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b21cdb9523
jump to FTRACE_ADDR if distance is out of reach Co-developed-by: Björn Töpel <bjorn@rivosinc.com> Signed-off-by: Björn Töpel <bjorn@rivosinc.com> Signed-off-by: Andy Chiu <andybnac@gmail.com> Link: https://lore.kernel.org/r/20250407180838.42877-11-andybnac@gmail.com Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
242 lines
6.4 KiB
C
242 lines
6.4 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/* Copyright (C) 2017 Andes Technology Corporation */
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#ifndef _ASM_RISCV_FTRACE_H
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#define _ASM_RISCV_FTRACE_H
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/*
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* The graph frame test is not possible if CONFIG_FRAME_POINTER is not enabled.
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* Check arch/riscv/kernel/mcount.S for detail.
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*/
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#if defined(CONFIG_FUNCTION_GRAPH_TRACER) && defined(CONFIG_FRAME_POINTER)
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#define HAVE_FUNCTION_GRAPH_FP_TEST
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#endif
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#define ARCH_SUPPORTS_FTRACE_OPS 1
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#ifndef __ASSEMBLY__
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extern void *return_address(unsigned int level);
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#define ftrace_return_address(n) return_address(n)
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void _mcount(void);
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unsigned long ftrace_call_adjust(unsigned long addr);
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unsigned long arch_ftrace_get_symaddr(unsigned long fentry_ip);
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#define ftrace_get_symaddr(fentry_ip) arch_ftrace_get_symaddr(fentry_ip)
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/*
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* Let's do like x86/arm64 and ignore the compat syscalls.
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*/
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#define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS
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static inline bool arch_trace_is_compat_syscall(struct pt_regs *regs)
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{
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return is_compat_task();
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}
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#define ARCH_HAS_SYSCALL_MATCH_SYM_NAME
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static inline bool arch_syscall_match_sym_name(const char *sym,
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const char *name)
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{
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/*
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* Since all syscall functions have __riscv_ prefix, we must skip it.
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* However, as we described above, we decided to ignore compat
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* syscalls, so we don't care about __riscv_compat_ prefix here.
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*/
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return !strcmp(sym + 8, name);
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}
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struct dyn_arch_ftrace {
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};
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#endif
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#ifdef CONFIG_DYNAMIC_FTRACE
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/*
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* A general call in RISC-V is a pair of insts:
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* 1) auipc: setting high-20 pc-related bits to ra register
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* 2) jalr: setting low-12 offset to ra, jump to ra, and set ra to
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* return address (original pc + 4)
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*
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* The first 2 instructions for each tracable function is compiled to 2 nop
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* instructions. Then, the kernel initializes the first instruction to auipc at
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* boot time (<ftrace disable>). The second instruction is patched to jalr to
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* start the trace.
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*
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*<Image>:
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* 0: nop
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* 4: nop
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*
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*<ftrace enable>:
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* 0: auipc t0, 0x?
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* 4: jalr t0, ?(t0)
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*
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*<ftrace disable>:
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* 0: auipc t0, 0x?
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* 4: nop
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*
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* Dynamic ftrace generates probes to call sites, so we must deal with
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* both auipc and jalr at the same time.
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*/
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#define MCOUNT_ADDR ((unsigned long)_mcount)
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#define JALR_SIGN_MASK (0x00000800)
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#define JALR_OFFSET_MASK (0x00000fff)
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#define AUIPC_OFFSET_MASK (0xfffff000)
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#define AUIPC_PAD (0x00001000)
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#define JALR_SHIFT 20
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#define JALR_T0 (0x000282e7)
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#define AUIPC_T0 (0x00000297)
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#define JALR_RANGE (JALR_SIGN_MASK - 1)
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#define to_jalr_t0(offset) \
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(((offset & JALR_OFFSET_MASK) << JALR_SHIFT) | JALR_T0)
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#define to_auipc_t0(offset) \
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((offset & JALR_SIGN_MASK) ? \
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(((offset & AUIPC_OFFSET_MASK) + AUIPC_PAD) | AUIPC_T0) : \
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((offset & AUIPC_OFFSET_MASK) | AUIPC_T0))
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#define make_call_t0(caller, callee, call) \
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do { \
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unsigned int offset = \
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(unsigned long) (callee) - (unsigned long) (caller); \
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call[0] = to_auipc_t0(offset); \
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call[1] = to_jalr_t0(offset); \
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} while (0)
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/*
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* Only the jalr insn in the auipc+jalr is patched, so we make it 4
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* bytes here.
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*/
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#define MCOUNT_INSN_SIZE 4
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#define MCOUNT_AUIPC_SIZE 4
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#define MCOUNT_JALR_SIZE 4
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#define MCOUNT_NOP4_SIZE 4
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#ifndef __ASSEMBLY__
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struct dyn_ftrace;
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int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec);
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#define ftrace_init_nop ftrace_init_nop
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#ifdef CONFIG_DYNAMIC_FTRACE_WITH_ARGS
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#define arch_ftrace_get_regs(regs) NULL
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#define HAVE_ARCH_FTRACE_REGS
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struct ftrace_ops;
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struct ftrace_regs;
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#define arch_ftrace_regs(fregs) ((struct __arch_ftrace_regs *)(fregs))
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struct __arch_ftrace_regs {
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unsigned long epc;
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unsigned long ra;
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unsigned long sp;
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unsigned long s0;
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unsigned long t1;
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#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
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unsigned long direct_tramp;
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#endif
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union {
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unsigned long args[8];
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struct {
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unsigned long a0;
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unsigned long a1;
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unsigned long a2;
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unsigned long a3;
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unsigned long a4;
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unsigned long a5;
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unsigned long a6;
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unsigned long a7;
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#ifdef CONFIG_CC_IS_CLANG
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unsigned long t2;
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unsigned long t3;
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unsigned long t4;
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unsigned long t5;
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unsigned long t6;
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#endif
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};
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};
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};
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static __always_inline unsigned long ftrace_regs_get_instruction_pointer(const struct ftrace_regs
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*fregs)
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{
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return arch_ftrace_regs(fregs)->epc;
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}
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static __always_inline void ftrace_regs_set_instruction_pointer(struct ftrace_regs *fregs,
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unsigned long pc)
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{
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arch_ftrace_regs(fregs)->epc = pc;
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}
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static __always_inline unsigned long ftrace_regs_get_stack_pointer(const struct ftrace_regs *fregs)
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{
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return arch_ftrace_regs(fregs)->sp;
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}
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static __always_inline unsigned long ftrace_regs_get_frame_pointer(const struct ftrace_regs *fregs)
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{
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return arch_ftrace_regs(fregs)->s0;
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}
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static __always_inline unsigned long ftrace_regs_get_argument(struct ftrace_regs *fregs,
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unsigned int n)
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{
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if (n < 8)
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return arch_ftrace_regs(fregs)->args[n];
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return 0;
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}
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static __always_inline unsigned long ftrace_regs_get_return_value(const struct ftrace_regs *fregs)
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{
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return arch_ftrace_regs(fregs)->a0;
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}
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static __always_inline unsigned long ftrace_regs_get_return_address(const struct ftrace_regs *fregs)
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{
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return arch_ftrace_regs(fregs)->ra;
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}
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static __always_inline void ftrace_regs_set_return_value(struct ftrace_regs *fregs,
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unsigned long ret)
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{
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arch_ftrace_regs(fregs)->a0 = ret;
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}
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static __always_inline void ftrace_override_function_with_return(struct ftrace_regs *fregs)
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{
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arch_ftrace_regs(fregs)->epc = arch_ftrace_regs(fregs)->ra;
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}
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static __always_inline struct pt_regs *
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ftrace_partial_regs(const struct ftrace_regs *fregs, struct pt_regs *regs)
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{
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struct __arch_ftrace_regs *afregs = arch_ftrace_regs(fregs);
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memcpy(®s->a_regs, afregs->args, sizeof(afregs->args));
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regs->epc = afregs->epc;
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regs->ra = afregs->ra;
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regs->sp = afregs->sp;
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regs->s0 = afregs->s0;
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regs->t1 = afregs->t1;
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return regs;
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}
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int ftrace_regs_query_register_offset(const char *name);
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void ftrace_graph_func(unsigned long ip, unsigned long parent_ip,
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struct ftrace_ops *op, struct ftrace_regs *fregs);
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#define ftrace_graph_func ftrace_graph_func
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#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
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static inline void arch_ftrace_set_direct_caller(struct ftrace_regs *fregs, unsigned long addr)
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{
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arch_ftrace_regs(fregs)->t1 = addr;
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}
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#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
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#endif /* CONFIG_DYNAMIC_FTRACE_WITH_ARGS */
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#endif /* __ASSEMBLY__ */
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#endif /* CONFIG_DYNAMIC_FTRACE */
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#endif /* _ASM_RISCV_FTRACE_H */
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