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authorGuo Ren <ren_guo@c-sky.com>2019-03-01 08:50:36 +0800
committerGuo Ren <ren_guo@c-sky.com>2019-04-22 13:44:57 +0800
commit28bb030f93334495ddc64ade0bff18721bf7023d (patch)
treed0a4e4eaa36575adf490165f63d2bd6160653124 /arch/csky/abiv2/mcount.S
parent3dfc242f11d792535db774613c6fd1df565c2137 (diff)
downloadlinux-sh-28bb030f93334495ddc64ade0bff18721bf7023d.tar.gz
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/mcount.S')
-rw-r--r--arch/csky/abiv2/mcount.S39
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