diff --git a/libunwind/src/UnwindCursor.hpp b/libunwind/src/UnwindCursor.hpp --- a/libunwind/src/UnwindCursor.hpp +++ b/libunwind/src/UnwindCursor.hpp @@ -31,7 +31,8 @@ #endif #if defined(_LIBUNWIND_TARGET_LINUX) && \ - (defined(_LIBUNWIND_TARGET_AARCH64) || defined(_LIBUNWIND_TARGET_S390X)) + (defined(_LIBUNWIND_TARGET_AARCH64) || defined(_LIBUNWIND_TARGET_RISCV) || \ + defined(_LIBUNWIND_TARGET_S390X)) #include #include #include @@ -993,6 +994,10 @@ bool setInfoForSigReturn(Registers_arm64 &); int stepThroughSigReturn(Registers_arm64 &); #endif +#if defined(_LIBUNWIND_TARGET_RISCV) + bool setInfoForSigReturn(Registers_riscv &); + int stepThroughSigReturn(Registers_riscv &); +#endif #if defined(_LIBUNWIND_TARGET_S390X) bool setInfoForSigReturn(Registers_s390x &); int stepThroughSigReturn(Registers_s390x &); @@ -2720,6 +2725,58 @@ #endif // defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) && // defined(_LIBUNWIND_TARGET_AARCH64) +#if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) && \ + defined(_LIBUNWIND_TARGET_RISCV) +template +bool UnwindCursor::setInfoForSigReturn(Registers_riscv &) { + const pint_t pc = static_cast(getReg(UNW_REG_IP)); + uint32_t instructions[2]; + struct iovec local_iov = {&instructions, sizeof instructions}; + struct iovec remote_iov = {reinterpret_cast(pc), sizeof instructions}; + long bytesRead = + syscall(SYS_process_vm_readv, getpid(), &local_iov, 1, &remote_iov, 1, 0); + // Look for the two instructions used in the sigreturn trampoline __vdso_rt_sigreturn: + // + // 0x08b00893 li a7,0x8b + // 0x00000073 ecall + if (bytesRead != sizeof instructions || instructions[0] != 0x08b00893 || + instructions[1] != 0x00000073) + return false; + + _info = {}; + _info.start_ip = pc; + _info.end_ip = pc + 4; + _isSigReturn = true; + return true; +} + +template +int UnwindCursor::stepThroughSigReturn(Registers_riscv &) { + // 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 + // - uc_mcontext + // [1] https://github.com/torvalds/linux/blob/master/arch/riscv/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_RISCV_X1; i <= UNW_RISCV_X31; ++i) { + uint64_t value = _addressSpace.get64(sigctx + static_cast(i * 8)); + _registers.setRegister(i, value); + } + _isSignalFrame = true; + return UNW_STEP_SUCCESS; +} +#endif // defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) && + // defined(_LIBUNWIND_TARGET_RISCV) + #if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) && \ defined(_LIBUNWIND_TARGET_S390X) template diff --git a/libunwind/test/signal_unwind.pass.cpp b/libunwind/test/signal_unwind.pass.cpp --- 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|s390x|x86_64)-.+linux.*}} +// REQUIRES: target={{(aarch64|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 --- 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|s390x|x86_64)-.+linux.*}} +// REQUIRES: target={{(aarch64|riscv64|s390x|x86_64)-.+linux.*}} // TODO: Figure out why this fails with Memory Sanitizer. // XFAIL: msan