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Commit c4c5716e authored by Catalin Marinas's avatar Catalin Marinas Committed by Russell King
Browse files

[ARM] 5385/2: unwind: Add unwinding information to exception entry points 



This is needed to allow or stop the unwinding at certain points in the
kernel like exception entries.

Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 2e1926e7

arch/arm/kernel/entry-armv.S

+19 −0
Original line number Diff line number Diff line
@@ -20,6 +20,7 @@ 
#include <asm/vfpmacros.h>

#include <mach/entry-macro.S>

#include <asm/thread_notify.h>

#include <asm/unwind.h>



#include "entry-header.S"
@@ -123,6 +124,8 @@ ENDPROC(__und_invalid) 
#endif



	.macro	svc_entry, stack_hole=0

 UNWIND(.fnstart		)

 UNWIND(.save {r0 - pc}		)

	sub	sp, sp, #(S_FRAME_SIZE + \stack_hole)

 SPFIX(	tst	sp, #4		)

 SPFIX(	bicne	sp, sp, #4	)
@@ -196,6 +199,7 @@ __dabt_svc: 
	ldr	r0, [sp, #S_PSR]

	msr	spsr_cxsf, r0

	ldmia	sp, {r0 - pc}^			@ load r0 - pc, cpsr

 UNWIND(.fnend		)

ENDPROC(__dabt_svc)



	.align	5
@@ -228,6 +232,7 @@ __irq_svc: 
	bleq	trace_hardirqs_on

#endif

	ldmia	sp, {r0 - pc}^			@ load r0 - pc, cpsr

 UNWIND(.fnend		)

ENDPROC(__irq_svc)



	.ltorg
@@ -278,6 +283,7 @@ __und_svc: 
	ldr	lr, [sp, #S_PSR]		@ Get SVC cpsr

	msr	spsr_cxsf, lr

	ldmia	sp, {r0 - pc}^			@ Restore SVC registers

 UNWIND(.fnend		)

ENDPROC(__und_svc)



	.align	5
@@ -320,6 +326,7 @@ __pabt_svc: 
	ldr	r0, [sp, #S_PSR]

	msr	spsr_cxsf, r0

	ldmia	sp, {r0 - pc}^			@ load r0 - pc, cpsr

 UNWIND(.fnend		)

ENDPROC(__pabt_svc)



	.align	5
@@ -343,6 +350,8 @@ ENDPROC(__pabt_svc) 
#endif



	.macro	usr_entry

 UNWIND(.fnstart	)

 UNWIND(.cantunwind	)	@ don't unwind the user space

	sub	sp, sp, #S_FRAME_SIZE

	stmib	sp, {r1 - r12}
@@ -420,6 +429,7 @@ __dabt_usr: 
	mov	r2, sp

	adr	lr, ret_from_exception

	b	do_DataAbort

 UNWIND(.fnend		)

ENDPROC(__dabt_usr)



	.align	5
@@ -450,6 +460,7 @@ __irq_usr: 


	mov	why, #0

	b	ret_to_user

 UNWIND(.fnend		)

ENDPROC(__irq_usr)



	.ltorg
@@ -484,6 +495,7 @@ __und_usr: 
#else

	b	__und_usr_unknown

#endif

 UNWIND(.fnend		)

ENDPROC(__und_usr)



	@
@@ -671,14 +683,18 @@ __pabt_usr: 
	enable_irq				@ Enable interrupts

	mov	r1, sp				@ regs

	bl	do_PrefetchAbort		@ call abort handler

 UNWIND(.fnend		)

	/* fall through */

/*

 * This is the return code to user mode for abort handlers

 */

ENTRY(ret_from_exception)

 UNWIND(.fnstart	)

 UNWIND(.cantunwind	)

	get_thread_info tsk

	mov	why, #0

	b	ret_to_user

 UNWIND(.fnend		)

ENDPROC(__pabt_usr)

ENDPROC(ret_from_exception)
@@ -688,6 +704,8 @@ ENDPROC(ret_from_exception) 
 * previous and next are guaranteed not to be the same.

 */

ENTRY(__switch_to)

 UNWIND(.fnstart	)

 UNWIND(.cantunwind	)

	add	ip, r1, #TI_CPU_SAVE

	ldr	r3, [r2, #TI_TP_VALUE]

	stmia	ip!, {r4 - sl, fp, sp, lr}	@ Store most regs on stack
@@ -717,6 +735,7 @@ ENTRY(__switch_to) 
	bl	atomic_notifier_call_chain

	mov	r0, r5

	ldmia	r4, {r4 - sl, fp, sp, pc}	@ Load all regs saved previously

 UNWIND(.fnend		)

ENDPROC(__switch_to)



	__INIT

arch/arm/kernel/entry-common.S

+4 −0
Original line number Diff line number Diff line
@@ -11,6 +11,7 @@ 
#include <asm/unistd.h>

#include <asm/ftrace.h>

#include <mach/entry-macro.S>

#include <asm/unwind.h>



#include "entry-header.S"
@@ -22,6 +23,8 @@ 
 * stack.

 */

ret_fast_syscall:

 UNWIND(.fnstart	)

 UNWIND(.cantunwind	)

	disable_irq				@ disable interrupts

	ldr	r1, [tsk, #TI_FLAGS]

	tst	r1, #_TIF_WORK_MASK
@@ -38,6 +41,7 @@ ret_fast_syscall: 
	mov	r0, r0

	add	sp, sp, #S_FRAME_SIZE - S_PC

	movs	pc, lr				@ return & move spsr_svc into cpsr

 UNWIND(.fnend		)



/*

 * Ok, we need to do extra processing, enter the slow path.