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 extern void *ftrace_func; 23 24 struct dyn_arch_ftrace { }; 25 26 #define MCOUNT_ADDR 0 27 #define FTRACE_ADDR ((unsigned long)ftrace_caller) 28 29 #define KPROBE_ON_FTRACE_NOP 0 30 #define KPROBE_ON_FTRACE_CALL 1 31 32 struct module; 33 struct dyn_ftrace; 34 /* 35 * Either -mhotpatch or -mnop-mcount is used - no explicit init is required 36 */ 37 static inline int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec) { return 0; } 38 #define ftrace_init_nop ftrace_init_nop 39 40 static 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 50 static inline void ftrace_generate_nop_insn(struct ftrace_insn *insn) 51 { 52 #ifdef CONFIG_FUNCTION_TRACER 53 /* brcl 0,0 */ 54 insn->opc = 0xc004; 55 insn->disp = 0; 56 #endif 57 } 58 59 static inline int is_ftrace_nop(struct ftrace_insn *insn) 60 { 61 #ifdef CONFIG_FUNCTION_TRACER 62 if (insn->disp == 0) 63 return 1; 64 #endif 65 return 0; 66 } 67 68 static inline void ftrace_generate_call_insn(struct ftrace_insn *insn, 69 unsigned long ip) 70 { 71 #ifdef CONFIG_FUNCTION_TRACER 72 unsigned long target; 73 74 /* brasl r0,ftrace_caller */ 75 target = is_module_addr((void *) ip) ? ftrace_plt : FTRACE_ADDR; 76 insn->opc = 0xc005; 77 insn->disp = (target - ip) / 2; 78 #endif 79 } 80 81 /* 82 * Even though the system call numbers are identical for s390/s390x a 83 * different system call table is used for compat tasks. This may lead 84 * to e.g. incorrect or missing trace event sysfs files. 85 * Therefore simply do not trace compat system calls at all. 86 * See kernel/trace/trace_syscalls.c. 87 */ 88 #define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS 89 static inline bool arch_trace_is_compat_syscall(struct pt_regs *regs) 90 { 91 return is_compat_task(); 92 } 93 94 #define ARCH_HAS_SYSCALL_MATCH_SYM_NAME 95 static inline bool arch_syscall_match_sym_name(const char *sym, 96 const char *name) 97 { 98 /* 99 * Skip __s390_ and __s390x_ prefix - due to compat wrappers 100 * and aliasing some symbols of 64 bit system call functions 101 * may get the __s390_ prefix instead of the __s390x_ prefix. 102 */ 103 return !strcmp(sym + 7, name) || !strcmp(sym + 8, name); 104 } 105 106 #endif /* __ASSEMBLY__ */ 107 #endif /* _ASM_S390_FTRACE_H */ 108