Re: [Patch v2 4/4] x86/speculation: Add prctl to control indirect branch speculation per process

From: Tim Chen
Date: Fri Oct 05 2018 - 14:13:04 EST


On 10/02/2018 10:58 AM, Thomas Gleixner wrote:
> On Tue, 25 Sep 2018, Tim Chen wrote:
>>
>> +void arch_set_dumpable(struct task_struct *tsk, struct mm_struct *mm, int value)
>> +{
>> + if (!static_branch_unlikely(&spectre_v2_app_lite))
>> + return;
>> + if (!static_cpu_has(X86_FEATURE_STIBP))
>> + return;
>> +
>> + if ((unsigned) value != SUID_DUMP_USER) {
>
> First of all we use unsigned int and not unsigned, Aside of that why is the
> argument not unsigned int right away?


The original set_dumpable passes suid_dumpable, which was
exposed via /proc/sys/fs/suid_dumpable and defined as int.
It will make sense to define suid_dumpable as an unsigned int instead.

Would you like me to redefine suid_dumpable as unsigned int
in sysctl.c in the patch revision as a separate clean up patch?

Thanks.

Tim