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Message-Id: <1304088194-6214-3-git-send-email-jolsa@redhat.com>
Date: Fri, 29 Apr 2011 16:43:13 +0200
From: Jiri Olsa <jolsa@...hat.com>
To: rostedt@...dmis.org, fweisbec@...il.com
Cc: linux-kernel@...r.kernel.org
Subject: [RFC 2/3] tracing: adding statical callers
adding statically generated code for 'mcount callback' providing
unique bitmask
---
arch/x86/include/asm/ftrace.h | 2 ++
arch/x86/kernel/entry_64.S | 22 +++++++++++++++++-----
arch/x86/kernel/ftrace.c | 13 +++++++++++++
include/linux/ftrace.h | 4 +---
kernel/trace/ftrace.c | 2 +-
5 files changed, 34 insertions(+), 9 deletions(-)
diff --git a/arch/x86/include/asm/ftrace.h b/arch/x86/include/asm/ftrace.h
index 45ae1fa..6ef436b 100644
--- a/arch/x86/include/asm/ftrace.h
+++ b/arch/x86/include/asm/ftrace.h
@@ -2,6 +2,7 @@
#define _ASM_X86_FTRACE_H
#define FTRACE_TRACERS_MAX 4
+#define FTRACE_CALLERS_MAX ((1 << FTRACE_TRACERS_MAX) - 1)
#ifdef __ASSEMBLY__
@@ -36,6 +37,7 @@
#ifndef __ASSEMBLY__
extern void mcount(void);
+extern unsigned long ftrace_callers[FTRACE_CALLERS_MAX];
static inline unsigned long ftrace_call_adjust(unsigned long addr)
{
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index e0ba7d9..1ec1668 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -69,19 +69,31 @@ ENTRY(mcount)
retq
END(mcount)
-ENTRY(ftrace_caller)
+ .section .rodata,"a"
+ENTRY(ftrace_callers)
+ .section .entry.text
+.macro FTRACE_GEN_CALLERS num
+i=1
+.rept (1 << \num) - 1
+1:
cmpl $0, function_trace_stop
jne ftrace_stub
-
MCOUNT_SAVE_FRAME
+ movq $i, %rdx
+ jmp ftrace_caller
+ .previous
+ .quad 1b
+ .section .entry.text
+i=i+1
+.endr
+.endm
+ FTRACE_GEN_CALLERS FTRACE_TRACERS_MAX
+ENTRY(ftrace_caller)
movq 0x38(%rsp), %rdi
movq 8(%rbp), %rsi
subq $MCOUNT_INSN_SIZE, %rdi
- /* by default call all registered handlers */
- movq $-1, %rdx
-
call ftrace_call
MCOUNT_RESTORE_FRAME
diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index dc92378..5a8e679 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -328,6 +328,19 @@ int __init ftrace_dyn_arch_init(void *data)
return 0;
}
+
+unsigned long ftrace_arch_tracer_addr(int mask)
+{
+ if (!mask)
+ return 0L;
+
+ /* tracer 1 is index 0 in ftrace_callers */
+ --mask;
+
+ BUG_ON(mask >= FTRACE_CALLERS_MAX);
+ return ftrace_callers[mask];
+}
+
#endif
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index b7ab09d..b12f5df 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -180,10 +180,8 @@ extern void ftrace_caller(void);
extern void ftrace_call(unsigned long ip, unsigned long parent_ip,
unsigned long flags);
extern void mcount_call(void);
+extern unsigned long ftrace_arch_tracer_addr(int mask);
-#ifndef FTRACE_ADDR
-#define FTRACE_ADDR ((unsigned long)ftrace_caller)
-#endif
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
extern void ftrace_graph_caller(void);
extern int ftrace_enable_ftrace_graph_caller(void);
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index f1eedda..b39dd52 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -963,7 +963,7 @@ __ftrace_replace_code(struct dyn_ftrace *rec, int enable)
unsigned long ftrace_addr;
unsigned long flag = 0UL;
- ftrace_addr = (unsigned long)FTRACE_ADDR;
+ ftrace_addr = ftrace_arch_tracer_addr(FTRACE_CALLERS_MAX);
/*
* If this record is not to be traced or we want to disable it,
--
1.7.1
--
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