LXR linux/arch/s390/include/asm/ftrace.h

   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
  18void ftrace_caller(void);
  19
  20extern void *ftrace_func;
  21
  22struct dyn_arch_ftrace { };
  23
  24#define MCOUNT_ADDR 0
  25#define FTRACE_ADDR ((unsigned long)ftrace_caller)
  26
  27#define KPROBE_ON_FTRACE_NOP    0
  28#define KPROBE_ON_FTRACE_CALL   1
  29
  30struct module;
  31struct dyn_ftrace;
  32
  33bool ftrace_need_init_nop(void);
  34#define ftrace_need_init_nop ftrace_need_init_nop
  35
  36int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec);
  37#define ftrace_init_nop ftrace_init_nop
  38
  39static inline unsigned long ftrace_call_adjust(unsigned long addr)
  40{
  41        return addr;
  42}
  43
  44struct ftrace_regs {
  45        struct pt_regs regs;
  46};
  47
  48static __always_inline struct pt_regs *arch_ftrace_get_regs(struct ftrace_regs *fregs)
  49{
  50        struct pt_regs *regs = &fregs->regs;
  51
  52        if (test_pt_regs_flag(regs, PIF_FTRACE_FULL_REGS))
  53                return regs;
  54        return NULL;
  55}
  56
  57static __always_inline void ftrace_instruction_pointer_set(struct ftrace_regs *fregs,
  58                                                           unsigned long ip)
  59{
  60        fregs->regs.psw.addr = ip;
  61}
  62
  63/*
  64 * When an ftrace registered caller is tracing a function that is
  65 * also set by a register_ftrace_direct() call, it needs to be
  66 * differentiated in the ftrace_caller trampoline. To do this,
  67 * place the direct caller in the ORIG_GPR2 part of pt_regs. This
  68 * tells the ftrace_caller that there's a direct caller.
  69 */
  70static inline void arch_ftrace_set_direct_caller(struct pt_regs *regs, unsigned long addr)
  71{
  72        regs->orig_gpr2 = addr;
  73}
  74
  75/*
  76 * Even though the system call numbers are identical for s390/s390x a
  77 * different system call table is used for compat tasks. This may lead
  78 * to e.g. incorrect or missing trace event sysfs files.
  79 * Therefore simply do not trace compat system calls at all.
  80 * See kernel/trace/trace_syscalls.c.
  81 */
  82#define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS
  83static inline bool arch_trace_is_compat_syscall(struct pt_regs *regs)
  84{
  85        return is_compat_task();
  86}
  87
  88#define ARCH_HAS_SYSCALL_MATCH_SYM_NAME
  89static inline bool arch_syscall_match_sym_name(const char *sym,
  90                                               const char *name)
  91{
  92        /*
  93         * Skip __s390_ and __s390x_ prefix - due to compat wrappers
  94         * and aliasing some symbols of 64 bit system call functions
  95         * may get the __s390_ prefix instead of the __s390x_ prefix.
  96         */
  97        return !strcmp(sym + 7, name) || !strcmp(sym + 8, name);
  98}
  99
 100#endif /* __ASSEMBLY__ */
 101
 102#ifdef CONFIG_FUNCTION_TRACER
 103
 104#define FTRACE_NOP_INSN .word 0xc004, 0x0000, 0x0000 /* brcl 0,0 */
 105
 106#ifndef CC_USING_HOTPATCH
 107
 108#define FTRACE_GEN_MCOUNT_RECORD(name)          \
 109        .section __mcount_loc, "a", @progbits;  \
 110        .quad name;                             \
 111        .previous;
 112
 113#else /* !CC_USING_HOTPATCH */
 114
 115#define FTRACE_GEN_MCOUNT_RECORD(name)
 116
 117#endif /* !CC_USING_HOTPATCH */
 118
 119#define FTRACE_GEN_NOP_ASM(name)                \
 120        FTRACE_GEN_MCOUNT_RECORD(name)          \
 121        FTRACE_NOP_INSN
 122
 123#else /* CONFIG_FUNCTION_TRACER */
 124
 125#define FTRACE_GEN_NOP_ASM(name)
 126
 127#endif /* CONFIG_FUNCTION_TRACER */
 128
 129#endif /* _ASM_S390_FTRACE_H */
 130