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From: "Dmitry V. Levin" <ldv@altlinux•org>
To: Nicholas Piggin <npiggin@gmail•com>
Cc: libc-alpha@sourceware•org, Matheus Castanho <msc@linux•ibm.com>,
	musl@lists•openwall.com, linux-api@vger•kernel.org,
	libc-dev@lists•llvm.org, linuxppc-dev@lists•ozlabs.org
Subject: Re: Linux powerpc new system call instruction and ABI
Date: Thu, 20 May 2021 06:06:11 +0300	[thread overview]
Message-ID: <20210520030611.GB27081@altlinux.org> (raw)
In-Reply-To: <1621478238.xha1ow4ujh.astroid@bobo.none>

On Thu, May 20, 2021 at 12:40:36PM +1000, Nicholas Piggin wrote:
[...]
> > Looks like struct pt_regs.trap already contains the information that could
> > be used to tell 'sc' from 'scv': if (pt_regs.trap & ~0xf) == 0x3000, then
> > it's scv.  Is my reading of arch/powerpc/include/asm/ptrace.h correct?
> 
> Hmm, I think it is. Certainly in the kernel regs struct it is, I had in 
> my mind that we put it to 0xc00 when populating the user struct for
> compatibility, but it seems not. So I guess this would work.

OK, can we state that (pt_regs.trap & ~0xf) == 0x3000 is a part of the scv
ABI, so it's not going to change and could be relied upon by userspace?
Could this be documented in Documentation/powerpc/syscall64-abi.rst,
please?


-- 
ldv

  reply	other threads:[~2021-05-20  3:06 UTC|newest]

Thread overview: 42+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-11  8:12 Linux powerpc new system call instruction and ABI Nicholas Piggin
2020-06-11  8:12 ` [PATCH 1/2] powerpc/64s/exception: treat NIA below __end_interrupts as soft-masked Nicholas Piggin
2020-07-24 13:25   ` Michael Ellerman
2020-06-11  8:12 ` [PATCH 2/2] powerpc/64s: system call support for scv/rfscv instructions Nicholas Piggin
2020-07-23  6:47   ` Michael Ellerman
2020-07-23 16:48     ` Christophe Leroy
2020-07-24 10:45       ` Michael Ellerman
2020-06-11 21:02 ` Linux powerpc new system call instruction and ABI Segher Boessenkool
2020-06-14  9:26   ` Nicholas Piggin
2021-05-18 23:13 ` Dmitry V. Levin
2021-05-19  2:50   ` Nicholas Piggin
2021-05-19  5:01     ` Nicholas Piggin
2021-05-21 19:40       ` Matheus Castanho
2021-05-21 19:52         ` Florian Weimer
2021-05-21 20:00           ` Matheus Castanho
2021-05-21 20:52             ` Dmitry V. Levin
2021-05-24 12:11               ` Matheus Castanho
2021-05-24 20:33                 ` Matheus Castanho
2021-05-19 10:24     ` Dmitry V. Levin
2021-05-19 10:59       ` Nicholas Piggin
2021-05-19 12:39         ` Tulio Magno Quites Machado Filho
2021-05-19 13:26         ` Dmitry V. Levin
2021-05-19 22:51           ` Nicholas Piggin
2021-05-19 23:27             ` Dmitry V. Levin
2021-05-20  2:40               ` Nicholas Piggin
2021-05-20  3:06                 ` Dmitry V. Levin [this message]
2021-05-20  5:12                   ` Nicholas Piggin
2021-05-19  7:33   ` Joakim Tjernlund
2021-05-19  7:55     ` Nicholas Piggin
2021-05-19  8:08       ` Joakim Tjernlund
2021-05-19  8:42         ` Nicholas Piggin
2021-05-19 11:12           ` Nicholas Piggin
2021-05-19 14:38           ` Segher Boessenkool
2021-05-19 15:06             ` Joakim Tjernlund
2021-05-19 15:22               ` Segher Boessenkool
2021-05-19 15:36                 ` [musl] " Rich Felker
2021-05-19 18:09                 ` Joakim Tjernlund
2021-05-19 23:48                   ` [musl] " Rich Felker
2021-05-20  1:06                     ` Dmitry V. Levin
2021-05-20  2:45                       ` Nicholas Piggin
2021-05-20  2:59                         ` Dmitry V. Levin
2021-05-20  7:20                           ` Nicholas Piggin

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