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| author | Guo Ren <ren_guo@c-sky.com> | 2019-03-01 01:50:36 +0100 |
|---|---|---|
| committer | Guo Ren <ren_guo@c-sky.com> | 2019-04-22 07:44:57 +0200 |
| commit | 28bb030f93334495ddc64ade0bff18721bf7023d (patch) | |
| tree | d0a4e4eaa36575adf490165f63d2bd6160653124 /arch/csky/abiv2 | |
| parent | csky: Fixup vdsp&fpu issues in kernel (diff) | |
| download | linux-28bb030f93334495ddc64ade0bff18721bf7023d.tar.xz linux-28bb030f93334495ddc64ade0bff18721bf7023d.zip | |
csky/ftrace: Add dynamic function tracer (include graph tracer)
Support dynamic ftrace including dynamic graph tracer. Gcc-csky with -pg
will produce call site in every function prologue and we can use these
call site to hook trace function.
gcc with -pg origin call site:
push lr
jbsr _mcount
nop32
nop32
If the (callee - caller)'s offset is in range of bsr instruction, we'll
modify code with:
push lr
bsr _mcount
nop32
nop32
Else if the (callee - caller)'s offset is out of bsr instrunction, we'll
modify code with:
push lr
movih r26, ...
ori r26, ...
jsr r26
(r26 is reserved for jsr link reg in csky abiv2 spec.)
Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Diffstat (limited to 'arch/csky/abiv2')
| -rw-r--r-- | arch/csky/abiv2/mcount.S | 39 |
1 files changed, 37 insertions, 2 deletions
diff --git a/arch/csky/abiv2/mcount.S b/arch/csky/abiv2/mcount.S index c633379956f5..326402e65f9e 100644 --- a/arch/csky/abiv2/mcount.S +++ b/arch/csky/abiv2/mcount.S @@ -61,10 +61,17 @@ addi sp, 16 .endm +.macro nop32_stub + nop32 + nop32 + nop32 +.endm + ENTRY(ftrace_stub) jmp lr END(ftrace_stub) +#ifndef CONFIG_DYNAMIC_FTRACE ENTRY(_mcount) mcount_enter @@ -76,7 +83,7 @@ ENTRY(_mcount) bf skip_ftrace mov a0, lr - subi a0, MCOUNT_INSN_SIZE + subi a0, 4 ldw a1, (sp, 24) jsr r26 @@ -101,13 +108,41 @@ skip_ftrace: mcount_exit #endif END(_mcount) +#else /* CONFIG_DYNAMIC_FTRACE */ +ENTRY(_mcount) + mov t1, lr + ldw lr, (sp, 0) + addi sp, 4 + jmp t1 +ENDPROC(_mcount) + +ENTRY(ftrace_caller) + mcount_enter + + ldw a0, (sp, 16) + subi a0, 4 + ldw a1, (sp, 24) + + nop +GLOBAL(ftrace_call) + nop32_stub + +#ifdef CONFIG_FUNCTION_GRAPH_TRACER + nop +GLOBAL(ftrace_graph_call) + nop32_stub +#endif + + mcount_exit +ENDPROC(ftrace_caller) +#endif /* CONFIG_DYNAMIC_FTRACE */ #ifdef CONFIG_FUNCTION_GRAPH_TRACER ENTRY(ftrace_graph_caller) mov a0, sp addi a0, 24 ldw a1, (sp, 16) - subi a1, MCOUNT_INSN_SIZE + subi a1, 4 mov a2, r8 lrw r26, prepare_ftrace_return jsr r26 |