From: "Jürgen Groß" <jgross@suse.com>
To: Miroslav Benes <mbenes@suse.cz>,
boris.ostrovsky@oracle.com, sstabellini@kernel.org,
tglx@linutronix.de, mingo@redhat.com, bp@alien8.de,
hpa@zytor.com, jpoimboe@redhat.com
Cc: andrew.cooper3@citrix.com, x86@kernel.org,
linux-kernel@vger.kernel.org, jbeulich@suse.com,
live-patching@vger.kernel.org, xen-devel@lists.xenproject.org,
jslaby@suse.cz
Subject: Re: [Xen-devel] [PATCH v3 2/2] x86/xen: Make the secondary CPU idle tasks reliable
Date: Thu, 26 Mar 2020 10:30:09 +0100 [thread overview]
Message-ID: <a39c8c7e-c793-7ec1-5159-102c824bdada@suse.com> (raw)
In-Reply-To: <20200326092603.7230-3-mbenes@suse.cz>
On 26.03.20 10:26, Miroslav Benes wrote:
> The unwinder reports the secondary CPU idle tasks' stack on XEN PV as
> unreliable, which affects at least live patching.
> cpu_initialize_context() sets up the context of the CPU through
> VCPUOP_initialise hypercall. After it is woken up, the idle task starts
> in cpu_bringup_and_idle() function and its stack starts at the offset
> right below pt_regs. The unwinder correctly detects the end of stack
> there but it is confused by NULL return address in the last frame.
>
> Introduce a wrapper in assembly, which just calls
> cpu_bringup_and_idle(). The return address is thus pushed on the stack
> and the wrapper contains the annotation hint for the unwinder regarding
> the stack state.
>
> Signed-off-by: Miroslav Benes <mbenes@suse.cz>
Reviewed-by: Juergen Gross <jgross@suse.com>
Juergen
prev parent reply other threads:[~2020-03-26 9:30 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-26 9:26 [Xen-devel] [PATCH v3 0/2] x86/xen: Make idle tasks reliable Miroslav Benes
2020-03-26 9:26 ` [Xen-devel] [PATCH v3 1/2] x86/xen: Make the boot CPU idle task reliable Miroslav Benes
2020-03-26 9:29 ` Jürgen Groß
2020-03-26 9:26 ` [Xen-devel] [PATCH v3 2/2] x86/xen: Make the secondary CPU idle tasks reliable Miroslav Benes
2020-03-26 9:30 ` Jürgen Groß [this message]
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