diff -up thunderbird-60.5.0/mfbt/LinuxSignal.h.mozilla-1238661 thunderbird-60.5.0/mfbt/LinuxSignal.h
--- thunderbird-60.5.0/mfbt/LinuxSignal.h.mozilla-1238661	2019-01-30 11:33:21.447003175 +0100
+++ thunderbird-60.5.0/mfbt/LinuxSignal.h	2019-01-30 11:35:13.848537051 +0100
@@ -22,7 +22,7 @@ __attribute__((naked)) void SignalTrampo
                                              void* aContext) {
   asm volatile("nop; nop; nop; nop" : : : "memory");
 
-  asm volatile("b %0" : : "X"(H) : "memory");
+  asm volatile("bx %0" : : "r"(H), "l"(aSignal), "l"(aInfo), "l"(aContext) : "memory");
 }
 
 #define MOZ_SIGNAL_TRAMPOLINE(h) (mozilla::SignalTrampoline)