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Diffstat (limited to 'kernel/trace/ftrace.c')
-rw-r--r--kernel/trace/ftrace.c100
1 files changed, 47 insertions, 53 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 8de8bec5f366..b01ae7d36021 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1183,18 +1183,19 @@ static void __add_hash_entry(struct ftrace_hash *hash,
hash->count++;
}
-static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip)
+static struct ftrace_func_entry *
+add_hash_entry(struct ftrace_hash *hash, unsigned long ip)
{
struct ftrace_func_entry *entry;
entry = kmalloc(sizeof(*entry), GFP_KERNEL);
if (!entry)
- return -ENOMEM;
+ return NULL;
entry->ip = ip;
__add_hash_entry(hash, entry);
- return 0;
+ return entry;
}
static void
@@ -1349,7 +1350,6 @@ alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash)
struct ftrace_func_entry *entry;
struct ftrace_hash *new_hash;
int size;
- int ret;
int i;
new_hash = alloc_ftrace_hash(size_bits);
@@ -1366,8 +1366,7 @@ alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash)
size = 1 << hash->size_bits;
for (i = 0; i < size; i++) {
hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
- ret = add_hash_entry(new_hash, entry->ip);
- if (ret < 0)
+ if (add_hash_entry(new_hash, entry->ip) == NULL)
goto free_hash;
}
}
@@ -2536,7 +2535,7 @@ ftrace_find_unique_ops(struct dyn_ftrace *rec)
#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
/* Protected by rcu_tasks for reading, and direct_mutex for writing */
-static struct ftrace_hash *direct_functions = EMPTY_HASH;
+static struct ftrace_hash __rcu *direct_functions = EMPTY_HASH;
static DEFINE_MUTEX(direct_mutex);
int ftrace_direct_func_count;
@@ -2555,39 +2554,6 @@ unsigned long ftrace_find_rec_direct(unsigned long ip)
return entry->direct;
}
-static struct ftrace_func_entry*
-ftrace_add_rec_direct(unsigned long ip, unsigned long addr,
- struct ftrace_hash **free_hash)
-{
- struct ftrace_func_entry *entry;
-
- if (ftrace_hash_empty(direct_functions) ||
- direct_functions->count > 2 * (1 << direct_functions->size_bits)) {
- struct ftrace_hash *new_hash;
- int size = ftrace_hash_empty(direct_functions) ? 0 :
- direct_functions->count + 1;
-
- if (size < 32)
- size = 32;
-
- new_hash = dup_hash(direct_functions, size);
- if (!new_hash)
- return NULL;
-
- *free_hash = direct_functions;
- direct_functions = new_hash;
- }
-
- entry = kmalloc(sizeof(*entry), GFP_KERNEL);
- if (!entry)
- return NULL;
-
- entry->ip = ip;
- entry->direct = addr;
- __add_hash_entry(direct_functions, entry);
- return entry;
-}
-
static void call_direct_funcs(unsigned long ip, unsigned long pip,
struct ftrace_ops *ops, struct ftrace_regs *fregs)
{
@@ -4223,8 +4189,8 @@ enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int clear_filter)
/* Do nothing if it exists */
if (entry)
return 0;
-
- ret = add_hash_entry(hash, rec->ip);
+ if (add_hash_entry(hash, rec->ip) == NULL)
+ ret = -ENOMEM;
}
return ret;
}
@@ -5266,7 +5232,8 @@ __ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove)
return 0;
}
- return add_hash_entry(hash, ip);
+ entry = add_hash_entry(hash, ip);
+ return entry ? 0 : -ENOMEM;
}
static int
@@ -5410,7 +5377,7 @@ static void remove_direct_functions_hash(struct ftrace_hash *hash, unsigned long
*/
int register_ftrace_direct(struct ftrace_ops *ops, unsigned long addr)
{
- struct ftrace_hash *hash, *free_hash = NULL;
+ struct ftrace_hash *hash, *new_hash = NULL, *free_hash = NULL;
struct ftrace_func_entry *entry, *new;
int err = -EBUSY, size, i;
@@ -5436,17 +5403,44 @@ int register_ftrace_direct(struct ftrace_ops *ops, unsigned long addr)
}
}
- /* ... and insert them to direct_functions hash. */
err = -ENOMEM;
+
+ /* Make a copy hash to place the new and the old entries in */
+ size = hash->count + direct_functions->count;
+ if (size > 32)
+ size = 32;
+ new_hash = alloc_ftrace_hash(fls(size));
+ if (!new_hash)
+ goto out_unlock;
+
+ /* Now copy over the existing direct entries */
+ size = 1 << direct_functions->size_bits;
+ for (i = 0; i < size; i++) {
+ hlist_for_each_entry(entry, &direct_functions->buckets[i], hlist) {
+ new = add_hash_entry(new_hash, entry->ip);
+ if (!new)
+ goto out_unlock;
+ new->direct = entry->direct;
+ }
+ }
+
+ /* ... and add the new entries */
+ size = 1 << hash->size_bits;
for (i = 0; i < size; i++) {
hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
- new = ftrace_add_rec_direct(entry->ip, addr, &free_hash);
+ new = add_hash_entry(new_hash, entry->ip);
if (!new)
- goto out_remove;
+ goto out_unlock;
+ /* Update both the copy and the hash entry */
+ new->direct = addr;
entry->direct = addr;
}
}
+ free_hash = direct_functions;
+ rcu_assign_pointer(direct_functions, new_hash);
+ new_hash = NULL;
+
ops->func = call_direct_funcs;
ops->flags = MULTI_FLAGS;
ops->trampoline = FTRACE_REGS_ADDR;
@@ -5454,17 +5448,17 @@ int register_ftrace_direct(struct ftrace_ops *ops, unsigned long addr)
err = register_ftrace_function_nolock(ops);
- out_remove:
- if (err)
- remove_direct_functions_hash(hash, addr);
-
out_unlock:
mutex_unlock(&direct_mutex);
- if (free_hash) {
+ if (free_hash && free_hash != EMPTY_HASH) {
synchronize_rcu_tasks();
free_ftrace_hash(free_hash);
}
+
+ if (new_hash)
+ free_ftrace_hash(new_hash);
+
return err;
}
EXPORT_SYMBOL_GPL(register_ftrace_direct);
@@ -6309,7 +6303,7 @@ ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer)
if (entry)
continue;
- if (add_hash_entry(hash, rec->ip) < 0)
+ if (add_hash_entry(hash, rec->ip) == NULL)
goto out;
} else {
if (entry) {