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Diffstat (limited to 'kernel/trace')
-rw-r--r--kernel/trace/blktrace.c86
-rw-r--r--kernel/trace/ftrace.c101
-rw-r--r--kernel/trace/ring_buffer.c2
-rw-r--r--kernel/trace/trace.c4
4 files changed, 156 insertions, 37 deletions
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index 5ef0484513ec..7ba62d68885a 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -348,7 +348,7 @@ static int __blk_trace_remove(struct request_queue *q)
struct blk_trace *bt;
bt = rcu_replace_pointer(q->blk_trace, NULL,
- lockdep_is_held(&q->blk_trace_mutex));
+ lockdep_is_held(&q->debugfs_mutex));
if (!bt)
return -EINVAL;
@@ -362,9 +362,9 @@ int blk_trace_remove(struct request_queue *q)
{
int ret;
- mutex_lock(&q->blk_trace_mutex);
+ mutex_lock(&q->debugfs_mutex);
ret = __blk_trace_remove(q);
- mutex_unlock(&q->blk_trace_mutex);
+ mutex_unlock(&q->debugfs_mutex);
return ret;
}
@@ -483,12 +483,11 @@ static int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
struct dentry *dir = NULL;
int ret;
+ lockdep_assert_held(&q->debugfs_mutex);
+
if (!buts->buf_size || !buts->buf_nr)
return -EINVAL;
- if (!blk_debugfs_root)
- return -ENOENT;
-
strncpy(buts->name, name, BLKTRACE_BDEV_SIZE);
buts->name[BLKTRACE_BDEV_SIZE - 1] = '\0';
@@ -503,7 +502,7 @@ static int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
* we can be.
*/
if (rcu_dereference_protected(q->blk_trace,
- lockdep_is_held(&q->blk_trace_mutex))) {
+ lockdep_is_held(&q->debugfs_mutex))) {
pr_warn("Concurrent blktraces are not allowed on %s\n",
buts->name);
return -EBUSY;
@@ -522,12 +521,29 @@ static int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
if (!bt->msg_data)
goto err;
- ret = -ENOENT;
-
- dir = debugfs_lookup(buts->name, blk_debugfs_root);
- if (!dir)
+ /*
+ * When tracing the whole disk reuse the existing debugfs directory
+ * created by the block layer on init. For partitions block devices,
+ * and scsi-generic block devices we create a temporary new debugfs
+ * directory that will be removed once the trace ends.
+ */
+ if (bdev && bdev == bdev->bd_contains)
+ dir = q->debugfs_dir;
+ else
bt->dir = dir = debugfs_create_dir(buts->name, blk_debugfs_root);
+ /*
+ * As blktrace relies on debugfs for its interface the debugfs directory
+ * is required, contrary to the usual mantra of not checking for debugfs
+ * files or directories.
+ */
+ if (IS_ERR_OR_NULL(dir)) {
+ pr_warn("debugfs_dir not present for %s so skipping\n",
+ buts->name);
+ ret = -ENOENT;
+ goto err;
+ }
+
bt->dev = dev;
atomic_set(&bt->dropped, 0);
INIT_LIST_HEAD(&bt->running_list);
@@ -563,8 +579,6 @@ static int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
ret = 0;
err:
- if (dir && !bt->dir)
- dput(dir);
if (ret)
blk_trace_free(bt);
return ret;
@@ -597,9 +611,9 @@ int blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
{
int ret;
- mutex_lock(&q->blk_trace_mutex);
+ mutex_lock(&q->debugfs_mutex);
ret = __blk_trace_setup(q, name, dev, bdev, arg);
- mutex_unlock(&q->blk_trace_mutex);
+ mutex_unlock(&q->debugfs_mutex);
return ret;
}
@@ -645,7 +659,7 @@ static int __blk_trace_startstop(struct request_queue *q, int start)
struct blk_trace *bt;
bt = rcu_dereference_protected(q->blk_trace,
- lockdep_is_held(&q->blk_trace_mutex));
+ lockdep_is_held(&q->debugfs_mutex));
if (bt == NULL)
return -EINVAL;
@@ -685,9 +699,9 @@ int blk_trace_startstop(struct request_queue *q, int start)
{
int ret;
- mutex_lock(&q->blk_trace_mutex);
+ mutex_lock(&q->debugfs_mutex);
ret = __blk_trace_startstop(q, start);
- mutex_unlock(&q->blk_trace_mutex);
+ mutex_unlock(&q->debugfs_mutex);
return ret;
}
@@ -716,7 +730,7 @@ int blk_trace_ioctl(struct block_device *bdev, unsigned cmd, char __user *arg)
if (!q)
return -ENXIO;
- mutex_lock(&q->blk_trace_mutex);
+ mutex_lock(&q->debugfs_mutex);
switch (cmd) {
case BLKTRACESETUP:
@@ -743,7 +757,7 @@ int blk_trace_ioctl(struct block_device *bdev, unsigned cmd, char __user *arg)
break;
}
- mutex_unlock(&q->blk_trace_mutex);
+ mutex_unlock(&q->debugfs_mutex);
return ret;
}
@@ -754,14 +768,14 @@ int blk_trace_ioctl(struct block_device *bdev, unsigned cmd, char __user *arg)
**/
void blk_trace_shutdown(struct request_queue *q)
{
- mutex_lock(&q->blk_trace_mutex);
+ mutex_lock(&q->debugfs_mutex);
if (rcu_dereference_protected(q->blk_trace,
- lockdep_is_held(&q->blk_trace_mutex))) {
+ lockdep_is_held(&q->debugfs_mutex))) {
__blk_trace_startstop(q, 0);
__blk_trace_remove(q);
}
- mutex_unlock(&q->blk_trace_mutex);
+ mutex_unlock(&q->debugfs_mutex);
}
#ifdef CONFIG_BLK_CGROUP
@@ -846,6 +860,13 @@ static void blk_add_trace_rq_issue(void *ignore,
blk_trace_request_get_cgid(q, rq));
}
+static void blk_add_trace_rq_merge(void *ignore,
+ struct request_queue *q, struct request *rq)
+{
+ blk_add_trace_rq(rq, 0, blk_rq_bytes(rq), BLK_TA_BACKMERGE,
+ blk_trace_request_get_cgid(q, rq));
+}
+
static void blk_add_trace_rq_requeue(void *ignore,
struct request_queue *q,
struct request *rq)
@@ -1130,6 +1151,8 @@ static void blk_register_tracepoints(void)
WARN_ON(ret);
ret = register_trace_block_rq_issue(blk_add_trace_rq_issue, NULL);
WARN_ON(ret);
+ ret = register_trace_block_rq_merge(blk_add_trace_rq_merge, NULL);
+ WARN_ON(ret);
ret = register_trace_block_rq_requeue(blk_add_trace_rq_requeue, NULL);
WARN_ON(ret);
ret = register_trace_block_rq_complete(blk_add_trace_rq_complete, NULL);
@@ -1176,6 +1199,7 @@ static void blk_unregister_tracepoints(void)
unregister_trace_block_bio_bounce(blk_add_trace_bio_bounce, NULL);
unregister_trace_block_rq_complete(blk_add_trace_rq_complete, NULL);
unregister_trace_block_rq_requeue(blk_add_trace_rq_requeue, NULL);
+ unregister_trace_block_rq_merge(blk_add_trace_rq_merge, NULL);
unregister_trace_block_rq_issue(blk_add_trace_rq_issue, NULL);
unregister_trace_block_rq_insert(blk_add_trace_rq_insert, NULL);
@@ -1642,7 +1666,7 @@ static int blk_trace_remove_queue(struct request_queue *q)
struct blk_trace *bt;
bt = rcu_replace_pointer(q->blk_trace, NULL,
- lockdep_is_held(&q->blk_trace_mutex));
+ lockdep_is_held(&q->debugfs_mutex));
if (bt == NULL)
return -EINVAL;
@@ -1817,10 +1841,10 @@ static ssize_t sysfs_blk_trace_attr_show(struct device *dev,
if (q == NULL)
goto out_bdput;
- mutex_lock(&q->blk_trace_mutex);
+ mutex_lock(&q->debugfs_mutex);
bt = rcu_dereference_protected(q->blk_trace,
- lockdep_is_held(&q->blk_trace_mutex));
+ lockdep_is_held(&q->debugfs_mutex));
if (attr == &dev_attr_enable) {
ret = sprintf(buf, "%u\n", !!bt);
goto out_unlock_bdev;
@@ -1838,7 +1862,7 @@ static ssize_t sysfs_blk_trace_attr_show(struct device *dev,
ret = sprintf(buf, "%llu\n", bt->end_lba);
out_unlock_bdev:
- mutex_unlock(&q->blk_trace_mutex);
+ mutex_unlock(&q->debugfs_mutex);
out_bdput:
bdput(bdev);
out:
@@ -1881,10 +1905,10 @@ static ssize_t sysfs_blk_trace_attr_store(struct device *dev,
if (q == NULL)
goto out_bdput;
- mutex_lock(&q->blk_trace_mutex);
+ mutex_lock(&q->debugfs_mutex);
bt = rcu_dereference_protected(q->blk_trace,
- lockdep_is_held(&q->blk_trace_mutex));
+ lockdep_is_held(&q->debugfs_mutex));
if (attr == &dev_attr_enable) {
if (!!value == !!bt) {
ret = 0;
@@ -1901,7 +1925,7 @@ static ssize_t sysfs_blk_trace_attr_store(struct device *dev,
if (bt == NULL) {
ret = blk_trace_setup_queue(q, bdev);
bt = rcu_dereference_protected(q->blk_trace,
- lockdep_is_held(&q->blk_trace_mutex));
+ lockdep_is_held(&q->debugfs_mutex));
}
if (ret == 0) {
@@ -1916,7 +1940,7 @@ static ssize_t sysfs_blk_trace_attr_store(struct device *dev,
}
out_unlock_bdev:
- mutex_unlock(&q->blk_trace_mutex);
+ mutex_unlock(&q->debugfs_mutex);
out_bdput:
bdput(bdev);
out:
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 1903b80db6eb..72064541bef2 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -2764,6 +2764,50 @@ void __weak arch_ftrace_trampoline_free(struct ftrace_ops *ops)
{
}
+/* List of trace_ops that have allocated trampolines */
+static LIST_HEAD(ftrace_ops_trampoline_list);
+
+static void ftrace_add_trampoline_to_kallsyms(struct ftrace_ops *ops)
+{
+ lockdep_assert_held(&ftrace_lock);
+ list_add_rcu(&ops->list, &ftrace_ops_trampoline_list);
+}
+
+static void ftrace_remove_trampoline_from_kallsyms(struct ftrace_ops *ops)
+{
+ lockdep_assert_held(&ftrace_lock);
+ list_del_rcu(&ops->list);
+}
+
+/*
+ * "__builtin__ftrace" is used as a module name in /proc/kallsyms for symbols
+ * for pages allocated for ftrace purposes, even though "__builtin__ftrace" is
+ * not a module.
+ */
+#define FTRACE_TRAMPOLINE_MOD "__builtin__ftrace"
+#define FTRACE_TRAMPOLINE_SYM "ftrace_trampoline"
+
+static void ftrace_trampoline_free(struct ftrace_ops *ops)
+{
+ if (ops && (ops->flags & FTRACE_OPS_FL_ALLOC_TRAMP) &&
+ ops->trampoline) {
+ /*
+ * Record the text poke event before the ksymbol unregister
+ * event.
+ */
+ perf_event_text_poke((void *)ops->trampoline,
+ (void *)ops->trampoline,
+ ops->trampoline_size, NULL, 0);
+ perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_OOL,
+ ops->trampoline, ops->trampoline_size,
+ true, FTRACE_TRAMPOLINE_SYM);
+ /* Remove from kallsyms after the perf events */
+ ftrace_remove_trampoline_from_kallsyms(ops);
+ }
+
+ arch_ftrace_trampoline_free(ops);
+}
+
static void ftrace_startup_enable(int command)
{
if (saved_ftrace_func != ftrace_trace_function) {
@@ -2934,7 +2978,7 @@ int ftrace_shutdown(struct ftrace_ops *ops, int command)
synchronize_rcu_tasks();
free_ops:
- arch_ftrace_trampoline_free(ops);
+ ftrace_trampoline_free(ops);
}
return 0;
@@ -6178,6 +6222,27 @@ struct ftrace_mod_map {
unsigned int num_funcs;
};
+static int ftrace_get_trampoline_kallsym(unsigned int symnum,
+ unsigned long *value, char *type,
+ char *name, char *module_name,
+ int *exported)
+{
+ struct ftrace_ops *op;
+
+ list_for_each_entry_rcu(op, &ftrace_ops_trampoline_list, list) {
+ if (!op->trampoline || symnum--)
+ continue;
+ *value = op->trampoline;
+ *type = 't';
+ strlcpy(name, FTRACE_TRAMPOLINE_SYM, KSYM_NAME_LEN);
+ strlcpy(module_name, FTRACE_TRAMPOLINE_MOD, MODULE_NAME_LEN);
+ *exported = 0;
+ return 0;
+ }
+
+ return -ERANGE;
+}
+
#ifdef CONFIG_MODULES
#define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next)
@@ -6514,6 +6579,7 @@ int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value,
{
struct ftrace_mod_map *mod_map;
struct ftrace_mod_func *mod_func;
+ int ret;
preempt_disable();
list_for_each_entry_rcu(mod_map, &ftrace_mod_maps, list) {
@@ -6540,8 +6606,10 @@ int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value,
WARN_ON(1);
break;
}
+ ret = ftrace_get_trampoline_kallsym(symnum, value, type, name,
+ module_name, exported);
preempt_enable();
- return -ERANGE;
+ return ret;
}
#else
@@ -6553,6 +6621,18 @@ allocate_ftrace_mod_map(struct module *mod,
{
return NULL;
}
+int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value,
+ char *type, char *name, char *module_name,
+ int *exported)
+{
+ int ret;
+
+ preempt_disable();
+ ret = ftrace_get_trampoline_kallsym(symnum, value, type, name,
+ module_name, exported);
+ preempt_enable();
+ return ret;
+}
#endif /* CONFIG_MODULES */
struct ftrace_init_func {
@@ -6733,7 +6813,24 @@ void __weak arch_ftrace_update_trampoline(struct ftrace_ops *ops)
static void ftrace_update_trampoline(struct ftrace_ops *ops)
{
+ unsigned long trampoline = ops->trampoline;
+
arch_ftrace_update_trampoline(ops);
+ if (ops->trampoline && ops->trampoline != trampoline &&
+ (ops->flags & FTRACE_OPS_FL_ALLOC_TRAMP)) {
+ /* Add to kallsyms before the perf events */
+ ftrace_add_trampoline_to_kallsyms(ops);
+ perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_OOL,
+ ops->trampoline, ops->trampoline_size, false,
+ FTRACE_TRAMPOLINE_SYM);
+ /*
+ * Record the perf text poke event after the ksymbol register
+ * event.
+ */
+ perf_event_text_poke((void *)ops->trampoline, NULL, 0,
+ (void *)ops->trampoline,
+ ops->trampoline_size);
+ }
}
void ftrace_init_trace_array(struct trace_array *tr)
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 00867ff82412..f15471ce969e 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -577,7 +577,7 @@ static void rb_wake_up_waiters(struct irq_work *work)
*/
int ring_buffer_wait(struct trace_buffer *buffer, int cpu, int full)
{
- struct ring_buffer_per_cpu *uninitialized_var(cpu_buffer);
+ struct ring_buffer_per_cpu *cpu_buffer;
DEFINE_WAIT(wait);
struct rb_irq_work *work;
int ret = 0;
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index bb62269724d5..848f67a5f16d 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -8945,9 +8945,7 @@ struct dentry *tracing_init_dentry(void)
if (tr->dir)
return NULL;
- if (WARN_ON(!tracefs_initialized()) ||
- (IS_ENABLED(CONFIG_DEBUG_FS) &&
- WARN_ON(!debugfs_initialized())))
+ if (WARN_ON(!tracefs_initialized()))
return ERR_PTR(-ENODEV);
/*
generated by cgit (git 2.34.1) at 2025-03-28 08:11:14 +0000