1 files changed, 72 insertions, 34 deletions

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 4d8e35575549..72ef4dccbcc4 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1045,7 +1045,7 @@ struct ftrace_ops global_ops = {
 };
 
 /*
- * Used by the stack undwinder to know about dynamic ftrace trampolines.
+ * Used by the stack unwinder to know about dynamic ftrace trampolines.
  */
 struct ftrace_ops *ftrace_ops_trampoline(unsigned long addr)
 {
@@ -1090,7 +1090,7 @@ struct ftrace_page {
 	struct ftrace_page	*next;
 	struct dyn_ftrace	*records;
 	int			index;
-	int			size;
+	int			order;
 };
 
 #define ENTRY_SIZE sizeof(struct dyn_ftrace)
@@ -1967,12 +1967,18 @@ static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops,
 
 static void print_ip_ins(const char *fmt, const unsigned char *p)
 {
+	char ins[MCOUNT_INSN_SIZE];
 	int i;
 
+	if (copy_from_kernel_nofault(ins, p, MCOUNT_INSN_SIZE)) {
+		printk(KERN_CONT "%s[FAULT] %px\n", fmt, p);
+		return;
+	}
+
 	printk(KERN_CONT "%s", fmt);
 
 	for (i = 0; i < MCOUNT_INSN_SIZE; i++)
-		printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]);
+		printk(KERN_CONT "%s%02x", i ? ":" : "", ins[i]);
 }
 
 enum ftrace_bug_type ftrace_bug_type;
@@ -3000,7 +3006,7 @@ int ftrace_shutdown(struct ftrace_ops *ops, int command)
 		 * When the kernel is preemptive, tasks can be preempted
 		 * while on a ftrace trampoline. Just scheduling a task on
 		 * a CPU is not good enough to flush them. Calling
-		 * synchornize_rcu_tasks() will wait for those tasks to
+		 * synchronize_rcu_tasks() will wait for those tasks to
 		 * execute and either schedule voluntarily or enter user space.
 		 */
 		if (IS_ENABLED(CONFIG_PREEMPTION))
@@ -3156,15 +3162,9 @@ static int ftrace_allocate_records(struct ftrace_page *pg, int count)
 	if (WARN_ON(!count))
 		return -EINVAL;
 
+	/* We want to fill as much as possible, with no empty pages */
 	pages = DIV_ROUND_UP(count, ENTRIES_PER_PAGE);
-	order = get_count_order(pages);
-
-	/*
-	 * We want to fill as much as possible. No more than a page
-	 * may be empty.
-	 */
-	if (!is_power_of_2(pages))
-		order--;
+	order = fls(pages) - 1;
 
  again:
 	pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
@@ -3181,7 +3181,7 @@ static int ftrace_allocate_records(struct ftrace_page *pg, int count)
 	ftrace_number_of_groups++;
 
 	cnt = (PAGE_SIZE << order) / ENTRY_SIZE;
-	pg->size = cnt;
+	pg->order = order;
 
 	if (cnt > count)
 		cnt = count;
@@ -3194,7 +3194,6 @@ ftrace_allocate_pages(unsigned long num_to_init)
 {
 	struct ftrace_page *start_pg;
 	struct ftrace_page *pg;
-	int order;
 	int cnt;
 
 	if (!num_to_init)
@@ -3230,12 +3229,13 @@ ftrace_allocate_pages(unsigned long num_to_init)
  free_pages:
 	pg = start_pg;
 	while (pg) {
-		order = get_count_order(pg->size / ENTRIES_PER_PAGE);
-		free_pages((unsigned long)pg->records, order);
+		if (pg->records) {
+			free_pages((unsigned long)pg->records, pg->order);
+			ftrace_number_of_pages -= 1 << pg->order;
+		}
 		start_pg = pg->next;
 		kfree(pg);
 		pg = start_pg;
-		ftrace_number_of_pages -= 1 << order;
 		ftrace_number_of_groups--;
 	}
 	pr_info("ftrace: FAILED to allocate memory for functions\n");
@@ -5045,6 +5045,20 @@ struct ftrace_direct_func *ftrace_find_direct_func(unsigned long addr)
 	return NULL;
 }
 
+static struct ftrace_direct_func *ftrace_alloc_direct_func(unsigned long addr)
+{
+	struct ftrace_direct_func *direct;
+
+	direct = kmalloc(sizeof(*direct), GFP_KERNEL);
+	if (!direct)
+		return NULL;
+	direct->addr = addr;
+	direct->count = 0;
+	list_add_rcu(&direct->next, &ftrace_direct_funcs);
+	ftrace_direct_func_count++;
+	return direct;
+}
+
 /**
  * register_ftrace_direct - Call a custom trampoline directly
  * @ip: The address of the nop at the beginning of a function
@@ -5120,15 +5134,11 @@ int register_ftrace_direct(unsigned long ip, unsigned long addr)
 
 	direct = ftrace_find_direct_func(addr);
 	if (!direct) {
-		direct = kmalloc(sizeof(*direct), GFP_KERNEL);
+		direct = ftrace_alloc_direct_func(addr);
 		if (!direct) {
 			kfree(entry);
 			goto out_unlock;
 		}
-		direct->addr = addr;
-		direct->count = 0;
-		list_add_rcu(&direct->next, &ftrace_direct_funcs);
-		ftrace_direct_func_count++;
 	}
 
 	entry->ip = ip;
@@ -5329,6 +5339,7 @@ int __weak ftrace_modify_direct_caller(struct ftrace_func_entry *entry,
 int modify_ftrace_direct(unsigned long ip,
 			 unsigned long old_addr, unsigned long new_addr)
 {
+	struct ftrace_direct_func *direct, *new_direct = NULL;
 	struct ftrace_func_entry *entry;
 	struct dyn_ftrace *rec;
 	int ret = -ENODEV;
@@ -5344,6 +5355,20 @@ int modify_ftrace_direct(unsigned long ip,
 	if (entry->direct != old_addr)
 		goto out_unlock;
 
+	direct = ftrace_find_direct_func(old_addr);
+	if (WARN_ON(!direct))
+		goto out_unlock;
+	if (direct->count > 1) {
+		ret = -ENOMEM;
+		new_direct = ftrace_alloc_direct_func(new_addr);
+		if (!new_direct)
+			goto out_unlock;
+		direct->count--;
+		new_direct->count++;
+	} else {
+		direct->addr = new_addr;
+	}
+
 	/*
 	 * If there's no other ftrace callback on the rec->ip location,
 	 * then it can be changed directly by the architecture.
@@ -5357,6 +5382,14 @@ int modify_ftrace_direct(unsigned long ip,
 		ret = 0;
 	}
 
+	if (unlikely(ret && new_direct)) {
+		direct->count++;
+		list_del_rcu(&new_direct->next);
+		synchronize_rcu_tasks();
+		kfree(new_direct);
+		ftrace_direct_func_count--;
+	}
+
  out_unlock:
 	mutex_unlock(&ftrace_lock);
 	mutex_unlock(&direct_mutex);
@@ -5373,7 +5406,7 @@ EXPORT_SYMBOL_GPL(modify_ftrace_direct);
  * @reset - non zero to reset all filters before applying this filter.
  *
  * Filters denote which functions should be enabled when tracing is enabled
- * If @ip is NULL, it failes to update filter.
+ * If @ip is NULL, it fails to update filter.
  */
 int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip,
 			 int remove, int reset)
@@ -5597,7 +5630,10 @@ int ftrace_regex_release(struct inode *inode, struct file *file)
 
 	parser = &iter->parser;
 	if (trace_parser_loaded(parser)) {
-		ftrace_match_records(iter->hash, parser->buffer, parser->idx);
+		int enable = !(iter->flags & FTRACE_ITER_NOTRACE);
+
+		ftrace_process_regex(iter, parser->buffer,
+				     parser->idx, enable);
 	}
 
 	trace_parser_put(parser);
@@ -6187,6 +6223,7 @@ static int ftrace_process_locs(struct module *mod,
 	p = start;
 	pg = start_pg;
 	while (p < end) {
+		unsigned long end_offset;
 		addr = ftrace_call_adjust(*p++);
 		/*
 		 * Some architecture linkers will pad between
@@ -6197,7 +6234,8 @@ static int ftrace_process_locs(struct module *mod,
 		if (!addr)
 			continue;
 
-		if (pg->index == pg->size) {
+		end_offset = (pg->index+1) * sizeof(pg->records[0]);
+		if (end_offset > PAGE_SIZE << pg->order) {
 			/* We should have allocated enough */
 			if (WARN_ON(!pg->next))
 				break;
@@ -6325,7 +6363,7 @@ clear_mod_from_hash(struct ftrace_page *pg, struct ftrace_hash *hash)
 	}
 }
 
-/* Clear any records from hashs */
+/* Clear any records from hashes */
 static void clear_mod_from_hashes(struct ftrace_page *pg)
 {
 	struct trace_array *tr;
@@ -6366,7 +6404,6 @@ void ftrace_release_mod(struct module *mod)
 	struct ftrace_page **last_pg;
 	struct ftrace_page *tmp_page = NULL;
 	struct ftrace_page *pg;
-	int order;
 
 	mutex_lock(&ftrace_lock);
 
@@ -6417,11 +6454,12 @@ void ftrace_release_mod(struct module *mod)
 		/* Needs to be called outside of ftrace_lock */
 		clear_mod_from_hashes(pg);
 
-		order = get_count_order(pg->size / ENTRIES_PER_PAGE);
-		free_pages((unsigned long)pg->records, order);
+		if (pg->records) {
+			free_pages((unsigned long)pg->records, pg->order);
+			ftrace_number_of_pages -= 1 << pg->order;
+		}
 		tmp_page = pg->next;
 		kfree(pg);
-		ftrace_number_of_pages -= 1 << order;
 		ftrace_number_of_groups--;
 	}
 }
@@ -6739,7 +6777,6 @@ void ftrace_free_mem(struct module *mod, void *start_ptr, void *end_ptr)
 	struct ftrace_mod_map *mod_map = NULL;
 	struct ftrace_init_func *func, *func_next;
 	struct list_head clear_hash;
-	int order;
 
 	INIT_LIST_HEAD(&clear_hash);
 
@@ -6777,9 +6814,10 @@ void ftrace_free_mem(struct module *mod, void *start_ptr, void *end_ptr)
 		ftrace_update_tot_cnt--;
 		if (!pg->index) {
 			*last_pg = pg->next;
-			order = get_count_order(pg->size / ENTRIES_PER_PAGE);
-			free_pages((unsigned long)pg->records, order);
-			ftrace_number_of_pages -= 1 << order;
+			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 = container_of(last_pg, struct ftrace_page, next);