1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _ASM_S390_FTRACE_H 3 #define _ASM_S390_FTRACE_H 4 5 #define HAVE_FUNCTION_GRAPH_RET_ADDR_PTR 6 #define ARCH_SUPPORTS_FTRACE_OPS 1 7 #define MCOUNT_INSN_SIZE 6 8 9 #ifndef __ASSEMBLY__ 10 11 #ifdef CONFIG_CC_IS_CLANG 12 /* https://bugs.llvm.org/show_bug.cgi?id=41424 */ 13 #define ftrace_return_address(n) 0UL 14 #else 15 #define ftrace_return_address(n) __builtin_return_address(n) 16 #endif 17 18 void ftrace_caller(void); 19 20 extern char ftrace_graph_caller_end; 21 extern unsigned long ftrace_plt; 22 23 struct dyn_arch_ftrace { }; 24 25 #define MCOUNT_ADDR 0 26 #define FTRACE_ADDR ((unsigned long)ftrace_caller) 27 28 #define KPROBE_ON_FTRACE_NOP 0 29 #define KPROBE_ON_FTRACE_CALL 1 30 31 struct module; 32 struct dyn_ftrace; 33 /* 34 * Either -mhotpatch or -mnop-mcount is used - no explicit init is required 35 */ 36 static inline int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec) { return 0; } 37 #define ftrace_init_nop ftrace_init_nop 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 /* brcl 0,0 */ 53 insn->opc = 0xc004; 54 insn->disp = 0; 55 #endif 56 } 57 58 static inline int is_ftrace_nop(struct ftrace_insn *insn) 59 { 60 #ifdef CONFIG_FUNCTION_TRACER 61 if (insn->disp == 0) 62 return 1; 63 #endif 64 return 0; 65 } 66 67 static inline void ftrace_generate_call_insn(struct ftrace_insn *insn, 68 unsigned long ip) 69 { 70 #ifdef CONFIG_FUNCTION_TRACER 71 unsigned long target; 72 73 /* brasl r0,ftrace_caller */ 74 target = is_module_addr((void *) ip) ? ftrace_plt : FTRACE_ADDR; 75 insn->opc = 0xc005; 76 insn->disp = (target - ip) / 2; 77 #endif 78 } 79 80 /* 81 * Even though the system call numbers are identical for s390/s390x a 82 * different system call table is used for compat tasks. This may lead 83 * to e.g. incorrect or missing trace event sysfs files. 84 * Therefore simply do not trace compat system calls at all. 85 * See kernel/trace/trace_syscalls.c. 86 */ 87 #define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS 88 static inline bool arch_trace_is_compat_syscall(struct pt_regs *regs) 89 { 90 return is_compat_task(); 91 } 92 93 #define ARCH_HAS_SYSCALL_MATCH_SYM_NAME 94 static inline bool arch_syscall_match_sym_name(const char *sym, 95 const char *name) 96 { 97 /* 98 * Skip __s390_ and __s390x_ prefix - due to compat wrappers 99 * and aliasing some symbols of 64 bit system call functions 100 * may get the __s390_ prefix instead of the __s390x_ prefix. 101 */ 102 return !strcmp(sym + 7, name) || !strcmp(sym + 8, name); 103 } 104 105 #endif /* __ASSEMBLY__ */ 106 #endif /* _ASM_S390_FTRACE_H */ 107