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ftrace: Create a global_ops to hold the filter and notrace hashes
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Combine the filter and notrace hashes to be accessed by a single entity,
the global_ops. The global_ops is a ftrace_ops structure that is passed
to different functions that can read or modify the filtering of the
function tracer.

The ftrace_ops structure was modified to hold a filter and notrace
hashes so that later patches may allow each ftrace_ops to have its own
set of rules to what functions may be filtered.

Signed-off-by: Steven Rostedt <[email protected]>
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@rostedt
Steven Rostedt authored and rostedt committed May 18, 2011
1 parent 1cf41dd commit f45948e
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Showing 2 changed files with 54 additions and 21 deletions.
10 changes: 8 additions & 2 deletions include/linux/ftrace.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -29,9 +29,15 @@ ftrace_enable_sysctl(struct ctl_table *table, int write,

typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip);

struct ftrace_hash;

struct ftrace_ops {
ftrace_func_t func;
struct ftrace_ops *next;
ftrace_func_t func;
struct ftrace_ops *next;
#ifdef CONFIG_DYNAMIC_FTRACE
struct ftrace_hash *notrace_hash;
struct ftrace_hash *filter_hash;
#endif
};

extern int function_trace_stop;
Expand Down
65 changes: 46 additions & 19 deletions kernel/trace/ftrace.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -889,6 +889,12 @@ static struct ftrace_hash filter_hash = {
.buckets = filter_buckets,
};

struct ftrace_ops global_ops = {
.func = ftrace_stub,
.notrace_hash = &notrace_hash,
.filter_hash = &filter_hash,
};

static struct dyn_ftrace *ftrace_new_addrs;

static DEFINE_MUTEX(ftrace_regex_lock);
Expand Down Expand Up @@ -1112,6 +1118,7 @@ int ftrace_text_reserved(void *start, void *end)
static int
__ftrace_replace_code(struct dyn_ftrace *rec, int enable)
{
struct ftrace_ops *ops = &global_ops;
unsigned long ftrace_addr;
unsigned long flag = 0UL;

Expand All @@ -1126,8 +1133,9 @@ __ftrace_replace_code(struct dyn_ftrace *rec, int enable)
* If we want to enable it and filtering is on, enable it only if
* it's filtered
*/
if (enable && !ftrace_lookup_ip(&notrace_hash, rec->ip)) {
if (!filter_hash.count || ftrace_lookup_ip(&filter_hash, rec->ip))
if (enable && !ftrace_lookup_ip(ops->notrace_hash, rec->ip)) {
if (!ops->filter_hash->count ||
ftrace_lookup_ip(ops->filter_hash, rec->ip))
flag = FTRACE_FL_ENABLED;
}

Expand Down Expand Up @@ -1531,6 +1539,7 @@ 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 dyn_ftrace *rec = NULL;

if (unlikely(ftrace_disabled))
Expand All @@ -1557,10 +1566,10 @@ t_next(struct seq_file *m, void *v, loff_t *pos)
if ((rec->flags & FTRACE_FL_FREE) ||

((iter->flags & FTRACE_ITER_FILTER) &&
!(ftrace_lookup_ip(&filter_hash, rec->ip))) ||
!(ftrace_lookup_ip(ops->filter_hash, rec->ip))) ||

((iter->flags & FTRACE_ITER_NOTRACE) &&
!ftrace_lookup_ip(&notrace_hash, rec->ip))) {
!ftrace_lookup_ip(ops->notrace_hash, rec->ip))) {
rec = NULL;
goto retry;
}
Expand All @@ -1584,6 +1593,7 @@ 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;
void *p = NULL;
loff_t l;

Expand All @@ -1603,7 +1613,7 @@ 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 && !filter_hash.count) {
if (iter->flags & FTRACE_ITER_FILTER && !ops->filter_hash->count) {
if (*pos > 0)
return t_hash_start(m, pos);
iter->flags |= FTRACE_ITER_PRINTALL;
Expand Down Expand Up @@ -1708,10 +1718,11 @@ static void ftrace_filter_reset(struct ftrace_hash *hash)
}

static int
ftrace_regex_open(struct ftrace_hash *hash, int flag,
ftrace_regex_open(struct ftrace_ops *ops, int flag,
struct inode *inode, struct file *file)
{
struct ftrace_iterator *iter;
struct ftrace_hash *hash;
int ret = 0;

if (unlikely(ftrace_disabled))
Expand All @@ -1726,6 +1737,11 @@ ftrace_regex_open(struct ftrace_hash *hash, int flag,
return -ENOMEM;
}

if (flag & FTRACE_ITER_NOTRACE)
hash = ops->notrace_hash;
else
hash = ops->filter_hash;

iter->hash = hash;

mutex_lock(&ftrace_regex_lock);
Expand Down Expand Up @@ -1755,14 +1771,14 @@ ftrace_regex_open(struct ftrace_hash *hash, int flag,
static int
ftrace_filter_open(struct inode *inode, struct file *file)
{
return ftrace_regex_open(&filter_hash, FTRACE_ITER_FILTER,
return ftrace_regex_open(&global_ops, FTRACE_ITER_FILTER,
inode, file);
}

static int
ftrace_notrace_open(struct inode *inode, struct file *file)
{
return ftrace_regex_open(&notrace_hash, FTRACE_ITER_NOTRACE,
return ftrace_regex_open(&global_ops, FTRACE_ITER_NOTRACE,
inode, file);
}

Expand Down Expand Up @@ -1923,6 +1939,7 @@ ftrace_match_module_records(struct ftrace_hash *hash, char *buff, char *mod)
static int
ftrace_mod_callback(char *func, char *cmd, char *param, int enable)
{
struct ftrace_ops *ops = &global_ops;
struct ftrace_hash *hash;
char *mod;
int ret = -EINVAL;
Expand All @@ -1944,9 +1961,9 @@ ftrace_mod_callback(char *func, char *cmd, char *param, int enable)
return ret;

if (enable)
hash = &filter_hash;
hash = ops->filter_hash;
else
hash = &notrace_hash;
hash = ops->notrace_hash;

ret = ftrace_match_module_records(hash, func, mod);
if (!ret)
Expand Down Expand Up @@ -2245,14 +2262,15 @@ int unregister_ftrace_command(struct ftrace_func_command *cmd)
static int ftrace_process_regex(char *buff, int len, int enable)
{
char *func, *command, *next = buff;
struct ftrace_ops *ops = &global_ops;
struct ftrace_func_command *p;
struct ftrace_hash *hash;
int ret;

if (enable)
hash = &filter_hash;
hash = ops->filter_hash;
else
hash = &notrace_hash;
hash = ops->notrace_hash;

func = strsep(&next, ":");

Expand Down Expand Up @@ -2339,11 +2357,19 @@ ftrace_notrace_write(struct file *file, const char __user *ubuf,
}

static void
ftrace_set_regex(struct ftrace_hash *hash, unsigned char *buf, int len, int reset)
ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
int reset, int enable)
{
struct ftrace_hash *hash;

if (unlikely(ftrace_disabled))
return;

if (enable)
hash = ops->filter_hash;
else
hash = ops->notrace_hash;

mutex_lock(&ftrace_regex_lock);
if (reset)
ftrace_filter_reset(hash);
Expand All @@ -2363,7 +2389,7 @@ ftrace_set_regex(struct ftrace_hash *hash, unsigned char *buf, int len, int rese
*/
void ftrace_set_filter(unsigned char *buf, int len, int reset)
{
ftrace_set_regex(&filter_hash, buf, len, reset);
ftrace_set_regex(&global_ops, buf, len, reset, 1);
}

/**
Expand All @@ -2378,7 +2404,7 @@ void ftrace_set_filter(unsigned char *buf, int len, int reset)
*/
void ftrace_set_notrace(unsigned char *buf, int len, int reset)
{
ftrace_set_regex(&notrace_hash, buf, len, reset);
ftrace_set_regex(&global_ops, buf, len, reset, 0);
}

/*
Expand Down Expand Up @@ -2430,22 +2456,23 @@ static void __init set_ftrace_early_graph(char *buf)
}
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */

static void __init set_ftrace_early_filter(struct ftrace_hash *hash, char *buf)
static void __init
set_ftrace_early_filter(struct ftrace_ops *ops, char *buf, int enable)
{
char *func;

while (buf) {
func = strsep(&buf, ",");
ftrace_set_regex(hash, func, strlen(func), 0);
ftrace_set_regex(ops, func, strlen(func), 0, enable);
}
}

static void __init set_ftrace_early_filters(void)
{
if (ftrace_filter_buf[0])
set_ftrace_early_filter(&filter_hash, ftrace_filter_buf);
set_ftrace_early_filter(&global_ops, ftrace_filter_buf, 1);
if (ftrace_notrace_buf[0])
set_ftrace_early_filter(&notrace_hash, ftrace_notrace_buf);
set_ftrace_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);
Expand Down

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