From 2190fed67ba6f3e8129513929f2395843645e928 Mon Sep 17 00:00:00 2001 From: Russell King Date: Thu, 20 Aug 2015 10:32:02 +0100 Subject: ARM: entry: provide uaccess assembly macro hooks Provide hooks into the kernel entry and exit paths to permit control of userspace visibility to the kernel. The intended use is: - on entry to kernel from user, uaccess_disable will be called to disable userspace visibility - on exit from kernel to user, uaccess_enable will be called to enable userspace visibility - on entry from a kernel exception, uaccess_save_and_disable will be called to save the current userspace visibility setting, and disable access - on exit from a kernel exception, uaccess_restore will be called to restore the userspace visibility as it was before the exception occurred. These hooks allows us to keep userspace visibility disabled for the vast majority of the kernel, except for localised regions where we want to explicitly access userspace. Signed-off-by: Russell King --- arch/arm/mm/abort-ev7.S | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/arm/mm/abort-ev7.S') diff --git a/arch/arm/mm/abort-ev7.S b/arch/arm/mm/abort-ev7.S index 4812ad054214..e8d0e08c227f 100644 --- a/arch/arm/mm/abort-ev7.S +++ b/arch/arm/mm/abort-ev7.S @@ -15,6 +15,7 @@ ENTRY(v7_early_abort) mrc p15, 0, r1, c5, c0, 0 @ get FSR mrc p15, 0, r0, c6, c0, 0 @ get FAR + uaccess_disable ip @ disable userspace access /* * V6 code adjusts the returned DFSR. -- cgit v1.2.3-70-g09d2