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.
--
Catalin
