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| author | Qing Zhang <zhangqing@loongson.cn> | 2022-12-10 17:40:15 +0300 |
|---|---|---|
| committer | Huacai Chen <chenhuacai@loongson.cn> | 2022-12-14 03:41:53 +0300 |
| commit | 5fcfad3d41cc70f39fb31e7ee314989cc4c5f02c (patch) | |
| tree | f28299e0707c961a823c59fba914afb5da7534af /arch/loongarch/kernel/mcount_dyn.S | |
| parent | 4733f09d880745953b88c3358b49ad495aecd8e9 (diff) | |
| download | linux-5fcfad3d41cc70f39fb31e7ee314989cc4c5f02c.tar.xz | |
LoongArch/ftrace: Add dynamic function graph tracer support
Once the function_graph tracer is enabled, a filtered function has the
following call sequence:
1) ftracer_caller ==> on/off by ftrace_make_call/ftrace_make_nop
2) ftrace_graph_caller
3) ftrace_graph_call ==> on/off by ftrace_en/disable_ftrace_graph_caller
4) prepare_ftrace_return
Considering the following DYNAMIC_FTRACE_WITH_REGS feature, it would be
more extendable to have a ftrace_graph_caller function, instead of
calling prepare_ftrace_return directly in ftrace_caller.
Co-developed-by: Jinyang He <hejinyang@loongson.cn>
Signed-off-by: Jinyang He <hejinyang@loongson.cn>
Signed-off-by: Qing Zhang <zhangqing@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Diffstat (limited to 'arch/loongarch/kernel/mcount_dyn.S')
| -rw-r--r-- | arch/loongarch/kernel/mcount_dyn.S | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/arch/loongarch/kernel/mcount_dyn.S b/arch/loongarch/kernel/mcount_dyn.S index 45ba88d2aacc..cce3daa2eb1e 100644 --- a/arch/loongarch/kernel/mcount_dyn.S +++ b/arch/loongarch/kernel/mcount_dyn.S @@ -57,6 +57,11 @@ SYM_CODE_START(ftrace_common) SYM_INNER_LABEL(ftrace_call, SYM_L_GLOBAL) bl ftrace_stub +#ifdef CONFIG_FUNCTION_GRAPH_TRACER +SYM_INNER_LABEL(ftrace_graph_call, SYM_L_GLOBAL) + nop /* b ftrace_graph_caller */ +#endif + /* * As we didn't use S series regs in this assmembly code and all calls * are C function which will save S series regs by themselves, there is @@ -83,3 +88,31 @@ SYM_CODE_START(ftrace_caller) ftrace_regs_entry b ftrace_common SYM_CODE_END(ftrace_caller) + +#ifdef CONFIG_FUNCTION_GRAPH_TRACER +SYM_CODE_START(ftrace_graph_caller) + PTR_L a0, sp, PT_ERA + PTR_ADDI a0, a0, -8 /* arg0: self_addr */ + PTR_ADDI a1, sp, PT_R1 /* arg1: parent */ + bl prepare_ftrace_return + b ftrace_common_return +SYM_CODE_END(ftrace_graph_caller) + +SYM_CODE_START(return_to_handler) + /* Save return value regs */ + PTR_ADDI sp, sp, -2 * SZREG + PTR_S a0, sp, 0 + PTR_S a1, sp, SZREG + + move a0, zero + bl ftrace_return_to_handler + move ra, a0 + + /* Restore return value regs */ + PTR_L a0, sp, 0 + PTR_L a1, sp, SZREG + PTR_ADDI sp, sp, 2 * SZREG + + jr ra +SYM_CODE_END(return_to_handler) +#endif |