Merge tag 'trace-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux...

[linux-2.6-block.git] / kernel / trace / ftrace.c

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 576c41644e77cec3f8c18f8b04580320deec3f49..eca34503f178ece3f25a469ed3d73f186fd98c9e 100644 (file)
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1622,6 +1622,11 @@ static bool test_rec_ops_needs_regs(struct dyn_ftrace *rec)
        return  keep_regs;
 }
 
+static struct ftrace_ops *
+ftrace_find_tramp_ops_any(struct dyn_ftrace *rec);
+static struct ftrace_ops *
+ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, struct ftrace_ops *ops);
+
 static bool __ftrace_hash_rec_update(struct ftrace_ops *ops,
                                     int filter_hash,
                                     bool inc)
@@ -1750,15 +1755,17 @@ static bool __ftrace_hash_rec_update(struct ftrace_ops *ops,
                        }
 
                        /*
-                        * If the rec had TRAMP enabled, then it needs to
-                        * be cleared. As TRAMP can only be enabled iff
-                        * there is only a single ops attached to it.
-                        * In otherwords, always disable it on decrementing.
-                        * In the future, we may set it if rec count is
-                        * decremented to one, and the ops that is left
-                        * has a trampoline.
+                        * The TRAMP needs to be set only if rec count
+                        * is decremented to one, and the ops that is
+                        * left has a trampoline. As TRAMP can only be
+                        * enabled if there is only a single ops attached
+                        * to it.
                         */
-                       rec->flags &= ~FTRACE_FL_TRAMP;
+                       if (ftrace_rec_count(rec) == 1 &&
+                           ftrace_find_tramp_ops_any(rec))
+                               rec->flags |= FTRACE_FL_TRAMP;
+                       else
+                               rec->flags &= ~FTRACE_FL_TRAMP;
 
                        /*
                         * flags will be cleared in ftrace_check_record()
@@ -1768,7 +1775,7 @@ static bool __ftrace_hash_rec_update(struct ftrace_ops *ops,
                count++;
 
                /* Must match FTRACE_UPDATE_CALLS in ftrace_modify_all_code() */
-               update |= ftrace_test_record(rec, 1) != FTRACE_UPDATE_IGNORE;
+               update |= ftrace_test_record(rec, true) != FTRACE_UPDATE_IGNORE;
 
                /* Shortcut, if we handled all records, we are done. */
                if (!all && count == hash->count)
@@ -1951,11 +1958,6 @@ static void print_ip_ins(const char *fmt, const unsigned char *p)
                printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]);
 }
 
-static struct ftrace_ops *
-ftrace_find_tramp_ops_any(struct dyn_ftrace *rec);
-static struct ftrace_ops *
-ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, struct ftrace_ops *ops);
-
 enum ftrace_bug_type ftrace_bug_type;
 const void *ftrace_expected;
 
@@ -2047,7 +2049,7 @@ void ftrace_bug(int failed, struct dyn_ftrace *rec)
        }
 }
 
-static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update)
+static int ftrace_check_record(struct dyn_ftrace *rec, bool enable, bool update)
 {
        unsigned long flag = 0UL;
 
@@ -2146,28 +2148,28 @@ static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update)
 /**
  * ftrace_update_record, set a record that now is tracing or not
  * @rec: the record to update
- * @enable: set to 1 if the record is tracing, zero to force disable
+ * @enable: set to true if the record is tracing, false to force disable
  *
  * The records that represent all functions that can be traced need
  * to be updated when tracing has been enabled.
  */
-int ftrace_update_record(struct dyn_ftrace *rec, int enable)
+int ftrace_update_record(struct dyn_ftrace *rec, bool enable)
 {
-       return ftrace_check_record(rec, enable, 1);
+       return ftrace_check_record(rec, enable, true);
 }
 
 /**
  * ftrace_test_record, check if the record has been enabled or not
  * @rec: the record to test
- * @enable: set to 1 to check if enabled, 0 if it is disabled
+ * @enable: set to true to check if enabled, false if it is disabled
  *
  * The arch code may need to test if a record is already set to
  * tracing to determine how to modify the function code that it
  * represents.
  */
-int ftrace_test_record(struct dyn_ftrace *rec, int enable)
+int ftrace_test_record(struct dyn_ftrace *rec, bool enable)
 {
-       return ftrace_check_record(rec, enable, 0);
+       return ftrace_check_record(rec, enable, false);
 }
 
 static struct ftrace_ops *
@@ -2356,7 +2358,7 @@ unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec)
 }
 
 static int
-__ftrace_replace_code(struct dyn_ftrace *rec, int enable)
+__ftrace_replace_code(struct dyn_ftrace *rec, bool enable)
 {
        unsigned long ftrace_old_addr;
        unsigned long ftrace_addr;
@@ -2395,7 +2397,7 @@ void __weak ftrace_replace_code(int mod_flags)
 {
        struct dyn_ftrace *rec;
        struct ftrace_page *pg;
-       int enable = mod_flags & FTRACE_MODIFY_ENABLE_FL;
+       bool enable = mod_flags & FTRACE_MODIFY_ENABLE_FL;
        int schedulable = mod_flags & FTRACE_MODIFY_MAY_SLEEP_FL;
        int failed;