From: Baoquan He <bhe@redhat.com>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>,
Junichi Nomura <j-nomura@ce.jp.nec.com>,
"fanc.fnst@cn.fujitsu.com" <fanc.fnst@cn.fujitsu.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"x86@kernel.org" <x86@kernel.org>
Subject: Re: [PATCH] x86/boot: Use EFI setup data if provided
Date: Mon, 25 Mar 2019 17:03:49 +0800 [thread overview]
Message-ID: <20190325090349.GE3659@MiWiFi-R3L-srv> (raw)
In-Reply-To: <alpine.DEB.2.21.1903250941020.1798@nanos.tec.linutronix.de>
On 03/25/19 at 09:43am, Thomas Gleixner wrote:
> On Mon, 25 Mar 2019, Baoquan He wrote:
>
> > On 03/25/19 at 08:53am, Borislav Petkov wrote:
> > > On Mon, Mar 25, 2019 at 03:27:10PM +0800, Baoquan He wrote:
> > > > Kexec kernel also need to get rsdp to get SRAT tables so that KASLR can
> > > > avoid those hotpluggable regions in boot compression stage.
> > > >
> > > > The kexec_file_load has filled in acpi_rsdp_addr of kexec kernel in
> > > > below code. It will return direclty in get_rsdp_addr() since
> > > > acpi_rsdp_addr is got from boot_params->acpi_rsdp_addr.
> > > >
> > > > arch/x86/kernel/kexec-bzimage64.c <<setup_boot_parameters>>
> > > > params->acpi_rsdp_addr = boot_params.acpi_rsdp_addr;
> > > >
> > > > The other interface, kexec_load, its boot_params filling is done in user
> > > > space kexec_tools. And we haven't made the acpi_rsdp_addr filling yet.
> > > > And the old kexec_tools utility can also cause the new kexec kernel to
> > > > search efi rspd pointer even thought it's fixed.
> > >
> > > Yes, kexec is a pile of ugly and fragile hackery.
> >
> > Well, yes, we have to admit that, since kexec is based on hacking.
>
> Well, then the right thing to do is to think about it proper and replace
> the hackery by something well thought out instead of adding duct tape to it
> every other day.
I could make mistakes on expressing. I meant the mechanism of kexec is
based on hacking into kernel booting stuff. So sometime we call kexec a
bootloader, at least a bootloader variant. That means we may need to adapt
code when any change is made in kernel boot side.
E.g for this acpi_rsdp_addr adding, it happened in boot compressing
stage, to get rsdp to fix the conflict between KASLR and HOTPLUG.
Accordingly, kexec code need be adpated too.
So, when maintain kexec/kdump, we have to track and test any change
which could happen in kernel boot.
Thanks
Baoquan
prev parent reply other threads:[~2019-03-25 9:03 UTC|newest]
Thread overview: 90+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-22 11:03 [PATCH] x86/boot: Use EFI setup data if provided Junichi Nomura
2019-03-22 15:23 ` Borislav Petkov
2019-03-25 0:27 ` Junichi Nomura
2019-03-25 6:01 ` Dave Young
2019-03-25 6:19 ` Dave Young
2019-03-25 6:45 ` Kairui Song
2019-03-25 6:47 ` Junichi Nomura
2019-03-25 6:59 ` Dave Young
2019-03-25 8:27 ` [PATCH v2] " Junichi Nomura
2019-03-25 8:54 ` Boris Petkov
2019-03-25 9:25 ` [PATCH v2] x86/boot: Don't try to search RSDP from EFI when kexec-booted Junichi Nomura
2019-03-25 10:15 ` [PATCH v2] x86/boot: Use EFI setup data if provided Dave Young
2019-03-25 10:36 ` Junichi Nomura
2019-03-25 11:16 ` Dave Young
2019-03-25 12:01 ` Borislav Petkov
2019-03-25 12:23 ` Dave Young
2019-03-25 12:32 ` Borislav Petkov
2019-03-25 23:10 ` Junichi Nomura
2019-03-26 12:46 ` Dave Young
2019-03-26 13:57 ` Borislav Petkov
2019-03-27 1:48 ` bhe
2019-03-27 12:14 ` Borislav Petkov
2019-03-28 4:17 ` Junichi Nomura
2019-03-28 6:26 ` Chao Fan
2019-03-28 6:43 ` bhe
2019-03-28 7:43 ` Junichi Nomura
2019-03-28 15:52 ` Borislav Petkov
2019-03-29 3:05 ` Junichi Nomura
2019-03-29 8:39 ` Borislav Petkov
2019-03-29 9:05 ` Chao Fan
2019-03-29 9:16 ` Borislav Petkov
2019-03-29 9:37 ` Junichi Nomura
2019-03-29 9:44 ` Chao Fan
2019-03-29 9:56 ` Junichi Nomura
2019-03-29 7:20 ` [PATCH] x86/boot: Use efi_setup_data for searching RSDP on kexec-ed kernel Junichi Nomura
2019-03-29 7:49 ` bhe
2019-03-29 8:29 ` Chao Fan
2019-03-29 8:39 ` Junichi Nomura
2019-03-29 9:18 ` Chao Fan
2019-03-29 9:16 ` bhe
2019-03-29 9:20 ` Chao Fan
2019-04-01 0:08 ` [PATCH v2] " Junichi Nomura
2019-04-02 9:41 ` Chao Fan
2019-04-02 9:53 ` Junichi Nomura
2019-04-02 11:06 ` Chao Fan
2019-04-02 10:22 ` Junichi Nomura
2019-04-02 12:03 ` Dave Young
2019-04-03 5:35 ` Chao Fan
2019-04-03 5:53 ` Dave Young
2019-04-03 6:39 ` Dave Young
2019-04-03 7:30 ` Chao Fan
2019-04-03 7:50 ` bhe
2019-04-03 8:23 ` Dave Young
2019-04-03 8:26 ` Dave Young
2019-04-03 16:14 ` Borislav Petkov
2019-04-04 1:02 ` Chao Fan
2019-04-03 9:28 ` Chao Fan
2019-04-03 7:21 ` Chao Fan
2019-04-03 8:09 ` Dave Young
2019-04-03 8:23 ` Chao Fan
2019-04-03 9:02 ` Chao Fan
2019-04-03 9:39 ` Chao Fan
2019-04-04 1:23 ` Junichi Nomura
2019-04-04 2:52 ` Dave Young
2019-04-04 3:00 ` bhe
2019-04-04 3:10 ` bhe
2019-04-04 3:22 ` Dave Young
2019-04-04 6:41 ` Dave Young
2019-04-04 7:20 ` Chao Fan
2019-04-04 7:41 ` Dave Young
2019-04-04 7:48 ` Chao Fan
2019-04-04 12:22 ` Borislav Petkov
2019-04-04 14:08 ` Dave Young
2019-04-03 8:18 ` Dave Young
2019-04-02 10:25 ` [PATCH v3] " Junichi Nomura
2019-04-04 7:32 ` Dave Young
2019-04-04 12:24 ` Borislav Petkov
2019-04-04 14:12 ` Dave Young
2019-04-04 14:41 ` Borislav Petkov
2019-04-05 1:36 ` Dave Young
2019-04-05 4:19 ` Junichi Nomura
2019-03-28 23:11 ` [PATCH v2] x86/boot: Use EFI setup data if provided bhe
2019-03-29 3:34 ` Junichi Nomura
2019-03-29 3:52 ` bhe
2019-03-29 5:16 ` Junichi Nomura
2019-03-25 7:27 ` [PATCH] " Baoquan He
2019-03-25 7:53 ` Borislav Petkov
2019-03-25 8:21 ` Baoquan He
2019-03-25 8:43 ` Thomas Gleixner
2019-03-25 9:03 ` Baoquan He [this message]
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