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 23 24#define STACK_FRAME_SIZE (STACK_FRAME_OVERHEAD + __PT_SIZE) 25#define STACK_PTREGS (STACK_FRAME_OVERHEAD) 26#define STACK_PTREGS_GPRS (STACK_PTREGS + __PT_GPRS) 27#define STACK_PTREGS_PSW (STACK_PTREGS + __PT_PSW) 28#ifdef __PACK_STACK 29/* allocate just enough for r14, r15 and backchain */ 30#define TRACED_FUNC_FRAME_SIZE 24 31#else 32#define TRACED_FUNC_FRAME_SIZE STACK_FRAME_OVERHEAD 33#endif 34 35ENTRY(_mcount) 36 BR_EX %r14 37 38EXPORT_SYMBOL(_mcount) 39 40ENTRY(ftrace_caller) 41 .globl ftrace_regs_caller 42 .set ftrace_regs_caller,ftrace_caller 43 lgr %r1,%r15 44#ifndef CC_USING_HOTPATCH 45 aghi %r0,MCOUNT_RETURN_FIXUP 46#endif 47 # allocate stack frame for ftrace_caller to contain traced function 48 aghi %r15,-TRACED_FUNC_FRAME_SIZE 49 stg %r1,__SF_BACKCHAIN(%r15) 50 stg %r0,(__SF_GPRS+8*8)(%r15) 51 stg %r15,(__SF_GPRS+9*8)(%r15) 52 # allocate pt_regs and stack frame for ftrace_trace_function 53 aghi %r15,-STACK_FRAME_SIZE 54 stg %r1,(STACK_PTREGS_GPRS+15*8)(%r15) 55 aghi %r1,-TRACED_FUNC_FRAME_SIZE 56 stg %r1,__SF_BACKCHAIN(%r15) 57 stg %r0,(STACK_PTREGS_PSW+8)(%r15) 58 stmg %r2,%r14,(STACK_PTREGS_GPRS+2*8)(%r15) 59#ifdef CONFIG_HAVE_MARCH_Z196_FEATURES 60 aghik %r2,%r0,-MCOUNT_INSN_SIZE 61 lgrl %r4,function_trace_op 62 lgrl %r1,ftrace_trace_function 63#else 64 lgr %r2,%r0 65 aghi %r2,-MCOUNT_INSN_SIZE 66 larl %r4,function_trace_op 67 lg %r4,0(%r4) 68 larl %r1,ftrace_trace_function 69 lg %r1,0(%r1) 70#endif 71 lgr %r3,%r14 72 la %r5,STACK_PTREGS(%r15) 73 BASR_EX %r14,%r1 74#ifdef CONFIG_FUNCTION_GRAPH_TRACER 75# The j instruction gets runtime patched to a nop instruction. 76# See ftrace_enable_ftrace_graph_caller. 77ENTRY(ftrace_graph_caller) 78 j ftrace_graph_caller_end 79 lg %r2,(STACK_PTREGS_GPRS+14*8)(%r15) 80 lg %r3,(STACK_PTREGS_PSW+8)(%r15) 81 brasl %r14,prepare_ftrace_return 82 stg %r2,(STACK_PTREGS_GPRS+14*8)(%r15) 83ftrace_graph_caller_end: 84 .globl ftrace_graph_caller_end 85#endif 86 lg %r1,(STACK_PTREGS_PSW+8)(%r15) 87 lmg %r2,%r15,(STACK_PTREGS_GPRS+2*8)(%r15) 88 BR_EX %r1 89 90#ifdef CONFIG_FUNCTION_GRAPH_TRACER 91 92ENTRY(return_to_handler) 93 stmg %r2,%r5,32(%r15) 94 lgr %r1,%r15 95 aghi %r15,-STACK_FRAME_OVERHEAD 96 stg %r1,__SF_BACKCHAIN(%r15) 97 brasl %r14,ftrace_return_to_handler 98 aghi %r15,STACK_FRAME_OVERHEAD 99 lgr %r14,%r2 100 lmg %r2,%r5,32(%r15) 101 BR_EX %r14 102 103#endif 104