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 extern void *ftrace_func; 31 32 struct dyn_arch_ftrace { }; 33 34 #define MCOUNT_ADDR ((unsigned long)_mcount) 35 #define FTRACE_ADDR ((unsigned long)ftrace_caller) 36 37 #define KPROBE_ON_FTRACE_NOP 0 38 #define KPROBE_ON_FTRACE_CALL 1 39 ftrace_call_adjust(unsigned long addr)40static inline unsigned long ftrace_call_adjust(unsigned long addr) 41 { 42 return addr; 43 } 44 45 struct ftrace_insn { 46 u16 opc; 47 s32 disp; 48 } __packed; 49 ftrace_generate_nop_insn(struct ftrace_insn * insn)50static inline void ftrace_generate_nop_insn(struct ftrace_insn *insn) 51 { 52 #ifdef CONFIG_FUNCTION_TRACER 53 #if defined(CC_USING_HOTPATCH) || defined(CC_USING_NOP_MCOUNT) 54 /* brcl 0,0 */ 55 insn->opc = 0xc004; 56 insn->disp = 0; 57 #else 58 /* jg .+24 */ 59 insn->opc = 0xc0f4; 60 insn->disp = MCOUNT_INSN_SIZE / 2; 61 #endif 62 #endif 63 } 64 is_ftrace_nop(struct ftrace_insn * insn)65static inline int is_ftrace_nop(struct ftrace_insn *insn) 66 { 67 #ifdef CONFIG_FUNCTION_TRACER 68 #if defined(CC_USING_HOTPATCH) || defined(CC_USING_NOP_MCOUNT) 69 if (insn->disp == 0) 70 return 1; 71 #else 72 if (insn->disp == MCOUNT_INSN_SIZE / 2) 73 return 1; 74 #endif 75 #endif 76 return 0; 77 } 78 ftrace_generate_call_insn(struct ftrace_insn * insn,unsigned long ip)79static inline void ftrace_generate_call_insn(struct ftrace_insn *insn, 80 unsigned long ip) 81 { 82 #ifdef CONFIG_FUNCTION_TRACER 83 unsigned long target; 84 85 /* brasl r0,ftrace_caller */ 86 target = is_module_addr((void *) ip) ? ftrace_plt : FTRACE_ADDR; 87 insn->opc = 0xc005; 88 insn->disp = (target - ip) / 2; 89 #endif 90 } 91 92 /* 93 * Even though the system call numbers are identical for s390/s390x a 94 * different system call table is used for compat tasks. This may lead 95 * to e.g. incorrect or missing trace event sysfs files. 96 * Therefore simply do not trace compat system calls at all. 97 * See kernel/trace/trace_syscalls.c. 98 */ 99 #define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS arch_trace_is_compat_syscall(struct pt_regs * regs)100static inline bool arch_trace_is_compat_syscall(struct pt_regs *regs) 101 { 102 return is_compat_task(); 103 } 104 105 #define ARCH_HAS_SYSCALL_MATCH_SYM_NAME arch_syscall_match_sym_name(const char * sym,const char * name)106static inline bool arch_syscall_match_sym_name(const char *sym, 107 const char *name) 108 { 109 /* 110 * Skip __s390_ and __s390x_ prefix - due to compat wrappers 111 * and aliasing some symbols of 64 bit system call functions 112 * may get the __s390_ prefix instead of the __s390x_ prefix. 113 */ 114 return !strcmp(sym + 7, name) || !strcmp(sym + 8, name); 115 } 116 117 #endif /* __ASSEMBLY__ */ 118 #endif /* _ASM_S390_FTRACE_H */ 119