1/* SPDX-License-Identifier: GPL-2.0 */ 2/* 3 * Copyright IBM Corp. 2008, 2009 4 * 5 * Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>, 6 * 7 */ 8 9#include <linux/linkage.h> 10#include <asm/asm-offsets.h> 11#include <asm/ftrace.h> 12#include <asm/nospec-insn.h> 13#include <asm/ptrace.h> 14#include <asm/export.h> 15 16 GEN_BR_THUNK %r1 17 GEN_BR_THUNK %r14 18 19 .section .kprobes.text, "ax" 20 21ENTRY(ftrace_stub) 22 BR_EX %r14 23ENDPROC(ftrace_stub) 24 25#define STACK_FRAME_SIZE (STACK_FRAME_OVERHEAD + __PT_SIZE) 26#define STACK_PTREGS (STACK_FRAME_OVERHEAD) 27#define STACK_PTREGS_GPRS (STACK_PTREGS + __PT_GPRS) 28#define STACK_PTREGS_PSW (STACK_PTREGS + __PT_PSW) 29#ifdef __PACK_STACK 30/* allocate just enough for r14, r15 and backchain */ 31#define TRACED_FUNC_FRAME_SIZE 24 32#else 33#define TRACED_FUNC_FRAME_SIZE STACK_FRAME_OVERHEAD 34#endif 35 36ENTRY(_mcount) 37 BR_EX %r14 38ENDPROC(_mcount) 39EXPORT_SYMBOL(_mcount) 40 41ENTRY(ftrace_caller) 42 .globl ftrace_regs_caller 43 .set ftrace_regs_caller,ftrace_caller 44 stg %r14,(__SF_GPRS+8*8)(%r15) # save traced function caller 45 lghi %r14,0 # save condition code 46 ipm %r14 # don't put any instructions 47 sllg %r14,%r14,16 # clobbering CC before this point 48 lgr %r1,%r15 49#if !(defined(CC_USING_HOTPATCH) || defined(CC_USING_NOP_MCOUNT)) 50 aghi %r0,MCOUNT_RETURN_FIXUP 51#endif 52 # allocate stack frame for ftrace_caller to contain traced function 53 aghi %r15,-TRACED_FUNC_FRAME_SIZE 54 stg %r1,__SF_BACKCHAIN(%r15) 55 stg %r0,(__SF_GPRS+8*8)(%r15) 56 stg %r15,(__SF_GPRS+9*8)(%r15) 57 # allocate pt_regs and stack frame for ftrace_trace_function 58 aghi %r15,-STACK_FRAME_SIZE 59 stg %r1,(STACK_PTREGS_GPRS+15*8)(%r15) 60 stg %r14,(STACK_PTREGS_PSW)(%r15) 61 lg %r14,(__SF_GPRS+8*8)(%r1) # restore original return address 62 stosm (STACK_PTREGS_PSW)(%r15),0 63 aghi %r1,-TRACED_FUNC_FRAME_SIZE 64 stg %r1,__SF_BACKCHAIN(%r15) 65 stg %r0,(STACK_PTREGS_PSW+8)(%r15) 66 stmg %r2,%r14,(STACK_PTREGS_GPRS+2*8)(%r15) 67#ifdef CONFIG_HAVE_MARCH_Z196_FEATURES 68 aghik %r2,%r0,-MCOUNT_INSN_SIZE 69 lgrl %r4,function_trace_op 70 lgrl %r1,ftrace_trace_function 71#else 72 lgr %r2,%r0 73 aghi %r2,-MCOUNT_INSN_SIZE 74 larl %r4,function_trace_op 75 lg %r4,0(%r4) 76 larl %r1,ftrace_trace_function 77 lg %r1,0(%r1) 78#endif 79 lgr %r3,%r14 80 la %r5,STACK_PTREGS(%r15) 81 BASR_EX %r14,%r1 82#ifdef CONFIG_FUNCTION_GRAPH_TRACER 83# The j instruction gets runtime patched to a nop instruction. 84# See ftrace_enable_ftrace_graph_caller. 85 .globl ftrace_graph_caller 86ftrace_graph_caller: 87 j ftrace_graph_caller_end 88 lmg %r2,%r3,(STACK_PTREGS_GPRS+14*8)(%r15) 89 lg %r4,(STACK_PTREGS_PSW+8)(%r15) 90 brasl %r14,prepare_ftrace_return 91 stg %r2,(STACK_PTREGS_GPRS+14*8)(%r15) 92ftrace_graph_caller_end: 93 .globl ftrace_graph_caller_end 94#endif 95 lg %r1,(STACK_PTREGS_PSW+8)(%r15) 96 lmg %r2,%r15,(STACK_PTREGS_GPRS+2*8)(%r15) 97 BR_EX %r1 98ENDPROC(ftrace_caller) 99 100#ifdef CONFIG_FUNCTION_GRAPH_TRACER 101 102ENTRY(return_to_handler) 103 stmg %r2,%r5,32(%r15) 104 lgr %r1,%r15 105 aghi %r15,-STACK_FRAME_OVERHEAD 106 stg %r1,__SF_BACKCHAIN(%r15) 107 brasl %r14,ftrace_return_to_handler 108 aghi %r15,STACK_FRAME_OVERHEAD 109 lgr %r14,%r2 110 lmg %r2,%r5,32(%r15) 111 BR_EX %r14 112ENDPROC(return_to_handler) 113 114#endif 115