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/* SPDX-License-Identifier: GPL-2.0 */
/* Copyright (C) 2017 Andes Technology Corporation */
#ifndef _ASM_RISCV_FTRACE_H
#define _ASM_RISCV_FTRACE_H
/*
* The graph frame test is not possible if CONFIG_FRAME_POINTER is not enabled.
* Check arch/riscv/kernel/mcount.S for detail.
*/
#if defined(CONFIG_FUNCTION_GRAPH_TRACER) && defined(CONFIG_FRAME_POINTER)
#define HAVE_FUNCTION_GRAPH_FP_TEST
#endif
#define HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
/*
* Clang prior to 13 had "mcount" instead of "_mcount":
* https://reviews.llvm.org/D98881
*/
#if defined(CONFIG_CC_IS_GCC) || CONFIG_CLANG_VERSION >= 130000
#define MCOUNT_NAME _mcount
#else
#define MCOUNT_NAME mcount
#endif
#define ARCH_SUPPORTS_FTRACE_OPS 1
#ifndef __ASSEMBLY__
void MCOUNT_NAME(void);
static inline unsigned long ftrace_call_adjust(unsigned long addr)
{
return addr;
}
/*
* Let's do like x86/arm64 and ignore the compat syscalls.
*/
#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 __riscv_ prefix, we must skip it.
* However, as we described above, we decided to ignore compat
* syscalls, so we don't care about __riscv_compat_ prefix here.
*/
return !strcmp(sym + 8, name);
}
struct dyn_arch_ftrace {
};
#endif
#ifdef CONFIG_DYNAMIC_FTRACE
/*
* A general call in RISC-V is a pair of insts:
* 1) auipc: setting high-20 pc-related bits to ra register
* 2) jalr: setting low-12 offset to ra, jump to ra, and set ra to
* return address (original pc + 4)
*
*<ftrace enable>:
* 0: auipc t0/ra, 0x?
* 4: jalr t0/ra, ?(t0/ra)
*
*<ftrace disable>:
* 0: nop
* 4: nop
*
* Dynamic ftrace generates probes to call sites, so we must deal with
* both auipc and jalr at the same time.
*/
#define MCOUNT_ADDR ((unsigned long)MCOUNT_NAME)
#define JALR_SIGN_MASK (0x00000800)
#define JALR_OFFSET_MASK (0x00000fff)
#define AUIPC_OFFSET_MASK (0xfffff000)
#define AUIPC_PAD (0x00001000)
#define JALR_SHIFT 20
#define JALR_RA (0x000080e7)
#define AUIPC_RA (0x00000097)
#define JALR_T0 (0x000282e7)
#define AUIPC_T0 (0x00000297)
#define NOP4 (0x00000013)
#define to_jalr_t0(offset) \
(((offset & JALR_OFFSET_MASK) << JALR_SHIFT) | JALR_T0)
#define to_auipc_t0(offset) \
((offset & JALR_SIGN_MASK) ? \
(((offset & AUIPC_OFFSET_MASK) + AUIPC_PAD) | AUIPC_T0) : \
((offset & AUIPC_OFFSET_MASK) | AUIPC_T0))
#define make_call_t0(caller, callee, call) \
do { \
unsigned int offset = \
(unsigned long) callee - (unsigned long) caller; \
call[0] = to_auipc_t0(offset); \
call[1] = to_jalr_t0(offset); \
} while (0)
#define to_jalr_ra(offset) \
(((offset & JALR_OFFSET_MASK) << JALR_SHIFT) | JALR_RA)
#define to_auipc_ra(offset) \
((offset & JALR_SIGN_MASK) ? \
(((offset & AUIPC_OFFSET_MASK) + AUIPC_PAD) | AUIPC_RA) : \
((offset & AUIPC_OFFSET_MASK) | AUIPC_RA))
#define make_call_ra(caller, callee, call) \
do { \
unsigned int offset = \
(unsigned long) callee - (unsigned long) caller; \
call[0] = to_auipc_ra(offset); \
call[1] = to_jalr_ra(offset); \
} while (0)
/*
* Let auipc+jalr be the basic *mcount unit*, so we make it 8 bytes here.
*/
#define MCOUNT_INSN_SIZE 8
#ifndef __ASSEMBLY__
struct dyn_ftrace;
int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec);
#define ftrace_init_nop ftrace_init_nop
#endif
#endif /* CONFIG_DYNAMIC_FTRACE */
#ifndef __ASSEMBLY__
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
struct fgraph_ret_regs {
unsigned long a1;
unsigned long a0;
unsigned long s0;
unsigned long ra;
};
static inline unsigned long fgraph_ret_regs_return_value(struct fgraph_ret_regs *ret_regs)
{
return ret_regs->a0;
}
static inline unsigned long fgraph_ret_regs_frame_pointer(struct fgraph_ret_regs *ret_regs)
{
return ret_regs->s0;
}
#endif /* ifdef CONFIG_FUNCTION_GRAPH_TRACER */
#endif
#endif /* _ASM_RISCV_FTRACE_H */
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