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Diffstat (limited to 'kernel/trace/ftrace.c')
-rw-r--r--kernel/trace/ftrace.c76
1 files changed, 48 insertions, 28 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index ef9271b69b4f..9f8e2e11020a 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -952,7 +952,7 @@ struct ftrace_func_probe {
};
enum {
- FTRACE_ENABLE_CALLS = (1 << 0),
+ FTRACE_UPDATE_CALLS = (1 << 0),
FTRACE_DISABLE_CALLS = (1 << 1),
FTRACE_UPDATE_TRACE_FUNC = (1 << 2),
FTRACE_START_FUNC_RET = (1 << 3),
@@ -1182,8 +1182,14 @@ alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash)
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;
@@ -1193,9 +1199,16 @@ ftrace_hash_move(struct ftrace_hash **dst, struct ftrace_hash *src)
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.
*/
@@ -1215,9 +1228,10 @@ ftrace_hash_move(struct ftrace_hash **dst, struct ftrace_hash *src)
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++) {
@@ -1236,7 +1250,16 @@ ftrace_hash_move(struct ftrace_hash **dst, struct ftrace_hash *src)
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;
}
/*
@@ -1498,7 +1521,7 @@ int ftrace_text_reserved(void *start, void *end)
static int
-__ftrace_replace_code(struct dyn_ftrace *rec, int enable)
+__ftrace_replace_code(struct dyn_ftrace *rec, int update)
{
unsigned long ftrace_addr;
unsigned long flag = 0UL;
@@ -1506,17 +1529,17 @@ __ftrace_replace_code(struct dyn_ftrace *rec, int enable)
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))
+ if (update && (rec->flags & ~FTRACE_FL_MASK))
flag = FTRACE_FL_ENABLED;
/* If the state of this record hasn't changed, then do nothing */
@@ -1532,7 +1555,7 @@ __ftrace_replace_code(struct dyn_ftrace *rec, int enable)
return ftrace_make_nop(NULL, rec, ftrace_addr);
}
-static void ftrace_replace_code(int enable)
+static void ftrace_replace_code(int update)
{
struct dyn_ftrace *rec;
struct ftrace_page *pg;
@@ -1546,7 +1569,7 @@ static void ftrace_replace_code(int enable)
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 */
@@ -1596,7 +1619,7 @@ static int __ftrace_modify_code(void *data)
{
int *command = data;
- if (*command & FTRACE_ENABLE_CALLS)
+ if (*command & FTRACE_UPDATE_CALLS)
ftrace_replace_code(1);
else if (*command & FTRACE_DISABLE_CALLS)
ftrace_replace_code(0);
@@ -1652,7 +1675,7 @@ 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) {
@@ -1704,8 +1727,7 @@ 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;
@@ -1727,7 +1749,7 @@ 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)
@@ -2877,7 +2899,11 @@ ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
ftrace_match_records(hash, buf, len);
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);
mutex_unlock(&ftrace_regex_lock);
@@ -3060,18 +3086,12 @@ ftrace_regex_release(struct inode *inode, struct file *file)
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);
generated by cgit v1.2.3 (git 2.0.4) at 2024-12-28 04:25:35 +0000