1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _ASM_S390_FTRACE_H 3 #define _ASM_S390_FTRACE_H 4 5 #define ARCH_SUPPORTS_FTRACE_OPS 1 6 7 #if defined(CC_USING_HOTPATCH) || defined(CC_USING_NOP_MCOUNT) 8 #define MCOUNT_INSN_SIZE 6 9 #else 10 #define MCOUNT_INSN_SIZE 24 11 #define MCOUNT_RETURN_FIXUP 18 12 #endif 13 14 #define HAVE_FUNCTION_GRAPH_RET_ADDR_PTR 15 16 #ifndef __ASSEMBLY__ 17 18 #ifdef CONFIG_CC_IS_CLANG 19 /* https://bugs.llvm.org/show_bug.cgi?id=41424 */ 20 #define ftrace_return_address(n) 0UL 21 #else 22 #define ftrace_return_address(n) __builtin_return_address(n) 23 #endif 24 25 void _mcount(void); 26 void ftrace_caller(void); 27 28 extern char ftrace_graph_caller_end; 29 extern unsigned long ftrace_plt; 30 31 struct dyn_arch_ftrace { }; 32 33 #define MCOUNT_ADDR ((unsigned long)_mcount) 34 #define FTRACE_ADDR ((unsigned long)ftrace_caller) 35 36 #define KPROBE_ON_FTRACE_NOP 0 37 #define KPROBE_ON_FTRACE_CALL 1 38 39 static inline unsigned long ftrace_call_adjust(unsigned long addr) 40 { 41 return addr; 42 } 43 44 struct ftrace_insn { 45 u16 opc; 46 s32 disp; 47 } __packed; 48 49 static inline void ftrace_generate_nop_insn(struct ftrace_insn *insn) 50 { 51 #ifdef CONFIG_FUNCTION_TRACER 52 #if defined(CC_USING_HOTPATCH) || defined(CC_USING_NOP_MCOUNT) 53 /* brcl 0,0 */ 54 insn->opc = 0xc004; 55 insn->disp = 0; 56 #else 57 /* jg .+24 */ 58 insn->opc = 0xc0f4; 59 insn->disp = MCOUNT_INSN_SIZE / 2; 60 #endif 61 #endif 62 } 63 64 static inline int is_ftrace_nop(struct ftrace_insn *insn) 65 { 66 #ifdef CONFIG_FUNCTION_TRACER 67 #if defined(CC_USING_HOTPATCH) || defined(CC_USING_NOP_MCOUNT) 68 if (insn->disp == 0) 69 return 1; 70 #else 71 if (insn->disp == MCOUNT_INSN_SIZE / 2) 72 return 1; 73 #endif 74 #endif 75 return 0; 76 } 77 78 static inline void ftrace_generate_call_insn(struct ftrace_insn *insn, 79 unsigned long ip) 80 { 81 #ifdef CONFIG_FUNCTION_TRACER 82 unsigned long target; 83 84 /* brasl r0,ftrace_caller */ 85 target = is_module_addr((void *) ip) ? ftrace_plt : FTRACE_ADDR; 86 insn->opc = 0xc005; 87 insn->disp = (target - ip) / 2; 88 #endif 89 } 90 91 /* 92 * Even though the system call numbers are identical for s390/s390x a 93 * different system call table is used for compat tasks. This may lead 94 * to e.g. incorrect or missing trace event sysfs files. 95 * Therefore simply do not trace compat system calls at all. 96 * See kernel/trace/trace_syscalls.c. 97 */ 98 #define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS 99 static inline bool arch_trace_is_compat_syscall(struct pt_regs *regs) 100 { 101 return is_compat_task(); 102 } 103 104 #define ARCH_HAS_SYSCALL_MATCH_SYM_NAME 105 static inline bool arch_syscall_match_sym_name(const char *sym, 106 const char *name) 107 { 108 /* 109 * Skip __s390_ and __s390x_ prefix - due to compat wrappers 110 * and aliasing some symbols of 64 bit system call functions 111 * may get the __s390_ prefix instead of the __s390x_ prefix. 112 */ 113 return !strcmp(sym + 7, name) || !strcmp(sym + 8, name); 114 } 115 116 #endif /* __ASSEMBLY__ */ 117 #endif /* _ASM_S390_FTRACE_H */ 118