This patch is for early kprobes, enables early kprobes to convert
target instruction into nop so it is possible to optimize them.
Signed-off-by: Wang Nan <wangn...@huawei.com>
---
include/linux/ftrace.h | 5 +++++
kernel/trace/ftrace.c | 18 ++++++++++++++++++
2 files changed, 23 insertions(+)
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index fe99166..9cb6061a 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -703,9 +703,14 @@ static inline void __ftrace_enabled_restore(int enabled)
#ifdef CONFIG_FTRACE_MCOUNT_RECORD
extern void ftrace_init(void);
extern void ftrace_init_early(void);
+extern int ftrace_process_loc_early(unsigned long ip);
#else
static inline void ftrace_init(void) { }
static inline void ftrace_init_early(void) { }
+static inline int ftrace_process_loc_early(unsigned long __unused)
+{
+ return 0;
+}
#endif
/*
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 78787d4..bb66b20 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -5046,6 +5046,24 @@ void __init ftrace_init_early(void)
ftrace_sort_mcount_area(__start_mcount_loc, __stop_mcount_loc);
}
+int __init ftrace_process_loc_early(unsigned long addr)
+{
+ unsigned long ip;
+ struct dyn_ftrace fake_rec;
+ int ret;
+
+ BUG_ON(ftrace_pages_start);
+
+ ip = ftrace_location(addr);
+ if (ip != addr)
+ return -EINVAL;
+
+ memset(&fake_rec, '\0', sizeof(fake_rec));
+ fake_rec.ip = ip;
+ ret = ftrace_make_nop(NULL, &fake_rec, MCOUNT_ADDR);
+ return ret;
+}
+
/* Do nothing if arch does not support this */
void __weak arch_ftrace_update_trampoline(struct ftrace_ops *ops)
{
--
1.8.4
--
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