From: Oleg Nesterov <oleg@redhat.com>
To: Zhao Gongyi <zhaogongyi@bytedance.com>
Cc: catalin.marinas@arm.com, will@kernel.org, mark.rutland@arm.com,
ruanjinjie@huawei.com, linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] arm64: ptrace: don't warn on missing siginfo in a group-stop
Date: Fri, 23 Oct 2026 15:24:04 +0200 [thread overview]
Message-ID: <attf9KALBQyOGyco@redhat.com> (raw)
In-Reply-To: <20261023110710.10145-1-zhaogongyi@bytedance.com>
On 10/23, Zhao Gongyi wrote:
>
> --- a/arch/arm64/kernel/ptrace.c
> +++ b/arch/arm64/kernel/ptrace.c
> @@ -573,10 +573,6 @@ static void update_syscall_orig_x0_after_ptrace(struct task_struct *target)
> if (regs->syscallno == NO_SYSCALL)
> return;
>
> - /* We should only be called when target is in a ptrace stop */
> - if (WARN_ON_ONCE(!info))
> - return;
> -
> /*
> * For compat tasks, orig_r0 is provided directly through GPR index
> * 17.
> @@ -588,7 +584,7 @@ static void update_syscall_orig_x0_after_ptrace(struct task_struct *target)
> * Don't update orig_x0 for a syscall-exit-stop, as x0 now contains the
> * return value of the system call.
> */
> - if ((info->si_code & ~0x80) == SIGTRAP &&
> + if (info && (info->si_code & ~0x80) == SIGTRAP &&
> target->ptrace_message == PTRACE_EVENTMSG_SYSCALL_EXIT) {
> return;
LGTM, but I don't understand this arm-specific code.
And... Do we need to check target->last_siginfo at all?
ptrace_signal() -> ptrace_stop() path sets ->ptrace_message = 0.
In all other cases: if info != NULL, then .si_code == target->exit_code.
ptrace_event(event) users always use event != 0 and != 0x80.
So it seems that we can just do
if ((target->exit_code & ~0x80) == SIGTRAP &&
target->ptrace_message == PTRACE_EVENTMSG_SYSCALL_EXIT)
?
I'll recheck... If I am right, perhaps it makes sense to simplify
ptrace_get_syscall_info_op().
Anyway, up to you.
Oleg.
prev parent reply other threads:[~2026-10-23 13:24 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-23 11:07 Zhao Gongyi
2026-10-23 13:24 ` Oleg Nesterov [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=attf9KALBQyOGyco@redhat.com \
--to=oleg@redhat.com \
--cc=catalin.marinas@arm.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mark.rutland@arm.com \
--cc=ruanjinjie@huawei.com \
--cc=will@kernel.org \
--cc=zhaogongyi@bytedance.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®