diff options
| author | Song Shuai | 2023-11-30 13:15:30 +0100 |
|---|---|---|
| committer | Palmer Dabbelt | 2024-01-17 18:17:09 -0800 |
| commit | 196c79f19a92764d45005599f35338cf0a9eafbb (patch) | |
| tree | d29441488a5f8f2db428abf1cb5deb6752d367ad /arch/riscv/kernel | |
| parent | 35e61e8827ee8ea09e6093ab4d8ba45efd537e36 (diff) | |
riscv: ftrace: Add DYNAMIC_FTRACE_WITH_DIRECT_CALLS support
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>
Diffstat (limited to 'arch/riscv/kernel')
| -rw-r--r-- | arch/riscv/kernel/mcount-dyn.S | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/arch/riscv/kernel/mcount-dyn.S b/arch/riscv/kernel/mcount-dyn.S index c902a7ddb310..b7ce001779c1 100644 --- a/arch/riscv/kernel/mcount-dyn.S +++ b/arch/riscv/kernel/mcount-dyn.S @@ -229,6 +229,7 @@ SYM_FUNC_END(ftrace_caller) #else /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */ SYM_FUNC_START(ftrace_regs_caller) + mv t1, zero SAVE_ABI_REGS 1 PREPARE_ARGS @@ -236,7 +237,10 @@ SYM_INNER_LABEL(ftrace_regs_call, SYM_L_GLOBAL) call ftrace_stub RESTORE_ABI_REGS 1 + bnez t1, .Ldirect jr t0 +.Ldirect: + jr t1 SYM_FUNC_END(ftrace_regs_caller) SYM_FUNC_START(ftrace_caller) @@ -250,3 +254,9 @@ SYM_INNER_LABEL(ftrace_call, SYM_L_GLOBAL) jr t0 SYM_FUNC_END(ftrace_caller) #endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */ + +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS +SYM_CODE_START(ftrace_stub_direct_tramp) + jr t0 +SYM_CODE_END(ftrace_stub_direct_tramp) +#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ |