From:   "Eric W. Biederman" <ebiederm@xmission.com>
To:     Al Viro <viro@zeniv.linux.org.uk>
Cc:     Geert Uytterhoeven <geert@linux-m68k.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Linux-Arch <linux-arch@vger.kernel.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Oleg Nesterov <oleg@redhat.com>,
        Kees Cook <keescook@chromium.org>,
        Linux API <linux-api@vger.kernel.org>,
        Michael Schmitz <schmitzmic@gmail.com>,
        linux-m68k <linux-m68k@lists.linux-m68k.org>
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        <CAMuHMdWsNBjOJh0QEx9sppA9x3WoL8H2icqukNqECFhOPremjw@mail.gmail.com>
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        <YdyZEAWKVTVnq2ef@zeniv-ca.linux.org.uk>
Date:   Mon, 10 Jan 2022 15:18:18 -0600
In-Reply-To: <YdyZEAWKVTVnq2ef@zeniv-ca.linux.org.uk> (Al Viro's message of
        "Mon, 10 Jan 2022 20:37:36 +0000")
Message-ID: <87zgo3thlx.fsf@email.froward.int.ebiederm.org>
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Subject: Re: [PATCH 08/17] ptrace/m68k: Stop open coding ptrace_report_syscall
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Al Viro <viro@zeniv.linux.org.uk> writes:

> On Mon, Jan 10, 2022 at 06:54:57PM +0100, Geert Uytterhoeven wrote:
>
>> In fact Michael did so in "[PATCH v7 1/2] m68k/kernel - wire up
>> syscall_trace_enter/leave for m68k"[1], but that's still stuck...
>> 
>> [1] https://lore.kernel.org/r/1624924520-17567-2-git-send-email-schmitzmic@gmail.com/
>
> Looks sane, but I'd split it in two - switch to calling syscall_trace_{enter,leave}
> and then handling the return values...
>
> The former would keep the current behaviour (modulo reporting enter vs. leave
> via PTRACE_GETEVENTMSG), the latter would allow syscall number change by tracer
> and/or handling of seccomp/audit/whatnot.
>
> For exit+signal work the former would suffice, and IMO it would be a good idea
> to put that one into a shared branch to be pulled both by seccomp and by signal
> series.  Would reduce the conflicts...
>
> Objections?

I have the version that Geert ack'ed queued up for v5.17 in my
signal-for-v5.17 branch, along with a couple others prior fixes in this
series of changes where it was clear they were just obviously correct
bug fixes.  No need to delay the removal of profiling bits for example.

I would love to see the m68k perform syscall_trace_{enter,leave} but
just getting as far as ptrace_report_syscall will be enough to avoid any
dependencies on my side.

Eric