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-rw-r--r--kernel/trace/ftrace.c39
-rw-r--r--kernel/trace/ring_buffer.c9
-rw-r--r--kernel/trace/trace_events_user.c181
3 files changed, 165 insertions, 64 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 83ba342aef..2f80239348 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1595,12 +1595,15 @@ static struct dyn_ftrace *lookup_rec(unsigned long start, unsigned long end)
unsigned long ftrace_location_range(unsigned long start, unsigned long end)
{
struct dyn_ftrace *rec;
+ unsigned long ip = 0;
+ rcu_read_lock();
rec = lookup_rec(start, end);
if (rec)
- return rec->ip;
+ ip = rec->ip;
+ rcu_read_unlock();
- return 0;
+ return ip;
}
/**
@@ -1613,25 +1616,22 @@ unsigned long ftrace_location_range(unsigned long start, unsigned long end)
*/
unsigned long ftrace_location(unsigned long ip)
{
- struct dyn_ftrace *rec;
+ unsigned long loc;
unsigned long offset;
unsigned long size;
- rec = lookup_rec(ip, ip);
- if (!rec) {
+ loc = ftrace_location_range(ip, ip);
+ if (!loc) {
if (!kallsyms_lookup_size_offset(ip, &size, &offset))
goto out;
/* map sym+0 to __fentry__ */
if (!offset)
- rec = lookup_rec(ip, ip + size - 1);
+ loc = ftrace_location_range(ip, ip + size - 1);
}
- if (rec)
- return rec->ip;
-
out:
- return 0;
+ return loc;
}
/**
@@ -6593,6 +6593,8 @@ static int ftrace_process_locs(struct module *mod,
/* We should have used all pages unless we skipped some */
if (pg_unuse) {
WARN_ON(!skipped);
+ /* Need to synchronize with ftrace_location_range() */
+ synchronize_rcu();
ftrace_free_pages(pg_unuse);
}
return ret;
@@ -6806,6 +6808,9 @@ void ftrace_release_mod(struct module *mod)
out_unlock:
mutex_unlock(&ftrace_lock);
+ /* Need to synchronize with ftrace_location_range() */
+ if (tmp_page)
+ synchronize_rcu();
for (pg = tmp_page; pg; pg = tmp_page) {
/* Needs to be called outside of ftrace_lock */
@@ -7139,6 +7144,7 @@ void ftrace_free_mem(struct module *mod, void *start_ptr, void *end_ptr)
unsigned long start = (unsigned long)(start_ptr);
unsigned long end = (unsigned long)(end_ptr);
struct ftrace_page **last_pg = &ftrace_pages_start;
+ struct ftrace_page *tmp_page = NULL;
struct ftrace_page *pg;
struct dyn_ftrace *rec;
struct dyn_ftrace key;
@@ -7180,12 +7186,8 @@ void ftrace_free_mem(struct module *mod, void *start_ptr, void *end_ptr)
ftrace_update_tot_cnt--;
if (!pg->index) {
*last_pg = pg->next;
- if (pg->records) {
- free_pages((unsigned long)pg->records, pg->order);
- ftrace_number_of_pages -= 1 << pg->order;
- }
- ftrace_number_of_groups--;
- kfree(pg);
+ pg->next = tmp_page;
+ tmp_page = pg;
pg = container_of(last_pg, struct ftrace_page, next);
if (!(*last_pg))
ftrace_pages = pg;
@@ -7202,6 +7204,11 @@ void ftrace_free_mem(struct module *mod, void *start_ptr, void *end_ptr)
clear_func_from_hashes(func);
kfree(func);
}
+ /* Need to synchronize with ftrace_location_range() */
+ if (tmp_page) {
+ synchronize_rcu();
+ ftrace_free_pages(tmp_page);
+ }
}
void __init ftrace_free_init_mem(void)
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index faf56d9a9e..943850b25f 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -1456,6 +1456,11 @@ static void rb_check_bpage(struct ring_buffer_per_cpu *cpu_buffer,
*
* As a safety measure we check to make sure the data pages have not
* been corrupted.
+ *
+ * Callers of this function need to guarantee that the list of pages doesn't get
+ * modified during the check. In particular, if it's possible that the function
+ * is invoked with concurrent readers which can swap in a new reader page then
+ * the caller should take cpu_buffer->reader_lock.
*/
static void rb_check_pages(struct ring_buffer_per_cpu *cpu_buffer)
{
@@ -2205,8 +2210,12 @@ int ring_buffer_resize(struct trace_buffer *buffer, unsigned long size,
*/
synchronize_rcu();
for_each_buffer_cpu(buffer, cpu) {
+ unsigned long flags;
+
cpu_buffer = buffer->buffers[cpu];
+ raw_spin_lock_irqsave(&cpu_buffer->reader_lock, flags);
rb_check_pages(cpu_buffer);
+ raw_spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);
}
atomic_dec(&buffer->record_disabled);
}
diff --git a/kernel/trace/trace_events_user.c b/kernel/trace/trace_events_user.c
index e76f5e1efd..704de62f7a 100644
--- a/kernel/trace/trace_events_user.c
+++ b/kernel/trace/trace_events_user.c
@@ -202,6 +202,8 @@ static struct user_event_mm *user_event_mm_get(struct user_event_mm *mm);
static struct user_event_mm *user_event_mm_get_all(struct user_event *user);
static void user_event_mm_put(struct user_event_mm *mm);
static int destroy_user_event(struct user_event *user);
+static bool user_fields_match(struct user_event *user, int argc,
+ const char **argv);
static u32 user_event_key(char *name)
{
@@ -1493,17 +1495,24 @@ static int destroy_user_event(struct user_event *user)
}
static struct user_event *find_user_event(struct user_event_group *group,
- char *name, u32 *outkey)
+ char *name, int argc, const char **argv,
+ u32 flags, u32 *outkey)
{
struct user_event *user;
u32 key = user_event_key(name);
*outkey = key;
- hash_for_each_possible(group->register_table, user, node, key)
- if (!strcmp(EVENT_NAME(user), name))
+ hash_for_each_possible(group->register_table, user, node, key) {
+ if (strcmp(EVENT_NAME(user), name))
+ continue;
+
+ if (user_fields_match(user, argc, argv))
return user_event_get(user);
+ return ERR_PTR(-EADDRINUSE);
+ }
+
return NULL;
}
@@ -1860,6 +1869,9 @@ static bool user_fields_match(struct user_event *user, int argc,
struct list_head *head = &user->fields;
int i = 0;
+ if (argc == 0)
+ return list_empty(head);
+
list_for_each_entry_reverse(field, head, link) {
if (!user_field_match(field, argc, argv, &i))
return false;
@@ -1880,10 +1892,8 @@ static bool user_event_match(const char *system, const char *event,
match = strcmp(EVENT_NAME(user), event) == 0 &&
(!system || strcmp(system, USER_EVENTS_SYSTEM) == 0);
- if (match && argc > 0)
+ if (match)
match = user_fields_match(user, argc, argv);
- else if (match && argc == 0)
- match = list_empty(&user->fields);
return match;
}
@@ -1914,6 +1924,80 @@ static int user_event_trace_register(struct user_event *user)
}
/*
+ * Counts how many ';' without a trailing space are in the args.
+ */
+static int count_semis_no_space(char *args)
+{
+ int count = 0;
+
+ while ((args = strchr(args, ';'))) {
+ args++;
+
+ if (!isspace(*args))
+ count++;
+ }
+
+ return count;
+}
+
+/*
+ * Copies the arguments while ensuring all ';' have a trailing space.
+ */
+static char *insert_space_after_semis(char *args, int count)
+{
+ char *fixed, *pos;
+ int len;
+
+ len = strlen(args) + count;
+ fixed = kmalloc(len + 1, GFP_KERNEL);
+
+ if (!fixed)
+ return NULL;
+
+ pos = fixed;
+
+ /* Insert a space after ';' if there is no trailing space. */
+ while (*args) {
+ *pos = *args++;
+
+ if (*pos++ == ';' && !isspace(*args))
+ *pos++ = ' ';
+ }
+
+ *pos = '\0';
+
+ return fixed;
+}
+
+static char **user_event_argv_split(char *args, int *argc)
+{
+ char **split;
+ char *fixed;
+ int count;
+
+ /* Count how many ';' without a trailing space */
+ count = count_semis_no_space(args);
+
+ /* No fixup is required */
+ if (!count)
+ return argv_split(GFP_KERNEL, args, argc);
+
+ /* We must fixup 'field;field' to 'field; field' */
+ fixed = insert_space_after_semis(args, count);
+
+ if (!fixed)
+ return NULL;
+
+ /* We do a normal split afterwards */
+ split = argv_split(GFP_KERNEL, fixed, argc);
+
+ /* We can free since argv_split makes a copy */
+ kfree(fixed);
+
+ return split;
+}
+
+/*
* Parses the event name, arguments and flags then registers if successful.
* The name buffer lifetime is owned by this method for success cases only.
* Upon success the returned user_event has its ref count increased by 1.
@@ -1922,11 +2006,11 @@ static int user_event_parse(struct user_event_group *group, char *name,
char *args, char *flags,
struct user_event **newuser, int reg_flags)
{
- int ret;
- u32 key;
struct user_event *user;
+ char **argv = NULL;
int argc = 0;
- char **argv;
+ int ret;
+ u32 key;
/* Currently don't support any text based flags */
if (flags != NULL)
@@ -1935,41 +2019,34 @@ static int user_event_parse(struct user_event_group *group, char *name,
if (!user_event_capable(reg_flags))
return -EPERM;
+ if (args) {
+ argv = user_event_argv_split(args, &argc);
+
+ if (!argv)
+ return -ENOMEM;
+ }
+
/* Prevent dyn_event from racing */
mutex_lock(&event_mutex);
- user = find_user_event(group, name, &key);
+ user = find_user_event(group, name, argc, (const char **)argv,
+ reg_flags, &key);
mutex_unlock(&event_mutex);
- if (user) {
- if (args) {
- argv = argv_split(GFP_KERNEL, args, &argc);
- if (!argv) {
- ret = -ENOMEM;
- goto error;
- }
+ if (argv)
+ argv_free(argv);
- ret = user_fields_match(user, argc, (const char **)argv);
- argv_free(argv);
-
- } else
- ret = list_empty(&user->fields);
-
- if (ret) {
- *newuser = user;
- /*
- * Name is allocated by caller, free it since it already exists.
- * Caller only worries about failure cases for freeing.
- */
- kfree(name);
- } else {
- ret = -EADDRINUSE;
- goto error;
- }
+ if (IS_ERR(user))
+ return PTR_ERR(user);
+
+ if (user) {
+ *newuser = user;
+ /*
+ * Name is allocated by caller, free it since it already exists.
+ * Caller only worries about failure cases for freeing.
+ */
+ kfree(name);
return 0;
-error:
- user_event_put(user, false);
- return ret;
}
user = kzalloc(sizeof(*user), GFP_KERNEL_ACCOUNT);
@@ -2052,25 +2129,33 @@ put_user:
}
/*
- * Deletes a previously created event if it is no longer being used.
+ * Deletes previously created events if they are no longer being used.
*/
static int delete_user_event(struct user_event_group *group, char *name)
{
- u32 key;
- struct user_event *user = find_user_event(group, name, &key);
+ struct user_event *user;
+ struct hlist_node *tmp;
+ u32 key = user_event_key(name);
+ int ret = -ENOENT;
- if (!user)
- return -ENOENT;
+ /* Attempt to delete all event(s) with the name passed in */
+ hash_for_each_possible_safe(group->register_table, user, tmp, node, key) {
+ if (strcmp(EVENT_NAME(user), name))
+ continue;
- user_event_put(user, true);
+ if (!user_event_last_ref(user))
+ return -EBUSY;
- if (!user_event_last_ref(user))
- return -EBUSY;
+ if (!user_event_capable(user->reg_flags))
+ return -EPERM;
- if (!user_event_capable(user->reg_flags))
- return -EPERM;
+ ret = destroy_user_event(user);
- return destroy_user_event(user);
+ if (ret)
+ goto out;
+ }
+out:
+ return ret;
}
/*