On 3/16/20 10:26 AM, Catalin Marinas wrote:

On Mon, Mar 16, 2020 at 10:22:15AM +0000, Mark Rutland wrote:

quoted

On Mon, Mar 16, 2020 at 09:42:32AM +0000, Vincenzo Frascino wrote:

quoted

On 3/15/20 6:30 PM, Catalin Marinas wrote:

quoted

On Fri, Mar 13, 2020 at 03:43:37PM +0000, Vincenzo Frascino wrote:

quoted

--- /dev/null
+++ b/arch/arm64/include/asm/vdso/processor.h

@@ -0,0 +1,31 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2020 ARM Ltd.
+ */
+#ifndef __ASM_VDSO_PROCESSOR_H
+#define __ASM_VDSO_PROCESSOR_H
+
+#ifndef __ASSEMBLY__
+
+#include <asm/page-def.h>
+
+#ifdef CONFIG_COMPAT
+#if defined(CONFIG_ARM64_64K_PAGES) && defined(CONFIG_KUSER_HELPERS)
+/*
+ * With CONFIG_ARM64_64K_PAGES enabled, the last page is occupied
+ * by the compat vectors page.
+ */
+#define TASK_SIZE_32		UL(0x100000000)
+#else
+#define TASK_SIZE_32		(UL(0x100000000) - PAGE_SIZE)
+#endif /* CONFIG_ARM64_64K_PAGES */
+#endif /* CONFIG_COMPAT */

Just curious, what's TASK_SIZE_32 used for in the vDSO code? You don't
seem to move TASK_SIZE.

I tried to fine grain the headers as much as I could in order to avoid
unneeded/unwanted inclusions:
 * TASK_SIZE_32 is used to verify ABI consistency on vdso32 (please refer to
   arch/arm64/kernel/vdso32/vgettimeofday.c).
 * TASK_SIZE is not required by the vdso library hence it is not present in
   these headers.

It would be worth noting the former point in the commit message, since
it can be surprising.

I also think it's worth keeping the definitions together if that's easy,
as it makes it easier to navigate the codebase, even if TASK_SIZE isn't
necessary for the VDSO itself.

It won't work as TASK_SIZE requires (on arm64) test_thread_flag() which
can't be made available to the vDSO.

Ups, I did not see this :) luckily I agree ;)

-- 
Regards,
Vincenzo

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel