Re: port-sh3/49597: swapcontext(3) stack pointer problem on NetBSD/sh3

[Yasushi Oshima <oshima-ya%yagoto-urayama.jp@localhost>]

The following reply was made to PR port-sh3/49597; it has been noted by GNATS.

From: Yasushi Oshima <oshima-ya%yagoto-urayama.jp@localhost>
To: gnats-bugs%NetBSD.org@localhost
Cc: 
Subject: Re: port-sh3/49597: swapcontext(3) stack pointer problem on
 NetBSD/sh3
Date: Wed, 28 Jan 2015 23:46:02 +0900 (JST)

 > From: Valery Ushakov <uwe%stderr.spb.ru@localhost>
 
 >  Thanks, I have applied the patch.  But it's got me thinking... We are
 >  tweaking oucp to resume "returning" from swapcontext, but we have
 >  already clobbered r12 and pr before/by calling getcontext, so oucp
 >  will get resumed with wrong r12 and pr values. 
 
 Ah!
 Yes, certainly, resuming r12 will be necessary. I forgot it. 
 
 >  It probably goes
 >  undetected since the caller saves and restores pr itself (since it
 >  calls swapcontext at least) and since r12 is not used because the test
 >  is not in a DSO.
 
 I try your patch,
 then, the atf-test in lib/libpthread/t_swapcontext
 became to work well! (this test-case has failed yet with my patch.)
 
 >  though I haven't tested error legs.
 
 It will be not enough but I tests very simple test:
 
  swapcontext(NULL,&ucp)
 
 It returns -1 with errno=14(EFAULT), its ok.
 
 Thank you very much.
 
 -- 
 Yasushi Oshima