Ingo and Steven,
Here's an updated version of the arch/arm changes for dynamic ftrace
based on top of your latest tip/master.
-Jim
---
From: Jim Radford <[EMAIL PROTECTED]>
Subject: ftrace: enable dynamic ftrace for arm
Update to the latest api, syncing functions with the x86 versions.
Index: linux-2.6/arch/arm/Kconfig
===================================================================
--- linux-2.6.orig/arch/arm/Kconfig
+++ linux-2.6/arch/arm/Kconfig
@@ -16,7 +16,9 @@ config ARM
select HAVE_ARCH_KGDB
select HAVE_KPROBES if (!XIP_KERNEL)
select HAVE_KRETPROBES if (HAVE_KPROBES)
- select HAVE_FUNCTION_TRACER if (!XIP_KERNEL)
+ select HAVE_FTRACE_MCOUNT_RECORD
+ select HAVE_DYNAMIC_FTRACE if (!XIP_KERNEL)
+ select HAVE_FUNCTION_TRACER
select HAVE_GENERIC_DMA_COHERENT
help
The ARM series is a line of low-power-consumption RISC chip designs
Index: linux-2.6/arch/arm/include/asm/ftrace.h
===================================================================
--- linux-2.6.orig/arch/arm/include/asm/ftrace.h
+++ linux-2.6/arch/arm/include/asm/ftrace.h
@@ -7,6 +7,19 @@
#ifndef __ASSEMBLY__
extern void mcount(void);
+
+static inline unsigned long ftrace_call_adjust(unsigned long addr)
+{
+ return addr;
+}
+
+#ifdef CONFIG_DYNAMIC_FTRACE
+
+struct dyn_arch_ftrace {
+ /* No extra data needed for x86 */
+};
+
+#endif /* CONFIG_DYNAMIC_FTRACE */
#endif
#endif
Index: linux-2.6/arch/arm/kernel/entry-common.S
===================================================================
--- linux-2.6.orig/arch/arm/kernel/entry-common.S
+++ linux-2.6/arch/arm/kernel/entry-common.S
@@ -104,14 +104,7 @@ ENDPROC(ret_from_fork)
#ifdef CONFIG_FUNCTION_TRACER
#ifdef CONFIG_DYNAMIC_FTRACE
ENTRY(mcount)
- stmdb sp!, {r0-r3, lr}
- mov r0, lr
- sub r0, r0, #MCOUNT_INSN_SIZE
-
- .globl mcount_call
-mcount_call:
- bl ftrace_stub
- ldmia sp!, {r0-r3, pc}
+ mov pc, lr
ENTRY(ftrace_caller)
stmdb sp!, {r0-r3, lr}
Index: linux-2.6/arch/arm/kernel/ftrace.c
===================================================================
--- linux-2.6.orig/arch/arm/kernel/ftrace.c
+++ linux-2.6/arch/arm/kernel/ftrace.c
@@ -23,13 +23,13 @@
static unsigned long bl_insn;
static const unsigned long NOP = 0xe1a00000; /* mov r0, r0 */
-unsigned char *ftrace_nop_replace(void)
+static unsigned char *ftrace_nop_replace(void)
{
return (char *)&NOP;
}
/* construct a branch (BL) instruction to addr */
-unsigned char *ftrace_call_replace(unsigned long pc, unsigned long addr)
+static unsigned char *ftrace_call_replace(unsigned long pc, unsigned long addr)
{
long offset;
@@ -46,7 +46,7 @@ unsigned char *ftrace_call_replace(unsig
return (unsigned char *)&bl_insn;
}
-int ftrace_modify_code(unsigned long pc, unsigned char *old_code,
+static int ftrace_modify_code(unsigned long pc, unsigned char *old_code,
unsigned char *new_code)
{
unsigned long err = 0, replaced = 0, old, new;
@@ -82,22 +82,46 @@ int ftrace_modify_code(unsigned long pc,
return err;
}
+int ftrace_make_nop(struct module *mod,
+ struct dyn_ftrace *rec, unsigned long addr)
+{
+ unsigned char *new, *old;
+ unsigned long ip = rec->ip;
+
+ old = ftrace_call_replace(ip, addr);
+ new = ftrace_nop_replace();
+
+ return ftrace_modify_code(rec->ip, old, new);
+}
+
+int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
+{
+ unsigned char *new, *old;
+ unsigned long ip = rec->ip;
+
+ old = ftrace_nop_replace();
+ new = ftrace_call_replace(ip, addr);
+
+ return ftrace_modify_code(rec->ip, old, new);
+}
+
int ftrace_update_ftrace_func(ftrace_func_t func)
{
+ unsigned long ip = (unsigned long)(&ftrace_call);
+ unsigned char old[MCOUNT_INSN_SIZE], *new;
int ret;
- unsigned long pc, old;
- unsigned char *new;
- pc = (unsigned long)&ftrace_call;
- memcpy(&old, &ftrace_call, MCOUNT_INSN_SIZE);
- new = ftrace_call_replace(pc, (unsigned long)func);
- ret = ftrace_modify_code(pc, (unsigned char *)&old, new);
+ memcpy(old, &ftrace_call, sizeof(old));
+ new = ftrace_call_replace(ip, (unsigned long)func);
+ ret = ftrace_modify_code(ip, (unsigned char *)&old, new);
+
return ret;
}
/* run from kstop_machine */
int __init ftrace_dyn_arch_init(void *data)
{
- ftrace_mcount_set(data);
+ /* The return code is retured via data */
+ *(unsigned long *)data = 0;
return 0;
}
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