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#ifdef __PACK_STACK 31/* allocate just enough for r14, r15 and backchain */ 32#define TRACED_FUNC_FRAME_SIZE 24 33#else 34#define TRACED_FUNC_FRAME_SIZE STACK_FRAME_OVERHEAD 35#endif 36 37 .macro ftrace_regs_entry, allregs=0 38 stg %r14,(__SF_GPRS+8*8)(%r15) # save traced function caller 39 40 .if \allregs == 1 41 lghi %r14,0 # save condition code 42 ipm %r14 # don't put any instructions 43 sllg %r14,%r14,16 # clobbering CC before this point 44 .endif 45 46 lgr %r1,%r15 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 xc STACK_PTREGS_ORIG_GPR2(8,%r15),STACK_PTREGS_ORIG_GPR2(%r15) 56 57 .if \allregs == 1 58 stg %r14,(STACK_PTREGS_PSW)(%r15) 59 stosm (STACK_PTREGS_PSW)(%r15),0 60 .endif 61 62 lg %r14,(__SF_GPRS+8*8)(%r1) # restore original return address 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 .endm 68 69SYM_CODE_START(ftrace_regs_caller) 70 ftrace_regs_entry 1 71 j ftrace_common 72SYM_CODE_END(ftrace_regs_caller) 73 74SYM_CODE_START(ftrace_caller) 75 ftrace_regs_entry 0 76 j ftrace_common 77SYM_CODE_END(ftrace_caller) 78 79SYM_CODE_START(ftrace_common) 80#ifdef CONFIG_HAVE_MARCH_Z196_FEATURES 81 aghik %r2,%r0,-MCOUNT_INSN_SIZE 82 lgrl %r4,function_trace_op 83 lgrl %r1,ftrace_func 84#else 85 lgr %r2,%r0 86 aghi %r2,-MCOUNT_INSN_SIZE 87 larl %r4,function_trace_op 88 lg %r4,0(%r4) 89 larl %r1,ftrace_func 90 lg %r1,0(%r1) 91#endif 92 lgr %r3,%r14 93 la %r5,STACK_PTREGS(%r15) 94 BASR_EX %r14,%r1 95#ifdef CONFIG_FUNCTION_GRAPH_TRACER 96# The j instruction gets runtime patched to a nop instruction. 97# See ftrace_enable_ftrace_graph_caller. 98SYM_INNER_LABEL(ftrace_graph_caller, SYM_L_GLOBAL) 99 j .Lftrace_graph_caller_end 100 lmg %r2,%r3,(STACK_PTREGS_GPRS+14*8)(%r15) 101 lg %r4,(STACK_PTREGS_PSW+8)(%r15) 102 brasl %r14,prepare_ftrace_return 103 stg %r2,(STACK_PTREGS_GPRS+14*8)(%r15) 104.Lftrace_graph_caller_end: 105#endif 106 lg %r0,(STACK_PTREGS_PSW+8)(%r15) 107#ifdef CONFIG_HAVE_MARCH_Z196_FEATURES 108 ltg %r1,STACK_PTREGS_ORIG_GPR2(%r15) 109 locgrz %r1,%r0 110#else 111 lg %r1,STACK_PTREGS_ORIG_GPR2(%r15) 112 ltgr %r1,%r1 113 jnz 0f 114 lgr %r1,%r0 115#endif 1160: lmg %r2,%r15,(STACK_PTREGS_GPRS+2*8)(%r15) 117 BR_EX %r1 118SYM_CODE_END(ftrace_common) 119 120#ifdef CONFIG_FUNCTION_GRAPH_TRACER 121 122SYM_FUNC_START(return_to_handler) 123 stmg %r2,%r5,32(%r15) 124 lgr %r1,%r15 125 aghi %r15,-STACK_FRAME_OVERHEAD 126 stg %r1,__SF_BACKCHAIN(%r15) 127 brasl %r14,ftrace_return_to_handler 128 aghi %r15,STACK_FRAME_OVERHEAD 129 lgr %r14,%r2 130 lmg %r2,%r5,32(%r15) 131 BR_EX %r14 132SYM_FUNC_END(return_to_handler) 133 134#endif 135