================
@@ -2868,6 +2872,61 @@ int UnwindCursor<A,
R>::stepThroughSigReturn(Registers_riscv &) {
#endif // defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) &&
// defined(_LIBUNWIND_TARGET_RISCV)
+#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_RISCV)
----------------
SixWeining wrote:
```suggestion
// defined(_LIBUNWIND_TARGET_LOONGARCH)
```
https://github.com/llvm/llvm-project/pull/123682
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