From: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Date: Thu, 20 Aug 2020 20:36:12 +0100
> We have
> asmlinkage void user_unaligned_trap(struct pt_regs *regs, unsigned int insn)
> {
> enum direction dir;
>
> if(!(current->thread.flags & SPARC_FLAG_UNALIGNED) ||
> (((insn >> 30) & 3) != 3))
> goto kill_user;
>
> there, followed by some work on emulating the insn. So while the default
> behaviour is to hit the process with SIGBUS, it can overridden by setting
> SPARC_FLAG_UNALIGNED in current->thread.flags. Fair enough, but... Just
> what could possibly set that flag?
>
> That stuff had been introduced back in 2.1.9 and even there (or through
> the 2.2, etc.) I don't see anything that would ever set it.
>
> Am I missing something, or had it really been dead code all along?
Relic from the SunOS and/or Solaris syscall emulation probably.
