From: Finn Thain <fthain@linux-m68k.org>
To: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-m68k@lists.linux-m68k.org,
Geert Uytterhoeven <geert@linux-m68k.org>,
Greg Ungerer <gerg@linux-m68k.org>,
linux-kernel@vger.kernel.org
Subject: Re: [RFC][CFT] signal handling fixes
Date: Thu, 16 Sep 2021 19:03:15 +1000 (AEST) [thread overview]
Message-ID: <89b7f0e5-21a5-5828-1eb8-5119fb8e2d58@linux-m68k.org> (raw)
In-Reply-To: <YP2c1xk9LJ0zE3KW@zeniv-ca.linux.org.uk>
On Sun, 25 Jul 2021, Al Viro wrote:
> ...
>
> PS: FWIW, ifdefs in arch/m68k/kernel/signal.c are wrong - it's not !MMU
> vs. coldfire/MMU vs. classic/MMU. It's actually 68000 vs. coldfire vs.
> everything else. These days it's nearly correct, but only because on
> MMU variants of coldfire we never see exception stack frames with type
> other than 4 - it's controlled by alignment of kernel stack pointer on
> those, and it's under the kernel control, so it's always 32bit-aligned.
> It used to be more serious back when we had 68360 support - that's !MMU
> and exception stack frames are like those on 68020, unless I'm
> misreading their manual...
>
I don't claim to understand this code but CPU32 cores appear to be
unsupported on either #ifdef branch: the MMU branch due to CACR and CAAR
used in push_cache(), and the !MMU branch due to frame format $4 used in
adjust_format().
The CPU32 Reference Manual appendix says these chips only supports control
registers SFC, DFC, VBR and stack frame formats $0, $2, $C.
https://www.nxp.com/files-static/microcontrollers/doc/ref_manual/CPU32RM.pdf
next prev parent reply other threads:[~2021-09-16 9:03 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-25 17:18 [RFC][CFT] signal handling fixes Al Viro
2021-07-25 17:19 ` [PATCH 1/3] m68k: handle arrivals of multiple signals correctly Al Viro
2021-09-15 22:08 ` Michael Schmitz
2021-07-25 17:19 ` [PATCH 2/3] m68k: update ->thread.esp0 before calling syscall_trace() in ret_from_signal Al Viro
2021-09-15 22:19 ` Michael Schmitz
2021-07-25 17:20 ` [PATCH 3/3] m68k: leave stack mangling to asm wrapper of sigreturn() Al Viro
2021-09-15 23:35 ` Michael Schmitz
2021-09-16 0:19 ` Al Viro
2021-09-16 0:53 ` Michael Schmitz
2021-09-16 3:21 ` Al Viro
2021-09-16 5:02 ` Michael Schmitz
2021-09-16 16:14 ` Al Viro
2021-07-27 10:21 ` [RFC][CFT] signal handling fixes Finn Thain
2021-07-27 14:42 ` Al Viro
2021-07-28 1:23 ` Finn Thain
2021-08-11 1:42 ` Finn Thain
2021-09-16 9:03 ` Finn Thain [this message]
2021-09-23 14:43 ` Geert Uytterhoeven
2021-09-23 14:45 ` Geert Uytterhoeven
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