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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_REGS
#define ARCH_SUPPORTS_FTRACE_OPS 1
#else
#define MCOUNT_ADDR ((unsigned long)function_nocfi(_mcount))
#endif
/* The BL at the callsite's adjusted rec->ip */
#define MCOUNT_INSN_SIZE AARCH64_INSN_SIZE
#define FTRACE_PLT_IDX 0
#define FTRACE_REGS_PLT_IDX 1
#define NR_FTRACE_PLTS 2
/*
* 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);
static inline unsigned long ftrace_call_adjust(unsigned long addr)
{
/*
* Adjust addr to point at the BL in the callsite.
* See ftrace_init_nop() for the callsite sequence.
*/
if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS))
return addr + AARCH64_INSN_SIZE;
/*
* addr is the address of the mcount call instruction.
* recordmcount does the necessary offset calculation.
*/
return addr;
}
#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
struct dyn_ftrace;
int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec);
#define ftrace_init_nop ftrace_init_nop
#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__ */
#endif /* __ASM_FTRACE_H */
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