From: Renzo Davoli <renzo@cs.unibo.it>
To: "Michal Suchánek" <msuchanek@suse.de>
Cc: linux-kernel@vger.kernel.org,
Andrew Morton <akpm@linux-foundation.org>,
Oleg Nesterov <oleg@redhat.com>, Shuah Khan <shuah@kernel.org>,
Alexey Gladkov <legion@kernel.org>,
Eugene Syromyatnikov <evgsyr@gmail.com>,
Davide Berardi <berardi.dav@gmail.com>,
strace-devel@lists.strace.io, "Dmitry V . Levin" <ldv@strace.io>
Subject: Re: [PATCH v5 0/2] PTRACE_SET_SYSCALL_INFO: add support for seccomp syscall skipping
Date: Fri, 10 Jul 2026 18:49:11 +0200 [thread overview]
Message-ID: <alEih9lMnDnpP64F@cs.unibo.it> (raw)
In-Reply-To: <alER-CLAgNdLQjRU@kunlun.suse.cz>
Hi Michal,
I am not an expert of the powerpc architecture.
On Fri, Jul 10, 2026 at 05:38:32PM +0200, Michal Suchánek wrote:
> On these architectures the syscall number and the syscall return value
> share the same register.
Reading the file arch/powerpc/include/asm/syscall.h
the functions
syscall_get_nr()
syscall_set_nr()
read and write regs->gpr[0]
while
syscall_get_return_value()
syscall_set_return_value()
read and write regs->gpr[3] (and one bit in regs->ccr as an error flag).
Am I missing another part of the entry/exit path where the two overlap?
Thank you.
renzo
prev parent reply other threads:[~2026-07-10 16:49 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-09 10:09 [PATCH v5 0/2] PTRACE_SET_SYSCALL_INFO: add support for seccomp syscall skipping Renzo Davoli
2026-07-09 10:09 ` [PATCH v5 1/2] ptrace: add PTRACE_SET_SYSCALL_INFO syscall skipping support Renzo Davoli
2026-07-09 10:09 ` [PATCH v5 2/2] selftests/ptrace: add a test case for PTRACE_SET_SYSCALL_INFO syscall skipping Renzo Davoli
2026-07-10 15:38 ` [PATCH v5 0/2] PTRACE_SET_SYSCALL_INFO: add support for seccomp " Michal Suchánek
2026-07-10 16:49 ` Renzo Davoli [this message]
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