Hi Catalin,
thank you for your review.
On 29/03/2019 12:12, Catalin Marinas wrote:
> On Tue, Mar 19, 2019 at 03:15:38PM +0000, Vincenzo Frascino wrote:
>> +static int __init aarch32_alloc_vdso_pages(void)
>> {
>> extern char __kuser_helper_start[], __kuser_helper_end[];
>> extern char __aarch32_sigret_code_start[], __aarch32_sigret_code_end[];
>>
>> int kuser_sz = __kuser_helper_end - __kuser_helper_start;
>> int sigret_sz = __aarch32_sigret_code_end - __aarch32_sigret_code_start;
>> - unsigned long vpage;
>> + unsigned long vdso_pages[2];
>>
>> - vpage = get_zeroed_page(GFP_ATOMIC);
>> + vdso_pages[0] = get_zeroed_page(GFP_ATOMIC);
>> + if (!vdso_pages[0])
>> + return -ENOMEM;
>>
>> - if (!vpage)
>> + vdso_pages[1] = get_zeroed_page(GFP_ATOMIC);
>> + if (!vdso_pages[1])
>> return -ENOMEM;
>>
>> /* kuser helpers */
>> - memcpy((void *)vpage + 0x1000 - kuser_sz, __kuser_helper_start,
>> - kuser_sz);
>> + memcpy((void *)(vdso_pages[0] + 0x1000 - kuser_sz),
>> + __kuser_helper_start,
>> + kuser_sz);
>>
>> /* sigreturn code */
>> - memcpy((void *)vpage + AARCH32_KERN_SIGRET_CODE_OFFSET,
>> - __aarch32_sigret_code_start, sigret_sz);
>> + memcpy((void *)vdso_pages[1],
>> + __aarch32_sigret_code_start,
>> + sigret_sz);
>>
>> - flush_icache_range(vpage, vpage + PAGE_SIZE);
>> - vectors_page[0] = virt_to_page(vpage);
>> + flush_icache_range(vdso_pages[0], vdso_pages[0] + PAGE_SIZE);
>> + flush_icache_range(vdso_pages[1], vdso_pages[1] + PAGE_SIZE);
>
> I wonder whether we still need the flush_icache_range() calls here.
> Normally set_pte_at() handles cache maintenance automatically if
> PG_dcache_clean is not set. We could probably just call
> flush_dcache_page() here.
>
I agree, I am going to update the code accordingly and re-post the set.
--
Regards,
Vincenzo
