[PATCH 2/2] mips: Remove rt_sigreturn usage on context function

[Maciej W. Rozycki]

On Wed, 17 Apr 2019, Adhemerval Zanella wrote:

> If no one opposes I will commit this shortly.
> 
> On 15/02/2019 12:11, Adhemerval Zanella wrote:
> > Similar to powerpc, mips also issues rt_sigreturn for setcontext
> > case the v0 value saved is not the one set by setcontext or
> > makecontext. As for powerpc, it is intention is no really supported
> > since setcontext is not async-signal-safe.

 This is an obsolete interface, but FYI according to the relevant version 
of SUS[1] you are supposed to be able to return from a signal handler by 
calling setcontext(3) similarly to siglongjmp(3) and by removing this code 
you make the context not to be fully restored in that case (on the MIPS 
target the distinction is due to the DSP register state).

 What do you mean by: "setcontext is not async-signal-safe"?  I think such 
an assertion (if indeed true) should have been explained in the commit 
message even if it was previously discussed (where?).

References:

[1] <http://pubs.opengroup.org/onlinepubs/009695399/functions/setcontext.html>

  Maciej