: [CRIU] [PATCH] restorer: Make sure the protection on code/data mm areas do fit the kernel requirements

[Pavel Emelyanov]

On 04/13/2012 02:34 PM, Cyrill Gorcunov wrote:
> On Fri, Apr 13, 2012 at 01:24:40PM +0400, Pavel Emelyanov wrote:
>>
>> You don't use the flags value after this AT ALL, wtf???
>>
> 
> This one should do the trick.
> 
> 	Cyrill

> +	sys_mmap((void *)args->mm.mm_start_code, PAGE_SIZE, prot, flags, -1, 0);
> +	ret |= sys_prctl_safe(PR_SET_MM, PR_SET_MM_START_CODE, (long)args->mm.mm_start_code, 0);
> +	sys_munmap((void *)args->mm.mm_start_code, PAGE_SIZE);
> +
> +	sys_mmap((void *)args->mm.mm_end_code, PAGE_SIZE, PROT_EXEC | PROT_READ, flags, -1, 0);
> +	ret |= sys_prctl_safe(PR_SET_MM, PR_SET_MM_END_CODE, (long)args->mm.mm_end_code, 0);
> +	sys_munmap((void *)args->mm.mm_end_code, PAGE_SIZE);


This is much nicer. Can we tune this a little bit more, i.e. like this

sys_mmap(code_start, code_end - code_start, ...)
sys_prctl(PR_SET_MM_START_CODE)
sys_prctl(PR_SET_MM_END_CODE)
sys_munmap()

i.e. mmap only one mapping per PR_SET_MM, not two?

And yes, talk to HPA in order to relax kernel's part of this.

Thanks,
Pavel