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From: Russell King - ARM Linux admin <linux@armlinux.org.uk>
To: Yu Chen <33988979@163.com>
Cc: yu.chen3@zte.com.cn, linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] arm: export memblock_reserve()d regions via /proc/iomem
Date: Sat, 21 Sep 2019 15:51:38 +0100	[thread overview]
Message-ID: <20190921145138.GN25745@shell.armlinux.org.uk> (raw)
In-Reply-To: <1569070969-5168-1-git-send-email-33988979@163.com>

On Sat, Sep 21, 2019 at 09:02:49PM +0800, Yu Chen wrote:
> From: Yu Chen <yu.chen3@zte.com.cn>
> 
> memblock reserved regions are not reported via /proc/iomem on ARM, kexec's
> user-space doesn't know about memblock_reserve()d regions and thus
> possible for kexec to overwrite with the new kernel or initrd.

Many reserved regions come from the kernel allocating memory during
boot.  We don't want to prevent kexec re-using those regions.

> [    0.000000] Booting Linux on physical CPU 0xf00
> [    0.000000] Linux version 4.9.115-rt93-dirty (yuchen@localhost.localdomain) (gcc version 6.2.0 (ZTE Embsys-TSP V3.07.2
> 0) ) #62 SMP PREEMPT Fri Sep 20 10:39:29 CST 2019
> [    0.000000] CPU: ARMv7 Processor [410fc075] revision 5 (ARMv7), cr=30c5387d
> [    0.000000] CPU: div instructions available: patching division code
> [    0.000000] CPU: PIPT / VIPT nonaliasing data cache, VIPT aliasing instruction cache
> [    0.000000] OF: fdt:Machine model: LS1021A TWR Board
> [    0.000000] INITRD: 0x80f7f000+0x03695e40 overlaps in-use memory region - disabling initrd

Is the overlapping region one that is marked as reserved in DT?
Where is the reserved region that overlaps the initrd coming from?

Thanks.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTC broadband for 0.8mile line in suburbia: sync at 12.1Mbps down 622kbps up
According to speedtest.net: 11.9Mbps down 500kbps up

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WARNING: multiple messages have this Message-ID (diff)
From: Russell King - ARM Linux admin <linux@armlinux.org.uk>
To: Yu Chen <33988979@163.com>
Cc: linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, yu.chen3@zte.com.cn
Subject: Re: [PATCH] arm: export memblock_reserve()d regions via /proc/iomem
Date: Sat, 21 Sep 2019 15:51:38 +0100	[thread overview]
Message-ID: <20190921145138.GN25745@shell.armlinux.org.uk> (raw)
In-Reply-To: <1569070969-5168-1-git-send-email-33988979@163.com>

On Sat, Sep 21, 2019 at 09:02:49PM +0800, Yu Chen wrote:
> From: Yu Chen <yu.chen3@zte.com.cn>
> 
> memblock reserved regions are not reported via /proc/iomem on ARM, kexec's
> user-space doesn't know about memblock_reserve()d regions and thus
> possible for kexec to overwrite with the new kernel or initrd.

Many reserved regions come from the kernel allocating memory during
boot.  We don't want to prevent kexec re-using those regions.

> [    0.000000] Booting Linux on physical CPU 0xf00
> [    0.000000] Linux version 4.9.115-rt93-dirty (yuchen@localhost.localdomain) (gcc version 6.2.0 (ZTE Embsys-TSP V3.07.2
> 0) ) #62 SMP PREEMPT Fri Sep 20 10:39:29 CST 2019
> [    0.000000] CPU: ARMv7 Processor [410fc075] revision 5 (ARMv7), cr=30c5387d
> [    0.000000] CPU: div instructions available: patching division code
> [    0.000000] CPU: PIPT / VIPT nonaliasing data cache, VIPT aliasing instruction cache
> [    0.000000] OF: fdt:Machine model: LS1021A TWR Board
> [    0.000000] INITRD: 0x80f7f000+0x03695e40 overlaps in-use memory region - disabling initrd

Is the overlapping region one that is marked as reserved in DT?
Where is the reserved region that overlaps the initrd coming from?

Thanks.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTC broadband for 0.8mile line in suburbia: sync at 12.1Mbps down 622kbps up
According to speedtest.net: 11.9Mbps down 500kbps up

  reply	other threads:[~2019-09-21 14:54 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-09-21 13:02 [PATCH] arm: export memblock_reserve()d regions via /proc/iomem Yu Chen
2019-09-21 13:02 ` Yu Chen
2019-09-21 14:51 ` Russell King - ARM Linux admin [this message]
2019-09-21 14:51   ` Russell King - ARM Linux admin
2019-09-22  8:36 ` kbuild test robot
2019-09-22  8:36   ` kbuild test robot
  -- strict thread matches above, loose matches on Subject: below --
2019-09-23 15:42 Yu Chen
2019-09-23 16:14 ` Russell King - ARM Linux admin
2019-09-23 16:14   ` Russell King - ARM Linux admin

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