linux-kernel - Re: [PATCH 3/5] powerpc/mm/32: Use page_is

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <87y3iofh2z.fsf@concordia.ellerman.id.au>
Date:   Mon, 19 Mar 2018 22:19:32 +1100
From:   Michael Ellerman <mpe@...erman.id.au>
To:     Jonathan Neuschäfer <j.neuschaefer@....net>,
        linuxppc-dev@...ts.ozlabs.org
Cc:     linux-kernel@...r.kernel.org,
        Jonathan Neuschäfer <j.neuschaefer@....net>,
        linux-mm@...ck.org, Paul Mackerras <paulus@...ba.org>,
        Joel Stanley <joel@....id.au>,
        Guenter Roeck <linux@...ck-us.net>
Subject: Re: [PATCH 3/5] powerpc/mm/32: Use page_is_ram to check for RAM

Michael Ellerman <mpe@...erman.id.au> writes:
> Jonathan Neuschäfer <j.neuschaefer@....net> writes:
>
>> Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@....net>
>> ---
>>  arch/powerpc/mm/pgtable_32.c | 3 +--
>>  1 file changed, 1 insertion(+), 2 deletions(-)
>>
>> diff --git a/arch/powerpc/mm/pgtable_32.c b/arch/powerpc/mm/pgtable_32.c
>> index d35d9ad3c1cd..d54e1a9c1c99 100644
>> --- a/arch/powerpc/mm/pgtable_32.c
>> +++ b/arch/powerpc/mm/pgtable_32.c
>> @@ -145,9 +145,8 @@ __ioremap_caller(phys_addr_t addr, unsigned long size, unsigned long flags,
>>  #ifndef CONFIG_CRASH_DUMP
>>  	/*
>>  	 * Don't allow anybody to remap normal RAM that we're using.
>> -	 * mem_init() sets high_memory so only do the check after that.
>>  	 */
>> -	if (slab_is_available() && (p < virt_to_phys(high_memory)) &&
>> +	if (page_is_ram(__phys_to_pfn(p)) &&
>>  	    !(__allow_ioremap_reserved && memblock_is_region_reserved(p, size))) {
>>  		printk("__ioremap(): phys addr 0x%llx is RAM lr %ps\n",
>>  		       (unsigned long long)p, __builtin_return_address(0));
>
>
> This is killing my p5020ds (Freescale e5500) unfortunately:

Duh, I should actually read the patch :)

This is a 32-bit system with 4G of RAM, so not all of RAM is mapped,
some of it is highem which is why removing the test against high_memory
above breaks it.

So I need the high_memory test on this system.

I'm not clear why it was a problem for you on the Wii, do you even build
the Wii kernel with HIGHMEM enabled?

cheers