ bool PointerAuthCFIAnalyzer::runOnFunction(BinaryFunction &BF) { // Not all functions have .cfi_negate_ra_state in them. But if one does, // we expect psign/pauth instructions to have the hasNegateRAState // annotation. - BC.outs() << "BOLT-INFO: inconsistent RAStates in function " - << BF.getPrintName() - << ": ptr sign/auth inst without .cfi_negate_ra_state\n"; + if (opts::Verbosity >= 1) + BC.outs() << "BOLT-INFO: inconsistent RAStates in function " + << BF.getPrintName() + << ": ptr sign/auth inst without .cfi_negate_ra_state\n"; std::lock_guard<std::mutex> Lock(IgnoreMutex); BF.setIgnored(); return false; @@ -65,9 +70,10 @@ bool PointerAuthCFIAnalyzer::runOnFunction(BinaryFunction &BF) { if (BC.MIB->isPSignOnLR(Inst)) { if (RAState) { // RA signing instructions should only follow unsigned RA state. - BC.outs() << "BOLT-INFO: inconsistent RAStates in function " - << BF.getPrintName() - << ": ptr signing inst encountered in Signed RA state\n"; + if (opts::Verbosity >= 1) + BC.outs() << "BOLT-INFO: inconsistent RAStates in function " + << BF.getPrintName() + << ": ptr signing inst encountered in Signed RA state\n"; std::lock_guard<std::mutex> Lock(IgnoreMutex); BF.setIgnored(); return false; @@ -75,10 +81,11 @@ bool PointerAuthCFIAnalyzer::runOnFunction(BinaryFunction &BF) { } else if (BC.MIB->isPAuthOnLR(Inst)) { if (!RAState) { // RA authenticating instructions should only follow signed RA state. - BC.outs() << "BOLT-INFO: inconsistent RAStates in function " - << BF.getPrintName() - << ": ptr authenticating inst encountered in Unsigned RA " - "state\n"; + if (opts::Verbosity >= 1) + BC.outs() << "BOLT-INFO: inconsistent RAStates in function " + << BF.getPrintName() + << ": ptr authenticating inst encountered in Unsigned RA " + "state\n"; std::lock_guard<std::mutex> Lock(IgnoreMutex); BF.setIgnored(); return false; diff --git a/bolt/test/AArch64/negate-ra-state-incorrect.s b/bolt/test/AArch64/negate-ra-state-incorrect.s index 390b3b824d6bc..68a6fc008ab06 100644 --- a/bolt/test/AArch64/negate-ra-state-incorrect.s +++ b/bolt/test/AArch64/negate-ra-state-incorrect.s @@ -8,7 +8,7 @@ # RUN: llvm-mc -filetype=obj -triple aarch64-unknown-unknown %s -o %t.o # RUN: %clang %cflags %t.o -o %t.exe -Wl,-q -# RUN: llvm-bolt %t.exe -o %t.exe.bolt --no-threads | FileCheck %s --check-prefix=CHECK-BOLT +# RUN: llvm-bolt %t.exe -o %t.exe.bolt -v=1 --no-threads | FileCheck %s --check-prefix=CHECK-BOLT # CHECK-BOLT: BOLT-INFO: inconsistent RAStates in function foo: ptr authenticating inst encountered in Unsigned RA state # CHECK-BOLT: BOLT-INFO: inconsistent RAStates in function bar: ptr signing inst encountered in Signed RA state _______________________________________________ llvm-branch-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
