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Date: Thu, 6 Aug 2026 11:02:15 -0600 (MDT)
From: Paul Walmsley <pjw@kernel.org>
To: Rui Qi <qirui.001@bytedance.com>
cc: Paul Walmsley <pjw@kernel.org>, Palmer Dabbelt <palmer@dabbelt.com>, 
    Albert Ou <aou@eecs.berkeley.edu>, Alexandre Ghiti <alex@ghiti.fr>, 
    Nam Cao <namcao@linutronix.de>, Thomas Gleixner <tglx@kernel.org>, 
    Zong Li <zong.li@sifive.com>, Ryan Roberts <ryan.roberts@arm.com>, 
    Deepak Gupta <debug@rivosinc.com>, linux-riscv@lists.infradead.org, 
    linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] riscv: kprobes: Prevent probes in breakpoint
 handlers
In-Reply-To: <20260806043807.2583001-1-qirui.001@bytedance.com>
Message-ID: <5b07524c-1b93-22a7-ed9b-037d499a5b3f@kernel.org>
References: <20260806043807.2583001-1-qirui.001@bytedance.com>
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On Thu, 6 Aug 2026, Rui Qi wrote:

> The ftrace selftest multiple_kprobes.tc registers kprobe events on
> the first 256 text symbols from /proc/kallsyms. If handle_break() is
> selected as a probe target on RISC-V, the breakpoint exception path
> can trap again before it reaches the kprobe breakpoint handler. That
> recursively enters do_trap_break() and can make the system
> unresponsive.
> 
> Mark handle_break() and its local probe dispatch helpers as nokprobe
> symbols so they are added to the kprobe blacklist, matching other
> low-level breakpoint exception paths.
> 
> Signed-off-by: Rui Qi <qirui.001@bytedance.com>
> Reviewed-by: Nam Cao <namcao@linutronix.de>

Thanks, queued for v7.3.


- Paul