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| author | Alan Kao <alankao@andestech.com> | 2018-02-13 06:13:17 +0100 |
|---|---|---|
| committer | Palmer Dabbelt <palmer@sifive.com> | 2018-04-03 04:59:12 +0200 |
| commit | c15ac4fd60d5ffdb151bb2c7805f377fd7f90363 (patch) | |
| tree | 758628a4b5779f5af742da0b1781e8a467736827 /arch/riscv/kernel/mcount.S | |
| parent | riscv/ftrace: Add RECORD_MCOUNT support (diff) | |
| download | linux-c15ac4fd60d5ffdb151bb2c7805f377fd7f90363.tar.xz linux-c15ac4fd60d5ffdb151bb2c7805f377fd7f90363.zip | |
riscv/ftrace: Add dynamic function tracer support
We now have dynamic ftrace with the following added items:
* ftrace_make_call, ftrace_make_nop (in kernel/ftrace.c)
The two functions turn each recorded call site of filtered functions
into a call to ftrace_caller or nops
* ftracce_update_ftrace_func (in kernel/ftrace.c)
turns the nops at ftrace_call into a call to a generic entry for
function tracers.
* ftrace_caller (in kernel/mcount-dyn.S)
The entry where each _mcount call sites calls to once they are
filtered to be traced.
Also, this patch fixes the semantic problems in mcount.S, which will be
treated as only a reference implementation once we have the dynamic
ftrace.
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.S | 22 |
1 files changed, 13 insertions, 9 deletions
diff --git a/arch/riscv/kernel/mcount.S b/arch/riscv/kernel/mcount.S index c46a778627be..ce9bdc57a2a1 100644 --- a/arch/riscv/kernel/mcount.S +++ b/arch/riscv/kernel/mcount.S @@ -32,13 +32,13 @@ addi s0, sp, 32 .endm - .macro STORE_ABI_STATE + .macro RESTORE_ABI_STATE ld ra, 8(sp) ld s0, 0(sp) addi sp, sp, 16 .endm - .macro STORE_RET_ABI_STATE + .macro RESTORE_RET_ABI_STATE ld ra, 24(sp) ld s0, 16(sp) ld a0, 8(sp) @@ -46,6 +46,10 @@ .endm ENTRY(ftrace_stub) +#ifdef CONFIG_DYNAMIC_FTRACE + .global _mcount + .set _mcount, ftrace_stub +#endif ret ENDPROC(ftrace_stub) @@ -66,15 +70,15 @@ ENTRY(return_to_handler) #ifdef HAVE_FUNCTION_GRAPH_FP_TEST mv a0, t6 #endif - la t0, ftrace_return_to_handler - jalr t0 + call ftrace_return_to_handler mv a1, a0 - STORE_RET_ABI_STATE + RESTORE_RET_ABI_STATE jalr a1 ENDPROC(return_to_handler) EXPORT_SYMBOL(return_to_handler) #endif +#ifndef CONFIG_DYNAMIC_FTRACE ENTRY(_mcount) la t4, ftrace_stub #ifdef CONFIG_FUNCTION_GRAPH_TRACER @@ -104,9 +108,8 @@ do_ftrace_graph_caller: ld a2, -16(s0) #endif SAVE_ABI_STATE - la t0, prepare_ftrace_return - jalr t0 - STORE_ABI_STATE + call prepare_ftrace_return + RESTORE_ABI_STATE ret #endif @@ -120,7 +123,8 @@ do_trace: SAVE_ABI_STATE jalr t5 - STORE_ABI_STATE + RESTORE_ABI_STATE ret ENDPROC(_mcount) EXPORT_SYMBOL(_mcount) +#endif |