Merge tag 'trace-v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "New feature:

   - A new "func-no-repeats" option in tracefs/options directory.

     When set the function tracer will detect if the current function
     being traced is the same as the previous one, and instead of
     recording it, it will keep track of the number of times that the
     function is repeated in a row. And when another function is
     recorded, it will write a new event that shows the function that
     repeated, the number of times it repeated and the time stamp of
     when the last repeated function occurred.

  Enhancements:

   - In order to implement the above "func-no-repeats" option, the ring
     buffer timestamp can now give the accurate timestamp of the event
     as it is being recorded, instead of having to record an absolute
     timestamp for all events. This helps the histogram code which no
     longer needs to waste ring buffer space.

   - New validation logic to make sure all trace events that access
     dereferenced pointers do so in a safe way, and will warn otherwise.

  Fixes:

   - No longer limit the PIDs of tasks that are recorded for
     "saved_cmdlines" to PID_MAX_DEFAULT (32768), as systemd now allows
     for a much larger range. This caused the mapping of PIDs to the
     task names to be dropped for all tasks with a PID greater than
     32768.

   - Change trace_clock_global() to never block. This caused a deadlock.

  Clean ups:

   - Typos, prototype fixes, and removing of duplicate or unused code.

   - Better management of ftrace_page allocations"

* tag 'trace-v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (32 commits)
  tracing: Restructure trace_clock_global() to never block
  tracing: Map all PIDs to command lines
  ftrace: Reuse the output of the function tracer for func_repeats
  tracing: Add "func_no_repeats" option for function tracing
  tracing: Unify the logic for function tracing options
  tracing: Add method for recording "func_repeats" events
  tracing: Add "last_func_repeats" to struct trace_array
  tracing: Define new ftrace event "func_repeats"
  tracing: Define static void trace_print_time()
  ftrace: Simplify the calculation of page number for ftrace_page->records some more
  ftrace: Store the order of pages allocated in ftrace_page
  tracing: Remove unused argument from "ring_buffer_time_stamp()
  tracing: Remove duplicate struct declaration in trace_events.h
  tracing: Update create_system_filter() kernel-doc comment
  tracing: A minor cleanup for create_system_filter()
  kernel: trace: Mundane typo fixes in the file trace_events_filter.c
  tracing: Fix various typos in comments
  scripts/recordmcount.pl: Make vim and emacs indent the same
  scripts/recordmcount.pl: Make indent spacing consistent
  tracing: Add a verifier to check string pointers for trace events
  ...

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);