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From: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
To: Michael Ellerman <mpe@ellerman.id.au>, linuxppc-dev@lists.ozlabs.org
Cc: linux-mm@kvack.org, Kefeng Wang <wangkefeng.wang@huawei.com>,
	Michal Hocko <mhocko@suse.com>
Subject: Re: [PATCH 3/3] powerpc/mm: Use VMALLOC_START to validate addr
Date: Mon, 27 Jun 2022 10:14:37 +0530	[thread overview]
Message-ID: <877d52zpe2.fsf@linux.ibm.com> (raw)
In-Reply-To: <87bkui6apn.fsf@mpe.ellerman.id.au>

Michael Ellerman <mpe@ellerman.id.au> writes:

> "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> writes:
>> Instead of high_memory use VMALLOC_START to validate that the address is
>> not in the vmalloc range.
>>
>> Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
>> Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
>> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
>
> Isn't this really the fix for ffa0b64e3be5 ("powerpc: Fix
> virt_addr_valid() for 64-bit Book3E & 32-bit") ?

If we are looking for a simpler backport yet. But what commit ffa0b64e3be5 
does is correct. high_memory is suppose to be the top of direct mapped
address range. Hence checking for high_meory will also avoid vmalloc address.

If we take patch 1 then patch 3 is not really a fix. I would consider it
a cleanup to switch to a more familiar VMALLOC_START variable.

>
> cheers
>
>> diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h
>> index e5f75c70eda8..256cad69e42e 100644
>> --- a/arch/powerpc/include/asm/page.h
>> +++ b/arch/powerpc/include/asm/page.h
>> @@ -134,7 +134,7 @@ static inline bool pfn_valid(unsigned long pfn)
>>  
>>  #define virt_addr_valid(vaddr)	({					\
>>  	unsigned long _addr = (unsigned long)vaddr;			\
>> -	_addr >= PAGE_OFFSET && _addr < (unsigned long)high_memory &&	\
>> +	_addr >= PAGE_OFFSET && _addr < (unsigned long)VMALLOC_START &&	\
>>  	pfn_valid(virt_to_pfn(_addr));					\
>>  })
>>  
>> -- 
>> 2.36.1

  reply	other threads:[~2022-06-27  4:45 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-06-23 12:29 [PATCH 1/3] powerpc/memhotplug: Add add_pages override for PPC Aneesh Kumar K.V
2022-06-23 12:29 ` [PATCH 2/3] powerpc/mm: Update max/min_low_pfn in the same function Aneesh Kumar K.V
2022-06-23 12:29 ` [PATCH 3/3] powerpc/mm: Use VMALLOC_START to validate addr Aneesh Kumar K.V
2022-06-24  2:45   ` Michael Ellerman
2022-06-27  4:44     ` Aneesh Kumar K.V [this message]
2022-06-24 11:51   ` Christophe Leroy
2022-06-27  4:49     ` Aneesh Kumar K.V
2022-06-27  5:42   ` Christophe Leroy
2022-06-27  6:49     ` Aneesh Kumar K.V

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