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#define STACK_PTREGS_ORIG_GPR2 (STACK_PTREGS + __PT_ORIG_GPR2) 30#define STACK_PTREGS_FLAGS (STACK_PTREGS + __PT_FLAGS) 31#ifdef __PACK_STACK 32/* allocate just enough for r14, r15 and backchain */ 33#define TRACED_FUNC_FRAME_SIZE 24 34#else 35#define TRACED_FUNC_FRAME_SIZE STACK_FRAME_OVERHEAD 36#endif 37 38 .macro ftrace_regs_entry, allregs=0 39 stg %r14,(__SF_GPRS+8*8)(%r15) # save traced function caller 40 41 .if \allregs == 1 42 lghi %r14,0 # save condition code 43 ipm %r14 # don't put any instructions 44 sllg %r14,%r14,16 # clobbering CC before this point 45 .endif 46 47 lgr %r1,%r15 48 # allocate stack frame for ftrace_caller to contain traced function 49 aghi %r15,-TRACED_FUNC_FRAME_SIZE 50 stg %r1,__SF_BACKCHAIN(%r15) 51 stg %r0,(__SF_GPRS+8*8)(%r15) 52 stg %r15,(__SF_GPRS+9*8)(%r15) 53 # allocate pt_regs and stack frame for ftrace_trace_function 54 aghi %r15,-STACK_FRAME_SIZE 55 stg %r1,(STACK_PTREGS_GPRS+15*8)(%r15) 56 xc STACK_PTREGS_ORIG_GPR2(8,%r15),STACK_PTREGS_ORIG_GPR2(%r15) 57 58 .if \allregs == 1 59 stg %r14,(STACK_PTREGS_PSW)(%r15) 60 stosm (STACK_PTREGS_PSW)(%r15),0 61#ifdef CONFIG_HAVE_MARCH_Z10_FEATURES 62 mvghi STACK_PTREGS_FLAGS(%r15),_PIF_FTRACE_FULL_REGS 63#else 64 lghi %r14,_PIF_FTRACE_FULL_REGS 65 stg %r14,STACK_PTREGS_FLAGS(%r15) 66#endif 67 .else 68 xc STACK_PTREGS_FLAGS(8,%r15),STACK_PTREGS_FLAGS(%r15) 69 .endif 70 71 lg %r14,(__SF_GPRS+8*8)(%r1) # restore original return address 72 aghi %r1,-TRACED_FUNC_FRAME_SIZE 73 stg %r1,__SF_BACKCHAIN(%r15) 74 stg %r0,(STACK_PTREGS_PSW+8)(%r15) 75 stmg %r2,%r14,(STACK_PTREGS_GPRS+2*8)(%r15) 76 .endm 77 78SYM_CODE_START(ftrace_regs_caller) 79 ftrace_regs_entry 1 80 j ftrace_common 81SYM_CODE_END(ftrace_regs_caller) 82 83SYM_CODE_START(ftrace_caller) 84 ftrace_regs_entry 0 85 j ftrace_common 86SYM_CODE_END(ftrace_caller) 87 88SYM_CODE_START(ftrace_common) 89#ifdef CONFIG_HAVE_MARCH_Z196_FEATURES 90 aghik %r2,%r0,-MCOUNT_INSN_SIZE 91 lgrl %r4,function_trace_op 92 lgrl %r1,ftrace_func 93#else 94 lgr %r2,%r0 95 aghi %r2,-MCOUNT_INSN_SIZE 96 larl %r4,function_trace_op 97 lg %r4,0(%r4) 98 larl %r1,ftrace_func 99 lg %r1,0(%r1) 100#endif 101 lgr %r3,%r14 102 la %r5,STACK_PTREGS(%r15) 103 BASR_EX %r14,%r1 104#ifdef CONFIG_FUNCTION_GRAPH_TRACER 105# The j instruction gets runtime patched to a nop instruction. 106# See ftrace_enable_ftrace_graph_caller. 107SYM_INNER_LABEL(ftrace_graph_caller, SYM_L_GLOBAL) 108 j .Lftrace_graph_caller_end 109 lmg %r2,%r3,(STACK_PTREGS_GPRS+14*8)(%r15) 110 lg %r4,(STACK_PTREGS_PSW+8)(%r15) 111 brasl %r14,prepare_ftrace_return 112 stg %r2,(STACK_PTREGS_GPRS+14*8)(%r15) 113.Lftrace_graph_caller_end: 114#endif 115 lg %r0,(STACK_PTREGS_PSW+8)(%r15) 116#ifdef CONFIG_HAVE_MARCH_Z196_FEATURES 117 ltg %r1,STACK_PTREGS_ORIG_GPR2(%r15) 118 locgrz %r1,%r0 119#else 120 lg %r1,STACK_PTREGS_ORIG_GPR2(%r15) 121 ltgr %r1,%r1 122 jnz 0f 123 lgr %r1,%r0 124#endif 1250: lmg %r2,%r15,(STACK_PTREGS_GPRS+2*8)(%r15) 126 BR_EX %r1 127SYM_CODE_END(ftrace_common) 128 129#ifdef CONFIG_FUNCTION_GRAPH_TRACER 130 131SYM_FUNC_START(return_to_handler) 132 stmg %r2,%r5,32(%r15) 133 lgr %r1,%r15 134 aghi %r15,-STACK_FRAME_OVERHEAD 135 stg %r1,__SF_BACKCHAIN(%r15) 136 brasl %r14,ftrace_return_to_handler 137 aghi %r15,STACK_FRAME_OVERHEAD 138 lgr %r14,%r2 139 lmg %r2,%r5,32(%r15) 140 BR_EX %r14 141SYM_FUNC_END(return_to_handler) 142 143#endif 144