1 files changed, 23 insertions, 30 deletions

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 3ba52d4e1314..792b5589ba64 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)
@@ -3000,7 +3000,7 @@ 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 +3156,9 @@ 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 +3175,7 @@ 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 +3188,6 @@ 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)
@@ -3230,13 +3223,13 @@ ftrace_allocate_pages(unsigned long num_to_init)
  free_pages:
 	pg = start_pg;
 	while (pg) {
-		order = get_count_order(pg->size / ENTRIES_PER_PAGE);
-		if (order >= 0)
-			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");
@@ -5407,7 +5400,7 @@ 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)
@@ -6221,6 +6214,7 @@ 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
@@ -6231,7 +6225,8 @@ 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;
@@ -6359,7 +6354,7 @@ 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;
@@ -6400,7 +6395,6 @@ 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);
 
@@ -6451,12 +6445,12 @@ 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);
-		if (order >= 0)
-			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--;
 	}
 }
@@ -6774,7 +6768,6 @@ 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);
 
@@ -6812,10 +6805,10 @@ 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);
-			if (order >= 0)
-				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);