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/* SPDX-License-Identifier: GPL-2.0-only */
/*
* arch/arm64/include/asm/ftrace.h
*
* Copyright (C) 2013 Linaro Limited
* Author: AKASHI Takahiro <takahiro.akashi@linaro.org>
*/
#ifndef __ASM_FTRACE_H
#define __ASM_FTRACE_H
#include <asm/insn.h>
#define HAVE_FUNCTION_GRAPH_FP_TEST
/*
* HAVE_FUNCTION_GRAPH_RET_ADDR_PTR means that the architecture can provide a
* "return address pointer" which can be used to uniquely identify a return
* address which has been overwritten.
*
* On arm64 we use the address of the caller's frame record, which remains the
* same for the lifetime of the instrumented function, unlike the return
* address in the LR.
*/
#define HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
#ifdef CONFIG_DYNAMIC_FTRACE_WITH_ARGS
#define ARCH_SUPPORTS_FTRACE_OPS 1
#else
#define MCOUNT_ADDR ((unsigned long)_mcount)
#endif
/* The BL at the callsite's adjusted rec->ip */
#define MCOUNT_INSN_SIZE AARCH64_INSN_SIZE
#define FTRACE_PLT_IDX 0
#define NR_FTRACE_PLTS 1
/*
* Currently, gcc tends to save the link register after the local variables
* on the stack. This causes the max stack tracer to report the function
* frame sizes for the wrong functions. By defining
* ARCH_FTRACE_SHIFT_STACK_TRACER, it will tell the stack tracer to expect
* to find the return address on the stack after the local variables have
* been set up.
*
* Note, this may change in the future, and we will need to deal with that
* if it were to happen.
*/
#define ARCH_FTRACE_SHIFT_STACK_TRACER 1
#ifndef __ASSEMBLY__
#include <linux/compat.h>
extern void _mcount(unsigned long);
extern void *return_address(unsigned int);
struct dyn_arch_ftrace {
/* No extra data needed for arm64 */
};
extern unsigned long ftrace_graph_call;
extern void return_to_handler(void);
unsigned long ftrace_call_adjust(unsigned long addr);
#ifdef CONFIG_DYNAMIC_FTRACE_WITH_ARGS
struct dyn_ftrace;
struct ftrace_ops;
#define arch_ftrace_get_regs(regs) NULL
/*
* Note: sizeof(struct ftrace_regs) must be a multiple of 16 to ensure correct
* stack alignment
*/
struct ftrace_regs {
/* x0 - x8 */
unsigned long regs[9];
#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
unsigned long direct_tramp;
#else
unsigned long __unused;
#endif
unsigned long fp;
unsigned long lr;
unsigned long sp;
unsigned long pc;
};
static __always_inline unsigned long
ftrace_regs_get_instruction_pointer(const struct ftrace_regs *fregs)
{
return fregs->pc;
}
static __always_inline void
ftrace_regs_set_instruction_pointer(struct ftrace_regs *fregs,
unsigned long pc)
{
fregs->pc = pc;
}
static __always_inline unsigned long
ftrace_regs_get_stack_pointer(const struct ftrace_regs *fregs)
{
return fregs->sp;
}
static __always_inline unsigned long
ftrace_regs_get_argument(struct ftrace_regs *fregs, unsigned int n)
{
if (n < 8)
return fregs->regs[n];
return 0;
}
static __always_inline unsigned long
ftrace_regs_get_return_value(const struct ftrace_regs *fregs)
{
return fregs->regs[0];
}
static __always_inline void
ftrace_regs_set_return_value(struct ftrace_regs *fregs,
unsigned long ret)
{
fregs->regs[0] = ret;
}
static __always_inline void
ftrace_override_function_with_return(struct ftrace_regs *fregs)
{
fregs->pc = fregs->lr;
}
int ftrace_regs_query_register_offset(const char *name);
int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec);
#define ftrace_init_nop ftrace_init_nop
void ftrace_graph_func(unsigned long ip, unsigned long parent_ip,
struct ftrace_ops *op, struct ftrace_regs *fregs);
#define ftrace_graph_func ftrace_graph_func
#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
static inline void arch_ftrace_set_direct_caller(struct ftrace_regs *fregs,
unsigned long addr)
{
/*
* The ftrace trampoline will return to this address instead of the
* instrumented function.
*/
fregs->direct_tramp = addr;
}
#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
#endif
#define ftrace_return_address(n) return_address(n)
/*
* Because AArch32 mode does not share the same syscall table with AArch64,
* tracing compat syscalls may result in reporting bogus syscalls or even
* hang-up, so just do not trace them.
* See kernel/trace/trace_syscalls.c
*
* x86 code says:
* If the user really wants these, then they should use the
* raw syscall tracepoints with filtering.
*/
#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)
{
/*
* Since all syscall functions have __arm64_ prefix, we must skip it.
* However, as we described above, we decided to ignore compat
* syscalls, so we don't care about __arm64_compat_ prefix here.
*/
return !strcmp(sym + 8, name);
}
#endif /* ifndef __ASSEMBLY__ */
#ifndef __ASSEMBLY__
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
struct fgraph_ret_regs {
/* x0 - x7 */
unsigned long regs[8];
unsigned long fp;
unsigned long __unused;
};
static inline unsigned long fgraph_ret_regs_return_value(struct fgraph_ret_regs *ret_regs)
{
return ret_regs->regs[0];
}
static inline unsigned long fgraph_ret_regs_frame_pointer(struct fgraph_ret_regs *ret_regs)
{
return ret_regs->fp;
}
void prepare_ftrace_return(unsigned long self_addr, unsigned long *parent,
unsigned long frame_pointer);
#endif /* ifdef CONFIG_FUNCTION_GRAPH_TRACER */
#endif
#endif /* __ASM_FTRACE_H */
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