All of lore.kernel.org
 help / color / mirror / Atom feed
From: Nam Cao <namcao@linutronix.de>
To: Xiaofeng Yuan <yuanxiaofeng@eswincomputing.com>,
	Paul Walmsley <pjw@kernel.org>,
	Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>,
	linux-riscv@lists.infradead.org,
	Xiaofeng Yuan <yuanxiaofeng@eswincomputing.com>,
	Naveen N Rao <naveen@kernel.org>,
	"David S. Miller" <davem@davemloft.net>,
	Masami Hiramatsu <mhiramat@kernel.org>,
	linux-trace-kernel@vger.kernel.org
Subject: Re: [PATCH v4 0/2] riscv: kprobes: reject probes inside LR/SC sequences
Date: Tue, 22 Sep 2026 17:40:11 +0200	[thread overview]
Message-ID: <87mrt9e1lw.fsf@yellow.woof> (raw)
In-Reply-To: <20260828091202.1124-1-yuanxiaofeng@eswincomputing.com>

Xiaofeng Yuan <yuanxiaofeng@eswincomputing.com> writes:
> A breakpoint trap taken in the middle of an LR/SC sequence clears the
> load reservation, so an SC following the probed instruction always fails
> and the enclosing retry loop re-enters the breakpoint, livelocking the
> CPU.
>
> This series makes the RISC-V kprobes implementation reject probes placed
> inside an LR/SC sequence:

CC: kprobes maintainers, I would appreciate your opinion on this. Should
kprobes reject it, or leave it to users to take care not to do that?

Nam

_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv

WARNING: multiple messages have this Message-ID (diff)
From: Nam Cao <namcao@linutronix.de>
To: Xiaofeng Yuan <yuanxiaofeng@eswincomputing.com>,
	Paul Walmsley <pjw@kernel.org>,
	Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>,
	linux-riscv@lists.infradead.org,
	Xiaofeng Yuan <yuanxiaofeng@eswincomputing.com>,
	Naveen N Rao <naveen@kernel.org>,
	"David S. Miller" <davem@davemloft.net>,
	Masami Hiramatsu <mhiramat@kernel.org>,
	linux-trace-kernel@vger.kernel.org
Subject: Re: [PATCH v4 0/2] riscv: kprobes: reject probes inside LR/SC sequences
Date: Tue, 22 Sep 2026 17:40:11 +0200	[thread overview]
Message-ID: <87mrt9e1lw.fsf@yellow.woof> (raw)
In-Reply-To: <20260828091202.1124-1-yuanxiaofeng@eswincomputing.com>

Xiaofeng Yuan <yuanxiaofeng@eswincomputing.com> writes:
> A breakpoint trap taken in the middle of an LR/SC sequence clears the
> load reservation, so an SC following the probed instruction always fails
> and the enclosing retry loop re-enters the breakpoint, livelocking the
> CPU.
>
> This series makes the RISC-V kprobes implementation reject probes placed
> inside an LR/SC sequence:

CC: kprobes maintainers, I would appreciate your opinion on this. Should
kprobes reject it, or leave it to users to take care not to do that?

Nam

  parent reply	other threads:[~2026-09-22 15:40 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-08-28  9:12 [PATCH v4 0/2] riscv: kprobes: reject probes inside LR/SC sequences Xiaofeng Yuan
2026-08-28  9:12 ` [PATCH v4 1/2] riscv: probes: reject kprobes " Xiaofeng Yuan
2026-09-22 13:37   ` Nam Cao
2026-08-28  9:12 ` [PATCH v4 2/2] riscv: kprobes: add KUnit test for LR/SC sequence rejection Xiaofeng Yuan
2026-09-22 13:46   ` Nam Cao
2026-09-20  8:02 ` [PATCH v4 0/2] riscv: kprobes: reject probes inside LR/SC sequences Xiaofeng Yuan
2026-09-22 15:40 ` Nam Cao [this message]
2026-09-22 15:40   ` Nam Cao

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=87mrt9e1lw.fsf@yellow.woof \
    --to=namcao@linutronix.de \
    --cc=aou@eecs.berkeley.edu \
    --cc=davem@davemloft.net \
    --cc=linux-riscv@lists.infradead.org \
    --cc=linux-trace-kernel@vger.kernel.org \
    --cc=mhiramat@kernel.org \
    --cc=naveen@kernel.org \
    --cc=palmer@dabbelt.com \
    --cc=pjw@kernel.org \
    --cc=yuanxiaofeng@eswincomputing.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.