196c79f19a
Select the DYNAMIC_FTRACE_WITH_DIRECT_CALLS to provide the register_ftrace_direct[_multi] interfaces allowing users to register the customed trampoline (direct_caller) as the mcount for one or more target functions. And modify_ftrace_direct[_multi] are also provided for modifying direct_caller. To make the direct_caller and the other ftrace hooks (e.g. function/fgraph tracer, k[ret]probes) co-exist, a temporary register is nominated to store the address of direct_caller in ftrace_regs_caller. After the setting of the address direct_caller by direct_ops->func and the RESTORE_REGS in ftrace_regs_caller, direct_caller will be jumped to by the `jr` inst. Add DYNAMIC_FTRACE_WITH_DIRECT_CALLS support for RISC-V. Signed-off-by: Song Shuai <suagrfillet@gmail.com> Tested-by: Guo Ren <guoren@kernel.org> Signed-off-by: Guo Ren <guoren@kernel.org> Acked-by: Björn Töpel <bjorn@rivosinc.com> Link: https://lore.kernel.org/r/20231130121531.1178502-4-bjorn@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
173 lines
4.6 KiB
C
173 lines
4.6 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 HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
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/*
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* Clang prior to 13 had "mcount" instead of "_mcount":
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* https://reviews.llvm.org/D98881
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*/
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#if defined(CONFIG_CC_IS_GCC) || CONFIG_CLANG_VERSION >= 130000
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#define MCOUNT_NAME _mcount
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#else
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#define MCOUNT_NAME mcount
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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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void MCOUNT_NAME(void);
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static inline unsigned long ftrace_call_adjust(unsigned long addr)
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{
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return addr;
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}
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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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*<ftrace enable>:
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* 0: auipc t0/ra, 0x?
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* 4: jalr t0/ra, ?(t0/ra)
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*
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*<ftrace disable>:
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* 0: nop
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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_NAME)
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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_RA (0x000080e7)
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#define AUIPC_RA (0x00000097)
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#define JALR_T0 (0x000282e7)
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#define AUIPC_T0 (0x00000297)
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#define NOP4 (0x00000013)
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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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#define to_jalr_ra(offset) \
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(((offset & JALR_OFFSET_MASK) << JALR_SHIFT) | JALR_RA)
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#define to_auipc_ra(offset) \
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((offset & JALR_SIGN_MASK) ? \
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(((offset & AUIPC_OFFSET_MASK) + AUIPC_PAD) | AUIPC_RA) : \
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((offset & AUIPC_OFFSET_MASK) | AUIPC_RA))
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#define make_call_ra(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_ra(offset); \
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call[1] = to_jalr_ra(offset); \
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} while (0)
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/*
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* Let auipc+jalr be the basic *mcount unit*, so we make it 8 bytes here.
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*/
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#define MCOUNT_INSN_SIZE 8
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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_REGS
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struct ftrace_ops;
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struct ftrace_regs;
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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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static inline void __arch_ftrace_set_direct_caller(struct pt_regs *regs, unsigned long addr)
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{
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regs->t1 = addr;
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}
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#define arch_ftrace_set_direct_caller(fregs, addr) \
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__arch_ftrace_set_direct_caller(&(fregs)->regs, addr)
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#endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */
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#endif /* __ASSEMBLY__ */
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#endif /* CONFIG_DYNAMIC_FTRACE */
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#ifndef __ASSEMBLY__
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#ifdef CONFIG_FUNCTION_GRAPH_TRACER
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struct fgraph_ret_regs {
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unsigned long a1;
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unsigned long a0;
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unsigned long s0;
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unsigned long ra;
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};
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static inline unsigned long fgraph_ret_regs_return_value(struct fgraph_ret_regs *ret_regs)
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{
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return ret_regs->a0;
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}
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static inline unsigned long fgraph_ret_regs_frame_pointer(struct fgraph_ret_regs *ret_regs)
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{
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return ret_regs->s0;
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}
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#endif /* ifdef CONFIG_FUNCTION_GRAPH_TRACER */
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#endif
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#endif /* _ASM_RISCV_FTRACE_H */
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