From: Joe Lawrence <joe.lawrence@redhat.com>
To: Petr Mladek <pmladek@suse.com>, Brian Gerst <brgerst@gmail.com>,
jpoimboe@kernel.org
Cc: linux-kernel@vger.kernel.org, x86@kernel.org,
Thomas Gleixner <tglx@linutronix.de>,
Borislav Petkov <bp@alien8.de>, "H . Peter Anvin" <hpa@zytor.com>,
Peter Zijlstra <peterz@infradead.org>,
Sami Tolvanen <samitolvanen@google.com>,
alyssa.milburn@linux.intel.com, keescook@chromium.org,
joao@overdrivepizza.com, tim.c.chen@linux.intel.com,
live-patching@vger.kernel.org
Subject: Re: [PATCH v2 2/2] x86: Rewrite ret_from_fork() in C
Date: Wed, 19 Jul 2023 16:33:26 -0400 [thread overview]
Message-ID: <b6941f79-5c9e-7c22-bee1-a00d32bea009@redhat.com> (raw)
In-Reply-To: <ZLf_Z5dCSm7zKDel@alley>
On 7/19/23 11:21, Petr Mladek wrote:
> On Fri 2023-06-23 18:55:29, Brian Gerst wrote:
>> When kCFI is enabled, special handling is needed for the indirect call
>> to the kernel thread function. Rewrite the ret_from_fork() function in
>> C so that the compiler can properly handle the indirect call.
>
> This patch broke livepatching. Kthreads never have a reliable stack.
> It works when I revert it.
>
Just curious -- did the selftests catch this anywhere? I'm not 100%
clear on what trees / frequency they all run, so maybe Petr you found
this by code inspection or other means?
--
Joe
next prev parent reply other threads:[~2023-07-19 20:35 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-23 22:55 [PATCH v2 0/2] " Brian Gerst
2023-06-23 22:55 ` [PATCH v2 1/2] x86/32: Remove schedule_tail_wrapper() Brian Gerst
2023-07-10 8:13 ` [tip: x86/urgent] " tip-bot2 for Brian Gerst
2023-06-23 22:55 ` [PATCH v2 2/2] x86: Rewrite ret_from_fork() in C Brian Gerst
2023-07-10 8:13 ` [tip: x86/urgent] " tip-bot2 for Brian Gerst
2023-07-19 15:21 ` [PATCH v2 2/2] " Petr Mladek
2023-07-19 20:02 ` Peter Zijlstra
2023-07-19 20:15 ` Peter Zijlstra
2023-07-19 20:50 ` Peter Zijlstra
2023-07-19 23:31 ` Josh Poimboeuf
2023-07-20 5:22 ` Peter Zijlstra
2023-07-20 9:28 ` Peter Zijlstra
2023-07-20 8:18 ` Petr Mladek
2023-07-21 9:20 ` [tip: x86/urgent] x86: Fix kthread unwind tip-bot2 for Peter Zijlstra
2023-07-19 20:33 ` Joe Lawrence [this message]
2023-07-19 20:41 ` [PATCH v2 2/2] x86: Rewrite ret_from_fork() in C Peter Zijlstra
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