1 /* SPDX-License-Identifier: GPL-2.0 */
3 * Copyright IBM Corp. 2008, 2009
7 #include <linux/linkage.h>
8 #include <asm/asm-offsets.h>
9 #include <asm/ftrace.h>
10 #include <asm/nospec-insn.h>
11 #include <asm/ptrace.h>
12 #include <asm/export.h>
15 #define STACK_FRAME_SIZE (STACK_FRAME_OVERHEAD + __PT_SIZE)
16 #define STACK_PTREGS (STACK_FRAME_OVERHEAD)
17 #define STACK_PTREGS_GPRS (STACK_PTREGS + __PT_GPRS)
18 #define STACK_PTREGS_PSW (STACK_PTREGS + __PT_PSW)
19 #define STACK_PTREGS_ORIG_GPR2 (STACK_PTREGS + __PT_ORIG_GPR2)
20 #define STACK_PTREGS_FLAGS (STACK_PTREGS + __PT_FLAGS)
21 /* packed stack: allocate just enough for r14, r15 and backchain */
22 #define TRACED_FUNC_FRAME_SIZE 24
24 #ifdef CONFIG_FUNCTION_TRACER
29 .section .kprobes.text, "ax"
31 SYM_FUNC_START(ftrace_stub)
33 SYM_FUNC_END(ftrace_stub)
35 .macro ftrace_regs_entry, allregs=0
36 stg %r14,(__SF_GPRS+8*8)(%r15) # save traced function caller
40 # don't put any instructions clobbering CC before this point
42 risbg %r14,%r1,0,31,32
46 # allocate stack frame for ftrace_caller to contain traced function
47 aghi %r15,-TRACED_FUNC_FRAME_SIZE
48 stg %r1,__SF_BACKCHAIN(%r15)
49 stg %r0,(__SF_GPRS+8*8)(%r15)
50 stg %r15,(__SF_GPRS+9*8)(%r15)
51 # allocate pt_regs and stack frame for ftrace_trace_function
52 aghi %r15,-STACK_FRAME_SIZE
53 stg %r1,(STACK_PTREGS_GPRS+15*8)(%r15)
54 xc STACK_PTREGS_ORIG_GPR2(8,%r15),STACK_PTREGS_ORIG_GPR2(%r15)
57 stg %r14,(STACK_PTREGS_PSW)(%r15)
58 mvghi STACK_PTREGS_FLAGS(%r15),_PIF_FTRACE_FULL_REGS
60 xc STACK_PTREGS_FLAGS(8,%r15),STACK_PTREGS_FLAGS(%r15)
63 lg %r14,(__SF_GPRS+8*8)(%r1) # restore original return address
64 aghi %r1,-TRACED_FUNC_FRAME_SIZE
65 stg %r1,__SF_BACKCHAIN(%r15)
66 stg %r0,(STACK_PTREGS_PSW+8)(%r15)
67 stmg %r2,%r14,(STACK_PTREGS_GPRS+2*8)(%r15)
70 SYM_CODE_START(ftrace_regs_caller)
73 SYM_CODE_END(ftrace_regs_caller)
75 SYM_CODE_START(ftrace_caller)
78 SYM_CODE_END(ftrace_caller)
80 SYM_CODE_START(ftrace_common)
81 #ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
82 aghik %r2,%r0,-MCOUNT_INSN_SIZE
83 lgrl %r4,function_trace_op
87 aghi %r2,-MCOUNT_INSN_SIZE
88 larl %r4,function_trace_op
94 la %r5,STACK_PTREGS(%r15)
96 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
97 # The j instruction gets runtime patched to a nop instruction.
98 # See ftrace_enable_ftrace_graph_caller.
99 SYM_INNER_LABEL(ftrace_graph_caller, SYM_L_GLOBAL)
100 j .Lftrace_graph_caller_end
101 lmg %r2,%r3,(STACK_PTREGS_GPRS+14*8)(%r15)
102 lg %r4,(STACK_PTREGS_PSW+8)(%r15)
103 brasl %r14,prepare_ftrace_return
104 stg %r2,(STACK_PTREGS_GPRS+14*8)(%r15)
105 .Lftrace_graph_caller_end:
107 lg %r0,(STACK_PTREGS_PSW+8)(%r15)
108 #ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
109 ltg %r1,STACK_PTREGS_ORIG_GPR2(%r15)
112 lg %r1,STACK_PTREGS_ORIG_GPR2(%r15)
117 0: lmg %r2,%r15,(STACK_PTREGS_GPRS+2*8)(%r15)
119 SYM_CODE_END(ftrace_common)
121 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
123 SYM_FUNC_START(return_to_handler)
124 stmg %r2,%r5,32(%r15)
126 aghi %r15,-STACK_FRAME_OVERHEAD
127 stg %r1,__SF_BACKCHAIN(%r15)
128 brasl %r14,ftrace_return_to_handler
129 aghi %r15,STACK_FRAME_OVERHEAD
133 SYM_FUNC_END(return_to_handler)
136 #endif /* CONFIG_FUNCTION_TRACER */
138 SYM_CODE_START(ftrace_shared_hotpatch_trampoline_br)
141 SYM_INNER_LABEL(ftrace_shared_hotpatch_trampoline_br_end, SYM_L_GLOBAL)
142 SYM_CODE_END(ftrace_shared_hotpatch_trampoline_br)
144 #ifdef CONFIG_EXPOLINE
145 SYM_CODE_START(ftrace_shared_hotpatch_trampoline_exrl)
150 SYM_INNER_LABEL(ftrace_shared_hotpatch_trampoline_exrl_end, SYM_L_GLOBAL)
151 SYM_CODE_END(ftrace_shared_hotpatch_trampoline_exrl)
152 #endif /* CONFIG_EXPOLINE */
154 #ifdef CONFIG_RETHOOK
156 SYM_CODE_START(arch_rethook_trampoline)
157 stg %r14,(__SF_GPRS+8*8)(%r15)
158 lay %r15,-STACK_FRAME_SIZE(%r15)
159 stmg %r0,%r14,STACK_PTREGS_GPRS(%r15)
161 # store original stack pointer in backchain and pt_regs
162 lay %r7,STACK_FRAME_SIZE(%r15)
163 stg %r7,__SF_BACKCHAIN(%r15)
164 stg %r7,STACK_PTREGS_GPRS+(15*8)(%r15)
168 risbg %r3,%r2,0,31,32
169 stg %r3,STACK_PTREGS_PSW(%r15)
170 larl %r1,arch_rethook_trampoline
171 stg %r1,STACK_PTREGS_PSW+8(%r15)
173 lay %r2,STACK_PTREGS(%r15)
174 brasl %r14,arch_rethook_trampoline_callback
176 mvc __SF_EMPTY(16,%r7),STACK_PTREGS_PSW(%r15)
177 lmg %r0,%r15,STACK_PTREGS_GPRS(%r15)
178 lpswe __SF_EMPTY(%r15)
179 SYM_CODE_END(arch_rethook_trampoline)
181 #endif /* CONFIG_RETHOOK */