1 files changed, 129 insertions, 0 deletions
diff --git a/arch/s390/include/asm/ftrace.h b/arch/s390/include/asm/ftrace.h
new file mode 100644
index 000000000..6f80ec9c0
--- /dev/null
+++ b/arch/s390/include/asm/ftrace.h
@@ -0,0 +1,129 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_S390_FTRACE_H
+#define _ASM_S390_FTRACE_H
+
+#define HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
+#define ARCH_SUPPORTS_FTRACE_OPS 1
+#define MCOUNT_INSN_SIZE	6
+
+#ifndef __ASSEMBLY__
+
+#ifdef CONFIG_CC_IS_CLANG
+/* https://bugs.llvm.org/show_bug.cgi?id=41424 */
+#define ftrace_return_address(n) 0UL
+#else
+#define ftrace_return_address(n) __builtin_return_address(n)
+#endif
+
+void ftrace_caller(void);
+
+extern void *ftrace_func;
+
+struct dyn_arch_ftrace { };
+
+#define MCOUNT_ADDR 0
+#define FTRACE_ADDR ((unsigned long)ftrace_caller)
+
+#define KPROBE_ON_FTRACE_NOP	0
+#define KPROBE_ON_FTRACE_CALL	1
+
+struct module;
+struct dyn_ftrace;
+
+bool ftrace_need_init_nop(void);
+#define ftrace_need_init_nop ftrace_need_init_nop
+
+int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec);
+#define ftrace_init_nop ftrace_init_nop
+
+static inline unsigned long ftrace_call_adjust(unsigned long addr)
+{
+	return addr;
+}
+
+struct ftrace_regs {
+	struct pt_regs regs;
+};
+
+static __always_inline struct pt_regs *arch_ftrace_get_regs(struct ftrace_regs *fregs)
+{
+	struct pt_regs *regs = &fregs->regs;
+
+	if (test_pt_regs_flag(regs, PIF_FTRACE_FULL_REGS))
+		return regs;
+	return NULL;
+}
+
+static __always_inline void ftrace_instruction_pointer_set(struct ftrace_regs *fregs,
+							   unsigned long ip)
+{
+	fregs->regs.psw.addr = ip;
+}
+
+/*
+ * When an ftrace registered caller is tracing a function that is
+ * also set by a register_ftrace_direct() call, it needs to be
+ * differentiated in the ftrace_caller trampoline. To do this,
+ * place the direct caller in the ORIG_GPR2 part of pt_regs. This
+ * tells the ftrace_caller that there's a direct caller.
+ */
+static inline void arch_ftrace_set_direct_caller(struct pt_regs *regs, unsigned long addr)
+{
+	regs->orig_gpr2 = addr;
+}
+
+/*
+ * Even though the system call numbers are identical for s390/s390x a
+ * different system call table is used for compat tasks. This may lead
+ * to e.g. incorrect or missing trace event sysfs files.
+ * Therefore simply do not trace compat system calls at all.
+ * See kernel/trace/trace_syscalls.c.
+ */
+#define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS
+static inline bool arch_trace_is_compat_syscall(struct pt_regs *regs)
+{
+	return is_compat_task();
+}
+
+#define ARCH_HAS_SYSCALL_MATCH_SYM_NAME
+static inline bool arch_syscall_match_sym_name(const char *sym,
+					       const char *name)
+{
+	/*
+	 * Skip __s390_ and __s390x_ prefix - due to compat wrappers
+	 * and aliasing some symbols of 64 bit system call functions
+	 * may get the __s390_ prefix instead of the __s390x_ prefix.
+	 */
+	return !strcmp(sym + 7, name) || !strcmp(sym + 8, name);
+}
+
+#endif /* __ASSEMBLY__ */
+
+#ifdef CONFIG_FUNCTION_TRACER
+
+#define FTRACE_NOP_INSN .word 0xc004, 0x0000, 0x0000 /* brcl 0,0 */
+
+#ifndef CC_USING_HOTPATCH
+
+#define FTRACE_GEN_MCOUNT_RECORD(name)		\
+	.section __mcount_loc, "a", @progbits;	\
+	.quad name;				\
+	.previous;
+
+#else /* !CC_USING_HOTPATCH */
+
+#define FTRACE_GEN_MCOUNT_RECORD(name)
+
+#endif /* !CC_USING_HOTPATCH */
+
+#define FTRACE_GEN_NOP_ASM(name)		\
+	FTRACE_GEN_MCOUNT_RECORD(name)		\
+	FTRACE_NOP_INSN
+
+#else /* CONFIG_FUNCTION_TRACER */
+
+#define FTRACE_GEN_NOP_ASM(name)
+
+#endif /* CONFIG_FUNCTION_TRACER */
+
+#endif /* _ASM_S390_FTRACE_H */