From: Oleg Nesterov <oleg@redhat.com>
To: "Dmitry V. Levin" <ldv@altlinux.org>
Cc: Andy Lutomirski <luto@kernel.org>,
Elvira Khabirova <lineprinter@altlinux.org>,
Eugene Syromyatnikov <esyr@redhat.com>,
Steven Rostedt <rostedt@goodmis.org>,
Ingo Molnar <mingo@redhat.com>, Kees Cook <keescook@chromium.org>,
Jann Horn <jannh@google.com>,
Michael Ellerman <mpe@ellerman.id.au>,
linux-api@vger.kernel.org, linux-kernel@vger.kernel.org,
strace-devel@lists.strace.io
Subject: Re: [PATCH v4 1/2] ptrace: save the type of syscall-stop in ptrace_message
Date: Wed, 28 Nov 2018 14:49:14 +0100 [thread overview]
Message-ID: <20181128134913.GC30395@redhat.com> (raw)
In-Reply-To: <20181128130601.GC28206@altlinux.org>
On 11/28, Dmitry V. Levin wrote:
>
> +/*
> + * These values are stored in task->ptrace_message by tracehook_report_syscall_*
> + * to describe current syscall-stop.
> + *
> + * Values for these constants are chosen so that they do not appear
> + * in task->ptrace_message by other means.
> + */
> +#define PTRACE_EVENTMSG_SYSCALL_ENTRY 0x80000000U
> +#define PTRACE_EVENTMSG_SYSCALL_EXIT 0x90000000U
Again, I do not really understand the comment... Why should we care about
"do not appear in task->ptrace_message by other means" ?
2/2 should detect ptrace_report_syscall() case correctly, so we can use any
numbers, say, 1 and 2?
If debugger does PTRACE_GETEVENTMSG it should know how to interpet the value
anyway after wait(status).
Oleg.
next prev parent reply other threads:[~2018-11-28 13:49 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-28 13:04 [PATCH v4 0/2] ptrace: add PTRACE_GET_SYSCALL_INFO request Dmitry V. Levin
2018-11-28 13:06 ` [PATCH v4 1/2] ptrace: save the type of syscall-stop in ptrace_message Dmitry V. Levin
2018-11-28 13:49 ` Oleg Nesterov [this message]
2018-11-28 14:05 ` Dmitry V. Levin
2018-11-28 14:20 ` Oleg Nesterov
2018-11-28 15:23 ` Dmitry V. Levin
2018-11-28 22:11 ` Dmitry V. Levin
2018-11-28 23:17 ` Andy Lutomirski
2018-11-29 10:34 ` Dmitry V. Levin
2018-11-29 15:03 ` Oleg Nesterov
2018-11-29 14:47 ` Oleg Nesterov
2018-11-29 21:10 ` Dmitry V. Levin
2018-11-30 11:29 ` Oleg Nesterov
2018-11-30 22:53 ` Dmitry V. Levin
2018-11-28 13:07 ` [PATCH v4 2/2] ptrace: add PTRACE_GET_SYSCALL_INFO request Dmitry V. Levin
2018-11-28 14:10 ` Oleg Nesterov
2018-11-28 14:29 ` Oleg Nesterov
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