4 files changed, 41 insertions, 7 deletions

diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index 4936489f9ed8..6b232a2460c0 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -165,10 +165,12 @@ ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3) { }
 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
 extern void ftrace_init(void);
 extern void ftrace_init_module(unsigned long *start, unsigned long *end);
+extern void ftrace_release(void *start, unsigned long size);
 #else
 static inline void ftrace_init(void) { }
 static inline void
 ftrace_init_module(unsigned long *start, unsigned long *end) { }
+static inline void ftrace_release(void *start, unsigned long size) { }
 #endif
 
 #endif /* _LINUX_FTRACE_H */
diff --git a/include/linux/init.h b/include/linux/init.h
index 93538b696e3d..27f61f6b3cb9 100644
--- a/include/linux/init.h
+++ b/include/linux/init.h
@@ -40,7 +40,7 @@
 
 /* These are for everybody (although not all archs will actually
    discard it in modules) */
-#define __init          __section(.init.text) __cold
+#define __init          __section(.init.text) __cold notrace
 #define __initdata      __section(.init.data)
 #define __initconst     __section(.init.rodata)
 #define __exitdata      __section(.exit.data)
diff --git a/kernel/module.c b/kernel/module.c
index d753fd9d83ec..7576c2d9462f 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -1431,6 +1431,9 @@ static void free_module(struct module *mod)
         /* Module unload stuff */
         module_unload_free(mod);
 
+        /* release any pointers to mcount in this module */
+        ftrace_release(mod->module_core, mod->core_size);
+
         /* This may be NULL, but that's OK */
         module_free(mod, mod->module_init);
         kfree(mod->args);
@@ -1839,6 +1842,7 @@ static noinline struct module *load_module(void __user *umod,
         struct module *mod;
         long err = 0;
         void *percpu = NULL, *ptr = NULL; /* Stops spurious gcc warning */
+        void *mseg;
         struct exception_table_entry *extable;
         mm_segment_t old_fs;
 
@@ -2190,10 +2194,9 @@ static noinline struct module *load_module(void __user *umod,
 #endif
         }
 
-        if (mcountindex) {
-                void *mseg = (void *)sechdrs[mcountindex].sh_addr;
-                ftrace_init_module(mseg, mseg + sechdrs[mcountindex].sh_size);
-        }
+        /* sechdrs[0].sh_size is always zero */
+        mseg = (void *)sechdrs[mcountindex].sh_addr;
+        ftrace_init_module(mseg, mseg + sechdrs[mcountindex].sh_size);
 
         err = module_finalize(hdr, sechdrs, mod);
         if (err < 0)
@@ -2264,6 +2267,7 @@ static noinline struct module *load_module(void __user *umod,
  cleanup:
         kobject_del(&mod->mkobj.kobj);
         kobject_put(&mod->mkobj.kobj);
+        ftrace_release(mod->module_core, mod->core_size);
  free_unload:
         module_unload_free(mod);
         module_free(mod, mod->module_init);
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 8affb6d00ec1..eadd0eaea9b6 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -294,13 +294,37 @@ static inline void ftrace_del_hash(struct dyn_ftrace *node)
 
 static void ftrace_free_rec(struct dyn_ftrace *rec)
 {
-        /* no locking, only called from kstop_machine */
-
         rec->ip = (unsigned long)ftrace_free_records;
         ftrace_free_records = rec;
         rec->flags |= FTRACE_FL_FREE;
 }
 
+void ftrace_release(void *start, unsigned long size)
+{
+        struct dyn_ftrace *rec;
+        struct ftrace_page *pg;
+        unsigned long s = (unsigned long)start;
+        unsigned long e = s + size;
+        int i;
+
+        if (!start)
+                return;
+
+        /* No interrupt should call this */
+        spin_lock(&ftrace_lock);
+
+        for (pg = ftrace_pages_start; pg; pg = pg->next) {
+                for (i = 0; i < pg->index; i++) {
+                        rec = &pg->records[i];
+
+                        if ((rec->ip >= s) && (rec->ip < e))
+                                ftrace_free_rec(rec);
+                }
+        }
+        spin_unlock(&ftrace_lock);
+
+}
+
 static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip)
 {
         struct dyn_ftrace *rec;
@@ -1527,7 +1551,9 @@ static int ftrace_convert_nops(unsigned long *start,
         p = start;
         while (p < end) {
                 addr = ftrace_call_adjust(*p++);
+                spin_lock(&ftrace_lock);
                 ftrace_record_ip(addr);
+                spin_unlock(&ftrace_lock);
                 ftrace_shutdown_replenish();
         }
 
@@ -1541,6 +1567,8 @@ static int ftrace_convert_nops(unsigned long *start,
 
 void ftrace_init_module(unsigned long *start, unsigned long *end)
 {
+        if (start == end)
+                return;
         ftrace_convert_nops(start, end);
 }