Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit ba9b5d76 authored by Nicolas Pitre's avatar Nicolas Pitre Committed by Russell King
Browse files

[ARM] 3746/2: Userspace helpers must be Thumb mode interworkable 



Patch from Nicolas Pitre

The userspace helpers in clean/arch/arm/kernel/entry-armv.S are called
directly in/from userspace. They need to cope with being called from
Thumb code.

Patch below uses the bx interworking instruction when
CONFIG_ARM_THUMB=y.

Based on an earlier patch from Paul Brook <paul@codesourcery.com>

Signed-off-by: default avatarNicolas Pitre <nico@cam.org>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 90af774a

arch/arm/kernel/entry-armv.S

+12 −9
Original line number Diff line number Diff line
@@ -634,6 +634,14 @@ ENTRY(__switch_to) 
 * purpose.

 */



	.macro	usr_ret, reg

#ifdef CONFIG_ARM_THUMB

	bx	\reg

#else

	mov	pc, \reg

#endif

	.endm



	.align	5

	.globl	__kuser_helper_start

__kuser_helper_start:
@@ -675,7 +683,7 @@ __kuser_memory_barrier: @ 0xffff0fa0 
#if __LINUX_ARM_ARCH__ >= 6 && defined(CONFIG_SMP)

	mcr	p15, 0, r0, c7, c10, 5	@ dmb

#endif

	mov	pc, lr

	usr_ret	lr



	.align	5
@@ -778,7 +786,7 @@ __kuser_cmpxchg: @ 0xffff0fc0 
	mov	r0, #-1

	adds	r0, r0, #0

#endif

	mov	pc, lr

	usr_ret	lr



#else
@@ -792,7 +800,7 @@ __kuser_cmpxchg: @ 0xffff0fc0 
#ifdef CONFIG_SMP

	mcr	p15, 0, r0, c7, c10, 5	@ dmb

#endif

	mov	pc, lr

	usr_ret	lr



#endif
@@ -834,16 +842,11 @@ __kuser_cmpxchg: @ 0xffff0fc0 
__kuser_get_tls:				@ 0xffff0fe0



#if !defined(CONFIG_HAS_TLS_REG) && !defined(CONFIG_TLS_REG_EMUL)



	ldr	r0, [pc, #(16 - 8)]		@ TLS stored at 0xffff0ff0

	mov	pc, lr



#else



	mrc	p15, 0, r0, c13, c0, 3		@ read TLS register

	mov	pc, lr



#endif

	usr_ret	lr



	.rep	5

	.word	0			@ pad up to __kuser_helper_version