* Based on code in the latency_tracer, that is:
*
* Copyright (C) 2004-2006 Ingo Molnar
- * Copyright (C) 2004 William Lee Irwin III
+ * Copyright (C) 2004 Nadia Yvette Chambers
*/
#include <linux/stop_machine.h>
#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>
#include <trace/events/sched.h>
-#include <asm/ftrace.h>
#include <asm/setup.h>
#include "trace_output.h"
#define FTRACE_HASH_DEFAULT_BITS 10
#define FTRACE_HASH_MAX_BITS 12
+#define FL_GLOBAL_CONTROL_MASK (FTRACE_OPS_FL_GLOBAL | FTRACE_OPS_FL_CONTROL)
+
+static struct ftrace_ops ftrace_list_end __read_mostly = {
+ .func = ftrace_stub,
+ .flags = FTRACE_OPS_FL_RECURSION_SAFE,
+};
+
/* ftrace_enabled is a method to turn ftrace on or off */
int ftrace_enabled __read_mostly;
static int last_ftrace_enabled;
/* Quick disabling of function tracer. */
-int function_trace_stop;
+int function_trace_stop __read_mostly;
+
+/* Current function tracing op */
+struct ftrace_ops *function_trace_op __read_mostly = &ftrace_list_end;
/* List for set_ftrace_pid's pids. */
LIST_HEAD(ftrace_pids);
static DEFINE_MUTEX(ftrace_lock);
-static struct ftrace_ops ftrace_list_end __read_mostly =
-{
- .func = ftrace_stub,
-};
-
static struct ftrace_ops *ftrace_global_list __read_mostly = &ftrace_list_end;
+static struct ftrace_ops *ftrace_control_list __read_mostly = &ftrace_list_end;
static struct ftrace_ops *ftrace_ops_list __read_mostly = &ftrace_list_end;
ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub;
-ftrace_func_t __ftrace_trace_function __read_mostly = ftrace_stub;
ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub;
static struct ftrace_ops global_ops;
+static struct ftrace_ops control_ops;
-static void
-ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip);
+#if ARCH_SUPPORTS_FTRACE_OPS
+static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
+ struct ftrace_ops *op, struct pt_regs *regs);
+#else
+/* See comment below, where ftrace_ops_list_func is defined */
+static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip);
+#define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops)
+#endif
/*
* Traverse the ftrace_global_list, invoking all entries. The reason that we
*
* Silly Alpha and silly pointer-speculation compiler optimizations!
*/
-static void ftrace_global_list_func(unsigned long ip,
- unsigned long parent_ip)
+#define do_for_each_ftrace_op(op, list) \
+ op = rcu_dereference_raw(list); \
+ do
+
+/*
+ * Optimized for just a single item in the list (as that is the normal case).
+ */
+#define while_for_each_ftrace_op(op) \
+ while (likely(op = rcu_dereference_raw((op)->next)) && \
+ unlikely((op) != &ftrace_list_end))
+
+/**
+ * ftrace_nr_registered_ops - return number of ops registered
+ *
+ * Returns the number of ftrace_ops registered and tracing functions
+ */
+int ftrace_nr_registered_ops(void)
{
- struct ftrace_ops *op = rcu_dereference_raw(ftrace_global_list); /*see above*/
+ struct ftrace_ops *ops;
+ int cnt = 0;
+
+ mutex_lock(&ftrace_lock);
- while (op != &ftrace_list_end) {
- op->func(ip, parent_ip);
- op = rcu_dereference_raw(op->next); /*see above*/
- };
+ for (ops = ftrace_ops_list;
+ ops != &ftrace_list_end; ops = ops->next)
+ cnt++;
+
+ mutex_unlock(&ftrace_lock);
+
+ return cnt;
}
-static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip)
+static void
+ftrace_global_list_func(unsigned long ip, unsigned long parent_ip,
+ struct ftrace_ops *op, struct pt_regs *regs)
+{
+ int bit;
+
+ bit = trace_test_and_set_recursion(TRACE_GLOBAL_START, TRACE_GLOBAL_MAX);
+ if (bit < 0)
+ return;
+
+ do_for_each_ftrace_op(op, ftrace_global_list) {
+ op->func(ip, parent_ip, op, regs);
+ } while_for_each_ftrace_op(op);
+
+ trace_clear_recursion(bit);
+}
+
+static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip,
+ struct ftrace_ops *op, struct pt_regs *regs)
{
if (!test_tsk_trace_trace(current))
return;
- ftrace_pid_function(ip, parent_ip);
+ ftrace_pid_function(ip, parent_ip, op, regs);
}
static void set_ftrace_pid_function(ftrace_func_t func)
void clear_ftrace_function(void)
{
ftrace_trace_function = ftrace_stub;
- __ftrace_trace_function = ftrace_stub;
ftrace_pid_function = ftrace_stub;
}
-#ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
-/*
- * For those archs that do not test ftrace_trace_stop in their
- * mcount call site, we need to do it from C.
- */
-static void ftrace_test_stop_func(unsigned long ip, unsigned long parent_ip)
+static void control_ops_disable_all(struct ftrace_ops *ops)
{
- if (function_trace_stop)
- return;
+ int cpu;
- __ftrace_trace_function(ip, parent_ip);
+ for_each_possible_cpu(cpu)
+ *per_cpu_ptr(ops->disabled, cpu) = 1;
+}
+
+static int control_ops_alloc(struct ftrace_ops *ops)
+{
+ int __percpu *disabled;
+
+ disabled = alloc_percpu(int);
+ if (!disabled)
+ return -ENOMEM;
+
+ ops->disabled = disabled;
+ control_ops_disable_all(ops);
+ return 0;
+}
+
+static void control_ops_free(struct ftrace_ops *ops)
+{
+ free_percpu(ops->disabled);
}
-#endif
static void update_global_ops(void)
{
* registered callers.
*/
if (ftrace_global_list == &ftrace_list_end ||
- ftrace_global_list->next == &ftrace_list_end)
+ ftrace_global_list->next == &ftrace_list_end) {
func = ftrace_global_list->func;
- else
+ /*
+ * As we are calling the function directly.
+ * If it does not have recursion protection,
+ * the function_trace_op needs to be updated
+ * accordingly.
+ */
+ if (ftrace_global_list->flags & FTRACE_OPS_FL_RECURSION_SAFE)
+ global_ops.flags |= FTRACE_OPS_FL_RECURSION_SAFE;
+ else
+ global_ops.flags &= ~FTRACE_OPS_FL_RECURSION_SAFE;
+ } else {
func = ftrace_global_list_func;
+ /* The list has its own recursion protection. */
+ global_ops.flags |= FTRACE_OPS_FL_RECURSION_SAFE;
+ }
+
/* If we filter on pids, update to use the pid function */
if (!list_empty(&ftrace_pids)) {
/*
* If we are at the end of the list and this ops is
- * not dynamic, then have the mcount trampoline call
- * the function directly
+ * recursion safe and not dynamic and the arch supports passing ops,
+ * then have the mcount trampoline call the function directly.
*/
if (ftrace_ops_list == &ftrace_list_end ||
(ftrace_ops_list->next == &ftrace_list_end &&
- !(ftrace_ops_list->flags & FTRACE_OPS_FL_DYNAMIC)))
+ !(ftrace_ops_list->flags & FTRACE_OPS_FL_DYNAMIC) &&
+ (ftrace_ops_list->flags & FTRACE_OPS_FL_RECURSION_SAFE) &&
+ !FTRACE_FORCE_LIST_FUNC)) {
+ /* Set the ftrace_ops that the arch callback uses */
+ if (ftrace_ops_list == &global_ops)
+ function_trace_op = ftrace_global_list;
+ else
+ function_trace_op = ftrace_ops_list;
func = ftrace_ops_list->func;
- else
+ } else {
+ /* Just use the default ftrace_ops */
+ function_trace_op = &ftrace_list_end;
func = ftrace_ops_list_func;
+ }
-#ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
ftrace_trace_function = func;
-#else
- __ftrace_trace_function = func;
- ftrace_trace_function = ftrace_test_stop_func;
-#endif
}
static void add_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops)
return 0;
}
+static void add_ftrace_list_ops(struct ftrace_ops **list,
+ struct ftrace_ops *main_ops,
+ struct ftrace_ops *ops)
+{
+ int first = *list == &ftrace_list_end;
+ add_ftrace_ops(list, ops);
+ if (first)
+ add_ftrace_ops(&ftrace_ops_list, main_ops);
+}
+
+static int remove_ftrace_list_ops(struct ftrace_ops **list,
+ struct ftrace_ops *main_ops,
+ struct ftrace_ops *ops)
+{
+ int ret = remove_ftrace_ops(list, ops);
+ if (!ret && *list == &ftrace_list_end)
+ ret = remove_ftrace_ops(&ftrace_ops_list, main_ops);
+ return ret;
+}
+
static int __register_ftrace_function(struct ftrace_ops *ops)
{
- if (ftrace_disabled)
+ if (unlikely(ftrace_disabled))
return -ENODEV;
if (FTRACE_WARN_ON(ops == &global_ops))
if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED))
return -EBUSY;
+ /* We don't support both control and global flags set. */
+ if ((ops->flags & FL_GLOBAL_CONTROL_MASK) == FL_GLOBAL_CONTROL_MASK)
+ return -EINVAL;
+
+#ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
+ /*
+ * If the ftrace_ops specifies SAVE_REGS, then it only can be used
+ * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set.
+ * Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant.
+ */
+ if (ops->flags & FTRACE_OPS_FL_SAVE_REGS &&
+ !(ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED))
+ return -EINVAL;
+
+ if (ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED)
+ ops->flags |= FTRACE_OPS_FL_SAVE_REGS;
+#endif
+
if (!core_kernel_data((unsigned long)ops))
ops->flags |= FTRACE_OPS_FL_DYNAMIC;
if (ops->flags & FTRACE_OPS_FL_GLOBAL) {
- int first = ftrace_global_list == &ftrace_list_end;
- add_ftrace_ops(&ftrace_global_list, ops);
+ add_ftrace_list_ops(&ftrace_global_list, &global_ops, ops);
ops->flags |= FTRACE_OPS_FL_ENABLED;
- if (first)
- add_ftrace_ops(&ftrace_ops_list, &global_ops);
+ } else if (ops->flags & FTRACE_OPS_FL_CONTROL) {
+ if (control_ops_alloc(ops))
+ return -ENOMEM;
+ add_ftrace_list_ops(&ftrace_control_list, &control_ops, ops);
} else
add_ftrace_ops(&ftrace_ops_list, ops);
return -EINVAL;
if (ops->flags & FTRACE_OPS_FL_GLOBAL) {
- ret = remove_ftrace_ops(&ftrace_global_list, ops);
- if (!ret && ftrace_global_list == &ftrace_list_end)
- ret = remove_ftrace_ops(&ftrace_ops_list, &global_ops);
+ ret = remove_ftrace_list_ops(&ftrace_global_list,
+ &global_ops, ops);
if (!ret)
ops->flags &= ~FTRACE_OPS_FL_ENABLED;
+ } else if (ops->flags & FTRACE_OPS_FL_CONTROL) {
+ ret = remove_ftrace_list_ops(&ftrace_control_list,
+ &control_ops, ops);
+ if (!ret) {
+ /*
+ * The ftrace_ops is now removed from the list,
+ * so there'll be no new users. We must ensure
+ * all current users are done before we free
+ * the control data.
+ */
+ synchronize_sched();
+ control_ops_free(ops);
+ }
} else
ret = remove_ftrace_ops(&ftrace_ops_list, ops);
pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE);
- for (i = 0; i < pages; i++) {
+ for (i = 1; i < pages; i++) {
pg->next = (void *)get_zeroed_page(GFP_KERNEL);
if (!pg->next)
goto out_free;
}
static void
-function_profile_call(unsigned long ip, unsigned long parent_ip)
+function_profile_call(unsigned long ip, unsigned long parent_ip,
+ struct ftrace_ops *ops, struct pt_regs *regs)
{
struct ftrace_profile_stat *stat;
struct ftrace_profile *rec;
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
static int profile_graph_entry(struct ftrace_graph_ent *trace)
{
- function_profile_call(trace->func, 0);
+ function_profile_call(trace->func, 0, NULL, NULL);
return 1;
}
unregister_ftrace_graph();
}
#else
-static struct ftrace_ops ftrace_profile_ops __read_mostly =
-{
+static struct ftrace_ops ftrace_profile_ops __read_mostly = {
.func = function_profile_call,
+ .flags = FTRACE_OPS_FL_RECURSION_SAFE,
};
static int register_ftrace_profiler(void)
size_t cnt, loff_t *ppos)
{
unsigned long val;
- char buf[64]; /* big enough to hold a number */
int ret;
- if (cnt >= sizeof(buf))
- return -EINVAL;
-
- if (copy_from_user(&buf, ubuf, cnt))
- return -EFAULT;
-
- buf[cnt] = 0;
-
- ret = strict_strtoul(buf, 10, &val);
- if (ret < 0)
+ ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
+ if (ret)
return ret;
val = !!val;
unsigned long flags;
unsigned long ip;
void *data;
- struct rcu_head rcu;
+ struct list_head free_list;
};
-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;
.func = ftrace_stub,
.notrace_hash = EMPTY_HASH,
.filter_hash = EMPTY_HASH,
+ .flags = FTRACE_OPS_FL_RECURSION_SAFE,
};
-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
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)
struct hlist_head *hhd;
struct hlist_node *n;
- if (!hash->count)
+ if (ftrace_hash_empty(hash))
return NULL;
if (hash->size_bits > 0)
call_rcu_sched(&hash->rcu, __free_ftrace_hash_rcu);
}
+void ftrace_free_filter(struct ftrace_ops *ops)
+{
+ free_ftrace_hash(ops->filter_hash);
+ free_ftrace_hash(ops->notrace_hash);
+}
+
static struct ftrace_hash *alloc_ftrace_hash(int size_bits)
{
struct ftrace_hash *hash;
return NULL;
size = 1 << size_bits;
- hash->buckets = kzalloc(sizeof(*hash->buckets) * size, GFP_KERNEL);
+ hash->buckets = kcalloc(size, sizeof(*hash->buckets), GFP_KERNEL);
if (!hash->buckets) {
kfree(hash);
return NULL;
/* Empty hash? */
- if (!hash || !hash->count)
+ if (ftrace_hash_empty(hash))
return new_hash;
size = 1 << hash->size_bits;
return NULL;
}
+static void
+ftrace_hash_rec_disable(struct ftrace_ops *ops, int filter_hash);
+static void
+ftrace_hash_rec_enable(struct ftrace_ops *ops, int filter_hash);
+
static int
-ftrace_hash_move(struct ftrace_hash **dst, struct ftrace_hash *src)
+ftrace_hash_move(struct ftrace_ops *ops, int enable,
+ struct ftrace_hash **dst, struct ftrace_hash *src)
{
struct ftrace_func_entry *entry;
struct hlist_node *tp, *tn;
unsigned long key;
int size = src->count;
int bits = 0;
+ int ret;
int i;
+ /*
+ * Remove the current set, update the hash and add
+ * them back.
+ */
+ ftrace_hash_rec_disable(ops, enable);
+
/*
* If the new source is empty, just free dst and assign it
* the empty_hash.
if (!src->count) {
free_ftrace_hash_rcu(*dst);
rcu_assign_pointer(*dst, EMPTY_HASH);
- return 0;
+ /* still need to update the function records */
+ ret = 0;
+ goto out;
}
/*
if (bits > FTRACE_HASH_MAX_BITS)
bits = FTRACE_HASH_MAX_BITS;
+ ret = -ENOMEM;
new_hash = alloc_ftrace_hash(bits);
if (!new_hash)
- return -ENOMEM;
+ goto out;
size = 1 << src->size_bits;
for (i = 0; i < size; i++) {
rcu_assign_pointer(*dst, new_hash);
free_ftrace_hash_rcu(old_hash);
- return 0;
+ ret = 0;
+ out:
+ /*
+ * Enable regardless of ret:
+ * On success, we enable the new hash.
+ * On failure, we re-enable the original hash.
+ */
+ ftrace_hash_rec_enable(ops, enable);
+
+ return ret;
}
/*
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
} \
}
+
+static int ftrace_cmp_recs(const void *a, const void *b)
+{
+ const struct dyn_ftrace *key = a;
+ const struct dyn_ftrace *rec = b;
+
+ if (key->flags < rec->ip)
+ return -1;
+ if (key->ip >= rec->ip + MCOUNT_INSN_SIZE)
+ return 1;
+ return 0;
+}
+
+static unsigned long ftrace_location_range(unsigned long start, unsigned long end)
+{
+ struct ftrace_page *pg;
+ struct dyn_ftrace *rec;
+ struct dyn_ftrace key;
+
+ key.ip = start;
+ key.flags = end; /* overload flags, as it is unsigned long */
+
+ for (pg = ftrace_pages_start; pg; pg = pg->next) {
+ if (end < pg->records[0].ip ||
+ start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE))
+ continue;
+ rec = bsearch(&key, pg->records, pg->index,
+ sizeof(struct dyn_ftrace),
+ ftrace_cmp_recs);
+ if (rec)
+ return rec->ip;
+ }
+
+ return 0;
+}
+
+/**
+ * ftrace_location - return true if the ip giving is a traced location
+ * @ip: the instruction pointer to check
+ *
+ * Returns rec->ip 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.
+ */
+unsigned long ftrace_location(unsigned long ip)
+{
+ return ftrace_location_range(ip, ip);
+}
+
+/**
+ * ftrace_text_reserved - return true if range contains an ftrace location
+ * @start: start of range to search
+ * @end: end of range to search (inclusive). @end points to the last byte to check.
+ *
+ * Returns 1 if @start and @end contains 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_text_reserved(void *start, void *end)
+{
+ unsigned long ret;
+
+ ret = ftrace_location_range((unsigned long)start,
+ (unsigned long)end);
+
+ return (int)!!ret;
+}
+
static void __ftrace_hash_rec_update(struct ftrace_ops *ops,
int filter_hash,
bool inc)
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;
* If the notrace hash has no items,
* then there's nothing to do.
*/
- if (hash && !hash->count)
+ if (ftrace_hash_empty(hash))
return;
}
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);
/*
*
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)
rec->flags++;
if (FTRACE_WARN_ON((rec->flags & ~FTRACE_FL_MASK) == FTRACE_REF_MAX))
return;
+ /*
+ * If any ops wants regs saved for this function
+ * then all ops will get saved regs.
+ */
+ if (ops->flags & FTRACE_OPS_FL_SAVE_REGS)
+ rec->flags |= FTRACE_FL_REGS;
} else {
if (FTRACE_WARN_ON((rec->flags & ~FTRACE_FL_MASK) == 0))
return;
__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;
- 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;
- }
-
- return &ftrace_pages->records[ftrace_pages->index++];
-}
-
-static struct dyn_ftrace *
-ftrace_record_ip(unsigned long ip)
-{
- struct dyn_ftrace *rec;
-
- if (ftrace_disabled)
- return NULL;
-
- rec = ftrace_alloc_dyn_node(ip);
- if (!rec)
- return NULL;
-
- rec->ip = ip;
- rec->newlist = ftrace_new_addrs;
- ftrace_new_addrs = rec;
-
- return rec;
-}
-
static void print_ip_ins(const char *fmt, unsigned char *p)
{
int i;
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:
}
}
-
-/* Return 1 if the address range is reserved for ftrace */
-int ftrace_text_reserved(void *start, void *end)
-{
- struct dyn_ftrace *rec;
- struct ftrace_page *pg;
-
- do_for_each_ftrace_rec(pg, rec) {
- if (rec->ip <= (unsigned long)end &&
- rec->ip + MCOUNT_INSN_SIZE > (unsigned long)start)
- return 1;
- } while_for_each_ftrace_rec();
- 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))
flag = FTRACE_FL_ENABLED;
+ /*
+ * If enabling and the REGS flag does not match the REGS_EN, then
+ * do not ignore this record. Set flags to fail the compare against
+ * ENABLED.
+ */
+ if (flag &&
+ (!(rec->flags & FTRACE_FL_REGS) != !(rec->flags & FTRACE_FL_REGS_EN)))
+ flag |= FTRACE_FL_REGS;
+
/* 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;
+ /* Save off if rec is being enabled (for return value) */
+ flag ^= rec->flags & FTRACE_FL_ENABLED;
+
+ if (update) {
+ rec->flags |= FTRACE_FL_ENABLED;
+ if (flag & FTRACE_FL_REGS) {
+ if (rec->flags & FTRACE_FL_REGS)
+ rec->flags |= FTRACE_FL_REGS_EN;
+ else
+ rec->flags &= ~FTRACE_FL_REGS_EN;
+ }
+ }
+
+ /*
+ * If this record is being updated from a nop, then
+ * return UPDATE_MAKE_CALL.
+ * Otherwise, if the EN flag is set, then return
+ * UPDATE_MODIFY_CALL_REGS to tell the caller to convert
+ * from the non-save regs, to a save regs function.
+ * Otherwise,
+ * return UPDATE_MODIFY_CALL to tell the caller to convert
+ * from the save regs, to a non-save regs function.
+ */
+ if (flag & FTRACE_FL_ENABLED)
+ return FTRACE_UPDATE_MAKE_CALL;
+ else if (rec->flags & FTRACE_FL_REGS_EN)
+ return FTRACE_UPDATE_MODIFY_CALL_REGS;
+ else
+ return FTRACE_UPDATE_MODIFY_CALL;
+ }
+
+ if (update) {
+ /* If there's no more users, clear all flags */
+ if (!(rec->flags & ~FTRACE_FL_MASK))
+ rec->flags = 0;
+ else
+ /* Just disable the record (keep REGS state) */
+ 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_old_addr;
+ unsigned long ftrace_addr;
+ int ret;
+
+ ret = ftrace_update_record(rec, enable);
+
+ if (rec->flags & FTRACE_FL_REGS)
+ ftrace_addr = (unsigned long)FTRACE_REGS_ADDR;
+ else
+ ftrace_addr = (unsigned long)FTRACE_ADDR;
+
+ 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);
+
+ case FTRACE_UPDATE_MODIFY_CALL_REGS:
+ case FTRACE_UPDATE_MODIFY_CALL:
+ if (rec->flags & FTRACE_FL_REGS)
+ ftrace_old_addr = (unsigned long)FTRACE_ADDR;
+ else
+ ftrace_old_addr = (unsigned long)FTRACE_REGS_ADDR;
+
+ return ftrace_modify_call(rec, ftrace_old_addr, 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)
+void __weak ftrace_replace_code(int enable)
{
struct dyn_ftrace *rec;
struct ftrace_page *pg;
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);
if (failed) {
ftrace_bug(failed, rec->ip);
} 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)
{
return 0;
}
-static int __ftrace_modify_code(void *data)
+void ftrace_modify_all_code(int command)
{
- int *command = data;
-
- if (*command & FTRACE_ENABLE_CALLS)
+ if (command & FTRACE_UPDATE_CALLS)
ftrace_replace_code(1);
- else if (*command & FTRACE_DISABLE_CALLS)
+ else if (command & FTRACE_DISABLE_CALLS)
ftrace_replace_code(0);
- if (*command & FTRACE_UPDATE_TRACE_FUNC)
+ if (command & FTRACE_UPDATE_TRACE_FUNC)
ftrace_update_ftrace_func(ftrace_trace_function);
- if (*command & FTRACE_START_FUNC_RET)
+ if (command & FTRACE_START_FUNC_RET)
ftrace_enable_ftrace_graph_caller();
- else if (*command & FTRACE_STOP_FUNC_RET)
+ else if (command & FTRACE_STOP_FUNC_RET)
ftrace_disable_ftrace_graph_caller();
+}
+
+static int __ftrace_modify_code(void *data)
+{
+ int *command = data;
+
+ ftrace_modify_all_code(*command);
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;
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);
+
+ function_trace_stop--;
ret = ftrace_arch_code_modify_post_process();
FTRACE_WARN_ON(ret);
ftrace_run_update_code(command);
}
-static void ftrace_startup(struct ftrace_ops *ops, int command)
+static int ftrace_startup(struct ftrace_ops *ops, int command)
{
bool hash_enable = true;
if (unlikely(ftrace_disabled))
- return;
+ 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) {
ftrace_hash_rec_enable(ops, 1);
ftrace_startup_enable(command);
+
+ return 0;
}
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;
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)
static unsigned long ftrace_update_cnt;
unsigned long ftrace_update_tot_cnt;
+static int ops_traces_mod(struct ftrace_ops *ops)
+{
+ struct ftrace_hash *hash;
+
+ hash = ops->filter_hash;
+ 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
+ * currently enabled and if they are set to trace all functions.
+ * If they are, we need to enable the module functions as well
+ * as update the reference counts for those function records.
+ */
+ if (mod) {
+ struct ftrace_ops *ops;
+
+ for (ops = ftrace_ops_list;
+ ops != &ftrace_list_end; ops = ops->next) {
+ if (ops->flags & FTRACE_OPS_FL_ENABLED &&
+ ops_traces_mod(ops))
+ ref++;
+ }
+ }
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 = 0L;
+ 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) {
- 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;
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--;
+
+ again:
+ pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
- pg = ftrace_pages = ftrace_pages_start;
+ if (!pg->records) {
+ /* if we can't allocate this size, try something smaller */
+ if (!order)
+ return -ENOMEM;
+ order >>= 1;
+ goto again;
+ }
- cnt = num_to_init / ENTRIES_PER_PAGE;
- pr_info("ftrace: allocating %ld entries in %d pages\n",
- num_to_init, cnt + 1);
+ cnt = (PAGE_SIZE << order) / ENTRY_SIZE;
+ pg->size = cnt;
- for (i = 0; i < cnt; i++) {
- pg->next = (void *)get_zeroed_page(GFP_KERNEL);
+ if (cnt > count)
+ cnt = count;
- /* If we fail, we'll try later anyway */
- if (!pg->next)
+ 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 */
void *p = NULL;
loff_t l;
+ if (!(iter->flags & FTRACE_ITER_DO_HASH))
+ return NULL;
+
if (iter->func_pos > *pos)
return NULL;
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))
}
} 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) &&
{
iter->pos = 0;
iter->func_pos = 0;
- iter->flags &= ~(FTRACE_ITER_PRINTALL & FTRACE_ITER_HASH);
+ iter->flags &= ~(FTRACE_ITER_PRINTALL | FTRACE_ITER_HASH);
}
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;
* 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;
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;
}
seq_printf(m, "%ps", (void *)rec->ip);
if (iter->flags & FTRACE_ITER_ENABLED)
- seq_printf(m, " (%ld)",
- rec->flags & ~FTRACE_FL_MASK);
+ seq_printf(m, " (%ld)%s",
+ rec->flags & ~FTRACE_FL_MASK,
+ rec->flags & FTRACE_FL_REGS ? " R" : "");
seq_printf(m, "\n");
return 0;
ftrace_avail_open(struct inode *inode, struct file *file)
{
struct ftrace_iterator *iter;
- int ret;
if (unlikely(ftrace_disabled))
return -ENODEV;
- iter = kzalloc(sizeof(*iter), GFP_KERNEL);
- if (!iter)
- return -ENOMEM;
-
- iter->pg = ftrace_pages_start;
-
- ret = seq_open(file, &show_ftrace_seq_ops);
- if (!ret) {
- struct seq_file *m = file->private_data;
-
- m->private = iter;
- } else {
- kfree(iter);
+ iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
+ if (iter) {
+ iter->pg = ftrace_pages_start;
+ iter->ops = &global_ops;
}
- return ret;
+ return iter ? 0 : -ENOMEM;
}
static int
ftrace_enabled_open(struct inode *inode, struct file *file)
{
struct ftrace_iterator *iter;
- int ret;
if (unlikely(ftrace_disabled))
return -ENODEV;
- iter = kzalloc(sizeof(*iter), GFP_KERNEL);
- if (!iter)
- return -ENOMEM;
-
- iter->pg = ftrace_pages_start;
- iter->flags = FTRACE_ITER_ENABLED;
-
- ret = seq_open(file, &show_ftrace_seq_ops);
- if (!ret) {
- struct seq_file *m = file->private_data;
-
- m->private = iter;
- } else {
- kfree(iter);
+ iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
+ if (iter) {
+ iter->pg = ftrace_pages_start;
+ iter->flags = FTRACE_ITER_ENABLED;
+ iter->ops = &global_ops;
}
- return ret;
+ return iter ? 0 : -ENOMEM;
}
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)
{
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
inode, file);
}
-static loff_t
-ftrace_regex_lseek(struct file *file, loff_t offset, int origin)
+loff_t
+ftrace_regex_lseek(struct file *file, loff_t offset, int whence)
{
loff_t ret;
if (file->f_mode & FMODE_READ)
- ret = seq_lseek(file, offset, origin);
+ ret = seq_lseek(file, offset, whence);
else
file->f_pos = ret = 1;
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) {
*/
static int
-ftrace_mod_callback(char *func, char *cmd, char *param, int enable)
+ftrace_mod_callback(struct ftrace_hash *hash,
+ char *func, char *cmd, char *param, int enable)
{
- struct ftrace_ops *ops = &global_ops;
- struct ftrace_hash *hash;
char *mod;
int ret = -EINVAL;
if (!strlen(mod))
return ret;
- if (enable)
- hash = ops->filter_hash;
- else
- hash = ops->notrace_hash;
-
ret = ftrace_match_module_records(hash, func, mod);
if (!ret)
ret = -EINVAL;
{
return register_ftrace_command(&ftrace_mod_cmd);
}
-device_initcall(ftrace_mod_cmd_init);
+core_initcall(ftrace_mod_cmd_init);
-static void
-function_trace_probe_call(unsigned long ip, unsigned long parent_ip)
+static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip,
+ struct ftrace_ops *op, struct pt_regs *pt_regs)
{
struct ftrace_func_probe *entry;
struct hlist_head *hhd;
ret = __register_ftrace_function(&trace_probe_ops);
if (!ret)
- ftrace_startup(&trace_probe_ops, 0);
+ ret = ftrace_startup(&trace_probe_ops, 0);
ftrace_probe_registered = 1;
}
}
-static void ftrace_free_entry_rcu(struct rcu_head *rhp)
+static void ftrace_free_entry(struct ftrace_func_probe *entry)
{
- struct ftrace_func_probe *entry =
- container_of(rhp, struct ftrace_func_probe, rcu);
-
if (entry->ops->free)
- entry->ops->free(&entry->data);
+ entry->ops->free(entry->ops, entry->ip, &entry->data);
kfree(entry);
}
-
int
register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
void *data)
{
struct ftrace_func_probe *entry;
+ struct ftrace_hash **orig_hash = &trace_probe_ops.filter_hash;
+ struct ftrace_hash *hash;
struct ftrace_page *pg;
struct dyn_ftrace *rec;
int type, len, not;
unsigned long key;
int count = 0;
char *search;
+ int ret;
type = filter_parse_regex(glob, strlen(glob), &search, ¬);
len = strlen(search);
mutex_lock(&ftrace_lock);
- if (unlikely(ftrace_disabled))
+ hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash);
+ if (!hash) {
+ count = -ENOMEM;
goto out_unlock;
+ }
+
+ if (unlikely(ftrace_disabled)) {
+ count = -ENODEV;
+ goto out_unlock;
+ }
do_for_each_ftrace_rec(pg, rec) {
* for each function we find. We call the callback
* to give the caller an opportunity to do so.
*/
- if (ops->callback) {
- if (ops->callback(rec->ip, &entry->data) < 0) {
+ if (ops->init) {
+ if (ops->init(ops, rec->ip, &entry->data) < 0) {
/* caller does not like this func */
kfree(entry);
continue;
}
}
+ ret = enter_record(hash, rec, 0);
+ if (ret < 0) {
+ kfree(entry);
+ count = ret;
+ goto out_unlock;
+ }
+
entry->ops = ops;
entry->ip = rec->ip;
hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]);
} while_for_each_ftrace_rec();
+
+ ret = ftrace_hash_move(&trace_probe_ops, 1, orig_hash, hash);
+ if (ret < 0)
+ count = ret;
+
__enable_ftrace_function_probe();
out_unlock:
mutex_unlock(&ftrace_lock);
+ free_ftrace_hash(hash);
return count;
}
__unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
void *data, int flags)
{
+ struct ftrace_func_entry *rec_entry;
struct ftrace_func_probe *entry;
+ struct ftrace_func_probe *p;
+ struct ftrace_hash **orig_hash = &trace_probe_ops.filter_hash;
+ struct list_head free_list;
+ struct ftrace_hash *hash;
struct hlist_node *n, *tmp;
char str[KSYM_SYMBOL_LEN];
int type = MATCH_FULL;
}
mutex_lock(&ftrace_lock);
+
+ hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash);
+ if (!hash)
+ /* Hmm, should report this somehow */
+ goto out_unlock;
+
+ INIT_LIST_HEAD(&free_list);
+
for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
struct hlist_head *hhd = &ftrace_func_hash[i];
continue;
}
- hlist_del(&entry->node);
- call_rcu(&entry->rcu, ftrace_free_entry_rcu);
+ rec_entry = ftrace_lookup_ip(hash, entry->ip);
+ /* It is possible more than one entry had this ip */
+ if (rec_entry)
+ free_hash_entry(hash, rec_entry);
+
+ hlist_del_rcu(&entry->node);
+ list_add(&entry->free_list, &free_list);
}
}
__disable_ftrace_function_probe();
+ /*
+ * Remove after the disable is called. Otherwise, if the last
+ * probe is removed, a null hash means *all enabled*.
+ */
+ ftrace_hash_move(&trace_probe_ops, 1, orig_hash, hash);
+ synchronize_sched();
+ list_for_each_entry_safe(entry, p, &free_list, free_list) {
+ list_del(&entry->free_list);
+ ftrace_free_entry(entry);
+ }
+
+ out_unlock:
mutex_unlock(&ftrace_lock);
+ free_ftrace_hash(hash);
}
void
{
char *func, *command, *next = buff;
struct ftrace_func_command *p;
- int ret;
+ int ret = -EINVAL;
func = strsep(&next, ":");
mutex_lock(&ftrace_cmd_mutex);
list_for_each_entry(p, &ftrace_commands, list) {
if (strcmp(p->name, command) == 0) {
- ret = p->func(func, command, next, enable);
+ ret = p->func(hash, func, command, next, enable);
goto 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)
{
}
static int
-ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
- int reset, int enable)
+ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove)
+{
+ struct ftrace_func_entry *entry;
+
+ if (!ftrace_location(ip))
+ return -EINVAL;
+
+ if (remove) {
+ entry = ftrace_lookup_ip(hash, ip);
+ if (!entry)
+ return -ENOENT;
+ free_hash_entry(hash, entry);
+ return 0;
+ }
+
+ return add_hash_entry(hash, ip);
+}
+
+static int
+ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len,
+ unsigned long ip, int remove, int reset, int enable)
{
struct ftrace_hash **orig_hash;
struct ftrace_hash *hash;
int ret;
+ /* All global ops uses the global ops filters */
+ if (ops->flags & FTRACE_OPS_FL_GLOBAL)
+ ops = &global_ops;
+
if (unlikely(ftrace_disabled))
return -ENODEV;
mutex_lock(&ftrace_regex_lock);
if (reset)
ftrace_filter_reset(hash);
- if (buf)
- ftrace_match_records(hash, buf, len);
+ if (buf && !ftrace_match_records(hash, buf, len)) {
+ ret = -EINVAL;
+ goto out_regex_unlock;
+ }
+ if (ip) {
+ ret = ftrace_match_addr(hash, ip, remove);
+ if (ret < 0)
+ goto out_regex_unlock;
+ }
mutex_lock(&ftrace_lock);
- ret = ftrace_hash_move(orig_hash, hash);
+ ret = ftrace_hash_move(ops, enable, orig_hash, hash);
+ if (!ret && ops->flags & FTRACE_OPS_FL_ENABLED
+ && ftrace_enabled)
+ ftrace_run_update_code(FTRACE_UPDATE_CALLS);
+
mutex_unlock(&ftrace_lock);
+ out_regex_unlock:
mutex_unlock(&ftrace_regex_lock);
free_ftrace_hash(hash);
return ret;
}
+static int
+ftrace_set_addr(struct ftrace_ops *ops, unsigned long ip, int remove,
+ int reset, int enable)
+{
+ return ftrace_set_hash(ops, 0, 0, ip, remove, reset, enable);
+}
+
+/**
+ * ftrace_set_filter_ip - set a function to filter on in ftrace by address
+ * @ops - the ops to set the filter with
+ * @ip - the address to add to or remove from the filter.
+ * @remove - non zero to remove the ip from the filter
+ * @reset - non zero to reset all filters before applying this filter.
+ *
+ * Filters denote which functions should be enabled when tracing is enabled
+ * If @ip is NULL, it failes to update filter.
+ */
+int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip,
+ int remove, int reset)
+{
+ return ftrace_set_addr(ops, ip, remove, reset, 1);
+}
+EXPORT_SYMBOL_GPL(ftrace_set_filter_ip);
+
+static int
+ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
+ int reset, int enable)
+{
+ return ftrace_set_hash(ops, buf, len, 0, 0, reset, enable);
+}
+
+/**
+ * ftrace_set_filter - set a function to filter on in ftrace
+ * @ops - the ops to set the filter with
+ * @buf - the string that holds the function filter text.
+ * @len - the length of the string.
+ * @reset - non zero to reset all filters before applying this filter.
+ *
+ * Filters denote which functions should be enabled when tracing is enabled.
+ * If @buf is NULL and reset is set, all functions will be enabled for tracing.
+ */
+int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
+ int len, int reset)
+{
+ return ftrace_set_regex(ops, buf, len, reset, 1);
+}
+EXPORT_SYMBOL_GPL(ftrace_set_filter);
+
+/**
+ * ftrace_set_notrace - set a function to not trace in ftrace
+ * @ops - the ops to set the notrace filter with
+ * @buf - the string that holds the function notrace text.
+ * @len - the length of the string.
+ * @reset - non zero to reset all filters before applying this filter.
+ *
+ * Notrace Filters denote which functions should not be enabled when tracing
+ * is enabled. If @buf is NULL and reset is set, all functions will be enabled
+ * for tracing.
+ */
+int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
+ int len, int reset)
+{
+ return ftrace_set_regex(ops, buf, len, reset, 0);
+}
+EXPORT_SYMBOL_GPL(ftrace_set_notrace);
/**
* ftrace_set_filter - set a function to filter on in ftrace
+ * @ops - the ops to set the filter with
* @buf - the string that holds the function filter text.
* @len - the length of the string.
* @reset - non zero to reset all filters before applying this filter.
* Filters denote which functions should be enabled when tracing is enabled.
* If @buf is NULL and reset is set, all functions will be enabled for tracing.
*/
-void ftrace_set_filter(unsigned char *buf, int len, int reset)
+void ftrace_set_global_filter(unsigned char *buf, int len, int reset)
{
ftrace_set_regex(&global_ops, buf, len, reset, 1);
}
+EXPORT_SYMBOL_GPL(ftrace_set_global_filter);
/**
* ftrace_set_notrace - set a function to not trace in ftrace
+ * @ops - the ops to set the notrace filter with
* @buf - the string that holds the function notrace text.
* @len - the length of the string.
* @reset - non zero to reset all filters before applying this filter.
* is enabled. If @buf is NULL and reset is set, all functions will be enabled
* for tracing.
*/
-void ftrace_set_notrace(unsigned char *buf, int len, int reset)
+void ftrace_set_global_notrace(unsigned char *buf, int len, int reset)
{
ftrace_set_regex(&global_ops, buf, len, reset, 0);
}
+EXPORT_SYMBOL_GPL(ftrace_set_global_notrace);
/*
* command line interface to allow users to set filters on boot up.
static int __init set_ftrace_notrace(char *str)
{
- strncpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE);
+ strlcpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE);
return 1;
}
__setup("ftrace_notrace=", set_ftrace_notrace);
static int __init set_ftrace_filter(char *str)
{
- strncpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE);
+ strlcpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE);
return 1;
}
__setup("ftrace_filter=", set_ftrace_filter);
}
#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;
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;
orig_hash = &iter->ops->notrace_hash;
mutex_lock(&ftrace_lock);
- /*
- * Remove the current set, update the hash and add
- * them back.
- */
- ftrace_hash_rec_disable(iter->ops, filter_hash);
- ret = ftrace_hash_move(orig_hash, iter->hash);
- if (!ret) {
- ftrace_hash_rec_enable(iter->ops, filter_hash);
- if (iter->ops->flags & FTRACE_OPS_FL_ENABLED
- && ftrace_enabled)
- ftrace_run_update_code(FTRACE_ENABLE_CALLS);
- }
+ ret = ftrace_hash_move(iter->ops, filter_hash,
+ orig_hash, iter->hash);
+ if (!ret && (iter->ops->flags & FTRACE_OPS_FL_ENABLED)
+ && ftrace_enabled)
+ ftrace_run_update_code(FTRACE_UPDATE_CALLS);
+
mutex_unlock(&ftrace_lock);
}
free_ftrace_hash(iter->hash);
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;
return 0;
}
+static int ftrace_cmp_ips(const void *a, const void *b)
+{
+ const unsigned long *ipa = a;
+ const unsigned long *ipb = b;
+
+ if (*ipa > *ipb)
+ return 1;
+ if (*ipa < *ipb)
+ return -1;
+ return 0;
+}
+
+static void ftrace_swap_ips(void *a, void *b, int size)
+{
+ unsigned long *ipa = a;
+ unsigned long *ipb = b;
+ unsigned long t;
+
+ t = *ipa;
+ *ipa = *ipb;
+ *ipb = t;
+}
+
static int ftrace_process_locs(struct module *mod,
unsigned long *start,
unsigned long *end)
{
+ struct ftrace_page *start_pg;
+ struct ftrace_page *pg;
+ struct dyn_ftrace *rec;
+ 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;
+
+ sort(start, count, sizeof(*start),
+ ftrace_cmp_ips, ftrace_swap_ips);
+
+ start_pg = ftrace_allocate_pages(count);
+ if (!start_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 = 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 = start_pg;
+ }
+
p = start;
+ pg = start_pg;
while (p < end) {
addr = ftrace_call_adjust(*p++);
/*
*/
if (!addr)
continue;
- ftrace_record_ip(addr);
+
+ if (pg->index == pg->size) {
+ /* We should have allocated enough */
+ if (WARN_ON(!pg->next))
+ break;
+ pg = pg->next;
+ }
+
+ rec = &pg->records[pg->index++];
+ rec->ip = addr;
}
+ /* We should have used all pages */
+ WARN_ON(pg->next);
+
+ /* Assign the last page to ftrace_pages */
+ ftrace_pages = pg;
+
+ /* These new locations need to be initialized */
+ ftrace_new_pgs = start_pg;
+
+ /*
+ * We only need to disable interrupts on start up
+ * because we are modifying code that an interrupt
+ * may execute, and the modification is not atomic.
+ * But for modules, nothing runs the code we modify
+ * until we are finished with it, and there's no
+ * reason to cause large interrupt latencies while we do it.
+ */
+ if (!mod)
+ local_irq_save(flags);
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);
}
ftrace_process_locs(mod, start, end);
}
-static int ftrace_module_notify(struct notifier_block *self,
- unsigned long val, void *data)
+static int ftrace_module_notify_enter(struct notifier_block *self,
+ unsigned long val, void *data)
{
struct module *mod = data;
- switch (val) {
- case MODULE_STATE_COMING:
+ if (val == MODULE_STATE_COMING)
ftrace_init_module(mod, mod->ftrace_callsites,
mod->ftrace_callsites +
mod->num_ftrace_callsites);
- break;
- case MODULE_STATE_GOING:
+ return 0;
+}
+
+static int ftrace_module_notify_exit(struct notifier_block *self,
+ unsigned long val, void *data)
+{
+ struct module *mod = data;
+
+ if (val == MODULE_STATE_GOING)
ftrace_release_mod(mod);
- break;
- }
return 0;
}
#else
-static int ftrace_module_notify(struct notifier_block *self,
- unsigned long val, void *data)
+static int ftrace_module_notify_enter(struct notifier_block *self,
+ unsigned long val, void *data)
+{
+ return 0;
+}
+static int ftrace_module_notify_exit(struct notifier_block *self,
+ unsigned long val, void *data)
{
return 0;
}
#endif /* CONFIG_MODULES */
-struct notifier_block ftrace_module_nb = {
- .notifier_call = ftrace_module_notify,
- .priority = 0,
+struct notifier_block ftrace_module_enter_nb = {
+ .notifier_call = ftrace_module_notify_enter,
+ .priority = INT_MAX, /* Run before anything that can use kprobes */
+};
+
+struct notifier_block ftrace_module_exit_nb = {
+ .notifier_call = ftrace_module_notify_exit,
+ .priority = INT_MIN, /* Run after anything that can remove kprobes */
};
extern unsigned long __start_mcount_loc[];
__start_mcount_loc,
__stop_mcount_loc);
- ret = register_module_notifier(&ftrace_module_nb);
+ ret = register_module_notifier(&ftrace_module_enter_nb);
+ if (ret)
+ pr_warning("Failed to register trace ftrace module enter notifier\n");
+
+ ret = register_module_notifier(&ftrace_module_exit_nb);
if (ret)
- pr_warning("Failed to register trace ftrace module notifier\n");
+ pr_warning("Failed to register trace ftrace module exit notifier\n");
set_ftrace_early_filters();
static struct ftrace_ops global_ops = {
.func = ftrace_stub,
+ .flags = FTRACE_OPS_FL_RECURSION_SAFE,
};
static int __init ftrace_nodyn_init(void)
ftrace_enabled = 1;
return 0;
}
-device_initcall(ftrace_nodyn_init);
+core_initcall(ftrace_nodyn_init);
static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; }
static inline void ftrace_startup_enable(int command) { }
/* Keep as macros so we do not need to define the commands */
-# define ftrace_startup(ops, command) do { } while (0)
+# define ftrace_startup(ops, command) \
+ ({ \
+ (ops)->flags |= FTRACE_OPS_FL_ENABLED; \
+ 0; \
+ })
# define ftrace_shutdown(ops, command) do { } while (0)
# define ftrace_startup_sysctl() do { } while (0)
# define ftrace_shutdown_sysctl() do { } while (0)
#endif /* CONFIG_DYNAMIC_FTRACE */
static void
-ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip)
+ftrace_ops_control_func(unsigned long ip, unsigned long parent_ip,
+ struct ftrace_ops *op, struct pt_regs *regs)
+{
+ if (unlikely(trace_recursion_test(TRACE_CONTROL_BIT)))
+ return;
+
+ /*
+ * Some of the ops may be dynamically allocated,
+ * they must be freed after a synchronize_sched().
+ */
+ preempt_disable_notrace();
+ trace_recursion_set(TRACE_CONTROL_BIT);
+ do_for_each_ftrace_op(op, ftrace_control_list) {
+ if (!ftrace_function_local_disabled(op) &&
+ ftrace_ops_test(op, ip))
+ op->func(ip, parent_ip, op, regs);
+ } while_for_each_ftrace_op(op);
+ trace_recursion_clear(TRACE_CONTROL_BIT);
+ preempt_enable_notrace();
+}
+
+static struct ftrace_ops control_ops = {
+ .func = ftrace_ops_control_func,
+ .flags = FTRACE_OPS_FL_RECURSION_SAFE,
+};
+
+static inline void
+__ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
+ struct ftrace_ops *ignored, struct pt_regs *regs)
{
struct ftrace_ops *op;
+ int bit;
+
+ if (function_trace_stop)
+ return;
+
+ bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX);
+ if (bit < 0)
+ return;
/*
* Some of the ops may be dynamically allocated,
* they must be freed after a synchronize_sched().
*/
preempt_disable_notrace();
- op = rcu_dereference_raw(ftrace_ops_list);
- while (op != &ftrace_list_end) {
+ do_for_each_ftrace_op(op, ftrace_ops_list) {
if (ftrace_ops_test(op, ip))
- op->func(ip, parent_ip);
- op = rcu_dereference_raw(op->next);
- };
+ op->func(ip, parent_ip, op, regs);
+ } while_for_each_ftrace_op(op);
preempt_enable_notrace();
+ trace_clear_recursion(bit);
+}
+
+/*
+ * Some archs only support passing ip and parent_ip. Even though
+ * the list function ignores the op parameter, we do not want any
+ * C side effects, where a function is called without the caller
+ * sending a third parameter.
+ * Archs are to support both the regs and ftrace_ops at the same time.
+ * If they support ftrace_ops, it is assumed they support regs.
+ * If call backs want to use regs, they must either check for regs
+ * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS.
+ * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved.
+ * An architecture can pass partial regs with ftrace_ops and still
+ * set the ARCH_SUPPORT_FTARCE_OPS.
+ */
+#if ARCH_SUPPORTS_FTRACE_OPS
+static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
+ struct ftrace_ops *op, struct pt_regs *regs)
+{
+ __ftrace_ops_list_func(ip, parent_ip, NULL, regs);
+}
+#else
+static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip)
+{
+ __ftrace_ops_list_func(ip, parent_ip, NULL, NULL);
}
+#endif
static void clear_ftrace_swapper(void)
{
if (strlen(tmp) == 0)
return 1;
- ret = strict_strtol(tmp, 10, &val);
+ ret = kstrtol(tmp, 10, &val);
if (ret < 0)
return ret;
clear_ftrace_function();
}
+/**
+ * Test if ftrace is dead or not.
+ */
+int ftrace_is_dead(void)
+{
+ return ftrace_disabled;
+}
+
/**
* register_ftrace_function - register a function for profiling
* @ops - ops structure that holds the function for profiling.
mutex_lock(&ftrace_lock);
- if (unlikely(ftrace_disabled))
- goto out_unlock;
-
ret = __register_ftrace_function(ops);
if (!ret)
- ftrace_startup(ops, 0);
-
+ ret = ftrace_startup(ops, 0);
- out_unlock:
mutex_unlock(&ftrace_lock);
+
return ret;
}
EXPORT_SYMBOL_GPL(register_ftrace_function);
ftrace_graph_return = retfunc;
ftrace_graph_entry = entryfunc;
- ftrace_startup(&global_ops, FTRACE_START_FUNC_RET);
+ ret = ftrace_startup(&global_ops, FTRACE_START_FUNC_RET);
out:
mutex_unlock(&ftrace_lock);
Code Review / linux-3.10.git / blobdiff