From: Baoquan He <bhe@redhat.com>
To: Borislav Petkov <bp@alien8.de>, dyoung@redhat.com
Cc: Pingfan Liu <kernelfans@gmail.com>,
x86@kernel.org, Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
Will Deacon <will.deacon@arm.com>,
Nicolas Pitre <nico@linaro.org>,
Chao Fan <fanc.fnst@cn.fujitsu.com>,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
Ard Biesheuvel <ard.biesheuvel@linaro.org>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] x86/boot/KASLR: skip the specified crashkernel reserved region
Date: Mon, 25 Feb 2019 21:05:04 +0800 [thread overview]
Message-ID: <20190225130452.GN14858@MiWiFi-R3L-srv> (raw)
In-Reply-To: <20190225094522.GC26145@zn.tnic>
On 02/25/19 at 10:45am, Borislav Petkov wrote:
> On Mon, Feb 25, 2019 at 03:59:56PM +0800, Pingfan Liu wrote:
> > crashkernel=x@y option may fail to reserve the required memory region if
> > KASLR puts kernel into the region. To avoid this uncertainty, making KASLR
> > skip the required region.
>
> Lemme see if I understand this correctly: supplying crashkernel=X@Y
> influences where KASLR would put the randomized kernel. And it should be
> the other way around, IMHO. crashkernel= will have to "work" with KASLR
> to find a suitable range and if the reservation at Y fails, then we tell
> the user to try the more relaxed variant crashkernel=M.
Hmm, asking user to try crashkernel=M is an option. Users may want to
specify a region for crashkernel reservation, Just I forget in what case
they want crashkernel=x@y set. In crashkernel=x@y specified case, we may
truly need to avoid the already specified region.
Not sure if Dave still remember it. If no need, removing it is also
good.
Thanks
Baoquan
next prev parent reply other threads:[~2019-02-25 13:05 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-25 7:59 [PATCH] x86/boot/KASLR: skip the specified crashkernel reserved region Pingfan Liu
2019-02-25 8:23 ` Chao Fan
2019-02-26 3:11 ` Pingfan Liu
2019-02-25 9:45 ` Borislav Petkov
2019-02-25 13:05 ` Baoquan He [this message]
2019-02-26 5:11 ` Dave Young
2019-02-26 3:08 ` Pingfan Liu
2019-02-26 10:46 ` Borislav Petkov
2019-02-27 1:30 ` Baoquan He
2019-02-27 7:39 ` Borislav Petkov
2019-03-06 7:58 ` Pingfan Liu
2019-03-11 2:49 ` Baoquan He
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