From: marc.zyngier@arm•com (Marc Zyngier)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH 4/6] arm64: mm: Drop the lowmem watermark check from virt_addr_valid()
Date: Fri, 15 Nov 2013 14:25:29 +0000 [thread overview]
Message-ID: <52862ED9.1050708@arm.com> (raw)
In-Reply-To: <20131115133948.GB1217@darko.cambridge.arm.com>
On 15/11/13 13:39, Catalin Marinas wrote:
> On Thu, Nov 14, 2013 at 07:37:44PM +0000, Santosh Shilimkar wrote:
>> Slab allocator can allocate memory beyond the lowmem watermark
>> which can lead to false failure of virt_addr_valid().
>>
>> So drop the check. The issue was seen with percpu_alloc()
>> in KVM code which was allocating memory beyond lowmem watermark.
>>
>> Am not completly sure whether this is the right fix and if it could
>> impact any other user of virt_addr_valid(). Without this fix as
>> pointed out the KVM init was failing in my testing.
>
> Do you have a problem on arm64? There is no lowmem watermark here.
I don't think that change is relevant for arm64. Actually, the more I
look at it, I don't think virt_addr_valid() should be touched at all.
The real issue is the use of virt_to_phys()/virt_addr_valid() on a
percpu pointer, which is wrong and only worked by chance so far.
I'm working on a patch to solve this.
M.
--
Jazz is not dead. It just smells funny...
next prev parent reply other threads:[~2013-11-15 14:25 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-14 19:37 [PATCH 0/6] ARM/AMR64: Few patches on kvm and mm code Santosh Shilimkar
2013-11-14 19:37 ` [PATCH 1/6] arm64: mm: Add __virt_to_idmap() to keep kvm build happy Santosh Shilimkar
2013-11-15 13:34 ` Catalin Marinas
2013-11-15 14:55 ` Santosh Shilimkar
2013-11-15 14:58 ` Catalin Marinas
2013-11-15 15:31 ` Santosh Shilimkar
2013-11-15 15:05 ` Marc Zyngier
2013-11-15 15:25 ` Santosh Shilimkar
2013-11-15 15:29 ` Marc Zyngier
2013-11-15 15:31 ` Catalin Marinas
2013-11-15 15:33 ` Santosh Shilimkar
2013-11-14 19:37 ` [PATCH 2/6] ARM: kvm: Use virt_to_idmap instead of virt_to_phys for idmap mappings Santosh Shilimkar
2013-11-15 0:12 ` Christoffer Dall
2013-11-14 19:37 ` [PATCH 3/6] ARM: mm: Drop the lowmem watermark check from virt_addr_valid() Santosh Shilimkar
2013-11-15 0:22 ` Christoffer Dall
2013-11-15 0:31 ` Santosh Shilimkar
2013-11-15 0:40 ` Christoffer Dall
2013-11-15 11:48 ` Marc Zyngier
2013-11-15 11:43 ` Marc Zyngier
2013-11-15 14:55 ` Santosh Shilimkar
2013-11-15 15:08 ` Marc Zyngier
2013-11-15 15:46 ` Christoffer Dall
2013-11-15 14:20 ` Russell King - ARM Linux
2013-11-15 15:40 ` Santosh Shilimkar
2013-11-14 19:37 ` [PATCH 4/6] arm64: " Santosh Shilimkar
2013-11-15 13:39 ` Catalin Marinas
2013-11-15 14:25 ` Marc Zyngier [this message]
2013-11-15 14:57 ` Santosh Shilimkar
2013-11-14 19:37 ` [PATCH 5/6] ARM: kvm: Use phys_addr_t instead of unsigned long in mm code Santosh Shilimkar
2013-11-15 0:09 ` Christoffer Dall
2013-11-15 0:10 ` Santosh Shilimkar
2013-11-15 11:58 ` Marc Zyngier
2013-11-14 19:37 ` [PATCH 6/6] ARM: kvm: TMP: Commit the hyp page tables to main memory Santosh Shilimkar
2013-11-14 22:36 ` Santosh Shilimkar
2013-11-15 0:11 ` Christoffer Dall
2013-11-15 0:15 ` Santosh Shilimkar
2013-11-15 0:27 ` Christoffer Dall
2013-11-15 0:36 ` Santosh Shilimkar
2013-11-15 0:42 ` Christoffer Dall
2013-11-15 1:19 ` Santosh Shilimkar
2013-11-15 1:35 ` Christoffer Dall
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