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| author |   Alan Kao <alankao@andestech.com> | 2018-02-13 13:13:18 +0800 |
|---|---|---|
| committer |   Palmer Dabbelt <palmer@sifive.com> | 2018-04-02 19:59:12 -0700 |
| commit | bc1a4c3a842556852bb02039887d73899d513532 (patch) | |
| tree | 122084b028e4384e9acfd6fa0ebc73a435c5715c /arch/riscv/kernel/mcount-dyn.S | |
| parent | riscv/ftrace: Add dynamic function tracer support (diff) | |
| download | linux-dev-bc1a4c3a842556852bb02039887d73899d513532.tar.xz linux-dev-bc1a4c3a842556852bb02039887d73899d513532.zip | |
riscv/ftrace: Add dynamic function graph tracer support
Once the function_graph tracer is enabled, a filtered function has the
following call sequence:
* ftracer_caller ==> on/off by ftrace_make_call/ftrace_make_nop
* ftrace_graph_caller
* ftrace_graph_call ==> on/off by ftrace_en/disable_ftrace_graph_caller
* 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.
Cc: Greentime Hu <greentime@andestech.com>
Signed-off-by: Alan Kao <alankao@andestech.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Diffstat (limited to '')
| -rw-r--r-- | arch/riscv/kernel/mcount-dyn.S | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/arch/riscv/kernel/mcount-dyn.S b/arch/riscv/kernel/mcount-dyn.S index a3ebeadbe698..739e07a6fd85 100644 --- a/arch/riscv/kernel/mcount-dyn.S +++ b/arch/riscv/kernel/mcount-dyn.S @@ -14,18 +14,62 @@ .text .macro SAVE_ABI_STATE +#ifdef CONFIG_FUNCTION_GRAPH_TRACER + addi sp, sp, -48 + sd s0, 32(sp) + sd ra, 40(sp) + addi s0, sp, 48 + sd t0, 24(sp) + sd t1, 16(sp) +#ifdef HAVE_FUNCTION_GRAPH_FP_TEST + sd t2, 8(sp) +#endif +#else addi sp, sp, -16 sd s0, 0(sp) sd ra, 8(sp) addi s0, sp, 16 +#endif .endm .macro RESTORE_ABI_STATE +#ifdef CONFIG_FUNCTION_GRAPH_TRACER + ld s0, 32(sp) + ld ra, 40(sp) + addi sp, sp, 48 +#else ld ra, 8(sp) ld s0, 0(sp) addi sp, sp, 16 +#endif .endm + .macro RESTORE_GRAPH_ARGS + ld a0, 24(sp) + ld a1, 16(sp) +#ifdef HAVE_FUNCTION_GRAPH_FP_TEST + ld a2, 8(sp) +#endif + .endm + +ENTRY(ftrace_graph_caller) + addi sp, sp, -16 + sd s0, 0(sp) + sd ra, 8(sp) + addi s0, sp, 16 +ftrace_graph_call: + .global ftrace_graph_call + /* + * Calling ftrace_enable/disable_ftrace_graph_caller would overwrite the + * call below. Check ftrace_modify_all_code for details. + */ + call ftrace_stub + ld ra, 8(sp) + ld s0, 0(sp) + addi sp, sp, 16 + ret +ENDPROC(ftrace_graph_caller) + ENTRY(ftrace_caller) /* * a0: the address in the caller when calling ftrace_caller @@ -33,6 +77,20 @@ ENTRY(ftrace_caller) */ ld a1, -8(s0) addi a0, ra, -MCOUNT_INSN_SIZE + +#ifdef CONFIG_FUNCTION_GRAPH_TRACER + /* + * the graph tracer (specifically, prepare_ftrace_return) needs these + * arguments but for now the function tracer occupies the regs, so we + * save them in temporary regs to recover later. + */ + addi t0, s0, -8 + mv t1, a0 +#ifdef HAVE_FUNCTION_GRAPH_FP_TEST + ld t2, -16(s0) +#endif +#endif + SAVE_ABI_STATE ftrace_call: .global ftrace_call @@ -45,6 +103,12 @@ ftrace_call: * Check ftrace_modify_all_code for details. */ call ftrace_stub + +#ifdef CONFIG_FUNCTION_GRAPH_TRACER + RESTORE_GRAPH_ARGS + call ftrace_graph_caller +#endif + RESTORE_ABI_STATE ret ENDPROC(ftrace_caller) |