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/* packed stack: allocate just enough for r14, r15 and backchain */ 30#define TRACED_FUNC_FRAME_SIZE 24 31 32 .macro ftrace_regs_entry, allregs=0 33 stg %r14,(__SF_GPRS+8*8)(%r15) # save traced function caller 34 35 .if \allregs == 1 36 # save psw mask 37 # don't put any instructions clobbering CC before this point 38 epsw %r1,%r14 39 risbg %r14,%r1,0,31,32 40 .endif 41 42 lgr %r1,%r15 43 # allocate stack frame for ftrace_caller to contain traced function 44 aghi %r15,-TRACED_FUNC_FRAME_SIZE 45 stg %r1,__SF_BACKCHAIN(%r15) 46 stg %r0,(__SF_GPRS+8*8)(%r15) 47 stg %r15,(__SF_GPRS+9*8)(%r15) 48 # allocate pt_regs and stack frame for ftrace_trace_function 49 aghi %r15,-STACK_FRAME_SIZE 50 stg %r1,(STACK_PTREGS_GPRS+15*8)(%r15) 51 xc STACK_PTREGS_ORIG_GPR2(8,%r15),STACK_PTREGS_ORIG_GPR2(%r15) 52 53 .if \allregs == 1 54 stg %r14,(STACK_PTREGS_PSW)(%r15) 55 mvghi STACK_PTREGS_FLAGS(%r15),_PIF_FTRACE_FULL_REGS 56 .else 57 xc STACK_PTREGS_FLAGS(8,%r15),STACK_PTREGS_FLAGS(%r15) 58 .endif 59 60 lg %r14,(__SF_GPRS+8*8)(%r1) # restore original return address 61 aghi %r1,-TRACED_FUNC_FRAME_SIZE 62 stg %r1,__SF_BACKCHAIN(%r15) 63 stg %r0,(STACK_PTREGS_PSW+8)(%r15) 64 stmg %r2,%r14,(STACK_PTREGS_GPRS+2*8)(%r15) 65 .endm 66 67SYM_CODE_START(ftrace_regs_caller) 68 ftrace_regs_entry 1 69 j ftrace_common 70SYM_CODE_END(ftrace_regs_caller) 71 72SYM_CODE_START(ftrace_caller) 73 ftrace_regs_entry 0 74 j ftrace_common 75SYM_CODE_END(ftrace_caller) 76 77SYM_CODE_START(ftrace_common) 78#ifdef CONFIG_HAVE_MARCH_Z196_FEATURES 79 aghik %r2,%r0,-MCOUNT_INSN_SIZE 80 lgrl %r4,function_trace_op 81 lgrl %r1,ftrace_func 82#else 83 lgr %r2,%r0 84 aghi %r2,-MCOUNT_INSN_SIZE 85 larl %r4,function_trace_op 86 lg %r4,0(%r4) 87 larl %r1,ftrace_func 88 lg %r1,0(%r1) 89#endif 90 lgr %r3,%r14 91 la %r5,STACK_PTREGS(%r15) 92 BASR_EX %r14,%r1 93#ifdef CONFIG_FUNCTION_GRAPH_TRACER 94# The j instruction gets runtime patched to a nop instruction. 95# See ftrace_enable_ftrace_graph_caller. 96SYM_INNER_LABEL(ftrace_graph_caller, SYM_L_GLOBAL) 97 j .Lftrace_graph_caller_end 98 lmg %r2,%r3,(STACK_PTREGS_GPRS+14*8)(%r15) 99 lg %r4,(STACK_PTREGS_PSW+8)(%r15) 100 brasl %r14,prepare_ftrace_return 101 stg %r2,(STACK_PTREGS_GPRS+14*8)(%r15) 102.Lftrace_graph_caller_end: 103#endif 104 lg %r0,(STACK_PTREGS_PSW+8)(%r15) 105#ifdef CONFIG_HAVE_MARCH_Z196_FEATURES 106 ltg %r1,STACK_PTREGS_ORIG_GPR2(%r15) 107 locgrz %r1,%r0 108#else 109 lg %r1,STACK_PTREGS_ORIG_GPR2(%r15) 110 ltgr %r1,%r1 111 jnz 0f 112 lgr %r1,%r0 113#endif 1140: lmg %r2,%r15,(STACK_PTREGS_GPRS+2*8)(%r15) 115 BR_EX %r1 116SYM_CODE_END(ftrace_common) 117 118#ifdef CONFIG_FUNCTION_GRAPH_TRACER 119 120SYM_FUNC_START(return_to_handler) 121 stmg %r2,%r5,32(%r15) 122 lgr %r1,%r15 123 aghi %r15,-STACK_FRAME_OVERHEAD 124 stg %r1,__SF_BACKCHAIN(%r15) 125 brasl %r14,ftrace_return_to_handler 126 aghi %r15,STACK_FRAME_OVERHEAD 127 lgr %r14,%r2 128 lmg %r2,%r5,32(%r15) 129 BR_EX %r14 130SYM_FUNC_END(return_to_handler) 131 132#endif 133