From: Borislav Petkov <bp@alien8.de>
To: Junichi Nomura <j-nomura@ce.jp.nec.com>
Cc: Dave Young <dyoung@redhat.com>,
Chao Fan <fanc.fnst@cn.fujitsu.com>, Baoquan He <bhe@redhat.com>,
Kairui Song <kasong@redhat.com>,
"x86@kernel.org" <x86@kernel.org>,
"kexec@lists.infradead.org" <kexec@lists.infradead.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v4] x86/boot: Use efi_setup_data for searching RSDP on kexec-ed kernel
Date: Fri, 12 Apr 2019 15:35:29 +0200 [thread overview]
Message-ID: <20190412133528.GD19808@zn.tnic> (raw)
In-Reply-To: <20190412084956.GC19808@zn.tnic>
On Fri, Apr 12, 2019 at 10:49:56AM +0200, Borislav Petkov wrote:
> Now I need to go figure out whether there's a reliable way to know in
> the kexec kernel that it *is* a kexec kernel.
Actually, thinking about this more, we don't need to know whether the
kernel was kexeced or not. Why?
Because if it is kexec'ed, kexec(1) passes the required info in
setup_data. Now, if for whatever reason the kexec'ed kernel fails to
parse that EFI info and get the systab to figure out the RDSP, then it
doesn't have any other choice but fail booting.
Because there's no way it can figure out where the EFI runtime has been
mapped and recover by finding the RDSP from there.
So I think we're perfectly fine with the old approach:
if (!pa)
pa = kexec_get_rsdp_addr();
if (!pa)
pa = efi_get_rsdp_addr();
--
Regards/Gruss,
Boris.
Good mailing practices for 400: avoid top-posting and trim the reply.
next prev parent reply other threads:[~2019-04-12 13:35 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-08 23:10 [PATCH v4] x86/boot: Use efi_setup_data for searching RSDP on kexec-ed kernel Junichi Nomura
2019-04-10 17:14 ` Borislav Petkov
2019-04-10 23:34 ` Junichi Nomura
2019-04-11 8:09 ` Borislav Petkov
2019-04-11 8:16 ` Junichi Nomura
2019-04-11 8:37 ` Borislav Petkov
2019-04-11 9:13 ` Junichi Nomura
2019-04-11 9:21 ` Boris Petkov
2019-04-11 9:32 ` Junichi Nomura
2019-04-11 9:40 ` Boris Petkov
2019-04-11 12:58 ` Borislav Petkov
2019-04-12 2:54 ` Junichi Nomura
2019-04-12 8:49 ` Borislav Petkov
2019-04-12 13:35 ` Borislav Petkov [this message]
2019-04-15 7:01 ` Junichi Nomura
2019-04-15 9:07 ` Borislav Petkov
2019-04-15 10:25 ` Borislav Petkov
2019-04-15 23:00 ` Junichi Nomura
2019-04-15 23:14 ` Junichi Nomura
2019-04-16 9:45 ` Borislav Petkov
2019-04-16 23:09 ` kexec crash on OVMF i386 + x86_64 kernel (Re: [PATCH v4] x86/boot: Use efi_setup_data for searching RSDP on kexec-ed kernel) Junichi Nomura
2019-04-17 5:14 ` Dave Young
2019-04-17 17:57 ` Prakhya, Sai Praneeth
2019-04-16 9:40 ` [PATCH v4] x86/boot: Use efi_setup_data for searching RSDP on kexec-ed kernel Borislav Petkov
2019-04-16 9:52 ` [PATCH] x86/boot: Use efi_setup_data for searching RSDP on kexec-ed kernels Borislav Petkov
2019-04-16 10:02 ` Ingo Molnar
2019-04-16 10:31 ` Borislav Petkov
2019-04-16 11:41 ` Dave Young
2019-04-16 13:22 ` Borislav Petkov
2019-04-17 1:38 ` Dave Young
2019-04-17 4:57 ` Dave Young
2019-04-17 6:00 ` Kairui Song
2019-04-17 7:08 ` Dave Young
2019-04-17 8:22 ` Borislav Petkov
2019-04-18 1:24 ` Dave Young
2019-04-19 8:34 ` [RFC PATCH] kexec, x86/boot: map systab region in identity mapping before accessing it Kairui Song
2019-04-19 8:58 ` Baoquan He
2019-04-19 9:39 ` Kairui Song
2019-04-16 22:44 ` [PATCH v4] x86/boot: Use efi_setup_data for searching RSDP on kexec-ed kernel Junichi Nomura
2019-04-17 7:02 ` Dave Young
2019-04-17 8:54 ` Borislav Petkov
2019-04-17 9:02 ` Borislav Petkov
2019-04-17 10:31 ` Chao Fan
2019-04-11 8:42 ` Baoquan He
2019-04-11 9:14 ` Junichi Nomura
2019-04-12 0:23 ` Baoquan He
2019-04-15 7:46 ` Dave Young
2019-06-06 19:22 ` [tip:x86/boot] x86/boot: Use efi_setup_data for searching RSDP on kexec-ed kernels tip-bot for Junichi Nomura
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