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 GEN_BR_THUNK %r1 15 GEN_BR_THUNK %r14 16 17 .section .kprobes.text, "ax" 18 19ENTRY(ftrace_stub) 20 BR_EX %r14 21ENDPROC(ftrace_stub) 22 23#define STACK_FRAME_SIZE (STACK_FRAME_OVERHEAD + __PT_SIZE) 24#define STACK_PTREGS (STACK_FRAME_OVERHEAD) 25#define STACK_PTREGS_GPRS (STACK_PTREGS + __PT_GPRS) 26#define STACK_PTREGS_PSW (STACK_PTREGS + __PT_PSW) 27#define STACK_PTREGS_ORIG_GPR2 (STACK_PTREGS + __PT_ORIG_GPR2) 28#define STACK_PTREGS_FLAGS (STACK_PTREGS + __PT_FLAGS) 29/* packed stack: allocate just enough for r14, r15 and backchain */ 30#define TRACED_FUNC_FRAME_SIZE 24 31 32 .macro ftrace_regs_entry, allregs=0 33 stg %r14,(__SF_GPRS+8*8)(%r15) # save traced function caller 34 35 .if \allregs == 1 36 lghi %r14,0 # save condition code 37 ipm %r14 # don't put any instructions 38 sllg %r14,%r14,16 # clobbering CC before this point 39 .endif 40 41 lgr %r1,%r15 42 # allocate stack frame for ftrace_caller to contain traced function 43 aghi %r15,-TRACED_FUNC_FRAME_SIZE 44 stg %r1,__SF_BACKCHAIN(%r15) 45 stg %r0,(__SF_GPRS+8*8)(%r15) 46 stg %r15,(__SF_GPRS+9*8)(%r15) 47 # allocate pt_regs and stack frame for ftrace_trace_function 48 aghi %r15,-STACK_FRAME_SIZE 49 stg %r1,(STACK_PTREGS_GPRS+15*8)(%r15) 50 xc STACK_PTREGS_ORIG_GPR2(8,%r15),STACK_PTREGS_ORIG_GPR2(%r15) 51 52 .if \allregs == 1 53 stg %r14,(STACK_PTREGS_PSW)(%r15) 54 stosm (STACK_PTREGS_PSW)(%r15),0 55#ifdef CONFIG_HAVE_MARCH_Z10_FEATURES 56 mvghi STACK_PTREGS_FLAGS(%r15),_PIF_FTRACE_FULL_REGS 57#else 58 lghi %r14,_PIF_FTRACE_FULL_REGS 59 stg %r14,STACK_PTREGS_FLAGS(%r15) 60#endif 61 .else 62 xc STACK_PTREGS_FLAGS(8,%r15),STACK_PTREGS_FLAGS(%r15) 63 .endif 64 65 lg %r14,(__SF_GPRS+8*8)(%r1) # restore original return address 66 aghi %r1,-TRACED_FUNC_FRAME_SIZE 67 stg %r1,__SF_BACKCHAIN(%r15) 68 stg %r0,(STACK_PTREGS_PSW+8)(%r15) 69 stmg %r2,%r14,(STACK_PTREGS_GPRS+2*8)(%r15) 70 .endm 71 72SYM_CODE_START(ftrace_regs_caller) 73 ftrace_regs_entry 1 74 j ftrace_common 75SYM_CODE_END(ftrace_regs_caller) 76 77SYM_CODE_START(ftrace_caller) 78 ftrace_regs_entry 0 79 j ftrace_common 80SYM_CODE_END(ftrace_caller) 81 82SYM_CODE_START(ftrace_common) 83#ifdef CONFIG_HAVE_MARCH_Z196_FEATURES 84 aghik %r2,%r0,-MCOUNT_INSN_SIZE 85 lgrl %r4,function_trace_op 86 lgrl %r1,ftrace_func 87#else 88 lgr %r2,%r0 89 aghi %r2,-MCOUNT_INSN_SIZE 90 larl %r4,function_trace_op 91 lg %r4,0(%r4) 92 larl %r1,ftrace_func 93 lg %r1,0(%r1) 94#endif 95 lgr %r3,%r14 96 la %r5,STACK_PTREGS(%r15) 97 BASR_EX %r14,%r1 98#ifdef CONFIG_FUNCTION_GRAPH_TRACER 99# The j instruction gets runtime patched to a nop instruction. 100# See ftrace_enable_ftrace_graph_caller. 101SYM_INNER_LABEL(ftrace_graph_caller, SYM_L_GLOBAL) 102 j .Lftrace_graph_caller_end 103 lmg %r2,%r3,(STACK_PTREGS_GPRS+14*8)(%r15) 104 lg %r4,(STACK_PTREGS_PSW+8)(%r15) 105 brasl %r14,prepare_ftrace_return 106 stg %r2,(STACK_PTREGS_GPRS+14*8)(%r15) 107.Lftrace_graph_caller_end: 108#endif 109 lg %r0,(STACK_PTREGS_PSW+8)(%r15) 110#ifdef CONFIG_HAVE_MARCH_Z196_FEATURES 111 ltg %r1,STACK_PTREGS_ORIG_GPR2(%r15) 112 locgrz %r1,%r0 113#else 114 lg %r1,STACK_PTREGS_ORIG_GPR2(%r15) 115 ltgr %r1,%r1 116 jnz 0f 117 lgr %r1,%r0 118#endif 1190: lmg %r2,%r15,(STACK_PTREGS_GPRS+2*8)(%r15) 120 BR_EX %r1 121SYM_CODE_END(ftrace_common) 122 123#ifdef CONFIG_FUNCTION_GRAPH_TRACER 124 125SYM_FUNC_START(return_to_handler) 126 stmg %r2,%r5,32(%r15) 127 lgr %r1,%r15 128 aghi %r15,-STACK_FRAME_OVERHEAD 129 stg %r1,__SF_BACKCHAIN(%r15) 130 brasl %r14,ftrace_return_to_handler 131 aghi %r15,STACK_FRAME_OVERHEAD 132 lgr %r14,%r2 133 lmg %r2,%r5,32(%r15) 134 BR_EX %r14 135SYM_FUNC_END(return_to_handler) 136 137#endif 138