Merge branch 'tip/perf/core' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace into perf/core

6 files changed, 768 insertions, 350 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 0293fc8daca3..31e3377d8e14 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -2437,6 +2437,14 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
         stacktrace      [FTRACE]
                         Enabled the stack tracer on boot up.
 
+        stacktrace_filter=[function-list]
+                        [FTRACE] Limit the functions that the stack tracer
+                        will trace at boot up. function-list is a comma separated
+                        list of functions. This list can be changed at run
+                        time by the stack_trace_filter file in the debugfs
+                        tracing directory. Note, this enables stack tracing
+                        and the stacktrace above is not needed.
+
         sti=            [PARISC,HW]
                         Format: <num>
                         Set the STI (builtin display/keyboard on the HP-PARISC
diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h
index 59e4028e833d..3fd17c249221 100644
--- a/include/linux/compiler-gcc.h
+++ b/include/linux/compiler-gcc.h
@@ -50,6 +50,11 @@
 # define inline         inline          __attribute__((always_inline))
 # define __inline__     __inline__      __attribute__((always_inline))
 # define __inline       __inline        __attribute__((always_inline))
+#else
+/* A lot of inline functions can cause havoc with function tracing */
+# define inline         inline          notrace
+# define __inline__     __inline__      notrace
+# define __inline       __inline        notrace
 #endif
 
 #define __deprecated                    __attribute__((deprecated))
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index 26eafcef75be..028e26f0bf08 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -133,6 +133,8 @@ struct ftrace_func_command {
 int ftrace_arch_code_modify_prepare(void);
 int ftrace_arch_code_modify_post_process(void);
 
+void ftrace_bug(int err, unsigned long ip);
+
 struct seq_file;
 
 struct ftrace_probe_ops {
@@ -161,7 +163,6 @@ extern int ftrace_text_reserved(void *start, void *end);
 
 enum {
         FTRACE_FL_ENABLED       = (1 << 30),
-        FTRACE_FL_FREE          = (1 << 31),
 };
 
 #define FTRACE_FL_MASK          (0x3UL << 30)
@@ -172,10 +173,7 @@ struct dyn_ftrace {
                 unsigned long           ip; /* address of mcount call-site */
                 struct dyn_ftrace       *freelist;
         };
-        union {
-                unsigned long           flags;
-                struct dyn_ftrace       *newlist;
-        };
+        unsigned long           flags;
         struct dyn_arch_ftrace          arch;
 };
 
@@ -190,6 +188,56 @@ void ftrace_set_global_notrace(unsigned char *buf, int len, int reset);
 int register_ftrace_command(struct ftrace_func_command *cmd);
 int unregister_ftrace_command(struct ftrace_func_command *cmd);
 
+enum {
+        FTRACE_UPDATE_CALLS             = (1 << 0),
+        FTRACE_DISABLE_CALLS            = (1 << 1),
+        FTRACE_UPDATE_TRACE_FUNC        = (1 << 2),
+        FTRACE_START_FUNC_RET           = (1 << 3),
+        FTRACE_STOP_FUNC_RET            = (1 << 4),
+};
+
+enum {
+        FTRACE_UPDATE_IGNORE,
+        FTRACE_UPDATE_MAKE_CALL,
+        FTRACE_UPDATE_MAKE_NOP,
+};
+
+enum {
+        FTRACE_ITER_FILTER      = (1 << 0),
+        FTRACE_ITER_NOTRACE     = (1 << 1),
+        FTRACE_ITER_PRINTALL    = (1 << 2),
+        FTRACE_ITER_DO_HASH     = (1 << 3),
+        FTRACE_ITER_HASH        = (1 << 4),
+        FTRACE_ITER_ENABLED     = (1 << 5),
+};
+
+void arch_ftrace_update_code(int command);
+
+struct ftrace_rec_iter;
+
+struct ftrace_rec_iter *ftrace_rec_iter_start(void);
+struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter);
+struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter);
+
+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);
+int ftrace_location(unsigned long ip);
+
+extern ftrace_func_t ftrace_trace_function;
+
+int ftrace_regex_open(struct ftrace_ops *ops, int flag,
+                  struct inode *inode, struct file *file);
+ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf,
+                            size_t cnt, loff_t *ppos);
+ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf,
+                             size_t cnt, loff_t *ppos);
+loff_t ftrace_regex_lseek(struct file *file, loff_t offset, int origin);
+int ftrace_regex_release(struct inode *inode, struct file *file);
+
+void __init
+ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable);
+
 /* defined in arch */
 extern int ftrace_ip_converted(unsigned long ip);
 extern int ftrace_dyn_arch_init(void *data);
@@ -284,6 +332,25 @@ static inline int ftrace_text_reserved(void *start, void *end)
 {
         return 0;
 }
+
+/*
+ * Again users of functions that have ftrace_ops may not
+ * have them defined when ftrace is not enabled, but these
+ * functions may still be called. Use a macro instead of inline.
+ */
+#define ftrace_regex_open(ops, flag, inod, file) ({ -ENODEV; })
+#define ftrace_set_early_filter(ops, buf, enable) do { } while (0)
+
+static inline ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf,
+                            size_t cnt, loff_t *ppos) { return -ENODEV; }
+static inline ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf,
+                             size_t cnt, loff_t *ppos) { return -ENODEV; }
+static inline loff_t ftrace_regex_lseek(struct file *file, loff_t offset, int origin)
+{
+        return -ENODEV;
+}
+static inline int
+ftrace_regex_release(struct inode *inode, struct file *file) { return -ENODEV; }
 #endif /* CONFIG_DYNAMIC_FTRACE */
 
 /* totally disable ftrace - can not re-enable after this */
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index b1e8943fed1d..683d559a0eef 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -22,11 +22,13 @@
 #include <linux/hardirq.h>
 #include <linux/kthread.h>
 #include <linux/uaccess.h>
+#include <linux/bsearch.h>
 #include <linux/module.h>
 #include <linux/ftrace.h>
 #include <linux/sysctl.h>
 #include <linux/slab.h>
 #include <linux/ctype.h>
+#include <linux/sort.h>
 #include <linux/list.h>
 #include <linux/hash.h>
 #include <linux/rcupdate.h>
@@ -947,13 +949,6 @@ struct ftrace_func_probe {
         struct rcu_head         rcu;
 };
 
-enum {
-        FTRACE_ENABLE_CALLS             = (1 << 0),
-        FTRACE_DISABLE_CALLS            = (1 << 1),
-        FTRACE_UPDATE_TRACE_FUNC        = (1 << 2),
-        FTRACE_START_FUNC_RET           = (1 << 3),
-        FTRACE_STOP_FUNC_RET            = (1 << 4),
-};
 struct ftrace_func_entry {
         struct hlist_node hlist;
         unsigned long ip;
@@ -984,18 +979,19 @@ static struct ftrace_ops global_ops = {
         .filter_hash            = EMPTY_HASH,
 };
 
-static struct dyn_ftrace *ftrace_new_addrs;
-
 static DEFINE_MUTEX(ftrace_regex_lock);
 
 struct ftrace_page {
         struct ftrace_page      *next;
+        struct dyn_ftrace       *records;
         int                     index;
-        struct dyn_ftrace       records[];
+        int                     size;
 };
 
-#define ENTRIES_PER_PAGE \
-  ((PAGE_SIZE - sizeof(struct ftrace_page)) / sizeof(struct dyn_ftrace))
+static struct ftrace_page *ftrace_new_pgs;
+
+#define ENTRY_SIZE sizeof(struct dyn_ftrace)
+#define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE)
 
 /* estimate from running different kernels */
 #define NR_TO_INIT              10000
@@ -1003,7 +999,10 @@ struct ftrace_page {
 static struct ftrace_page       *ftrace_pages_start;
 static struct ftrace_page       *ftrace_pages;
 
-static struct dyn_ftrace *ftrace_free_records;
+static bool ftrace_hash_empty(struct ftrace_hash *hash)
+{
+        return !hash || !hash->count;
+}
 
 static struct ftrace_func_entry *
 ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip)
@@ -1013,7 +1012,7 @@ ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip)
         struct hlist_head *hhd;
         struct hlist_node *n;
 
-        if (!hash->count)
+        if (ftrace_hash_empty(hash))
                 return NULL;
 
         if (hash->size_bits > 0)
@@ -1157,7 +1156,7 @@ alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash)
                 return NULL;
 
         /* Empty hash? */
-        if (!hash || !hash->count)
+        if (ftrace_hash_empty(hash))
                 return new_hash;
 
         size = 1 << hash->size_bits;
@@ -1282,9 +1281,9 @@ ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip)
         filter_hash = rcu_dereference_raw(ops->filter_hash);
         notrace_hash = rcu_dereference_raw(ops->notrace_hash);
 
-        if ((!filter_hash || !filter_hash->count ||
+        if ((ftrace_hash_empty(filter_hash) ||
              ftrace_lookup_ip(filter_hash, ip)) &&
-            (!notrace_hash || !notrace_hash->count ||
+            (ftrace_hash_empty(notrace_hash) ||
              !ftrace_lookup_ip(notrace_hash, ip)))
                 ret = 1;
         else
@@ -1307,6 +1306,47 @@ ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip)
                 }                               \
         }
 
+
+static int ftrace_cmp_recs(const void *a, const void *b)
+{
+        const struct dyn_ftrace *reca = a;
+        const struct dyn_ftrace *recb = b;
+
+        if (reca->ip > recb->ip)
+                return 1;
+        if (reca->ip < recb->ip)
+                return -1;
+        return 0;
+}
+
+/**
+ * ftrace_location - return true if the ip giving is a traced location
+ * @ip: the instruction pointer to check
+ *
+ * Returns 1 if @ip given is a pointer to a ftrace location.
+ * That is, the instruction that is either a NOP or call to
+ * the function tracer. It checks the ftrace internal tables to
+ * determine if the address belongs or not.
+ */
+int ftrace_location(unsigned long ip)
+{
+        struct ftrace_page *pg;
+        struct dyn_ftrace *rec;
+        struct dyn_ftrace key;
+
+        key.ip = ip;
+
+        for (pg = ftrace_pages_start; pg; pg = pg->next) {
+                rec = bsearch(&key, pg->records, pg->index,
+                              sizeof(struct dyn_ftrace),
+                              ftrace_cmp_recs);
+                if (rec)
+                        return 1;
+        }
+
+        return 0;
+}
+
 static void __ftrace_hash_rec_update(struct ftrace_ops *ops,
                                      int filter_hash,
                                      bool inc)
@@ -1336,7 +1376,7 @@ static void __ftrace_hash_rec_update(struct ftrace_ops *ops,
         if (filter_hash) {
                 hash = ops->filter_hash;
                 other_hash = ops->notrace_hash;
-                if (!hash || !hash->count)
+                if (ftrace_hash_empty(hash))
                         all = 1;
         } else {
                 inc = !inc;
@@ -1346,7 +1386,7 @@ static void __ftrace_hash_rec_update(struct ftrace_ops *ops,
                  * If the notrace hash has no items,
                  * then there's nothing to do.
                  */
-                if (hash && !hash->count)
+                if (ftrace_hash_empty(hash))
                         return;
         }
 
@@ -1363,8 +1403,8 @@ static void __ftrace_hash_rec_update(struct ftrace_ops *ops,
                         if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip))
                                 match = 1;
                 } else {
-                        in_hash = hash && !!ftrace_lookup_ip(hash, rec->ip);
-                        in_other_hash = other_hash && !!ftrace_lookup_ip(other_hash, rec->ip);
+                        in_hash = !!ftrace_lookup_ip(hash, rec->ip);
+                        in_other_hash = !!ftrace_lookup_ip(other_hash, rec->ip);
 
                         /*
                          *
@@ -1372,7 +1412,7 @@ static void __ftrace_hash_rec_update(struct ftrace_ops *ops,
                         if (filter_hash && in_hash && !in_other_hash)
                                 match = 1;
                         else if (!filter_hash && in_hash &&
-                                 (in_other_hash || !other_hash->count))
+                                 (in_other_hash || ftrace_hash_empty(other_hash)))
                                 match = 1;
                 }
                 if (!match)
@@ -1406,40 +1446,12 @@ static void ftrace_hash_rec_enable(struct ftrace_ops *ops,
         __ftrace_hash_rec_update(ops, filter_hash, 1);
 }
 
-static void ftrace_free_rec(struct dyn_ftrace *rec)
-{
-        rec->freelist = ftrace_free_records;
-        ftrace_free_records = rec;
-        rec->flags |= FTRACE_FL_FREE;
-}
-
 static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip)
 {
-        struct dyn_ftrace *rec;
-
-        /* First check for freed records */
-        if (ftrace_free_records) {
-                rec = ftrace_free_records;
-
-                if (unlikely(!(rec->flags & FTRACE_FL_FREE))) {
-                        FTRACE_WARN_ON_ONCE(1);
-                        ftrace_free_records = NULL;
+        if (ftrace_pages->index == ftrace_pages->size) {
+                /* We should have allocated enough */
+                if (WARN_ON(!ftrace_pages->next))
                         return NULL;
-                }
-
-                ftrace_free_records = rec->freelist;
-                memset(rec, 0, sizeof(*rec));
-                return rec;
-        }
-
-        if (ftrace_pages->index == ENTRIES_PER_PAGE) {
-                if (!ftrace_pages->next) {
-                        /* allocate another page */
-                        ftrace_pages->next =
-                                (void *)get_zeroed_page(GFP_KERNEL);
-                        if (!ftrace_pages->next)
-                                return NULL;
-                }
                 ftrace_pages = ftrace_pages->next;
         }
 
@@ -1459,8 +1471,6 @@ ftrace_record_ip(unsigned long ip)
                 return NULL;
 
         rec->ip = ip;
-        rec->newlist = ftrace_new_addrs;
-        ftrace_new_addrs = rec;
 
         return rec;
 }
@@ -1475,7 +1485,19 @@ static void print_ip_ins(const char *fmt, unsigned char *p)
                 printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]);
 }
 
-static void ftrace_bug(int failed, unsigned long ip)
+/**
+ * ftrace_bug - report and shutdown function tracer
+ * @failed: The failed type (EFAULT, EINVAL, EPERM)
+ * @ip: The address that failed
+ *
+ * The arch code that enables or disables the function tracing
+ * can call ftrace_bug() when it has detected a problem in
+ * modifying the code. @failed should be one of either:
+ * EFAULT - if the problem happens on reading the @ip address
+ * EINVAL - if what is read at @ip is not what was expected
+ * EPERM - if the problem happens on writting to the @ip address
+ */
+void ftrace_bug(int failed, unsigned long ip)
 {
         switch (failed) {
         case -EFAULT:
@@ -1517,24 +1539,19 @@ int ftrace_text_reserved(void *start, void *end)
         return 0;
 }
 
-
-static int
-__ftrace_replace_code(struct dyn_ftrace *rec, int enable)
+static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update)
 {
-        unsigned long ftrace_addr;
         unsigned long flag = 0UL;
 
-        ftrace_addr = (unsigned long)FTRACE_ADDR;
-
         /*
-         * If we are enabling tracing:
+         * If we are updating calls:
          *
          *   If the record has a ref count, then we need to enable it
          *   because someone is using it.
          *
          *   Otherwise we make sure its disabled.
          *
-         * If we are disabling tracing, then disable all records that
+         * If we are disabling calls, then disable all records that
          * are enabled.
          */
         if (enable && (rec->flags & ~FTRACE_FL_MASK))
@@ -1542,18 +1559,72 @@ __ftrace_replace_code(struct dyn_ftrace *rec, int enable)
 
         /* If the state of this record hasn't changed, then do nothing */
         if ((rec->flags & FTRACE_FL_ENABLED) == flag)
-                return 0;
+                return FTRACE_UPDATE_IGNORE;
 
         if (flag) {
-                rec->flags |= FTRACE_FL_ENABLED;
+                if (update)
+                        rec->flags |= FTRACE_FL_ENABLED;
+                return FTRACE_UPDATE_MAKE_CALL;
+        }
+
+        if (update)
+                rec->flags &= ~FTRACE_FL_ENABLED;
+
+        return FTRACE_UPDATE_MAKE_NOP;
+}
+
+/**
+ * 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
+ *
+ * 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)
+{
+        return ftrace_check_record(rec, enable, 1);
+}
+
+/**
+ * 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
+ *
+ * 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)
+{
+        return ftrace_check_record(rec, enable, 0);
+}
+
+static int
+__ftrace_replace_code(struct dyn_ftrace *rec, int enable)
+{
+        unsigned long ftrace_addr;
+        int ret;
+
+        ftrace_addr = (unsigned long)FTRACE_ADDR;
+
+        ret = ftrace_update_record(rec, enable);
+
+        switch (ret) {
+        case FTRACE_UPDATE_IGNORE:
+                return 0;
+
+        case FTRACE_UPDATE_MAKE_CALL:
                 return ftrace_make_call(rec, ftrace_addr);
+
+        case FTRACE_UPDATE_MAKE_NOP:
+                return ftrace_make_nop(NULL, rec, ftrace_addr);
         }
 
-        rec->flags &= ~FTRACE_FL_ENABLED;
-        return ftrace_make_nop(NULL, rec, ftrace_addr);
+        return -1; /* unknow ftrace bug */
 }
 
-static void ftrace_replace_code(int enable)
+static void ftrace_replace_code(int update)
 {
         struct dyn_ftrace *rec;
         struct ftrace_page *pg;
@@ -1563,11 +1634,7 @@ static void ftrace_replace_code(int enable)
                 return;
 
         do_for_each_ftrace_rec(pg, rec) {
-                /* Skip over free records */
-                if (rec->flags & FTRACE_FL_FREE)
-                        continue;
-
-                failed = __ftrace_replace_code(rec, enable);
+                failed = __ftrace_replace_code(rec, update);
                 if (failed) {
                         ftrace_bug(failed, rec->ip);
                         /* Stop processing */
@@ -1576,6 +1643,78 @@ static void ftrace_replace_code(int enable)
         } while_for_each_ftrace_rec();
 }
 
+struct ftrace_rec_iter {
+        struct ftrace_page      *pg;
+        int                     index;
+};
+
+/**
+ * ftrace_rec_iter_start, start up iterating over traced functions
+ *
+ * Returns an iterator handle that is used to iterate over all
+ * the records that represent address locations where functions
+ * are traced.
+ *
+ * May return NULL if no records are available.
+ */
+struct ftrace_rec_iter *ftrace_rec_iter_start(void)
+{
+        /*
+         * We only use a single iterator.
+         * Protected by the ftrace_lock mutex.
+         */
+        static struct ftrace_rec_iter ftrace_rec_iter;
+        struct ftrace_rec_iter *iter = &ftrace_rec_iter;
+
+        iter->pg = ftrace_pages_start;
+        iter->index = 0;
+
+        /* Could have empty pages */
+        while (iter->pg && !iter->pg->index)
+                iter->pg = iter->pg->next;
+
+        if (!iter->pg)
+                return NULL;
+
+        return iter;
+}
+
+/**
+ * ftrace_rec_iter_next, get the next record to process.
+ * @iter: The handle to the iterator.
+ *
+ * Returns the next iterator after the given iterator @iter.
+ */
+struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter)
+{
+        iter->index++;
+
+        if (iter->index >= iter->pg->index) {
+                iter->pg = iter->pg->next;
+                iter->index = 0;
+
+                /* Could have empty pages */
+                while (iter->pg && !iter->pg->index)
+                        iter->pg = iter->pg->next;
+        }
+
+        if (!iter->pg)
+                return NULL;
+
+        return iter;
+}
+
+/**
+ * ftrace_rec_iter_record, get the record at the iterator location
+ * @iter: The current iterator location
+ *
+ * Returns the record that the current @iter is at.
+ */
+struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter)
+{
+        return &iter->pg->records[iter->index];
+}
+
 static int
 ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec)
 {
@@ -1617,13 +1756,7 @@ static int __ftrace_modify_code(void *data)
 {
         int *command = data;
 
-        /*
-         * Do not call function tracer while we update the code.
-         * We are in stop machine, no worrying about races.
-         */
-        function_trace_stop++;
-
-        if (*command & FTRACE_ENABLE_CALLS)
+        if (*command & FTRACE_UPDATE_CALLS)
                 ftrace_replace_code(1);
         else if (*command & FTRACE_DISABLE_CALLS)
                 ftrace_replace_code(0);
@@ -1636,21 +1769,33 @@ static int __ftrace_modify_code(void *data)
         else if (*command & FTRACE_STOP_FUNC_RET)
                 ftrace_disable_ftrace_graph_caller();
 
-#ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
-        /*
-         * For archs that call ftrace_test_stop_func(), we must
-         * wait till after we update all the function callers
-         * before we update the callback. This keeps different
-         * ops that record different functions from corrupting
-         * each other.
-         */
-        __ftrace_trace_function = __ftrace_trace_function_delay;
-#endif
-        function_trace_stop--;
-
         return 0;
 }
 
+/**
+ * ftrace_run_stop_machine, go back to the stop machine method
+ * @command: The command to tell ftrace what to do
+ *
+ * If an arch needs to fall back to the stop machine method, the
+ * it can call this function.
+ */
+void ftrace_run_stop_machine(int command)
+{
+        stop_machine(__ftrace_modify_code, &command, NULL);
+}
+
+/**
+ * arch_ftrace_update_code, modify the code to trace or not trace
+ * @command: The command that needs to be done
+ *
+ * Archs can override this function if it does not need to
+ * run stop_machine() to modify code.
+ */
+void __weak arch_ftrace_update_code(int command)
+{
+        ftrace_run_stop_machine(command);
+}
+
 static void ftrace_run_update_code(int command)
 {
         int ret;
@@ -1659,8 +1804,31 @@ static void ftrace_run_update_code(int command)
         FTRACE_WARN_ON(ret);
         if (ret)
                 return;
+        /*
+         * Do not call function tracer while we update the code.
+         * We are in stop machine.
+         */
+        function_trace_stop++;
 
-        stop_machine(__ftrace_modify_code, &command, NULL);
+        /*
+         * By default we use stop_machine() to modify the code.
+         * But archs can do what ever they want as long as it
+         * is safe. The stop_machine() is the safest, but also
+         * produces the most overhead.
+         */
+        arch_ftrace_update_code(command);
+
+#ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
+        /*
+         * For archs that call ftrace_test_stop_func(), we must
+         * wait till after we update all the function callers
+         * before we update the callback. This keeps different
+         * ops that record different functions from corrupting
+         * each other.
+         */
+        __ftrace_trace_function = __ftrace_trace_function_delay;
+#endif
+        function_trace_stop--;
 
         ret = ftrace_arch_code_modify_post_process();
         FTRACE_WARN_ON(ret);
@@ -1691,7 +1859,7 @@ static int ftrace_startup(struct ftrace_ops *ops, int command)
                 return -ENODEV;
 
         ftrace_start_up++;
-        command |= FTRACE_ENABLE_CALLS;
+        command |= FTRACE_UPDATE_CALLS;
 
         /* ops marked global share the filter hashes */
         if (ops->flags & FTRACE_OPS_FL_GLOBAL) {
@@ -1743,8 +1911,7 @@ static void ftrace_shutdown(struct ftrace_ops *ops, int command)
         if (ops != &global_ops || !global_start_up)
                 ops->flags &= ~FTRACE_OPS_FL_ENABLED;
 
-        if (!ftrace_start_up)
-                command |= FTRACE_DISABLE_CALLS;
+        command |= FTRACE_UPDATE_CALLS;
 
         if (saved_ftrace_func != ftrace_trace_function) {
                 saved_ftrace_func = ftrace_trace_function;
@@ -1766,7 +1933,7 @@ static void ftrace_startup_sysctl(void)
         saved_ftrace_func = NULL;
         /* ftrace_start_up is true if we want ftrace running */
         if (ftrace_start_up)
-                ftrace_run_update_code(FTRACE_ENABLE_CALLS);
+                ftrace_run_update_code(FTRACE_UPDATE_CALLS);
 }
 
 static void ftrace_shutdown_sysctl(void)
@@ -1788,14 +1955,16 @@ static int ops_traces_mod(struct ftrace_ops *ops)
         struct ftrace_hash *hash;
 
         hash = ops->filter_hash;
-        return !!(!hash || !hash->count);
+        return ftrace_hash_empty(hash);
 }
 
 static int ftrace_update_code(struct module *mod)
 {
+        struct ftrace_page *pg;
         struct dyn_ftrace *p;
         cycle_t start, stop;
         unsigned long ref = 0;
+        int i;
 
         /*
          * When adding a module, we need to check if tracers are
@@ -1817,46 +1986,44 @@ static int ftrace_update_code(struct module *mod)
         start = ftrace_now(raw_smp_processor_id());
         ftrace_update_cnt = 0;
 
-        while (ftrace_new_addrs) {
+        for (pg = ftrace_new_pgs; pg; pg = pg->next) {
 
-                /* If something went wrong, bail without enabling anything */
-                if (unlikely(ftrace_disabled))
-                        return -1;
+                for (i = 0; i < pg->index; i++) {
+                        /* If something went wrong, bail without enabling anything */
+                        if (unlikely(ftrace_disabled))
+                                return -1;
 
-                p = ftrace_new_addrs;
-                ftrace_new_addrs = p->newlist;
-                p->flags = ref;
+                        p = &pg->records[i];
+                        p->flags = ref;
 
-                /*
-                 * Do the initial record conversion from mcount jump
-                 * to the NOP instructions.
-                 */
-                if (!ftrace_code_disable(mod, p)) {
-                        ftrace_free_rec(p);
-                        /* Game over */
-                        break;
-                }
+                        /*
+                         * Do the initial record conversion from mcount jump
+                         * to the NOP instructions.
+                         */
+                        if (!ftrace_code_disable(mod, p))
+                                break;
 
-                ftrace_update_cnt++;
+                        ftrace_update_cnt++;
 
-                /*
-                 * If the tracing is enabled, go ahead and enable the record.
-                 *
-                 * The reason not to enable the record immediatelly is the
-                 * inherent check of ftrace_make_nop/ftrace_make_call for
-                 * correct previous instructions.  Making first the NOP
-                 * conversion puts the module to the correct state, thus
-                 * passing the ftrace_make_call check.
-                 */
-                if (ftrace_start_up && ref) {
-                        int failed = __ftrace_replace_code(p, 1);
-                        if (failed) {
-                                ftrace_bug(failed, p->ip);
-                                ftrace_free_rec(p);
+                        /*
+                         * If the tracing is enabled, go ahead and enable the record.
+                         *
+                         * The reason not to enable the record immediatelly is the
+                         * inherent check of ftrace_make_nop/ftrace_make_call for
+                         * correct previous instructions.  Making first the NOP
+                         * conversion puts the module to the correct state, thus
+                         * passing the ftrace_make_call check.
+                         */
+                        if (ftrace_start_up && ref) {
+                                int failed = __ftrace_replace_code(p, 1);
+                                if (failed)
+                                        ftrace_bug(failed, p->ip);
                         }
                 }
         }
 
+        ftrace_new_pgs = NULL;
+
         stop = ftrace_now(raw_smp_processor_id());
         ftrace_update_time = stop - start;
         ftrace_update_tot_cnt += ftrace_update_cnt;
@@ -1864,57 +2031,108 @@ static int ftrace_update_code(struct module *mod)
         return 0;
 }
 
-static int __init ftrace_dyn_table_alloc(unsigned long num_to_init)
+static int ftrace_allocate_records(struct ftrace_page *pg, int count)
 {
-        struct ftrace_page *pg;
+        int order;
         int cnt;
-        int i;
 
-        /* allocate a few pages */
-        ftrace_pages_start = (void *)get_zeroed_page(GFP_KERNEL);
-        if (!ftrace_pages_start)
-                return -1;
+        if (WARN_ON(!count))
+                return -EINVAL;
+
+        order = get_count_order(DIV_ROUND_UP(count, ENTRIES_PER_PAGE));
 
         /*
-         * Allocate a few more pages.
-         *
-         * TODO: have some parser search vmlinux before
-         *   final linking to find all calls to ftrace.
-         *   Then we can:
-         *    a) know how many pages to allocate.
-         *     and/or
-         *    b) set up the table then.
-         *
-         *  The dynamic code is still necessary for
-         *  modules.
+         * We want to fill as much as possible. No more than a page
+         * may be empty.
          */
+        while ((PAGE_SIZE << order) / ENTRY_SIZE >= count + ENTRIES_PER_PAGE)
+                order--;
 
-        pg = ftrace_pages = ftrace_pages_start;
+ again:
+        pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
 
-        cnt = num_to_init / ENTRIES_PER_PAGE;
-        pr_info("ftrace: allocating %ld entries in %d pages\n",
-                num_to_init, cnt + 1);
+        if (!pg->records) {
+                /* if we can't allocate this size, try something smaller */
+                if (!order)
+                        return -ENOMEM;
+                order >>= 1;
+                goto again;
+        }
 
-        for (i = 0; i < cnt; i++) {
-                pg->next = (void *)get_zeroed_page(GFP_KERNEL);
+        cnt = (PAGE_SIZE << order) / ENTRY_SIZE;
+        pg->size = cnt;
 
-                /* If we fail, we'll try later anyway */
-                if (!pg->next)
+        if (cnt > count)
+                cnt = count;
+
+        return cnt;
+}
+
+static struct ftrace_page *
+ftrace_allocate_pages(unsigned long num_to_init)
+{
+        struct ftrace_page *start_pg;
+        struct ftrace_page *pg;
+        int order;
+        int cnt;
+
+        if (!num_to_init)
+                return 0;
+
+        start_pg = pg = kzalloc(sizeof(*pg), GFP_KERNEL);
+        if (!pg)
+                return NULL;
+
+        /*
+         * Try to allocate as much as possible in one continues
+         * location that fills in all of the space. We want to
+         * waste as little space as possible.
+         */
+        for (;;) {
+                cnt = ftrace_allocate_records(pg, num_to_init);
+                if (cnt < 0)
+                        goto free_pages;
+
+                num_to_init -= cnt;
+                if (!num_to_init)
                         break;
 
+                pg->next = kzalloc(sizeof(*pg), GFP_KERNEL);
+                if (!pg->next)
+                        goto free_pages;
+
                 pg = pg->next;
         }
 
-        return 0;
+        return start_pg;
+
+ free_pages:
+        while (start_pg) {
+                order = get_count_order(pg->size / ENTRIES_PER_PAGE);
+                free_pages((unsigned long)pg->records, order);
+                start_pg = pg->next;
+                kfree(pg);
+                pg = start_pg;
+        }
+        pr_info("ftrace: FAILED to allocate memory for functions\n");
+        return NULL;
 }
 
-enum {
-        FTRACE_ITER_FILTER      = (1 << 0),
-        FTRACE_ITER_NOTRACE     = (1 << 1),
-        FTRACE_ITER_PRINTALL    = (1 << 2),
-        FTRACE_ITER_HASH        = (1 << 3),
-        FTRACE_ITER_ENABLED     = (1 << 4),
-};
+static int __init ftrace_dyn_table_alloc(unsigned long num_to_init)
+{
+        int cnt;
+
+        if (!num_to_init) {
+                pr_info("ftrace: No functions to be traced?\n");
+                return -1;
+        }
+
+        cnt = num_to_init / ENTRIES_PER_PAGE;
+        pr_info("ftrace: allocating %ld entries in %d pages\n",
+                num_to_init, cnt + 1);
+
+        return 0;
+}
 
 #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
 
@@ -1980,6 +2198,9 @@ static void *t_hash_start(struct seq_file *m, loff_t *pos)
         void *p = NULL;
         loff_t l;
 
+        if (!(iter->flags & FTRACE_ITER_DO_HASH))
+                return NULL;
+
         if (iter->func_pos > *pos)
                 return NULL;
 
@@ -2023,7 +2244,7 @@ static void *
 t_next(struct seq_file *m, void *v, loff_t *pos)
 {
         struct ftrace_iterator *iter = m->private;
-        struct ftrace_ops *ops = &global_ops;
+        struct ftrace_ops *ops = iter->ops;
         struct dyn_ftrace *rec = NULL;
 
         if (unlikely(ftrace_disabled))
@@ -2047,9 +2268,7 @@ t_next(struct seq_file *m, void *v, loff_t *pos)
                 }
         } else {
                 rec = &iter->pg->records[iter->idx++];
-                if ((rec->flags & FTRACE_FL_FREE) ||
-
-                    ((iter->flags & FTRACE_ITER_FILTER) &&
+                if (((iter->flags & FTRACE_ITER_FILTER) &&
                      !(ftrace_lookup_ip(ops->filter_hash, rec->ip))) ||
 
                     ((iter->flags & FTRACE_ITER_NOTRACE) &&
@@ -2081,7 +2300,7 @@ static void reset_iter_read(struct ftrace_iterator *iter)
 static void *t_start(struct seq_file *m, loff_t *pos)
 {
         struct ftrace_iterator *iter = m->private;
-        struct ftrace_ops *ops = &global_ops;
+        struct ftrace_ops *ops = iter->ops;
         void *p = NULL;
         loff_t l;
 
@@ -2101,7 +2320,8 @@ static void *t_start(struct seq_file *m, loff_t *pos)
          * off, we can short cut and just print out that all
          * functions are enabled.
          */
-        if (iter->flags & FTRACE_ITER_FILTER && !ops->filter_hash->count) {
+        if (iter->flags & FTRACE_ITER_FILTER &&
+            ftrace_hash_empty(ops->filter_hash)) {
                 if (*pos > 0)
                         return t_hash_start(m, pos);
                 iter->flags |= FTRACE_ITER_PRINTALL;
@@ -2126,12 +2346,8 @@ static void *t_start(struct seq_file *m, loff_t *pos)
                         break;
         }
 
-        if (!p) {
-                if (iter->flags & FTRACE_ITER_FILTER)
-                        return t_hash_start(m, pos);
-
-                return NULL;
-        }
+        if (!p)
+                return t_hash_start(m, pos);
 
         return iter;
 }
@@ -2189,6 +2405,7 @@ ftrace_avail_open(struct inode *inode, struct file *file)
                 return -ENOMEM;
 
         iter->pg = ftrace_pages_start;
+        iter->ops = &global_ops;
 
         ret = seq_open(file, &show_ftrace_seq_ops);
         if (!ret) {
@@ -2217,6 +2434,7 @@ ftrace_enabled_open(struct inode *inode, struct file *file)
 
         iter->pg = ftrace_pages_start;
         iter->flags = FTRACE_ITER_ENABLED;
+        iter->ops = &global_ops;
 
         ret = seq_open(file, &show_ftrace_seq_ops);
         if (!ret) {
@@ -2237,7 +2455,23 @@ static void ftrace_filter_reset(struct ftrace_hash *hash)
         mutex_unlock(&ftrace_lock);
 }
 
-static int
+/**
+ * ftrace_regex_open - initialize function tracer filter files
+ * @ops: The ftrace_ops that hold the hash filters
+ * @flag: The type of filter to process
+ * @inode: The inode, usually passed in to your open routine
+ * @file: The file, usually passed in to your open routine
+ *
+ * ftrace_regex_open() initializes the filter files for the
+ * @ops. Depending on @flag it may process the filter hash or
+ * the notrace hash of @ops. With this called from the open
+ * routine, you can use ftrace_filter_write() for the write
+ * routine if @flag has FTRACE_ITER_FILTER set, or
+ * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set.
+ * ftrace_regex_lseek() should be used as the lseek routine, and
+ * release must call ftrace_regex_release().
+ */
+int
 ftrace_regex_open(struct ftrace_ops *ops, int flag,
                   struct inode *inode, struct file *file)
 {
@@ -2306,8 +2540,9 @@ ftrace_regex_open(struct ftrace_ops *ops, int flag,
 static int
 ftrace_filter_open(struct inode *inode, struct file *file)
 {
-        return ftrace_regex_open(&global_ops, FTRACE_ITER_FILTER,
-                                 inode, file);
+        return ftrace_regex_open(&global_ops,
+                        FTRACE_ITER_FILTER | FTRACE_ITER_DO_HASH,
+                        inode, file);
 }
 
 static int
@@ -2317,7 +2552,7 @@ ftrace_notrace_open(struct inode *inode, struct file *file)
                                  inode, file);
 }
 
-static loff_t
+loff_t
 ftrace_regex_lseek(struct file *file, loff_t offset, int origin)
 {
         loff_t ret;
@@ -2426,7 +2661,6 @@ match_records(struct ftrace_hash *hash, char *buff,
                 goto out_unlock;
 
         do_for_each_ftrace_rec(pg, rec) {
-
                 if (ftrace_match_record(rec, mod, search, search_len, type)) {
                         ret = enter_record(hash, rec, not);
                         if (ret < 0) {
@@ -2871,14 +3105,14 @@ out_unlock:
         return ret;
 }
 
-static ssize_t
+ssize_t
 ftrace_filter_write(struct file *file, const char __user *ubuf,
                     size_t cnt, loff_t *ppos)
 {
         return ftrace_regex_write(file, ubuf, cnt, ppos, 1);
 }
 
-static ssize_t
+ssize_t
 ftrace_notrace_write(struct file *file, const char __user *ubuf,
                      size_t cnt, loff_t *ppos)
 {
@@ -2919,7 +3153,7 @@ ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
         ret = ftrace_hash_move(ops, enable, orig_hash, hash);
         if (!ret && ops->flags & FTRACE_OPS_FL_ENABLED
             && ftrace_enabled)
-                ftrace_run_update_code(FTRACE_ENABLE_CALLS);
+                ftrace_run_update_code(FTRACE_UPDATE_CALLS);
 
         mutex_unlock(&ftrace_lock);
 
@@ -3045,8 +3279,8 @@ static void __init set_ftrace_early_graph(char *buf)
 }
 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
 
-static void __init
-set_ftrace_early_filter(struct ftrace_ops *ops, char *buf, int enable)
+void __init
+ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable)
 {
         char *func;
 
@@ -3059,17 +3293,16 @@ set_ftrace_early_filter(struct ftrace_ops *ops, char *buf, int enable)
 static void __init set_ftrace_early_filters(void)
 {
         if (ftrace_filter_buf[0])
-                set_ftrace_early_filter(&global_ops, ftrace_filter_buf, 1);
+                ftrace_set_early_filter(&global_ops, ftrace_filter_buf, 1);
         if (ftrace_notrace_buf[0])
-                set_ftrace_early_filter(&global_ops, ftrace_notrace_buf, 0);
+                ftrace_set_early_filter(&global_ops, ftrace_notrace_buf, 0);
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
         if (ftrace_graph_buf[0])
                 set_ftrace_early_graph(ftrace_graph_buf);
 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
 }
 
-static int
-ftrace_regex_release(struct inode *inode, struct file *file)
+int ftrace_regex_release(struct inode *inode, struct file *file)
 {
         struct seq_file *m = (struct seq_file *)file->private_data;
         struct ftrace_iterator *iter;
@@ -3107,7 +3340,7 @@ ftrace_regex_release(struct inode *inode, struct file *file)
                                        orig_hash, iter->hash);
                 if (!ret && (iter->ops->flags & FTRACE_OPS_FL_ENABLED)
                     && ftrace_enabled)
-                        ftrace_run_update_code(FTRACE_ENABLE_CALLS);
+                        ftrace_run_update_code(FTRACE_UPDATE_CALLS);
 
                 mutex_unlock(&ftrace_lock);
         }
@@ -3270,9 +3503,6 @@ ftrace_set_func(unsigned long *array, int *idx, char *buffer)
 
         do_for_each_ftrace_rec(pg, rec) {
 
-                if (rec->flags & FTRACE_FL_FREE)
-                        continue;
-
                 if (ftrace_match_record(rec, NULL, search, search_len, type)) {
                         /* if it is in the array */
                         exists = false;
@@ -3381,15 +3611,62 @@ static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer)
         return 0;
 }
 
+static void ftrace_swap_recs(void *a, void *b, int size)
+{
+        struct dyn_ftrace *reca = a;
+        struct dyn_ftrace *recb = b;
+        struct dyn_ftrace t;
+
+        t = *reca;
+        *reca = *recb;
+        *recb = t;
+}
+
 static int ftrace_process_locs(struct module *mod,
                                unsigned long *start,
                                unsigned long *end)
 {
+        struct ftrace_page *pg;
+        unsigned long count;
         unsigned long *p;
         unsigned long addr;
         unsigned long flags = 0; /* Shut up gcc */
+        int ret = -ENOMEM;
+
+        count = end - start;
+
+        if (!count)
+                return 0;
+
+        pg = ftrace_allocate_pages(count);
+        if (!pg)
+                return -ENOMEM;
 
         mutex_lock(&ftrace_lock);
+
+        /*
+         * Core and each module needs their own pages, as
+         * modules will free them when they are removed.
+         * Force a new page to be allocated for modules.
+         */
+        if (!mod) {
+                WARN_ON(ftrace_pages || ftrace_pages_start);
+                /* First initialization */
+                ftrace_pages = ftrace_pages_start = pg;
+        } else {
+                if (!ftrace_pages)
+                        goto out;
+
+                if (WARN_ON(ftrace_pages->next)) {
+                        /* Hmm, we have free pages? */
+                        while (ftrace_pages->next)
+                                ftrace_pages = ftrace_pages->next;
+                }
+
+                ftrace_pages->next = pg;
+                ftrace_pages = pg;
+        }
+
         p = start;
         while (p < end) {
                 addr = ftrace_call_adjust(*p++);
@@ -3401,9 +3678,18 @@ static int ftrace_process_locs(struct module *mod,
                  */
                 if (!addr)
                         continue;
-                ftrace_record_ip(addr);
+                if (!ftrace_record_ip(addr))
+                        break;
         }
 
+        /* These new locations need to be initialized */
+        ftrace_new_pgs = pg;
+
+        /* Make each individual set of pages sorted by ips */
+        for (; pg; pg = pg->next)
+                sort(pg->records, pg->index, sizeof(struct dyn_ftrace),
+                     ftrace_cmp_recs, ftrace_swap_recs);
+
         /*
          * We only need to disable interrupts on start up
          * because we are modifying code that an interrupt
@@ -3417,32 +3703,55 @@ static int ftrace_process_locs(struct module *mod,
         ftrace_update_code(mod);
         if (!mod)
                 local_irq_restore(flags);
+        ret = 0;
+ out:
         mutex_unlock(&ftrace_lock);
 
-        return 0;
+        return ret;
 }
 
 #ifdef CONFIG_MODULES
+
+#define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next)
+
 void ftrace_release_mod(struct module *mod)
 {
         struct dyn_ftrace *rec;
+        struct ftrace_page **last_pg;
         struct ftrace_page *pg;
+        int order;
 
         mutex_lock(&ftrace_lock);
 
         if (ftrace_disabled)
                 goto out_unlock;
 
-        do_for_each_ftrace_rec(pg, rec) {
+        /*
+         * Each module has its own ftrace_pages, remove
+         * them from the list.
+         */
+        last_pg = &ftrace_pages_start;
+        for (pg = ftrace_pages_start; pg; pg = *last_pg) {
+                rec = &pg->records[0];
                 if (within_module_core(rec->ip, mod)) {
                         /*
-                         * rec->ip is changed in ftrace_free_rec()
-                         * It should not between s and e if record was freed.
+                         * As core pages are first, the first
+                         * page should never be a module page.
                          */
-                        FTRACE_WARN_ON(rec->flags & FTRACE_FL_FREE);
-                        ftrace_free_rec(rec);
-                }
-        } while_for_each_ftrace_rec();
+                        if (WARN_ON(pg == ftrace_pages_start))
+                                goto out_unlock;
+
+                        /* Check if we are deleting the last page */
+                        if (pg == ftrace_pages)
+                                ftrace_pages = next_to_ftrace_page(last_pg);
+
+                        *last_pg = pg->next;
+                        order = get_count_order(pg->size / ENTRIES_PER_PAGE);
+                        free_pages((unsigned long)pg->records, order);
+                        kfree(pg);
+                } else
+                        last_pg = &pg->next;
+        }
  out_unlock:
         mutex_unlock(&ftrace_lock);
 }
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index f04cc3136bd3..24aee7127451 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -1738,11 +1738,121 @@ static int replace_system_preds(struct event_subsystem *system,
         return -ENOMEM;
 }
 
+static int create_filter_start(char *filter_str, bool set_str,
+                               struct filter_parse_state **psp,
+                               struct event_filter **filterp)
+{
+        struct event_filter *filter;
+        struct filter_parse_state *ps = NULL;
+        int err = 0;
+
+        WARN_ON_ONCE(*psp || *filterp);
+
+        /* allocate everything, and if any fails, free all and fail */
+        filter = __alloc_filter();
+        if (filter && set_str)
+                err = replace_filter_string(filter, filter_str);
+
+        ps = kzalloc(sizeof(*ps), GFP_KERNEL);
+
+        if (!filter || !ps || err) {
+                kfree(ps);
+                __free_filter(filter);
+                return -ENOMEM;
+        }
+
+        /* we're committed to creating a new filter */
+        *filterp = filter;
+        *psp = ps;
+
+        parse_init(ps, filter_ops, filter_str);
+        err = filter_parse(ps);
+        if (err && set_str)
+                append_filter_err(ps, filter);
+        return err;
+}
+
+static void create_filter_finish(struct filter_parse_state *ps)
+{
+        if (ps) {
+                filter_opstack_clear(ps);
+                postfix_clear(ps);
+                kfree(ps);
+        }
+}
+
+/**
+ * create_filter - create a filter for a ftrace_event_call
+ * @call: ftrace_event_call to create a filter for
+ * @filter_str: filter string
+ * @set_str: remember @filter_str and enable detailed error in filter
+ * @filterp: out param for created filter (always updated on return)
+ *
+ * Creates a filter for @call with @filter_str.  If @set_str is %true,
+ * @filter_str is copied and recorded in the new filter.
+ *
+ * On success, returns 0 and *@filterp points to the new filter.  On
+ * failure, returns -errno and *@filterp may point to %NULL or to a new
+ * filter.  In the latter case, the returned filter contains error
+ * information if @set_str is %true and the caller is responsible for
+ * freeing it.
+ */
+static int create_filter(struct ftrace_event_call *call,
+                         char *filter_str, bool set_str,
+                         struct event_filter **filterp)
+{
+        struct event_filter *filter = NULL;
+        struct filter_parse_state *ps = NULL;
+        int err;
+
+        err = create_filter_start(filter_str, set_str, &ps, &filter);
+        if (!err) {
+                err = replace_preds(call, filter, ps, filter_str, false);
+                if (err && set_str)
+                        append_filter_err(ps, filter);
+        }
+        create_filter_finish(ps);
+
+        *filterp = filter;
+        return err;
+}
+
+/**
+ * create_system_filter - create a filter for an event_subsystem
+ * @system: event_subsystem to create a filter for
+ * @filter_str: filter string
+ * @filterp: out param for created filter (always updated on return)
+ *
+ * Identical to create_filter() except that it creates a subsystem filter
+ * and always remembers @filter_str.
+ */
+static int create_system_filter(struct event_subsystem *system,
+                                char *filter_str, struct event_filter **filterp)
+{
+        struct event_filter *filter = NULL;
+        struct filter_parse_state *ps = NULL;
+        int err;
+
+        err = create_filter_start(filter_str, true, &ps, &filter);
+        if (!err) {
+                err = replace_system_preds(system, ps, filter_str);
+                if (!err) {
+                        /* System filters just show a default message */
+                        kfree(filter->filter_string);
+                        filter->filter_string = NULL;
+                } else {
+                        append_filter_err(ps, filter);
+                }
+        }
+        create_filter_finish(ps);
+
+        *filterp = filter;
+        return err;
+}
+
 int apply_event_filter(struct ftrace_event_call *call, char *filter_string)
 {
-        struct filter_parse_state *ps;
         struct event_filter *filter;
-        struct event_filter *tmp;
         int err = 0;
 
         mutex_lock(&event_mutex);
@@ -1759,49 +1869,30 @@ int apply_event_filter(struct ftrace_event_call *call, char *filter_string)
                 goto out_unlock;
         }
 
-        err = -ENOMEM;
-        ps = kzalloc(sizeof(*ps), GFP_KERNEL);
-        if (!ps)
-                goto out_unlock;
-
-        filter = __alloc_filter();
-        if (!filter) {
-                kfree(ps);
-                goto out_unlock;
-        }
-
-        replace_filter_string(filter, filter_string);
-
-        parse_init(ps, filter_ops, filter_string);
-        err = filter_parse(ps);
-        if (err) {
-                append_filter_err(ps, filter);
-                goto out;
-        }
+        err = create_filter(call, filter_string, true, &filter);
 
-        err = replace_preds(call, filter, ps, filter_string, false);
-        if (err) {
-                filter_disable(call);
-                append_filter_err(ps, filter);
-        } else
-                call->flags |= TRACE_EVENT_FL_FILTERED;
-out:
         /*
          * Always swap the call filter with the new filter
          * even if there was an error. If there was an error
          * in the filter, we disable the filter and show the error
          * string
          */
-        tmp = call->filter;
-        rcu_assign_pointer(call->filter, filter);
-        if (tmp) {
-                /* Make sure the call is done with the filter */
-                synchronize_sched();
-                __free_filter(tmp);
+        if (filter) {
+                struct event_filter *tmp = call->filter;
+
+                if (!err)
+                        call->flags |= TRACE_EVENT_FL_FILTERED;
+                else
+                        filter_disable(call);
+
+                rcu_assign_pointer(call->filter, filter);
+
+                if (tmp) {
+                        /* Make sure the call is done with the filter */
+                        synchronize_sched();
+                        __free_filter(tmp);
+                }
         }
-        filter_opstack_clear(ps);
-        postfix_clear(ps);
-        kfree(ps);
 out_unlock:
         mutex_unlock(&event_mutex);
 
@@ -1811,7 +1902,6 @@ out_unlock:
 int apply_subsystem_event_filter(struct event_subsystem *system,
                                  char *filter_string)
 {
-        struct filter_parse_state *ps;
         struct event_filter *filter;
         int err = 0;
 
@@ -1835,48 +1925,19 @@ int apply_subsystem_event_filter(struct event_subsystem *system,
                 goto out_unlock;
         }
 
-        err = -ENOMEM;
-        ps = kzalloc(sizeof(*ps), GFP_KERNEL);
-        if (!ps)
-                goto out_unlock;
-
-        filter = __alloc_filter();
-        if (!filter)
-                goto out;
-
-        /* System filters just show a default message */
-        kfree(filter->filter_string);
-        filter->filter_string = NULL;
-
-        /*
-         * No event actually uses the system filter
-         * we can free it without synchronize_sched().
-         */
-        __free_filter(system->filter);
-        system->filter = filter;
-
-        parse_init(ps, filter_ops, filter_string);
-        err = filter_parse(ps);
-        if (err)
-                goto err_filter;
-
-        err = replace_system_preds(system, ps, filter_string);
-        if (err)
-                goto err_filter;
-
-out:
-        filter_opstack_clear(ps);
-        postfix_clear(ps);
-        kfree(ps);
+        err = create_system_filter(system, filter_string, &filter);
+        if (filter) {
+                /*
+                 * No event actually uses the system filter
+                 * we can free it without synchronize_sched().
+                 */
+                __free_filter(system->filter);
+                system->filter = filter;
+        }
 out_unlock:
         mutex_unlock(&event_mutex);
 
         return err;
-
-err_filter:
-        replace_filter_string(filter, filter_string);
-        append_filter_err(ps, system->filter);
-        goto out;
 }
 
 #ifdef CONFIG_PERF_EVENTS
@@ -1894,7 +1955,6 @@ int ftrace_profile_set_filter(struct perf_event *event, int event_id,
 {
         int err;
         struct event_filter *filter;
-        struct filter_parse_state *ps;
         struct ftrace_event_call *call;
 
         mutex_lock(&event_mutex);
@@ -1909,33 +1969,10 @@ int ftrace_profile_set_filter(struct perf_event *event, int event_id,
         if (event->filter)
                 goto out_unlock;
 
-        filter = __alloc_filter();
-        if (!filter) {
-                err = PTR_ERR(filter);
-                goto out_unlock;
-        }
-
-        err = -ENOMEM;
-        ps = kzalloc(sizeof(*ps), GFP_KERNEL);
-        if (!ps)
-                goto free_filter;
-
-        parse_init(ps, filter_ops, filter_str);
-        err = filter_parse(ps);
-        if (err)
-                goto free_ps;
-
-        err = replace_preds(call, filter, ps, filter_str, false);
+        err = create_filter(call, filter_str, false, &filter);
         if (!err)
                 event->filter = filter;
-
-free_ps:
-        filter_opstack_clear(ps);
-        postfix_clear(ps);
-        kfree(ps);
-
-free_filter:
-        if (err)
+        else
                 __free_filter(filter);
 
 out_unlock:
@@ -1954,43 +1991,6 @@ out_unlock:
 #define CREATE_TRACE_POINTS
 #include "trace_events_filter_test.h"
 
-static int test_get_filter(char *filter_str, struct ftrace_event_call *call,
-                           struct event_filter **pfilter)
-{
-        struct event_filter *filter;
-        struct filter_parse_state *ps;
-        int err = -ENOMEM;
-
-        filter = __alloc_filter();
-        if (!filter)
-                goto out;
-
-        ps = kzalloc(sizeof(*ps), GFP_KERNEL);
-        if (!ps)
-                goto free_filter;
-
-        parse_init(ps, filter_ops, filter_str);
-        err = filter_parse(ps);
-        if (err)
-                goto free_ps;
-
-        err = replace_preds(call, filter, ps, filter_str, false);
-        if (!err)
-                *pfilter = filter;
-
- free_ps:
-        filter_opstack_clear(ps);
-        postfix_clear(ps);
-        kfree(ps);
-
- free_filter:
-        if (err)
-                __free_filter(filter);
-
- out:
-        return err;
-}
-
 #define DATA_REC(m, va, vb, vc, vd, ve, vf, vg, vh, nvisit) \
 { \
         .filter = FILTER, \
@@ -2109,12 +2109,13 @@ static __init int ftrace_test_event_filter(void)
                 struct test_filter_data_t *d = &test_filter_data[i];
                 int err;
 
-                err = test_get_filter(d->filter, &event_ftrace_test_filter,
-                                      &filter);
+                err = create_filter(&event_ftrace_test_filter, d->filter,
+                                    false, &filter);
                 if (err) {
                         printk(KERN_INFO
                                "Failed to get filter for '%s', err %d\n",
                                d->filter, err);
+                        __free_filter(filter);
                         break;
                 }
 
diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
index 77575b386d97..d4545f49242e 100644
--- a/kernel/trace/trace_stack.c
+++ b/kernel/trace/trace_stack.c
@@ -13,6 +13,9 @@
 #include <linux/sysctl.h>
 #include <linux/init.h>
 #include <linux/fs.h>
+
+#include <asm/setup.h>
+
 #include "trace.h"
 
 #define STACK_TRACE_ENTRIES 500
@@ -133,7 +136,6 @@ stack_trace_call(unsigned long ip, unsigned long parent_ip)
 static struct ftrace_ops trace_ops __read_mostly =
 {
         .func = stack_trace_call,
-        .flags = FTRACE_OPS_FL_GLOBAL,
 };
 
 static ssize_t
@@ -311,6 +313,21 @@ static const struct file_operations stack_trace_fops = {
         .release        = seq_release,
 };
 
+static int
+stack_trace_filter_open(struct inode *inode, struct file *file)
+{
+        return ftrace_regex_open(&trace_ops, FTRACE_ITER_FILTER,
+                                 inode, file);
+}
+
+static const struct file_operations stack_trace_filter_fops = {
+        .open = stack_trace_filter_open,
+        .read = seq_read,
+        .write = ftrace_filter_write,
+        .llseek = ftrace_regex_lseek,
+        .release = ftrace_regex_release,
+};
+
 int
 stack_trace_sysctl(struct ctl_table *table, int write,
                    void __user *buffer, size_t *lenp,
@@ -338,8 +355,13 @@ stack_trace_sysctl(struct ctl_table *table, int write,
         return ret;
 }
 
+static char stack_trace_filter_buf[COMMAND_LINE_SIZE+1] __initdata;
+
 static __init int enable_stacktrace(char *str)
 {
+        if (strncmp(str, "_filter=", 8) == 0)
+                strncpy(stack_trace_filter_buf, str+8, COMMAND_LINE_SIZE);
+
         stack_tracer_enabled = 1;
         last_stack_tracer_enabled = 1;
         return 1;
@@ -358,6 +380,12 @@ static __init int stack_trace_init(void)
         trace_create_file("stack_trace", 0444, d_tracer,
                         NULL, &stack_trace_fops);
 
+        trace_create_file("stack_trace_filter", 0444, d_tracer,
+                        NULL, &stack_trace_filter_fops);
+
+        if (stack_trace_filter_buf[0])
+                ftrace_set_early_filter(&trace_ops, stack_trace_filter_buf, 1);
+
         if (stack_tracer_enabled)
                 register_ftrace_function(&trace_ops);