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#include <asm/march.h> 13 14#define STACK_FRAME_SIZE_PTREGS (STACK_FRAME_OVERHEAD + __PT_SIZE) 15#define STACK_PTREGS (STACK_FRAME_OVERHEAD) 16#define STACK_PTREGS_GPRS (STACK_PTREGS + __PT_GPRS) 17#define STACK_PTREGS_PSW (STACK_PTREGS + __PT_PSW) 18 19#define STACK_FRAME_SIZE_FREGS (STACK_FRAME_OVERHEAD + __FTRACE_REGS_SIZE) 20#define STACK_FREGS (STACK_FRAME_OVERHEAD) 21#define STACK_FREGS_PTREGS (STACK_FRAME_OVERHEAD + __FTRACE_REGS_PT_REGS) 22#define STACK_FREGS_PTREGS_GPRS (STACK_FREGS_PTREGS + __PT_GPRS) 23#define STACK_FREGS_PTREGS_PSW (STACK_FREGS_PTREGS + __PT_PSW) 24#define STACK_FREGS_PTREGS_ORIG_GPR2 (STACK_FREGS_PTREGS + __PT_ORIG_GPR2) 25#define STACK_FREGS_PTREGS_FLAGS (STACK_FREGS_PTREGS + __PT_FLAGS) 26 27/* packed stack: allocate just enough for r14, r15 and backchain */ 28#define TRACED_FUNC_FRAME_SIZE 24 29 30#ifdef CONFIG_FUNCTION_TRACER 31 32 GEN_BR_THUNK %r1 33 GEN_BR_THUNK %r14 34 35 .section .kprobes.text, "ax" 36 37SYM_FUNC_START(ftrace_stub) 38 BR_EX %r14 39SYM_FUNC_END(ftrace_stub) 40 41SYM_CODE_START(ftrace_stub_direct_tramp) 42 lgr %r1, %r0 43 BR_EX %r1 44SYM_CODE_END(ftrace_stub_direct_tramp) 45 46 .macro ftrace_regs_entry, allregs=0 47 stg %r14,(__SF_GPRS+8*8)(%r15) # save traced function caller 48 49 .if \allregs == 1 50 # save psw mask 51 # don't put any instructions clobbering CC before this point 52 epsw %r1,%r14 53 risbg %r14,%r1,0,31,32 54 .endif 55 56 lgr %r1,%r15 57 # allocate stack frame for ftrace_caller to contain traced function 58 aghi %r15,-TRACED_FUNC_FRAME_SIZE 59 stg %r1,__SF_BACKCHAIN(%r15) 60 stg %r0,(__SF_GPRS+8*8)(%r15) 61 stg %r15,(__SF_GPRS+9*8)(%r15) 62 # allocate ftrace_regs and stack frame for ftrace_trace_function 63 aghi %r15,-STACK_FRAME_SIZE_FREGS 64 stg %r1,(STACK_FREGS_PTREGS_GPRS+15*8)(%r15) 65 xc STACK_FREGS_PTREGS_ORIG_GPR2(8,%r15),STACK_FREGS_PTREGS_ORIG_GPR2(%r15) 66 67 .if \allregs == 1 68 stg %r14,(STACK_FREGS_PTREGS_PSW)(%r15) 69 mvghi STACK_FREGS_PTREGS_FLAGS(%r15),_PIF_FTRACE_FULL_REGS 70 .else 71 xc STACK_FREGS_PTREGS_FLAGS(8,%r15),STACK_FREGS_PTREGS_FLAGS(%r15) 72 .endif 73 74 lg %r14,(__SF_GPRS+8*8)(%r1) # restore original return address 75 aghi %r1,-TRACED_FUNC_FRAME_SIZE 76 stg %r1,__SF_BACKCHAIN(%r15) 77 stg %r0,(STACK_FREGS_PTREGS_PSW+8)(%r15) 78 stmg %r2,%r14,(STACK_FREGS_PTREGS_GPRS+2*8)(%r15) 79 .endm 80 81SYM_CODE_START(ftrace_regs_caller) 82 ftrace_regs_entry 1 83 j ftrace_common 84SYM_CODE_END(ftrace_regs_caller) 85 86SYM_CODE_START(ftrace_caller) 87 ftrace_regs_entry 0 88 j ftrace_common 89SYM_CODE_END(ftrace_caller) 90 91SYM_CODE_START(ftrace_common) 92#ifdef MARCH_HAS_Z196_FEATURES 93 aghik %r2,%r0,-MCOUNT_INSN_SIZE 94 lgrl %r4,function_trace_op 95 lgrl %r1,ftrace_func 96#else 97 lgr %r2,%r0 98 aghi %r2,-MCOUNT_INSN_SIZE 99 larl %r4,function_trace_op 100 lg %r4,0(%r4) 101 larl %r1,ftrace_func 102 lg %r1,0(%r1) 103#endif 104 lgr %r3,%r14 105 la %r5,STACK_FREGS(%r15) 106 BASR_EX %r14,%r1 107#ifdef CONFIG_FUNCTION_GRAPH_TRACER 108# The j instruction gets runtime patched to a nop instruction. 109# See ftrace_enable_ftrace_graph_caller. 110SYM_INNER_LABEL(ftrace_graph_caller, SYM_L_GLOBAL) 111 j .Lftrace_graph_caller_end 112 lmg %r2,%r3,(STACK_FREGS_PTREGS_GPRS+14*8)(%r15) 113 lg %r4,(STACK_FREGS_PTREGS_PSW+8)(%r15) 114 brasl %r14,prepare_ftrace_return 115 stg %r2,(STACK_FREGS_PTREGS_GPRS+14*8)(%r15) 116.Lftrace_graph_caller_end: 117#endif 118 lg %r0,(STACK_FREGS_PTREGS_PSW+8)(%r15) 119#ifdef MARCH_HAS_Z196_FEATURES 120 ltg %r1,STACK_FREGS_PTREGS_ORIG_GPR2(%r15) 121 locgrz %r1,%r0 122#else 123 lg %r1,STACK_FREGS_PTREGS_ORIG_GPR2(%r15) 124 ltgr %r1,%r1 125 jnz 0f 126 lgr %r1,%r0 127#endif 1280: lmg %r2,%r15,(STACK_FREGS_PTREGS_GPRS+2*8)(%r15) 129 BR_EX %r1 130SYM_CODE_END(ftrace_common) 131 132#ifdef CONFIG_FUNCTION_GRAPH_TRACER 133 134SYM_FUNC_START(return_to_handler) 135 stmg %r2,%r5,32(%r15) 136 lgr %r1,%r15 137 aghi %r15,-(STACK_FRAME_OVERHEAD+__FGRAPH_RET_SIZE) 138 stg %r1,__SF_BACKCHAIN(%r15) 139 la %r3,STACK_FRAME_OVERHEAD(%r15) 140 stg %r1,__FGRAPH_RET_FP(%r3) 141 stg %r2,__FGRAPH_RET_GPR2(%r3) 142 lgr %r2,%r3 143 brasl %r14,ftrace_return_to_handler 144 aghi %r15,STACK_FRAME_OVERHEAD+__FGRAPH_RET_SIZE 145 lgr %r14,%r2 146 lmg %r2,%r5,32(%r15) 147 BR_EX %r14 148SYM_FUNC_END(return_to_handler) 149 150#endif 151#endif /* CONFIG_FUNCTION_TRACER */ 152 153SYM_CODE_START(ftrace_shared_hotpatch_trampoline_br) 154 lmg %r0,%r1,2(%r1) 155 br %r1 156SYM_INNER_LABEL(ftrace_shared_hotpatch_trampoline_br_end, SYM_L_GLOBAL) 157SYM_CODE_END(ftrace_shared_hotpatch_trampoline_br) 158 159#ifdef CONFIG_EXPOLINE 160SYM_CODE_START(ftrace_shared_hotpatch_trampoline_exrl) 161 lmg %r0,%r1,2(%r1) 162 exrl %r0,0f 163 j . 1640: br %r1 165SYM_INNER_LABEL(ftrace_shared_hotpatch_trampoline_exrl_end, SYM_L_GLOBAL) 166SYM_CODE_END(ftrace_shared_hotpatch_trampoline_exrl) 167#endif /* CONFIG_EXPOLINE */ 168 169#ifdef CONFIG_RETHOOK 170 171SYM_CODE_START(arch_rethook_trampoline) 172 stg %r14,(__SF_GPRS+8*8)(%r15) 173 lay %r15,-STACK_FRAME_SIZE_PTREGS(%r15) 174 stmg %r0,%r14,STACK_PTREGS_GPRS(%r15) 175 176 # store original stack pointer in backchain and pt_regs 177 lay %r7,STACK_FRAME_SIZE_PTREGS(%r15) 178 stg %r7,__SF_BACKCHAIN(%r15) 179 stg %r7,STACK_PTREGS_GPRS+(15*8)(%r15) 180 181 # store full psw 182 epsw %r2,%r3 183 risbg %r3,%r2,0,31,32 184 stg %r3,STACK_PTREGS_PSW(%r15) 185 larl %r1,arch_rethook_trampoline 186 stg %r1,STACK_PTREGS_PSW+8(%r15) 187 188 lay %r2,STACK_PTREGS(%r15) 189 brasl %r14,arch_rethook_trampoline_callback 190 191 mvc __SF_EMPTY(16,%r7),STACK_PTREGS_PSW(%r15) 192 lmg %r0,%r15,STACK_PTREGS_GPRS(%r15) 193 lpswe __SF_EMPTY(%r15) 194SYM_CODE_END(arch_rethook_trampoline) 195 196#endif /* CONFIG_RETHOOK */ 197