1/* SPDX-License-Identifier: GPL-2.0 */ 2/* 3 * Copyright IBM Corp. 2008, 2009 4 * 5 */ 6 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 13#define STACK_FRAME_SIZE_PTREGS (STACK_FRAME_OVERHEAD + __PT_SIZE) 14#define STACK_PTREGS (STACK_FRAME_OVERHEAD) 15#define STACK_PTREGS_GPRS (STACK_PTREGS + __PT_GPRS) 16#define STACK_PTREGS_PSW (STACK_PTREGS + __PT_PSW) 17 18#define STACK_FRAME_SIZE_FREGS (STACK_FRAME_OVERHEAD + __FTRACE_REGS_SIZE) 19#define STACK_FREGS (STACK_FRAME_OVERHEAD) 20#define STACK_FREGS_PTREGS (STACK_FRAME_OVERHEAD + __FTRACE_REGS_PT_REGS) 21#define STACK_FREGS_PTREGS_GPRS (STACK_FREGS_PTREGS + __PT_GPRS) 22#define STACK_FREGS_PTREGS_PSW (STACK_FREGS_PTREGS + __PT_PSW) 23#define STACK_FREGS_PTREGS_ORIG_GPR2 (STACK_FREGS_PTREGS + __PT_ORIG_GPR2) 24#define STACK_FREGS_PTREGS_FLAGS (STACK_FREGS_PTREGS + __PT_FLAGS) 25 26/* packed stack: allocate just enough for r14, r15 and backchain */ 27#define TRACED_FUNC_FRAME_SIZE 24 28 29#ifdef CONFIG_FUNCTION_TRACER 30 31 GEN_BR_THUNK %r1 32 GEN_BR_THUNK %r14 33 34 .section .kprobes.text, "ax" 35 36SYM_FUNC_START(ftrace_stub) 37 BR_EX %r14 38SYM_FUNC_END(ftrace_stub) 39 40SYM_CODE_START(ftrace_stub_direct_tramp) 41 lgr %r1, %r0 42 BR_EX %r1 43SYM_CODE_END(ftrace_stub_direct_tramp) 44 45 .macro ftrace_regs_entry, allregs=0 46 stg %r14,(__SF_GPRS+8*8)(%r15) # save traced function caller 47 48 .if \allregs == 1 49 # save psw mask 50 # don't put any instructions clobbering CC before this point 51 epsw %r1,%r14 52 risbg %r14,%r1,0,31,32 53 .endif 54 55 lgr %r1,%r15 56 # allocate stack frame for ftrace_caller to contain traced function 57 aghi %r15,-TRACED_FUNC_FRAME_SIZE 58 stg %r1,__SF_BACKCHAIN(%r15) 59 stg %r0,(__SF_GPRS+8*8)(%r15) 60 stg %r15,(__SF_GPRS+9*8)(%r15) 61 # allocate ftrace_regs and stack frame for ftrace_trace_function 62 aghi %r15,-STACK_FRAME_SIZE_FREGS 63 stg %r1,(STACK_FREGS_PTREGS_GPRS+15*8)(%r15) 64 xc STACK_FREGS_PTREGS_ORIG_GPR2(8,%r15),STACK_FREGS_PTREGS_ORIG_GPR2(%r15) 65 66 .if \allregs == 1 67 stg %r14,(STACK_FREGS_PTREGS_PSW)(%r15) 68 mvghi STACK_FREGS_PTREGS_FLAGS(%r15),_PIF_FTRACE_FULL_REGS 69 .else 70 xc STACK_FREGS_PTREGS_FLAGS(8,%r15),STACK_FREGS_PTREGS_FLAGS(%r15) 71 .endif 72 73 lg %r14,(__SF_GPRS+8*8)(%r1) # restore original return address 74 aghi %r1,-TRACED_FUNC_FRAME_SIZE 75 stg %r1,__SF_BACKCHAIN(%r15) 76 stg %r0,(STACK_FREGS_PTREGS_PSW+8)(%r15) 77 stmg %r2,%r14,(STACK_FREGS_PTREGS_GPRS+2*8)(%r15) 78 .endm 79 80SYM_CODE_START(ftrace_regs_caller) 81 ftrace_regs_entry 1 82 j ftrace_common 83SYM_CODE_END(ftrace_regs_caller) 84 85SYM_CODE_START(ftrace_caller) 86 ftrace_regs_entry 0 87 j ftrace_common 88SYM_CODE_END(ftrace_caller) 89 90SYM_CODE_START(ftrace_common) 91#ifdef CONFIG_HAVE_MARCH_Z196_FEATURES 92 aghik %r2,%r0,-MCOUNT_INSN_SIZE 93 lgrl %r4,function_trace_op 94 lgrl %r1,ftrace_func 95#else 96 lgr %r2,%r0 97 aghi %r2,-MCOUNT_INSN_SIZE 98 larl %r4,function_trace_op 99 lg %r4,0(%r4) 100 larl %r1,ftrace_func 101 lg %r1,0(%r1) 102#endif 103 lgr %r3,%r14 104 la %r5,STACK_FREGS(%r15) 105 BASR_EX %r14,%r1 106#ifdef CONFIG_FUNCTION_GRAPH_TRACER 107# The j instruction gets runtime patched to a nop instruction. 108# See ftrace_enable_ftrace_graph_caller. 109SYM_INNER_LABEL(ftrace_graph_caller, SYM_L_GLOBAL) 110 j .Lftrace_graph_caller_end 111 lmg %r2,%r3,(STACK_FREGS_PTREGS_GPRS+14*8)(%r15) 112 lg %r4,(STACK_FREGS_PTREGS_PSW+8)(%r15) 113 brasl %r14,prepare_ftrace_return 114 stg %r2,(STACK_FREGS_PTREGS_GPRS+14*8)(%r15) 115.Lftrace_graph_caller_end: 116#endif 117 lg %r0,(STACK_FREGS_PTREGS_PSW+8)(%r15) 118#ifdef CONFIG_HAVE_MARCH_Z196_FEATURES 119 ltg %r1,STACK_FREGS_PTREGS_ORIG_GPR2(%r15) 120 locgrz %r1,%r0 121#else 122 lg %r1,STACK_FREGS_PTREGS_ORIG_GPR2(%r15) 123 ltgr %r1,%r1 124 jnz 0f 125 lgr %r1,%r0 126#endif 1270: lmg %r2,%r15,(STACK_FREGS_PTREGS_GPRS+2*8)(%r15) 128 BR_EX %r1 129SYM_CODE_END(ftrace_common) 130 131#ifdef CONFIG_FUNCTION_GRAPH_TRACER 132 133SYM_FUNC_START(return_to_handler) 134 stmg %r2,%r5,32(%r15) 135 lgr %r1,%r15 136 aghi %r15,-(STACK_FRAME_OVERHEAD+__FGRAPH_RET_SIZE) 137 stg %r1,__SF_BACKCHAIN(%r15) 138 la %r3,STACK_FRAME_OVERHEAD(%r15) 139 stg %r1,__FGRAPH_RET_FP(%r3) 140 stg %r2,__FGRAPH_RET_GPR2(%r3) 141 lgr %r2,%r3 142 brasl %r14,ftrace_return_to_handler 143 aghi %r15,STACK_FRAME_OVERHEAD+__FGRAPH_RET_SIZE 144 lgr %r14,%r2 145 lmg %r2,%r5,32(%r15) 146 BR_EX %r14 147SYM_FUNC_END(return_to_handler) 148 149#endif 150#endif /* CONFIG_FUNCTION_TRACER */ 151 152SYM_CODE_START(ftrace_shared_hotpatch_trampoline_br) 153 lmg %r0,%r1,2(%r1) 154 br %r1 155SYM_INNER_LABEL(ftrace_shared_hotpatch_trampoline_br_end, SYM_L_GLOBAL) 156SYM_CODE_END(ftrace_shared_hotpatch_trampoline_br) 157 158#ifdef CONFIG_EXPOLINE 159SYM_CODE_START(ftrace_shared_hotpatch_trampoline_exrl) 160 lmg %r0,%r1,2(%r1) 161 exrl %r0,0f 162 j . 1630: br %r1 164SYM_INNER_LABEL(ftrace_shared_hotpatch_trampoline_exrl_end, SYM_L_GLOBAL) 165SYM_CODE_END(ftrace_shared_hotpatch_trampoline_exrl) 166#endif /* CONFIG_EXPOLINE */ 167 168#ifdef CONFIG_RETHOOK 169 170SYM_CODE_START(arch_rethook_trampoline) 171 stg %r14,(__SF_GPRS+8*8)(%r15) 172 lay %r15,-STACK_FRAME_SIZE_PTREGS(%r15) 173 stmg %r0,%r14,STACK_PTREGS_GPRS(%r15) 174 175 # store original stack pointer in backchain and pt_regs 176 lay %r7,STACK_FRAME_SIZE_PTREGS(%r15) 177 stg %r7,__SF_BACKCHAIN(%r15) 178 stg %r7,STACK_PTREGS_GPRS+(15*8)(%r15) 179 180 # store full psw 181 epsw %r2,%r3 182 risbg %r3,%r2,0,31,32 183 stg %r3,STACK_PTREGS_PSW(%r15) 184 larl %r1,arch_rethook_trampoline 185 stg %r1,STACK_PTREGS_PSW+8(%r15) 186 187 lay %r2,STACK_PTREGS(%r15) 188 brasl %r14,arch_rethook_trampoline_callback 189 190 mvc __SF_EMPTY(16,%r7),STACK_PTREGS_PSW(%r15) 191 lmg %r0,%r15,STACK_PTREGS_GPRS(%r15) 192 lpswe __SF_EMPTY(%r15) 193SYM_CODE_END(arch_rethook_trampoline) 194 195#endif /* CONFIG_RETHOOK */ 196