From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andreas Schwab Subject: Re: Crash in entry.S:resume on Atari ST Date: Fri, 16 Sep 2016 11:29:38 +0200 Message-ID: <87r38kxke5.fsf@linux-m68k.org> References: <8132f924080d98f2bbe149d35352507d@hu-berlin.de> Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: <8132f924080d98f2bbe149d35352507d@hu-berlin.de> (Matthias Reis's message of "Fri, 16 Sep 2016 00:35:53 +0200") Sender: linux-m68k-owner@vger.kernel.org List-Id: linux-m68k@vger.kernel.org To: Matthias Reis Cc: linux-m68k@lists.linux-m68k.org On Sep 16 2016, Matthias Reis wrote: > === objdump -D vmlinux output: > 000048cc : > 48cc: 2208 movel %a0,%d1 > 48ce: 40e8 0320 movew %sr,%a0@(800) > 48d2: 48e7 031e moveml %d6-%d7/%a3-%fp,%sp@- > 48d6: 214f 0318 movel %sp,%a0@(792) > 48da: 4e6b movel %usp,%a3 > 48dc: 214b 031c movel %a3,%a0@(796) > 48e0: 2669 031c moveal %a1@(796),%a3 > 48e4: 4e63 movel %a3,%usp > 48e6: 2e69 0318 moveal %a1@(792),%sp > 48ea: 4cdf 78c0 moveml %sp@+,%d6-%d7/%a3-%fp > 48ee: 46e9 0320 movew %a1@(800),%sr > 48f2: 4e75 rtsp > === > > It can be seen from the register dump given by the hatari debugger, that > USP contains 0x0 and the superuser bit (indicated by "S=0") is not set: SR should never contain S=0 at this point, as returning from kernel context always happens with RTE (via resume_userspace). Andreas. -- Andreas Schwab, schwab@linux-m68k.org GPG Key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5 "And now for something completely different."