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Diffstat (limited to 'kernel/trace/ftrace.c')
-rw-r--r--kernel/trace/ftrace.c127
1 files changed, 82 insertions, 45 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index fa7ece649fe..ebd80d50c47 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -884,10 +884,8 @@ enum {
FTRACE_ENABLE_CALLS = (1 << 0),
FTRACE_DISABLE_CALLS = (1 << 1),
FTRACE_UPDATE_TRACE_FUNC = (1 << 2),
- FTRACE_ENABLE_MCOUNT = (1 << 3),
- FTRACE_DISABLE_MCOUNT = (1 << 4),
- FTRACE_START_FUNC_RET = (1 << 5),
- FTRACE_STOP_FUNC_RET = (1 << 6),
+ FTRACE_START_FUNC_RET = (1 << 3),
+ FTRACE_STOP_FUNC_RET = (1 << 4),
};
static int ftrace_filtered;
@@ -1226,8 +1224,6 @@ static void ftrace_shutdown(int command)
static void ftrace_startup_sysctl(void)
{
- int command = FTRACE_ENABLE_MCOUNT;
-
if (unlikely(ftrace_disabled))
return;
@@ -1235,23 +1231,17 @@ static void ftrace_startup_sysctl(void)
saved_ftrace_func = NULL;
/* ftrace_start_up is true if we want ftrace running */
if (ftrace_start_up)
- command |= FTRACE_ENABLE_CALLS;
-
- ftrace_run_update_code(command);
+ ftrace_run_update_code(FTRACE_ENABLE_CALLS);
}
static void ftrace_shutdown_sysctl(void)
{
- int command = FTRACE_DISABLE_MCOUNT;
-
if (unlikely(ftrace_disabled))
return;
/* ftrace_start_up is true if ftrace is running */
if (ftrace_start_up)
- command |= FTRACE_DISABLE_CALLS;
-
- ftrace_run_update_code(command);
+ ftrace_run_update_code(FTRACE_DISABLE_CALLS);
}
static cycle_t ftrace_update_time;
@@ -1368,24 +1358,29 @@ enum {
#define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
struct ftrace_iterator {
- struct ftrace_page *pg;
- int hidx;
- int idx;
- unsigned flags;
- struct trace_parser parser;
+ loff_t pos;
+ loff_t func_pos;
+ struct ftrace_page *pg;
+ struct dyn_ftrace *func;
+ struct ftrace_func_probe *probe;
+ struct trace_parser parser;
+ int hidx;
+ int idx;
+ unsigned flags;
};
static void *
-t_hash_next(struct seq_file *m, void *v, loff_t *pos)
+t_hash_next(struct seq_file *m, loff_t *pos)
{
struct ftrace_iterator *iter = m->private;
- struct hlist_node *hnd = v;
+ struct hlist_node *hnd = NULL;
struct hlist_head *hhd;
- WARN_ON(!(iter->flags & FTRACE_ITER_HASH));
-
(*pos)++;
+ iter->pos = *pos;
+ if (iter->probe)
+ hnd = &iter->probe->node;
retry:
if (iter->hidx >= FTRACE_FUNC_HASHSIZE)
return NULL;
@@ -1408,7 +1403,12 @@ t_hash_next(struct seq_file *m, void *v, loff_t *pos)
}
}
- return hnd;
+ if (WARN_ON_ONCE(!hnd))
+ return NULL;
+
+ iter->probe = hlist_entry(hnd, struct ftrace_func_probe, node);
+
+ return iter;
}
static void *t_hash_start(struct seq_file *m, loff_t *pos)
@@ -1417,26 +1417,32 @@ static void *t_hash_start(struct seq_file *m, loff_t *pos)
void *p = NULL;
loff_t l;
- if (!(iter->flags & FTRACE_ITER_HASH))
- *pos = 0;
-
- iter->flags |= FTRACE_ITER_HASH;
+ if (iter->func_pos > *pos)
+ return NULL;
iter->hidx = 0;
- for (l = 0; l <= *pos; ) {
- p = t_hash_next(m, p, &l);
+ for (l = 0; l <= (*pos - iter->func_pos); ) {
+ p = t_hash_next(m, &l);
if (!p)
break;
}
- return p;
+ if (!p)
+ return NULL;
+
+ /* Only set this if we have an item */
+ iter->flags |= FTRACE_ITER_HASH;
+
+ return iter;
}
-static int t_hash_show(struct seq_file *m, void *v)
+static int
+t_hash_show(struct seq_file *m, struct ftrace_iterator *iter)
{
struct ftrace_func_probe *rec;
- struct hlist_node *hnd = v;
- rec = hlist_entry(hnd, struct ftrace_func_probe, node);
+ rec = iter->probe;
+ if (WARN_ON_ONCE(!rec))
+ return -EIO;
if (rec->ops->print)
return rec->ops->print(m, rec->ip, rec->ops, rec->data);
@@ -1457,12 +1463,13 @@ t_next(struct seq_file *m, void *v, loff_t *pos)
struct dyn_ftrace *rec = NULL;
if (iter->flags & FTRACE_ITER_HASH)
- return t_hash_next(m, v, pos);
+ return t_hash_next(m, pos);
(*pos)++;
+ iter->pos = *pos;
if (iter->flags & FTRACE_ITER_PRINTALL)
- return NULL;
+ return t_hash_start(m, pos);
retry:
if (iter->idx >= iter->pg->index) {
@@ -1491,7 +1498,20 @@ t_next(struct seq_file *m, void *v, loff_t *pos)
}
}
- return rec;
+ if (!rec)
+ return t_hash_start(m, pos);
+
+ iter->func_pos = *pos;
+ iter->func = rec;
+
+ return iter;
+}
+
+static void reset_iter_read(struct ftrace_iterator *iter)
+{
+ iter->pos = 0;
+ iter->func_pos = 0;
+ iter->flags &= ~(FTRACE_ITER_PRINTALL & FTRACE_ITER_HASH);
}
static void *t_start(struct seq_file *m, loff_t *pos)
@@ -1502,6 +1522,12 @@ static void *t_start(struct seq_file *m, loff_t *pos)
mutex_lock(&ftrace_lock);
/*
+ * If an lseek was done, then reset and start from beginning.
+ */
+ if (*pos < iter->pos)
+ reset_iter_read(iter);
+
+ /*
* For set_ftrace_filter reading, if we have the filter
* off, we can short cut and just print out that all
* functions are enabled.
@@ -1518,6 +1544,11 @@ static void *t_start(struct seq_file *m, loff_t *pos)
if (iter->flags & FTRACE_ITER_HASH)
return t_hash_start(m, pos);
+ /*
+ * Unfortunately, we need to restart at ftrace_pages_start
+ * every time we let go of the ftrace_mutex. This is because
+ * those pointers can change without the lock.
+ */
iter->pg = ftrace_pages_start;
iter->idx = 0;
for (l = 0; l <= *pos; ) {
@@ -1526,10 +1557,14 @@ static void *t_start(struct seq_file *m, loff_t *pos)
break;
}
- if (!p && iter->flags & FTRACE_ITER_FILTER)
- return t_hash_start(m, pos);
+ if (!p) {
+ if (iter->flags & FTRACE_ITER_FILTER)
+ return t_hash_start(m, pos);
- return p;
+ return NULL;
+ }
+
+ return iter;
}
static void t_stop(struct seq_file *m, void *p)
@@ -1540,16 +1575,18 @@ static void t_stop(struct seq_file *m, void *p)
static int t_show(struct seq_file *m, void *v)
{
struct ftrace_iterator *iter = m->private;
- struct dyn_ftrace *rec = v;
+ struct dyn_ftrace *rec;
if (iter->flags & FTRACE_ITER_HASH)
- return t_hash_show(m, v);
+ return t_hash_show(m, iter);
if (iter->flags & FTRACE_ITER_PRINTALL) {
seq_printf(m, "#### all functions enabled ####\n");
return 0;
}
+ rec = iter->func;
+
if (!rec)
return 0;
@@ -1601,8 +1638,8 @@ ftrace_failures_open(struct inode *inode, struct file *file)
ret = ftrace_avail_open(inode, file);
if (!ret) {
- m = (struct seq_file *)file->private_data;
- iter = (struct ftrace_iterator *)m->private;
+ m = file->private_data;
+ iter = m->private;
iter->flags = FTRACE_ITER_FAILURES;
}
@@ -2418,7 +2455,7 @@ static const struct file_operations ftrace_filter_fops = {
.open = ftrace_filter_open,
.read = seq_read,
.write = ftrace_filter_write,
- .llseek = no_llseek,
+ .llseek = ftrace_regex_lseek,
.release = ftrace_filter_release,
};
generated by cgit v1.2.3-18-g5258 (git 2.32.0) at 2024-12-29 12:43:46 +0000