Re: [PATCH 1/5] arm64: compat: Alloc separate pages for vectors and sigpage
From: Catalin Marinas <catalin.marinas@arm.com>
Date: 2019-03-29 12:12:30
Also in:
linux-arch
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 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel