Author: Ami-zhang Date: 2025-02-08T09:48:41+08:00 New Revision: 12a154a94a9c2f6f0690adc7302da9c9e47ec806
URL: https://github.com/llvm/llvm-project/commit/12a154a94a9c2f6f0690adc7302da9c9e47ec806 DIFF: https://github.com/llvm/llvm-project/commit/12a154a94a9c2f6f0690adc7302da9c9e47ec806.diff LOG: [libunwind] Unwind through loongarch64/Linux sigreturn frame (#123682) Similar to D90898 (Linux AArch64), D124765 (SystemZ), and D148499 (RISCV). In this commit, I enabled two test cases, while zhuqizheng supported with the source code development. Co-Authored-By: zhuqizheng <zhuqizh...@loongson.cn> Co-authored-by: zhuqizheng <zhuqizh...@loongson.cn> Added: Modified: libunwind/src/UnwindCursor.hpp libunwind/test/signal_unwind.pass.cpp libunwind/test/unwind_leaffunction.pass.cpp Removed: ################################################################################ diff --git a/libunwind/src/UnwindCursor.hpp b/libunwind/src/UnwindCursor.hpp index 3831d8e071ef3a2..0923052b1b588cf 100644 --- a/libunwind/src/UnwindCursor.hpp +++ b/libunwind/src/UnwindCursor.hpp @@ -31,8 +31,9 @@ #endif #if defined(_LIBUNWIND_TARGET_LINUX) && \ - (defined(_LIBUNWIND_TARGET_AARCH64) || defined(_LIBUNWIND_TARGET_RISCV) || \ - defined(_LIBUNWIND_TARGET_S390X)) + (defined(_LIBUNWIND_TARGET_AARCH64) || \ + defined(_LIBUNWIND_TARGET_LOONGARCH) || \ + defined(_LIBUNWIND_TARGET_RISCV) || defined(_LIBUNWIND_TARGET_S390X)) #include <errno.h> #include <signal.h> #include <sys/syscall.h> @@ -996,6 +997,10 @@ class UnwindCursor : public AbstractUnwindCursor{ bool setInfoForSigReturn(Registers_arm64 &); int stepThroughSigReturn(Registers_arm64 &); #endif +#if defined(_LIBUNWIND_TARGET_LOONGARCH) + bool setInfoForSigReturn(Registers_loongarch &); + int stepThroughSigReturn(Registers_loongarch &); +#endif #if defined(_LIBUNWIND_TARGET_RISCV) bool setInfoForSigReturn(Registers_riscv &); int stepThroughSigReturn(Registers_riscv &); @@ -2815,6 +2820,61 @@ int UnwindCursor<A, R>::stepThroughSigReturn() { #endif // defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) && // defined(_LIBUNWIND_TARGET_AARCH64) +#if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) && \ + defined(_LIBUNWIND_TARGET_LOONGARCH) +template <typename A, typename R> +bool UnwindCursor<A, R>::setInfoForSigReturn(Registers_loongarch &) { + const pint_t pc = static_cast<pint_t>(getReg(UNW_REG_IP)); + // The PC might contain an invalid address if the unwind info is bad, so + // directly accessing it could cause a SIGSEGV. + if (!isReadableAddr(pc)) + return false; + const auto *instructions = reinterpret_cast<const uint32_t *>(pc); + // Look for the two instructions used in the sigreturn trampoline + // __vdso_rt_sigreturn: + // + // 0x03822c0b li a7,0x8b + // 0x002b0000 syscall 0 + if (instructions[0] != 0x03822c0b || instructions[1] != 0x002b0000) + return false; + + _info = {}; + _info.start_ip = pc; + _info.end_ip = pc + 4; + _isSigReturn = true; + return true; +} + +template <typename A, typename R> +int UnwindCursor<A, R>::stepThroughSigReturn(Registers_loongarch &) { + // In the signal trampoline frame, sp points to an rt_sigframe[1], which is: + // - 128-byte siginfo struct + // - ucontext_t struct: + // - 8-byte long (__uc_flags) + // - 8-byte pointer (*uc_link) + // - 24-byte uc_stack + // - 8-byte uc_sigmask + // - 120-byte of padding to allow sigset_t to be expanded in the future + // - 8 bytes of padding because sigcontext has 16-byte alignment + // - struct sigcontext uc_mcontext + // [1] + // https://github.com/torvalds/linux/blob/master/arch/loongarch/kernel/signal.c + const pint_t kOffsetSpToSigcontext = 128 + 8 + 8 + 24 + 8 + 128; + + const pint_t sigctx = _registers.getSP() + kOffsetSpToSigcontext; + _registers.setIP(_addressSpace.get64(sigctx)); + for (int i = UNW_LOONGARCH_R1; i <= UNW_LOONGARCH_R31; ++i) { + // skip R0 + uint64_t value = + _addressSpace.get64(sigctx + static_cast<pint_t>((i + 1) * 8)); + _registers.setRegister(i, value); + } + _isSignalFrame = true; + return UNW_STEP_SUCCESS; +} +#endif // defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) && + // defined(_LIBUNWIND_TARGET_LOONGARCH) + #if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) && \ defined(_LIBUNWIND_TARGET_RISCV) template <typename A, typename R> diff --git a/libunwind/test/signal_unwind.pass.cpp b/libunwind/test/signal_unwind.pass.cpp index 1c1566415a4d4b4..4de271ecb886bd8 100644 --- a/libunwind/test/signal_unwind.pass.cpp +++ b/libunwind/test/signal_unwind.pass.cpp @@ -8,7 +8,7 @@ //===----------------------------------------------------------------------===// // Ensure that the unwinder can cope with the signal handler. -// REQUIRES: target={{(aarch64|riscv64|s390x|x86_64)-.+linux.*}} +// REQUIRES: target={{(aarch64|loongarch64|riscv64|s390x|x86_64)-.+linux.*}} // TODO: Figure out why this fails with Memory Sanitizer. // XFAIL: msan diff --git a/libunwind/test/unwind_leaffunction.pass.cpp b/libunwind/test/unwind_leaffunction.pass.cpp index 98de7dc43260c29..d336c159c131b53 100644 --- a/libunwind/test/unwind_leaffunction.pass.cpp +++ b/libunwind/test/unwind_leaffunction.pass.cpp @@ -8,7 +8,7 @@ //===----------------------------------------------------------------------===// // Ensure that leaf function can be unwund. -// REQUIRES: target={{(aarch64|riscv64|s390x|x86_64)-.+linux.*}} +// REQUIRES: target={{(aarch64|loongarch64|riscv64|s390x|x86_64)-.+linux.*}} // TODO: Figure out why this fails with Memory Sanitizer. // XFAIL: msan _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
