From: Oleg Nesterov <oleg@redhat.com>
To: Elvira Khabirova <lineprinter@altlinux.org>
Cc: Andy Lutomirski <luto@amacapital.net>,
rostedt@goodmis.org, mingo@redhat.com,
linux-kernel@vger.kernel.org, ldv@altlinux.org, esyr@redhat.com,
luto@kernel.org, strace-devel@lists.strace.io
Subject: Re: [RFC PATCH] ptrace: add PTRACE_GET_SYSCALL_INFO request
Date: Thu, 8 Nov 2018 10:16:38 +0100 [thread overview]
Message-ID: <20181108091638.GA9939@redhat.com> (raw)
In-Reply-To: <20181107210251.542cf8a1@akathisia>
On 11/07, Elvira Khabirova wrote:
>
> On Wed, 7 Nov 2018 17:44:44 +0100
> Oleg Nesterov <oleg@redhat.com> wrote:
>
> > To me PT_IN_SYSCALL_STOP makes no real sense, but I won't argue.
> >
> > At least I'd ask to not abuse task->ptrace. ptrace_report_syscall() can clear
> > ->ptrace_message on exit if we really want PTRACE_GET_SYSCALL_INFO to fail after
> > that.
>
> I really would not like to rely on ->ptrace_message remaining empty;
> this looks too fragile.
Well. I do not understand why this is fragile. And certainly this is not more
fragile than
current->ptrace |= PT_IN_SYSCALL_STOP;
trace_notify();
current->ptrace &= ~PT_IN_SYSCALL_STOP;
simply because both ->ptrace updates are technically wrong. The tracee can race
with the exiting tracer which clears ->ptrace.
But even if this was correct. This patch manipulates ->ptrace_message anyway,
I do not understand why should we abuse ->ptrace too just to for the sanity
check in PTRACE_GET_SYSCALL_INFO.
Oleg.
next prev parent reply other threads:[~2018-11-08 9:16 UTC|newest]
Thread overview: 84+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-07 3:27 [RFC PATCH] ptrace: add PTRACE_GET_SYSCALL_INFO request Elvira Khabirova
2018-11-07 11:21 ` Oleg Nesterov
2018-11-07 14:06 ` Andy Lutomirski
2018-11-07 16:44 ` Oleg Nesterov
2018-11-07 20:02 ` Elvira Khabirova
2018-11-08 9:16 ` Oleg Nesterov [this message]
2018-11-07 20:20 ` Andy Lutomirski
2018-11-08 14:33 ` Oleg Nesterov
2018-11-07 16:12 ` Dmitry V. Levin
2018-11-07 15:50 ` Dmitry V. Levin
2018-11-07 20:44 ` Andy Lutomirski
2018-11-09 3:13 ` [PATCH 00/13] Prepare for PTRACE_GET_SYSCALL_INFO Dmitry V. Levin
2018-11-09 3:15 ` [PATCH 01/13] Move EM_HEXAGON to uapi/linux/elf-em.h Dmitry V. Levin
2018-11-09 3:15 ` [PATCH 02/13] elf-em.h: add EM_ARC Dmitry V. Levin
2018-11-09 14:20 ` Alexey Brodkin
2018-11-09 16:41 ` Vineet Gupta
2018-11-09 21:44 ` Dmitry V. Levin
2018-11-09 23:33 ` [PATCH 02/13 v2] Move EM_ARCOMPACT and EM_ARCV2 to uapi/linux/elf-em.h Dmitry V. Levin
2018-11-09 23:42 ` Vineet Gupta
2018-11-09 3:15 ` [PATCH 03/13] elf-em.h: add EM_NDS32 Dmitry V. Levin
2018-11-09 3:15 ` [PATCH 04/13] elf-em.h: add EM_XTENSA Dmitry V. Levin
2018-11-09 6:45 ` Max Filippov
2018-11-09 3:15 ` [PATCH 05/13] m68k: define syscall_get_arch() Dmitry V. Levin
2018-11-09 3:16 ` [PATCH 06/13] arc: " Dmitry V. Levin
2018-11-09 14:22 ` Alexey Brodkin
2018-11-09 15:17 ` Andy Lutomirski
2018-11-09 15:27 ` Alexey Brodkin
2018-11-09 15:56 ` Andy Lutomirski
2018-11-09 16:11 ` Alexey Brodkin
2018-11-09 16:35 ` Andy Lutomirski
2018-11-09 23:33 ` [PATCH 06/13 v2] " Dmitry V. Levin
2018-11-09 23:39 ` Vineet Gupta
2018-11-09 23:54 ` [PATCH 06/13 v3] " Dmitry V. Levin
2018-11-10 0:06 ` Vineet Gupta
2018-11-09 16:50 ` [PATCH 06/13] " Vineet Gupta
2018-11-09 19:03 ` Andy Lutomirski
2018-11-09 19:13 ` Vineet Gupta
2018-11-09 3:16 ` [PATCH 07/13] c6x: " Dmitry V. Levin
2018-11-10 2:01 ` [PATCH 07/13 v2] " Dmitry V. Levin
2018-11-09 3:16 ` [PATCH 08/13] h8300: " Dmitry V. Levin
2018-11-09 3:16 ` [PATCH 09/13] hexagon: " Dmitry V. Levin
2018-11-09 3:16 ` [PATCH 10/13] nds32: " Dmitry V. Levin
2018-11-10 2:01 ` [PATCH 10/13 v2] " Dmitry V. Levin
2018-11-09 3:17 ` [PATCH 11/13] nios2: " Dmitry V. Levin
2018-11-09 3:17 ` [PATCH 12/13] riscv: " Dmitry V. Levin
2018-11-09 6:59 ` David Abdurachmanov
2018-11-09 22:28 ` Dmitry V. Levin
2018-11-10 5:12 ` David Abdurachmanov
2018-11-10 9:27 ` Andreas Schwab
2018-11-09 18:45 ` Palmer Dabbelt
2018-11-09 21:31 ` Dmitry V. Levin
2018-11-09 22:48 ` [PATCH 12/13 v2] " Dmitry V. Levin
2018-11-11 21:21 ` Palmer Dabbelt
2018-11-09 3:17 ` [PATCH 13/13] xtensa: " Dmitry V. Levin
2018-11-09 6:48 ` Max Filippov
2018-11-09 6:06 ` [PATCH 00/13] Prepare for PTRACE_GET_SYSCALL_INFO Andy Lutomirski
2018-11-10 14:09 ` [PATCH 14/13] Move EM_UNICORE to uapi/linux/elf-em.h Dmitry V. Levin
2018-11-10 14:10 ` [PATCH 15/13] unicore32: define syscall_get_arch() Dmitry V. Levin
2018-11-13 3:38 ` [RFC PATCH] ptrace: add PTRACE_GET_SYSCALL_INFO request Dmitry V. Levin
2018-11-20 0:11 ` [PATCH v2 00/15] Prepare for PTRACE_GET_SYSCALL_INFO Dmitry V. Levin
2018-11-20 0:14 ` [PATCH v2 01/15] Move EM_HEXAGON to uapi/linux/elf-em.h Dmitry V. Levin
2018-11-20 0:14 ` [PATCH v2 02/15] Move EM_ARCOMPACT and EM_ARCV2 " Dmitry V. Levin
2018-11-20 0:14 ` [PATCH v2 03/15] Move EM_UNICORE " Dmitry V. Levin
2018-11-20 0:15 ` [PATCH v2 04/15] elf-em.h: add EM_NDS32 Dmitry V. Levin
2018-11-20 0:15 ` [PATCH v2 05/15] elf-em.h: add EM_XTENSA Dmitry V. Levin
2018-11-20 0:15 ` [PATCH v2 06/15] m68k: define syscall_get_arch() Dmitry V. Levin
2018-12-02 10:29 ` Geert Uytterhoeven
2018-12-03 0:24 ` Dmitry V. Levin
2018-12-03 7:36 ` Geert Uytterhoeven
2018-11-20 0:15 ` [PATCH v2 07/15] arc: " Dmitry V. Levin
2018-11-20 0:15 ` [PATCH v2 08/15] c6x: " Dmitry V. Levin
2018-11-20 0:16 ` [PATCH v2 09/15] h8300: " Dmitry V. Levin
2018-11-20 0:16 ` [PATCH v2 10/15] hexagon: " Dmitry V. Levin
2018-11-20 0:16 ` [PATCH v2 11/15] nds32: " Dmitry V. Levin
2018-11-20 0:16 ` [PATCH v2 12/15] nios2: " Dmitry V. Levin
2018-11-20 0:16 ` [PATCH v2 13/15] riscv: " Dmitry V. Levin
2018-11-20 0:16 ` [PATCH v2 14/15] unicore32: " Dmitry V. Levin
2018-11-20 0:17 ` [PATCH v2 15/15] xtensa: " Dmitry V. Levin
2018-11-20 20:26 ` [PATCH v2 00/15] Prepare for PTRACE_GET_SYSCALL_INFO Paul Moore
[not found] ` <20181121004422.GA29053@altlinux.org>
[not found] ` <20181121184004.jro532jopnbmru2m@pburton-laptop>
2018-11-21 19:00 ` [PATCH v2 16/15] syscall_get_arch: add "struct task_struct *" argument Dmitry V. Levin
2018-11-21 19:14 ` [PATCH] mips: fix mips_get_syscall_arg o32 check Dmitry V. Levin
2018-11-21 19:23 ` Paul Burton
2018-11-21 19:35 ` [PATCH v2 16/15 v2] syscall_get_arch: add "struct task_struct *" argument Dmitry V. Levin
2018-11-21 19:45 ` Paul Burton
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