1/* SPDX-License-Identifier: GPL-2.0 */ 2/* 3 * Copyright IBM Corp. 2008, 2009 4 * 5 */ 6 7#include <linux/cfi_types.h> 8#include <linux/linkage.h> 9#include <asm/asm-offsets.h> 10#include <asm/ftrace.h> 11#include <asm/nospec-insn.h> 12#include <asm/ptrace.h> 13#include <asm/march.h> 14 15#define STACK_FRAME_SIZE_PTREGS (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 20#define STACK_FRAME_SIZE_FREGS (STACK_FRAME_OVERHEAD + __FTRACE_REGS_SIZE) 21#define STACK_FREGS (STACK_FRAME_OVERHEAD) 22#define STACK_FREGS_PTREGS (STACK_FRAME_OVERHEAD + __FTRACE_REGS_PT_REGS) 23#define STACK_FREGS_PTREGS_GPRS (STACK_FREGS_PTREGS + __PT_GPRS) 24#define STACK_FREGS_PTREGS_PSW (STACK_FREGS_PTREGS + __PT_PSW) 25#define STACK_FREGS_PTREGS_ORIG_GPR2 (STACK_FREGS_PTREGS + __PT_ORIG_GPR2) 26#define STACK_FREGS_PTREGS_FLAGS (STACK_FREGS_PTREGS + __PT_FLAGS) 27 28/* packed stack: allocate just enough for r14, r15 and backchain */ 29#define TRACED_FUNC_FRAME_SIZE 24 30 31#ifdef CONFIG_FUNCTION_TRACER 32 33 GEN_BR_THUNK %r1 34 GEN_BR_THUNK %r14 35 36 .section .kprobes.text, "ax" 37 38SYM_TYPED_FUNC_START(ftrace_stub) 39 BR_EX %r14 40SYM_FUNC_END(ftrace_stub) 41 42#ifdef CONFIG_FUNCTION_GRAPH_TRACER 43SYM_TYPED_FUNC_START(ftrace_stub_graph) 44 BR_EX %r14 45SYM_FUNC_END(ftrace_stub_graph) 46#endif 47 48SYM_CODE_START(ftrace_stub_direct_tramp) 49 lgr %r1, %r0 50 BR_EX %r1 51SYM_CODE_END(ftrace_stub_direct_tramp) 52 53 .macro ftrace_regs_entry, allregs=0 54 stg %r14,(__SF_GPRS+8*8)(%r15) # save traced function caller 55 56 .if \allregs == 1 57 # save psw mask 58 # don't put any instructions clobbering CC before this point 59 epsw %r1,%r14 60 risbg %r14,%r1,0,31,32 61 .endif 62 63 lgr %r1,%r15 64 # allocate stack frame for ftrace_caller to contain traced function 65 aghi %r15,-TRACED_FUNC_FRAME_SIZE 66 stg %r1,__SF_BACKCHAIN(%r15) 67 stg %r0,(__SF_GPRS+8*8)(%r15) 68 stg %r15,(__SF_GPRS+9*8)(%r15) 69 # allocate ftrace_regs and stack frame for ftrace_trace_function 70 aghi %r15,-STACK_FRAME_SIZE_FREGS 71 stg %r1,(STACK_FREGS_PTREGS_GPRS+15*8)(%r15) 72 xc STACK_FREGS_PTREGS_ORIG_GPR2(8,%r15),STACK_FREGS_PTREGS_ORIG_GPR2(%r15) 73 74 .if \allregs == 1 75 stg %r14,(STACK_FREGS_PTREGS_PSW)(%r15) 76 mvghi STACK_FREGS_PTREGS_FLAGS(%r15),_PIF_FTRACE_FULL_REGS 77 .else 78 xc STACK_FREGS_PTREGS_FLAGS(8,%r15),STACK_FREGS_PTREGS_FLAGS(%r15) 79 .endif 80 81 lg %r14,(__SF_GPRS+8*8)(%r1) # restore original return address 82 aghi %r1,-TRACED_FUNC_FRAME_SIZE 83 stg %r1,__SF_BACKCHAIN(%r15) 84 stg %r0,(STACK_FREGS_PTREGS_PSW+8)(%r15) 85 stmg %r2,%r14,(STACK_FREGS_PTREGS_GPRS+2*8)(%r15) 86 .endm 87 88SYM_CODE_START(ftrace_regs_caller) 89 ftrace_regs_entry 1 90 j ftrace_common 91SYM_CODE_END(ftrace_regs_caller) 92 93SYM_CODE_START(ftrace_caller) 94 ftrace_regs_entry 0 95 j ftrace_common 96SYM_CODE_END(ftrace_caller) 97 98SYM_CODE_START(ftrace_common) 99#ifdef MARCH_HAS_Z196_FEATURES 100 aghik %r2,%r0,-MCOUNT_INSN_SIZE 101 lgrl %r4,function_trace_op 102 lgrl %r1,ftrace_func 103#else 104 lgr %r2,%r0 105 aghi %r2,-MCOUNT_INSN_SIZE 106 larl %r4,function_trace_op 107 lg %r4,0(%r4) 108 larl %r1,ftrace_func 109 lg %r1,0(%r1) 110#endif 111 lgr %r3,%r14 112 la %r5,STACK_FREGS(%r15) 113 BASR_EX %r14,%r1 114 lg %r0,(STACK_FREGS_PTREGS_PSW+8)(%r15) 115#ifdef MARCH_HAS_Z196_FEATURES 116 ltg %r1,STACK_FREGS_PTREGS_ORIG_GPR2(%r15) 117 locgrz %r1,%r0 118#else 119 lg %r1,STACK_FREGS_PTREGS_ORIG_GPR2(%r15) 120 ltgr %r1,%r1 121 jnz 0f 122 lgr %r1,%r0 123#endif 1240: lmg %r2,%r15,(STACK_FREGS_PTREGS_GPRS+2*8)(%r15) 125 BR_EX %r1 126SYM_CODE_END(ftrace_common) 127 128#ifdef CONFIG_FUNCTION_GRAPH_TRACER 129 130SYM_FUNC_START(return_to_handler) 131 stmg %r2,%r5,32(%r15) 132 lgr %r1,%r15 133 # allocate ftrace_regs and stack frame for ftrace_return_to_handler 134 aghi %r15,-STACK_FRAME_SIZE_FREGS 135 stg %r1,__SF_BACKCHAIN(%r15) 136 stg %r2,(STACK_FREGS_PTREGS_GPRS+2*8)(%r15) 137 stg %r1,(STACK_FREGS_PTREGS_GPRS+15*8)(%r15) 138 la %r2,STACK_FRAME_OVERHEAD(%r15) 139 brasl %r14,ftrace_return_to_handler 140 aghi %r15,STACK_FRAME_SIZE_FREGS 141 lgr %r14,%r2 142 lmg %r2,%r5,32(%r15) 143 BR_EX %r14 144SYM_FUNC_END(return_to_handler) 145 146#endif 147#endif /* CONFIG_FUNCTION_TRACER */ 148 149SYM_CODE_START(ftrace_shared_hotpatch_trampoline_br) 150 lmg %r0,%r1,2(%r1) 151 br %r1 152SYM_INNER_LABEL(ftrace_shared_hotpatch_trampoline_br_end, SYM_L_GLOBAL) 153SYM_CODE_END(ftrace_shared_hotpatch_trampoline_br) 154 155#ifdef CONFIG_EXPOLINE 156SYM_CODE_START(ftrace_shared_hotpatch_trampoline_exrl) 157 lmg %r0,%r1,2(%r1) 158 exrl %r0,0f 159 j . 1600: br %r1 161SYM_INNER_LABEL(ftrace_shared_hotpatch_trampoline_exrl_end, SYM_L_GLOBAL) 162SYM_CODE_END(ftrace_shared_hotpatch_trampoline_exrl) 163#endif /* CONFIG_EXPOLINE */ 164 165#ifdef CONFIG_RETHOOK 166 167SYM_CODE_START(arch_rethook_trampoline) 168 stg %r14,(__SF_GPRS+8*8)(%r15) 169 lay %r15,-STACK_FRAME_SIZE_PTREGS(%r15) 170 stmg %r0,%r14,STACK_PTREGS_GPRS(%r15) 171 172 # store original stack pointer in backchain and pt_regs 173 lay %r7,STACK_FRAME_SIZE_PTREGS(%r15) 174 stg %r7,__SF_BACKCHAIN(%r15) 175 stg %r7,STACK_PTREGS_GPRS+(15*8)(%r15) 176 177 # store full psw 178 epsw %r2,%r3 179 risbg %r3,%r2,0,31,32 180 stg %r3,STACK_PTREGS_PSW(%r15) 181 larl %r1,arch_rethook_trampoline 182 stg %r1,STACK_PTREGS_PSW+8(%r15) 183 184 lay %r2,STACK_PTREGS(%r15) 185 brasl %r14,arch_rethook_trampoline_callback 186 187 mvc __SF_EMPTY(16,%r7),STACK_PTREGS_PSW(%r15) 188 lmg %r0,%r15,STACK_PTREGS_GPRS(%r15) 189 lpswe __SF_EMPTY(%r15) 190SYM_CODE_END(arch_rethook_trampoline) 191 192#endif /* CONFIG_RETHOOK */ 193