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#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 36 .macro ftrace_regs_entry, allregs=0 37 stg %r14,(__SF_GPRS+8*8)(%r15) # save traced function caller 38 39 .if \allregs == 1 40 lghi %r14,0 # save condition code 41 ipm %r14 # don't put any instructions 42 sllg %r14,%r14,16 # clobbering CC before this point 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 stosm (STACK_PTREGS_PSW)(%r15),0 59#ifdef CONFIG_HAVE_MARCH_Z10_FEATURES 60 mvghi STACK_PTREGS_FLAGS(%r15),_PIF_FTRACE_FULL_REGS 61#else 62 lghi %r14,_PIF_FTRACE_FULL_REGS 63 stg %r14,STACK_PTREGS_FLAGS(%r15) 64#endif 65 .else 66 xc STACK_PTREGS_FLAGS(8,%r15),STACK_PTREGS_FLAGS(%r15) 67 .endif 68 69 lg %r14,(__SF_GPRS+8*8)(%r1) # restore original return address 70 aghi %r1,-TRACED_FUNC_FRAME_SIZE 71 stg %r1,__SF_BACKCHAIN(%r15) 72 stg %r0,(STACK_PTREGS_PSW+8)(%r15) 73 stmg %r2,%r14,(STACK_PTREGS_GPRS+2*8)(%r15) 74 .endm 75 76SYM_CODE_START(ftrace_regs_caller) 77 ftrace_regs_entry 1 78 j ftrace_common 79SYM_CODE_END(ftrace_regs_caller) 80 81SYM_CODE_START(ftrace_caller) 82 ftrace_regs_entry 0 83 j ftrace_common 84SYM_CODE_END(ftrace_caller) 85 86SYM_CODE_START(ftrace_common) 87#ifdef CONFIG_HAVE_MARCH_Z196_FEATURES 88 aghik %r2,%r0,-MCOUNT_INSN_SIZE 89 lgrl %r4,function_trace_op 90 lgrl %r1,ftrace_func 91#else 92 lgr %r2,%r0 93 aghi %r2,-MCOUNT_INSN_SIZE 94 larl %r4,function_trace_op 95 lg %r4,0(%r4) 96 larl %r1,ftrace_func 97 lg %r1,0(%r1) 98#endif 99 lgr %r3,%r14 100 la %r5,STACK_PTREGS(%r15) 101 BASR_EX %r14,%r1 102#ifdef CONFIG_FUNCTION_GRAPH_TRACER 103# The j instruction gets runtime patched to a nop instruction. 104# See ftrace_enable_ftrace_graph_caller. 105SYM_INNER_LABEL(ftrace_graph_caller, SYM_L_GLOBAL) 106 j .Lftrace_graph_caller_end 107 lmg %r2,%r3,(STACK_PTREGS_GPRS+14*8)(%r15) 108 lg %r4,(STACK_PTREGS_PSW+8)(%r15) 109 brasl %r14,prepare_ftrace_return 110 stg %r2,(STACK_PTREGS_GPRS+14*8)(%r15) 111.Lftrace_graph_caller_end: 112#endif 113 lg %r0,(STACK_PTREGS_PSW+8)(%r15) 114#ifdef CONFIG_HAVE_MARCH_Z196_FEATURES 115 ltg %r1,STACK_PTREGS_ORIG_GPR2(%r15) 116 locgrz %r1,%r0 117#else 118 lg %r1,STACK_PTREGS_ORIG_GPR2(%r15) 119 ltgr %r1,%r1 120 jnz 0f 121 lgr %r1,%r0 122#endif 1230: lmg %r2,%r15,(STACK_PTREGS_GPRS+2*8)(%r15) 124 BR_EX %r1 125SYM_CODE_END(ftrace_common) 126 127#ifdef CONFIG_FUNCTION_GRAPH_TRACER 128 129SYM_FUNC_START(return_to_handler) 130 stmg %r2,%r5,32(%r15) 131 lgr %r1,%r15 132 aghi %r15,-STACK_FRAME_OVERHEAD 133 stg %r1,__SF_BACKCHAIN(%r15) 134 brasl %r14,ftrace_return_to_handler 135 aghi %r15,STACK_FRAME_OVERHEAD 136 lgr %r14,%r2 137 lmg %r2,%r5,32(%r15) 138 BR_EX %r14 139SYM_FUNC_END(return_to_handler) 140 141#endif 142