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From: Thomas Gleixner <tglx@linutronix.de>
To: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
	LKML <linux-kernel@vger.kernel.org>
Cc: "Paul E. McKenney" <paulmck@kernel.org>,
	Boqun Feng <boqun.feng@gmail.com>,
	Jonathan Corbet <corbet@lwn.net>,
	Prakash Sangappa <prakash.sangappa@oracle.com>,
	Madadi Vineeth Reddy <vineethr@linux.ibm.com>,
	K Prateek Nayak <kprateek.nayak@amd.com>,
	Steven Rostedt <rostedt@goodmis.org>,
	Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
	Arnd Bergmann <arnd@arndb.de>,
	linux-arch@vger.kernel.org, Randy Dunlap <rdunlap@infradead.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Ron Geva <rongevarg@gmail.com>, Waiman Long <longman@redhat.com>
Subject: Re: [patch V6 06/11] rseq: Implement syscall entry work for time slice extensions
Date: Thu, 18 Dec 2025 23:28:48 +0100	[thread overview]
Message-ID: <87ms3fbf1b.ffs@tglx> (raw)
In-Reply-To: <6a0344be-e105-4f09-bf41-02940e730293@efficios.com>

On Tue, Dec 16 2025 at 10:05, Mathieu Desnoyers wrote:
> On 2025-12-15 13:24, Thomas Gleixner wrote:
> [...]
>> 
>> If the code detects inconsistent user space that result in a SIGSEGV for
>> the application.
>
> With these last updates that allow userspace to call arbitrary system
> calls to terminate the grant, the only scenario which triggers SIGSEGV
> is if the put_user() storing to the rseq area fails. Perhaps we should

Nope. There is also the debug path which will catch offenders which
fiddle with the state.

Thanks,

        tglx

  reply	other threads:[~2025-12-18 22:28 UTC|newest]

Thread overview: 44+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-12-15 16:52 [patch V6 00/11] rseq: Implement time slice extension mechanism Thomas Gleixner
2025-12-15 16:52 ` [patch V6 01/11] rseq: Add fields and constants for time slice extension Thomas Gleixner
2025-12-15 18:24   ` Thomas Gleixner
2025-12-16 14:36   ` Mathieu Desnoyers
2025-12-18 23:21     ` Thomas Gleixner
2025-12-15 16:52 ` [patch V6 02/11] rseq: Provide static branch for time slice extensions Thomas Gleixner
2025-12-15 18:24   ` Thomas Gleixner
2025-12-15 16:52 ` [patch V6 03/11] rseq: Add statistics " Thomas Gleixner
2025-12-15 18:24   ` Thomas Gleixner
2025-12-15 16:52 ` [patch V6 04/11] rseq: Add prctl() to enable " Thomas Gleixner
2025-12-15 18:24   ` Thomas Gleixner
2025-12-15 16:52 ` [patch V6 05/11] rseq: Implement sys_rseq_slice_yield() Thomas Gleixner
2025-12-15 18:24   ` Thomas Gleixner
2025-12-16 14:59   ` Mathieu Desnoyers
2025-12-15 16:52 ` [patch V6 06/11] rseq: Implement syscall entry work for time slice extensions Thomas Gleixner
2025-12-15 18:24   ` Thomas Gleixner
2025-12-16 15:05   ` Mathieu Desnoyers
2025-12-18 22:28     ` Thomas Gleixner [this message]
2025-12-18 22:30       ` Mathieu Desnoyers
2025-12-15 16:52 ` [patch V6 07/11] rseq: Implement time slice extension enforcement timer Thomas Gleixner
2025-12-15 18:24   ` Thomas Gleixner
2025-12-16  7:18   ` Randy Dunlap
2025-12-16 17:55     ` Prakash Sangappa
2025-12-16  8:26   ` [patch V6.1 " Thomas Gleixner
2025-12-16 15:13   ` [patch V6 " Mathieu Desnoyers
2025-12-18 15:05   ` Peter Zijlstra
2025-12-18 23:26     ` Thomas Gleixner
2025-12-19 10:05       ` Peter Zijlstra
2025-12-18 15:18   ` Peter Zijlstra
2025-12-18 23:25     ` Thomas Gleixner
2025-12-15 16:52 ` [patch V6 08/11] rseq: Reset slice extension when scheduled Thomas Gleixner
2025-12-15 18:24   ` Thomas Gleixner
2025-12-16 15:17   ` Mathieu Desnoyers
2025-12-15 16:52 ` [patch V6 09/11] rseq: Implement rseq_grant_slice_extension() Thomas Gleixner
2025-12-15 18:24   ` Thomas Gleixner
2025-12-16 15:25   ` Mathieu Desnoyers
2025-12-18 23:28     ` Thomas Gleixner
2025-12-15 16:52 ` [patch V6 10/11] entry: Hook up rseq time slice extension Thomas Gleixner
2025-12-15 18:24   ` Thomas Gleixner
2025-12-16 15:37   ` Mathieu Desnoyers
2025-12-19 11:07     ` Peter Zijlstra
2025-12-15 16:52 ` [patch V6 11/11] selftests/rseq: Implement time slice extension test Thomas Gleixner
2025-12-15 18:24   ` Thomas Gleixner
2025-12-15 18:24 ` [patch V6 00/11] rseq: Implement time slice extension mechanism Thomas Gleixner

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