From: Will Deacon <will@kernel.org>
To: Pu Hu <hupu@transsion.com>
Cc: "mhiramat@kernel.org" <mhiramat@kernel.org>,
"ada.coupriediaz@arm.com" <ada.coupriediaz@arm.com>,
"catalin.marinas@arm.com" <catalin.marinas@arm.com>,
"davem@davemloft.net" <davem@davemloft.net>,
Hongyan Xia <hongyan.xia@transsion.com>,
Jiazi Li <jiazi.li@transsion.com>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-trace-kernel@vger.kernel.org"
<linux-trace-kernel@vger.kernel.org>,
"naveen@kernel.org" <naveen@kernel.org>,
"yang@os.amperecomputing.com" <yang@os.amperecomputing.com>
Subject: Re: [RFC v3 2/2] arm64: kprobes: Allow reentering kprobes while single-stepping
Date: Thu, 16 Jul 2026 14:24:15 +0100 [thread overview]
Message-ID: <aljbf_RmOd9U2KDT@willie-the-truck> (raw)
In-Reply-To: <20260710063242.228714-3-hupu@transsion.com>
On Fri, Jul 10, 2026 at 06:32:55AM +0000, Pu Hu wrote:
> From: Pu Hu <hupu@transsion.com>
>
> A kprobe can be hit while another kprobe is in KPROBE_HIT_SS state. This
> can happen when tracing or perf code runs from the debug exception path
> while the first kprobe is preparing or executing its out-of-line
> single-step instruction.
I don't understand this part. The single-step runs with debug exceptions
disabled (kprobes_save_local_irqflag() sets PSTATE.D) so how do we end
up taking one?
Will
next prev parent reply other threads:[~2026-07-16 13:24 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-10 6:32 [RFC v3 0/2] rm64: kprobes: Fix single-step fault and reentry handling Pu Hu
2026-07-10 6:32 ` [RFC v3 1/2] arm64: kprobes: Only handle faults originating from XOL slot Pu Hu
2026-07-10 6:32 ` [RFC v3 2/2] arm64: kprobes: Allow reentering kprobes while single-stepping Pu Hu
2026-07-10 9:38 ` Masami Hiramatsu
2026-07-15 13:56 ` Pu Hu
2026-07-16 13:24 ` Will Deacon [this message]
2026-07-16 14:38 ` Pu Hu
2026-07-16 15:20 ` Will Deacon
2026-07-17 1:51 ` Hongyan Xia
2026-07-17 11:01 ` Will Deacon
2026-07-17 11:31 ` Hongyan Xia
2026-07-17 18:02 ` Will Deacon
2026-07-18 3:17 ` Hongyan Xia
2026-07-17 18:23 ` [RFC v3 0/2] rm64: kprobes: Fix single-step fault and reentry handling Will Deacon
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