1 /* SPDX-License-Identifier: GPL-2.0 */
3 * Copyright IBM Corp. 2008, 2009
5 * Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>,
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>
19 .section .kprobes.text, "ax"
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)
30 /* allocate just enough for r14, r15 and backchain */
31 #define TRACED_FUNC_FRAME_SIZE 24
33 #define TRACED_FUNC_FRAME_SIZE STACK_FRAME_OVERHEAD
39 EXPORT_SYMBOL(_mcount)
42 .globl ftrace_regs_caller
43 .set ftrace_regs_caller,ftrace_caller
44 stg %r14,(__SF_GPRS+8*8)(%r15) # save traced function caller
45 lghi %r14,0 # save condition code
46 ipm %r14 # don't put any instructions
47 sllg %r14,%r14,16 # clobbering CC before this point
49 #if !(defined(CC_USING_HOTPATCH) || defined(CC_USING_NOP_MCOUNT))
50 aghi %r0,MCOUNT_RETURN_FIXUP
52 # allocate stack frame for ftrace_caller to contain traced function
53 aghi %r15,-TRACED_FUNC_FRAME_SIZE
54 stg %r1,__SF_BACKCHAIN(%r15)
55 stg %r0,(__SF_GPRS+8*8)(%r15)
56 stg %r15,(__SF_GPRS+9*8)(%r15)
57 # allocate pt_regs and stack frame for ftrace_trace_function
58 aghi %r15,-STACK_FRAME_SIZE
59 stg %r1,(STACK_PTREGS_GPRS+15*8)(%r15)
60 stg %r14,(STACK_PTREGS_PSW)(%r15)
61 lg %r14,(__SF_GPRS+8*8)(%r1) # restore original return address
62 stosm (STACK_PTREGS_PSW)(%r15),0
63 aghi %r1,-TRACED_FUNC_FRAME_SIZE
64 stg %r1,__SF_BACKCHAIN(%r15)
65 stg %r0,(STACK_PTREGS_PSW+8)(%r15)
66 stmg %r2,%r14,(STACK_PTREGS_GPRS+2*8)(%r15)
67 #ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
68 aghik %r2,%r0,-MCOUNT_INSN_SIZE
69 lgrl %r4,function_trace_op
70 lgrl %r1,ftrace_trace_function
73 aghi %r2,-MCOUNT_INSN_SIZE
74 larl %r4,function_trace_op
76 larl %r1,ftrace_trace_function
80 la %r5,STACK_PTREGS(%r15)
82 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
83 # The j instruction gets runtime patched to a nop instruction.
84 # See ftrace_enable_ftrace_graph_caller.
85 .globl ftrace_graph_caller
87 j ftrace_graph_caller_end
88 lmg %r2,%r3,(STACK_PTREGS_GPRS+14*8)(%r15)
89 lg %r4,(STACK_PTREGS_PSW+8)(%r15)
90 brasl %r14,prepare_ftrace_return
91 stg %r2,(STACK_PTREGS_GPRS+14*8)(%r15)
92 ftrace_graph_caller_end:
93 .globl ftrace_graph_caller_end
95 lg %r1,(STACK_PTREGS_PSW+8)(%r15)
96 lmg %r2,%r15,(STACK_PTREGS_GPRS+2*8)(%r15)
98 ENDPROC(ftrace_caller)
100 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
102 ENTRY(return_to_handler)
103 stmg %r2,%r5,32(%r15)
105 aghi %r15,-STACK_FRAME_OVERHEAD
106 stg %r1,__SF_BACKCHAIN(%r15)
107 brasl %r14,ftrace_return_to_handler
108 aghi %r15,STACK_FRAME_OVERHEAD
112 ENDPROC(return_to_handler)