linux-kernel - Re: [PATCH v2 3/3] arm64: Silence first allocation with CONFIG_ARM64_MODULE

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]

Date:   Thu, 27 Apr 2017 11:09:45 -0700
From:   Florian Fainelli <f.fainelli@...il.com>
To:     Ard Biesheuvel <ard.biesheuvel@...aro.org>
Cc:     linux-arm-kernel@...ts.infradead.org,
        Russell King <linux@...linux.org.uk>,
        Catalin Marinas <catalin.marinas@....com>,
        Will Deacon <will.deacon@....com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Michal Hocko <mhocko@...e.com>, zijun_hu <zijun_hu@....com>,
        "Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>,
        Andrey Ryabinin <aryabinin@...tuozzo.com>,
        Chris Wilson <chris@...is-wilson.co.uk>,
        open list <linux-kernel@...r.kernel.org>,
        "open list:MEMORY MANAGEMENT" <linux-mm@...ck.org>,
        angus@...usclark.org
Subject: Re: [PATCH v2 3/3] arm64: Silence first allocation with
 CONFIG_ARM64_MODULE_PLTS=y

On 04/27/2017 11:07 AM, Ard Biesheuvel wrote:
> 
>> On 27 Apr 2017, at 18:39, Florian Fainelli <f.fainelli@...il.com> wrote:
>>
>> When CONFIG_ARM64_MODULE_PLTS is enabled, the first allocation using the
>> module space fails, because the module is too big, and then the module
>> allocation is attempted from vmalloc space. Silence the first allocation
>> failure in that case by setting __GFP_NOWARN.
>>
>> Signed-off-by: Florian Fainelli <f.fainelli@...il.com>
>> ---
>> arch/arm64/kernel/module.c | 7 ++++++-
>> 1 file changed, 6 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/arm64/kernel/module.c b/arch/arm64/kernel/module.c
>> index 7f316982ce00..58bd5cfdd544 100644
>> --- a/arch/arm64/kernel/module.c
>> +++ b/arch/arm64/kernel/module.c
>> @@ -32,11 +32,16 @@
>>
>> void *module_alloc(unsigned long size)
>> {
>> +    gfp_t gfp_mask = GFP_KERNEL;
>>    void *p;
>>
>> +#if IS_ENABLED(CONFIG_ARM64_MODULE_PLTS)
>> +    /* Silence the initial allocation */
>> +    gfp_mask |= __GFP_NOWARN;
>> +#endif
> 
> Please use IS_ENABLED() instead here

How do you mean?

if (IS_ENABLED()) vs. #if IS_ENABLED()?

> 
>>    p = __vmalloc_node_range(size, MODULE_ALIGN, module_alloc_base,
>>                module_alloc_base + MODULES_VSIZE,
>> -                GFP_KERNEL, PAGE_KERNEL_EXEC, 0,
>> +                gfp_mask, PAGE_KERNEL_EXEC, 0,
>>                NUMA_NO_NODE, __builtin_return_address(0));
>>
>>    if (!p && IS_ENABLED(CONFIG_ARM64_MODULE_PLTS) &&
>> -- 
>> 2.9.3
>>
> 
> Other than that, and with Michal's nit addressed:
> 
> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@...aro.org>
> 


-- 
Florian