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/export.h> 13 14 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 23 24#ifdef CONFIG_FUNCTION_TRACER 25 26 GEN_BR_THUNK %r1 27 GEN_BR_THUNK %r14 28 29 .section .kprobes.text, "ax" 30 31ENTRY(ftrace_stub) 32 BR_EX %r14 33ENDPROC(ftrace_stub) 34 35 .macro ftrace_regs_entry, allregs=0 36 stg %r14,(__SF_GPRS+8*8)(%r15) # save traced function caller 37 38 .if \allregs == 1 39 # save psw mask 40 # don't put any instructions clobbering CC before this point 41 epsw %r1,%r14 42 risbg %r14,%r1,0,31,32 43 .endif 44 45 lgr %r1,%r15 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) 55 56 .if \allregs == 1 57 stg %r14,(STACK_PTREGS_PSW)(%r15) 58 mvghi STACK_PTREGS_FLAGS(%r15),_PIF_FTRACE_FULL_REGS 59 .else 60 xc STACK_PTREGS_FLAGS(8,%r15),STACK_PTREGS_FLAGS(%r15) 61 .endif 62 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) 68 .endm 69 70SYM_CODE_START(ftrace_regs_caller) 71 ftrace_regs_entry 1 72 j ftrace_common 73SYM_CODE_END(ftrace_regs_caller) 74 75SYM_CODE_START(ftrace_caller) 76 ftrace_regs_entry 0 77 j ftrace_common 78SYM_CODE_END(ftrace_caller) 79 80SYM_CODE_START(ftrace_common) 81#ifdef CONFIG_HAVE_MARCH_Z196_FEATURES 82 aghik %r2,%r0,-MCOUNT_INSN_SIZE 83 lgrl %r4,function_trace_op 84 lgrl %r1,ftrace_func 85#else 86 lgr %r2,%r0 87 aghi %r2,-MCOUNT_INSN_SIZE 88 larl %r4,function_trace_op 89 lg %r4,0(%r4) 90 larl %r1,ftrace_func 91 lg %r1,0(%r1) 92#endif 93 lgr %r3,%r14 94 la %r5,STACK_PTREGS(%r15) 95 BASR_EX %r14,%r1 96#ifdef CONFIG_FUNCTION_GRAPH_TRACER 97# The j instruction gets runtime patched to a nop instruction. 98# See ftrace_enable_ftrace_graph_caller. 99SYM_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: 106#endif 107 lg %r0,(STACK_PTREGS_PSW+8)(%r15) 108#ifdef CONFIG_HAVE_MARCH_Z196_FEATURES 109 ltg %r1,STACK_PTREGS_ORIG_GPR2(%r15) 110 locgrz %r1,%r0 111#else 112 lg %r1,STACK_PTREGS_ORIG_GPR2(%r15) 113 ltgr %r1,%r1 114 jnz 0f 115 lgr %r1,%r0 116#endif 1170: lmg %r2,%r15,(STACK_PTREGS_GPRS+2*8)(%r15) 118 BR_EX %r1 119SYM_CODE_END(ftrace_common) 120 121#ifdef CONFIG_FUNCTION_GRAPH_TRACER 122 123SYM_FUNC_START(return_to_handler) 124 stmg %r2,%r5,32(%r15) 125 lgr %r1,%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 130 lgr %r14,%r2 131 lmg %r2,%r5,32(%r15) 132 BR_EX %r14 133SYM_FUNC_END(return_to_handler) 134 135#endif 136#endif /* CONFIG_FUNCTION_TRACER */ 137 138#ifdef CONFIG_RETHOOK 139 140SYM_FUNC_START(arch_rethook_trampoline) 141 142 stg %r14,(__SF_GPRS+8*8)(%r15) 143 lay %r15,-STACK_FRAME_SIZE(%r15) 144 stmg %r0,%r14,STACK_PTREGS_GPRS(%r15) 145 146 # store original stack pointer in backchain and pt_regs 147 lay %r7,STACK_FRAME_SIZE(%r15) 148 stg %r7,__SF_BACKCHAIN(%r15) 149 stg %r7,STACK_PTREGS_GPRS+(15*8)(%r15) 150 151 # store full psw 152 epsw %r2,%r3 153 risbg %r3,%r2,0,31,32 154 stg %r3,STACK_PTREGS_PSW(%r15) 155 larl %r1,arch_rethook_trampoline 156 stg %r1,STACK_PTREGS_PSW+8(%r15) 157 158 lay %r2,STACK_PTREGS(%r15) 159 brasl %r14,arch_rethook_trampoline_callback 160 161 mvc __SF_EMPTY(16,%r7),STACK_PTREGS_PSW(%r15) 162 lmg %r0,%r15,STACK_PTREGS_GPRS(%r15) 163 lpswe __SF_EMPTY(%r15) 164 165SYM_FUNC_END(arch_rethook_trampoline) 166 167#endif /* CONFIG_RETHOOK */ 168