[for-next][PATCH 10/13] ftrace: Make get_ftrace_addr() and get_ftrace_addr_old() global

Steven Rostedt
2014-05-12T15:14:48Z

[-- Attachment #1: 0010-ftrace-Make-get_ftrace_addr-and-get_ftrace_addr_old-.patch --]
[-- Type: text/plain, Size: 5459 bytes --]

From: "Steven Rostedt (Red Hat)" <rostedt@goodmis.org>

Move and rename get_ftrace_addr() and get_ftrace_addr_old() to
ftrace_get_addr_new() and ftrace_get_addr_curr() respectively.

This moves these two helper functions in the generic code out from
the arch specific code, and renames them to have a better generic
name. This will allow other archs to use them as well as makes it
a bit easier to work on getting separate trampolines for different
functions.

ftrace_get_addr_new() returns the trampoline address that the mcount
call address will be converted to.

ftrace_get_addr_curr() returns the trampoline address of what the
mcount call address currently jumps to.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
arch/x86/kernel/ftrace.c | 36 +++++-------------------------------
include/linux/ftrace.h | 2 ++
kernel/trace/ftrace.c | 36 ++++++++++++++++++++++++++++++++++++
3 files changed, 43 insertions(+), 31 deletions(-)

diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index 4b3c195..5ef43ce 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -349,38 +349,12 @@ static int add_brk_on_nop(struct dyn_ftrace *rec)
return add_break(rec->ip, old);
}

-/*
- * If the record has the FTRACE_FL_REGS set, that means that it
- * wants to convert to a callback that saves all regs. If FTRACE_FL_REGS
- * is not not set, then it wants to convert to the normal callback.
- */
-static unsigned long get_ftrace_addr(struct dyn_ftrace *rec)
-{
- if (rec->flags & FTRACE_FL_REGS)
- return (unsigned long)FTRACE_REGS_ADDR;
- else
- return (unsigned long)FTRACE_ADDR;
-}
-
-/*
- * The FTRACE_FL_REGS_EN is set when the record already points to
- * a function that saves all the regs. Basically the '_EN' version
- * represents the current state of the function.
- */
-static unsigned long get_ftrace_old_addr(struct dyn_ftrace *rec)
-{
- if (rec->flags & FTRACE_FL_REGS_EN)
- return (unsigned long)FTRACE_REGS_ADDR;
- else
- return (unsigned long)FTRACE_ADDR;
-}
-
static int add_breakpoints(struct dyn_ftrace *rec, int enable)
{
unsigned long ftrace_addr;
int ret;

- ftrace_addr = get_ftrace_old_addr(rec);
+ ftrace_addr = ftrace_get_addr_curr(rec);

ret = ftrace_test_record(rec, enable);

@@ -438,14 +412,14 @@ static int remove_breakpoint(struct dyn_ftrace *rec)
* If not, don't touch the breakpoint, we make just create
* a disaster.
*/
- ftrace_addr = get_ftrace_addr(rec);
+ ftrace_addr = ftrace_get_addr_new(rec);
nop = ftrace_call_replace(ip, ftrace_addr);

if (memcmp(&ins[1], &nop[1], MCOUNT_INSN_SIZE - 1) == 0)
goto update;

/* Check both ftrace_addr and ftrace_old_addr */
- ftrace_addr = get_ftrace_old_addr(rec);
+ ftrace_addr = ftrace_get_addr_curr(rec);
nop = ftrace_call_replace(ip, ftrace_addr);

if (memcmp(&ins[1], &nop[1], MCOUNT_INSN_SIZE - 1) != 0)
@@ -489,7 +463,7 @@ static int add_update(struct dyn_ftrace *rec, int enable)

ret = ftrace_test_record(rec, enable);

- ftrace_addr = get_ftrace_addr(rec);
+ ftrace_addr = ftrace_get_addr_new(rec);

switch (ret) {
case FTRACE_UPDATE_IGNORE:
@@ -536,7 +510,7 @@ static int finish_update(struct dyn_ftrace *rec, int enable)

ret = ftrace_update_record(rec, enable);

- ftrace_addr = get_ftrace_addr(rec);
+ ftrace_addr = ftrace_get_addr_new(rec);

switch (ret) {
case FTRACE_UPDATE_IGNORE:
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index f0ff2c2..2f8cbff 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -400,6 +400,8 @@ int ftrace_update_record(struct dyn_ftrace *rec, int enable);
int ftrace_test_record(struct dyn_ftrace *rec, int enable);
void ftrace_run_stop_machine(int command);
unsigned long ftrace_location(unsigned long ip);
+unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec);
+unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec);

extern ftrace_func_t ftrace_trace_function;

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 98fa931..e825fde 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1755,6 +1755,42 @@ int ftrace_test_record(struct dyn_ftrace *rec, int enable)
return ftrace_check_record(rec, enable, 0);
}

+/**
+ * ftrace_get_addr_new - Get the call address to set to
+ * @rec: The ftrace record descriptor
+ *
+ * If the record has the FTRACE_FL_REGS set, that means that it
+ * wants to convert to a callback that saves all regs. If FTRACE_FL_REGS
+ * is not not set, then it wants to convert to the normal callback.
+ *
+ * Returns the address of the trampoline to set to
+ */
+unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec)
+{
+ if (rec->flags & FTRACE_FL_REGS)
+ return (unsigned long)FTRACE_REGS_ADDR;
+ else
+ return (unsigned long)FTRACE_ADDR;
+}
+
+/**
+ * ftrace_get_addr_curr - Get the call address that is already there
+ * @rec: The ftrace record descriptor
+ *
+ * The FTRACE_FL_REGS_EN is set when the record already points to
+ * a function that saves all the regs. Basically the '_EN' version
+ * represents the current state of the function.
+ *
+ * Returns the address of the trampoline that is currently being called
+ */
+unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec)
+{
+ if (rec->flags & FTRACE_FL_REGS_EN)
+ return (unsigned long)FTRACE_REGS_ADDR;
+ else
+ return (unsigned long)FTRACE_ADDR;
+}
+
static int
__ftrace_replace_code(struct dyn_ftrace *rec, int enable)
{
--
1.8.5.3