I believe this may address recent unwinder failures in Fedora if the vDSO unwinder does not contain unwinding data:
<https://bugzilla.redhat.com/show_bug.cgi?id=1659295> The question is: Do we want to move in that direction? Or should we make clear that the userspace ABI *requires* unwinding information? Thanks, Florian 2018-12-14 Florian Weimer <fwei...@redhat.com> * config/i386/linux-unwind.h (x86_frob_update_context): Also check for __NR_sigreturn. diff --git a/libgcc/config/i386/linux-unwind.h b/libgcc/config/i386/linux-unwind.h index ea838e4e47b..502a87a2cb0 100644 --- a/libgcc/config/i386/linux-unwind.h +++ b/libgcc/config/i386/linux-unwind.h @@ -190,9 +190,10 @@ x86_frob_update_context (struct _Unwind_Context *context, { unsigned char *pc = context->ra; - /* movl $__NR_rt_sigreturn,%eax ; {int $0x80 | syscall} */ + /* movl $__NR_{rt_|}sigreturn,%eax ; {int $0x80 | syscall} */ if (*(unsigned char *)(pc+0) == 0xb8 - && *(unsigned int *)(pc+1) == 173 + && (*(unsigned int *)(pc+1) == 119 + || *(unsigned int *)(pc+1) == 173) && (*(unsigned short *)(pc+5) == 0x80cd || *(unsigned short *)(pc+5) == 0x050f)) _Unwind_SetSignalFrame (context, 1);
