1/*
 2 * Copyright IBM Corp. 2008, 2009
 3 *
 4 *   Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>,
 5 *
 6 */
 7
 8#include <linux/linkage.h>
 9#include <asm/asm-offsets.h>
10#include <asm/ftrace.h>
 
 
 
 
 
 
11
12	.section .kprobes.text, "ax"
13
14ENTRY(ftrace_stub)
15	br	%r14
 
16
17ENTRY(_mcount)
18#ifdef CONFIG_DYNAMIC_FTRACE
19	br	%r14
 
 
 
 
 
 
 
20
21ENTRY(ftrace_caller)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
22#endif
23	stm	%r2,%r5,16(%r15)
24	bras	%r1,2f
250:	.long	ftrace_trace_function
261:	.long	function_trace_stop
272:	l	%r2,1b-0b(%r1)
28	icm	%r2,0xf,0(%r2)
29	jnz	3f
30	st	%r14,56(%r15)
31	lr	%r0,%r15
32	ahi	%r15,-96
33	l	%r3,100(%r15)
34	la	%r2,0(%r14)
35	st	%r0,__SF_BACKCHAIN(%r15)
36	la	%r3,0(%r3)
37	ahi	%r2,-MCOUNT_INSN_SIZE
38	l	%r14,0b-0b(%r1)
39	l	%r14,0(%r14)
40	basr	%r14,%r14
41#ifdef CONFIG_FUNCTION_GRAPH_TRACER
42	l	%r2,100(%r15)
43	l	%r3,152(%r15)
44ENTRY(ftrace_graph_caller)
45# The bras instruction gets runtime patched to call prepare_ftrace_return.
46# See ftrace_enable_ftrace_graph_caller. The patched instruction is:
47#	bras	%r14,prepare_ftrace_return
48	bras	%r14,0f
490:	st	%r2,100(%r15)
 
 
 
50#endif
51	ahi	%r15,96
52	l	%r14,56(%r15)
533:	lm	%r2,%r5,16(%r15)
54	br	%r14
55
56#ifdef CONFIG_FUNCTION_GRAPH_TRACER
57
58ENTRY(return_to_handler)
59	stm	%r2,%r5,16(%r15)
60	st	%r14,56(%r15)
61	lr	%r0,%r15
62	ahi	%r15,-96
63	st	%r0,__SF_BACKCHAIN(%r15)
64	bras	%r1,0f
65	.long	ftrace_return_to_handler
660:	l	%r2,0b-0b(%r1)
67	basr	%r14,%r2
68	lr	%r14,%r2
69	ahi	%r15,96
70	lm	%r2,%r5,16(%r15)
71	br	%r14
72
73#endif

  1/* SPDX-License-Identifier: GPL-2.0 */
  2/*
  3 * Copyright IBM Corp. 2008, 2009
  4 *
  5 *   Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>,
  6 *
  7 */
  8
  9#include <linux/linkage.h>
 10#include <asm/asm-offsets.h>
 11#include <asm/ftrace.h>
 12#include <asm/nospec-insn.h>
 13#include <asm/ptrace.h>
 14#include <asm/export.h>
 15
 16	GEN_BR_THUNK %r1
 17	GEN_BR_THUNK %r14
 18
 19	.section .kprobes.text, "ax"
 20
 21ENTRY(ftrace_stub)
 22	BR_EX	%r14
 23ENDPROC(ftrace_stub)
 24
 25#define STACK_FRAME_SIZE  (STACK_FRAME_OVERHEAD + __PT_SIZE)
 26#define STACK_PTREGS	  (STACK_FRAME_OVERHEAD)
 27#define STACK_PTREGS_GPRS (STACK_PTREGS + __PT_GPRS)
 28#define STACK_PTREGS_PSW  (STACK_PTREGS + __PT_PSW)
 29#ifdef __PACK_STACK
 30/* allocate just enough for r14, r15 and backchain */
 31#define TRACED_FUNC_FRAME_SIZE	24
 32#else
 33#define TRACED_FUNC_FRAME_SIZE	STACK_FRAME_OVERHEAD
 34#endif
 35
 36ENTRY(ftrace_caller)
 37	.globl	ftrace_regs_caller
 38	.set	ftrace_regs_caller,ftrace_caller
 39	stg	%r14,(__SF_GPRS+8*8)(%r15)	# save traced function caller
 40	lghi	%r14,0				# save condition code
 41	ipm	%r14				# don't put any instructions
 42	sllg	%r14,%r14,16			# clobbering CC before this point
 43	lgr	%r1,%r15
 44	# allocate stack frame for ftrace_caller to contain traced function
 45	aghi	%r15,-TRACED_FUNC_FRAME_SIZE
 46	stg	%r1,__SF_BACKCHAIN(%r15)
 47	stg	%r0,(__SF_GPRS+8*8)(%r15)
 48	stg	%r15,(__SF_GPRS+9*8)(%r15)
 49	# allocate pt_regs and stack frame for ftrace_trace_function
 50	aghi	%r15,-STACK_FRAME_SIZE
 51	stg	%r1,(STACK_PTREGS_GPRS+15*8)(%r15)
 52	stg	%r14,(STACK_PTREGS_PSW)(%r15)
 53	lg	%r14,(__SF_GPRS+8*8)(%r1)	# restore original return address
 54	stosm	(STACK_PTREGS_PSW)(%r15),0
 55	aghi	%r1,-TRACED_FUNC_FRAME_SIZE
 56	stg	%r1,__SF_BACKCHAIN(%r15)
 57	stg	%r0,(STACK_PTREGS_PSW+8)(%r15)
 58	stmg	%r2,%r14,(STACK_PTREGS_GPRS+2*8)(%r15)
 59#ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
 60	aghik	%r2,%r0,-MCOUNT_INSN_SIZE
 61	lgrl	%r4,function_trace_op
 62	lgrl	%r1,ftrace_func
 63#else
 64	lgr	%r2,%r0
 65	aghi	%r2,-MCOUNT_INSN_SIZE
 66	larl	%r4,function_trace_op
 67	lg	%r4,0(%r4)
 68	larl	%r1,ftrace_func
 69	lg	%r1,0(%r1)
 70#endif
 71	lgr	%r3,%r14
 72	la	%r5,STACK_PTREGS(%r15)
 73	BASR_EX	%r14,%r1
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 74#ifdef CONFIG_FUNCTION_GRAPH_TRACER
 75# The j instruction gets runtime patched to a nop instruction.
 76# See ftrace_enable_ftrace_graph_caller.
 77	.globl ftrace_graph_caller
 78ftrace_graph_caller:
 79	j	ftrace_graph_caller_end
 80	lmg	%r2,%r3,(STACK_PTREGS_GPRS+14*8)(%r15)
 81	lg	%r4,(STACK_PTREGS_PSW+8)(%r15)
 82	brasl	%r14,prepare_ftrace_return
 83	stg	%r2,(STACK_PTREGS_GPRS+14*8)(%r15)
 84ftrace_graph_caller_end:
 85	.globl	ftrace_graph_caller_end
 86#endif
 87	lg	%r1,(STACK_PTREGS_PSW+8)(%r15)
 88	lmg	%r2,%r15,(STACK_PTREGS_GPRS+2*8)(%r15)
 89	BR_EX	%r1
 90ENDPROC(ftrace_caller)
 91
 92#ifdef CONFIG_FUNCTION_GRAPH_TRACER
 93
 94ENTRY(return_to_handler)
 95	stmg	%r2,%r5,32(%r15)
 96	lgr	%r1,%r15
 97	aghi	%r15,-STACK_FRAME_OVERHEAD
 98	stg	%r1,__SF_BACKCHAIN(%r15)
 99	brasl	%r14,ftrace_return_to_handler
100	aghi	%r15,STACK_FRAME_OVERHEAD
101	lgr	%r14,%r2
102	lmg	%r2,%r5,32(%r15)
103	BR_EX	%r14
104ENDPROC(return_to_handler)
 
 
 
105
106#endif