diff --git a/Source/JavaScriptCore/heap/MachineStackMarker.cpp b/Source/JavaScriptCore/heap/MachineStackMarker.cpp
index 883914fd3d1..9c0209ad2f3 100644
--- a/Source/JavaScriptCore/heap/MachineStackMarker.cpp
+++ b/Source/JavaScriptCore/heap/MachineStackMarker.cpp
@@ -683,7 +683,19 @@ void* MachineThreads::Thread::Registers::framePointer() const
 #endif
 
 #else
-#error Need a way to get the frame pointer for another thread on this platform
+
+// The following sequence depends on musl libc's sys/ucontext.h.
+#if CPU(X86)
+    return reinterpret_cast<void*>((uintptr_t) regs.machineContext.gregs[REG_EBP]);
+#elif CPU(X86_64)
+    return reinterpret_cast<void*>((uintptr_t) regs.machineContext.gregs[REG_RBP]);
+#elif CPU(ARM)
+    return reinterpret_cast<void*>((uintptr_t) regs.machineContext.arm_fp);
+#elif CPU(ARM64)
+    return reinterpret_cast<void*>((uintptr_t) regs.machineContext.regs[29]);
+#elif CPU(MIPS) 
+    return reinterpret_cast<void*>((uintptr_t) regs.machineContext.gregs[30]);
+#endif
 #endif
 }
 
@@ -765,7 +777,19 @@ void* MachineThreads::Thread::Registers::instructionPointer() const
 #endif
 
 #else
-#error Need a way to get the instruction pointer for another thread on this platform
+
+// The following sequence depends on musl libc's sys/ucontext.h.
+#if CPU(X86)
+    return reinterpret_cast<void*>((uintptr_t) regs.machineContext.gregs[REG_EIP]);
+#elif CPU(X86_64)
+    return reinterpret_cast<void*>((uintptr_t) regs.machineContext.gregs[REG_RIP]);
+#elif CPU(ARM)
+    return reinterpret_cast<void*>((uintptr_t) regs.machineContext.arm_pc);
+#elif CPU(ARM64)
+    return reinterpret_cast<void*>((uintptr_t) regs.machineContext.pc);
+#elif CPU(MIPS) 
+    return reinterpret_cast<void *>((uintptr_t)regs.machineContext.pc);
+#endif
 #endif
 }
 void* MachineThreads::Thread::Registers::llintPC() const
@@ -856,7 +880,19 @@ void* MachineThreads::Thread::Registers::llintPC() const
 #endif
 
 #else
-#error Need a way to get the LLIntPC for another thread on this platform
+
+// The following sequence depends on musl libc's sys/ucontext.h.
+#if CPU(X86)
+    return reinterpret_cast<void*>((uintptr_t) regs.machineContext.gregs[REG_ESI]);
+#elif CPU(X86_64)
+    return reinterpret_cast<void*>((uintptr_t) regs.machineContext.gregs[REG_R8]);
+#elif CPU(ARM)
+    return reinterpret_cast<void*>((uintptr_t) regs.machineContext.arm_r8);
+#elif CPU(ARM64)
+    return reinterpret_cast<void*>((uintptr_t) regs.machineContext.regs[4]);
+#elif CPU(MIPS)
+    return reinterpret_cast<void*>((uintptr_t) regs.machineContext.gregs[12]);
+#endif
 #endif
 }
 #endif // ENABLE(SAMPLING_PROFILER)