Merge tag 'trace-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "The major update to this release is that there's a new arch config
  option called CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS.

  Currently, only x86_64 enables it. All the ftrace callbacks now take a
  struct ftrace_regs instead of a struct pt_regs. If the architecture
  has HAVE_DYNAMIC_FTRACE_WITH_ARGS enabled, then the ftrace_regs will
  have enough information to read the arguments of the function being
  traced, as well as access to the stack pointer.

  This way, if a user (like live kernel patching) only cares about the
  arguments, then it can avoid using the heavier weight "regs" callback,
  that puts in enough information in the struct ftrace_regs to simulate
  a breakpoint exception (needed for kprobes).

  A new config option that audits the timestamps of the ftrace ring
  buffer at most every event recorded.

  Ftrace recursion protection has been cleaned up to move the protection
  to the callback itself (this saves on an extra function call for those
  callbacks).

  Perf now handles its own RCU protection and does not depend on ftrace
  to do it for it (saving on that extra function call).

  New debug option to add "recursed_functions" file to tracefs that
  lists all the places that triggered the recursion protection of the
  function tracer. This will show where things need to be fixed as
  recursion slows down the function tracer.

  The eval enum mapping updates done at boot up are now offloaded to a
  work queue, as it caused a noticeable pause on slow embedded boards.

  Various clean ups and last minute fixes"

* tag 'trace-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (33 commits)
  tracing: Offload eval map updates to a work queue
  Revert: "ring-buffer: Remove HAVE_64BIT_ALIGNED_ACCESS"
  ring-buffer: Add rb_check_bpage in __rb_allocate_pages
  ring-buffer: Fix two typos in comments
  tracing: Drop unneeded assignment in ring_buffer_resize()
  tracing: Disable ftrace selftests when any tracer is running
  seq_buf: Avoid type mismatch for seq_buf_init
  ring-buffer: Fix a typo in function description
  ring-buffer: Remove obsolete rb_event_is_commit()
  ring-buffer: Add test to validate the time stamp deltas
  ftrace/documentation: Fix RST C code blocks
  tracing: Clean up after filter logic rewriting
  tracing: Remove the useless value assignment in test_create_synth_event()
  livepatch: Use the default ftrace_ops instead of REGS when ARGS is available
  ftrace/x86: Allow for arguments to be passed in to ftrace_regs by default
  ftrace: Have the callbacks receive a struct ftrace_regs instead of pt_regs
  MAINTAINERS: assign ./fs/tracefs to TRACING
  tracing: Fix some typos in comments
  ftrace: Remove unused varible 'ret'
  ring-buffer: Add recording of ring buffer recursion into recursed_functions
  ...

1 files changed, 28 insertions, 29 deletions

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 9c1bba8cc51b..4d8e35575549 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -80,7 +80,7 @@ enum {
 
 struct ftrace_ops ftrace_list_end __read_mostly = {
 	.func		= ftrace_stub,
-	.flags		= FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_STUB,
+	.flags		= FTRACE_OPS_FL_STUB,
 	INIT_OPS_HASH(ftrace_list_end)
 };
 
@@ -121,7 +121,7 @@ struct ftrace_ops global_ops;
 
 #if ARCH_SUPPORTS_FTRACE_OPS
 static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
-				 struct ftrace_ops *op, struct pt_regs *regs);
+				 struct ftrace_ops *op, struct ftrace_regs *fregs);
 #else
 /* See comment below, where ftrace_ops_list_func is defined */
 static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip);
@@ -140,7 +140,7 @@ static inline void ftrace_ops_init(struct ftrace_ops *ops)
 }
 
 static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip,
-			    struct ftrace_ops *op, struct pt_regs *regs)
+			    struct ftrace_ops *op, struct ftrace_regs *fregs)
 {
 	struct trace_array *tr = op->private;
 	int pid;
@@ -154,7 +154,7 @@ static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip,
 			return;
 	}
 
-	op->saved_func(ip, parent_ip, op, regs);
+	op->saved_func(ip, parent_ip, op, fregs);
 }
 
 static void ftrace_sync_ipi(void *data)
@@ -754,7 +754,7 @@ ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip)
 
 static void
 function_profile_call(unsigned long ip, unsigned long parent_ip,
-		      struct ftrace_ops *ops, struct pt_regs *regs)
+		      struct ftrace_ops *ops, struct ftrace_regs *fregs)
 {
 	struct ftrace_profile_stat *stat;
 	struct ftrace_profile *rec;
@@ -866,7 +866,7 @@ static void unregister_ftrace_profiler(void)
 #else
 static struct ftrace_ops ftrace_profile_ops __read_mostly = {
 	.func		= function_profile_call,
-	.flags		= FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED,
+	.flags		= FTRACE_OPS_FL_INITIALIZED,
 	INIT_OPS_HASH(ftrace_profile_ops)
 };
 
@@ -1040,8 +1040,7 @@ struct ftrace_ops global_ops = {
 	.local_hash.notrace_hash	= EMPTY_HASH,
 	.local_hash.filter_hash		= EMPTY_HASH,
 	INIT_OPS_HASH(global_ops)
-	.flags				= FTRACE_OPS_FL_RECURSION_SAFE |
-					  FTRACE_OPS_FL_INITIALIZED |
+	.flags				= FTRACE_OPS_FL_INITIALIZED |
 					  FTRACE_OPS_FL_PID,
 };
 
@@ -2146,6 +2145,7 @@ static int ftrace_check_record(struct dyn_ftrace *rec, bool enable, bool update)
 				else
 					rec->flags &= ~FTRACE_FL_TRAMP_EN;
 			}
+
 			if (flag & FTRACE_FL_DIRECT) {
 				/*
 				 * If there's only one user (direct_ops helper)
@@ -2389,8 +2389,9 @@ unsigned long ftrace_find_rec_direct(unsigned long ip)
 }
 
 static void call_direct_funcs(unsigned long ip, unsigned long pip,
-			      struct ftrace_ops *ops, struct pt_regs *regs)
+			      struct ftrace_ops *ops, struct ftrace_regs *fregs)
 {
+	struct pt_regs *regs = ftrace_get_regs(fregs);
 	unsigned long addr;
 
 	addr = ftrace_find_rec_direct(ip);
@@ -2402,7 +2403,7 @@ static void call_direct_funcs(unsigned long ip, unsigned long pip,
 
 struct ftrace_ops direct_ops = {
 	.func		= call_direct_funcs,
-	.flags		= FTRACE_OPS_FL_IPMODIFY | FTRACE_OPS_FL_RECURSION_SAFE
+	.flags		= FTRACE_OPS_FL_IPMODIFY
 			  | FTRACE_OPS_FL_DIRECT | FTRACE_OPS_FL_SAVE_REGS
 			  | FTRACE_OPS_FL_PERMANENT,
 	/*
@@ -4183,7 +4184,6 @@ static void process_mod_list(struct list_head *head, struct ftrace_ops *ops,
 	struct ftrace_hash **orig_hash, *new_hash;
 	LIST_HEAD(process_mods);
 	char *func;
-	int ret;
 
 	mutex_lock(&ops->func_hash->regex_lock);
 
@@ -4236,7 +4236,7 @@ static void process_mod_list(struct list_head *head, struct ftrace_ops *ops,
 
 	mutex_lock(&ftrace_lock);
 
-	ret = ftrace_hash_move_and_update_ops(ops, orig_hash,
+	ftrace_hash_move_and_update_ops(ops, orig_hash,
 					      new_hash, enable);
 	mutex_unlock(&ftrace_lock);
 
@@ -4314,7 +4314,7 @@ static int __init ftrace_mod_cmd_init(void)
 core_initcall(ftrace_mod_cmd_init);
 
 static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip,
-				      struct ftrace_ops *op, struct pt_regs *pt_regs)
+				      struct ftrace_ops *op, struct ftrace_regs *fregs)
 {
 	struct ftrace_probe_ops *probe_ops;
 	struct ftrace_func_probe *probe;
@@ -5588,7 +5588,6 @@ int ftrace_regex_release(struct inode *inode, struct file *file)
 	struct ftrace_hash **orig_hash;
 	struct trace_parser *parser;
 	int filter_hash;
-	int ret;
 
 	if (file->f_mode & FMODE_READ) {
 		iter = m->private;
@@ -5616,7 +5615,7 @@ int ftrace_regex_release(struct inode *inode, struct file *file)
 			orig_hash = &iter->ops->func_hash->notrace_hash;
 
 		mutex_lock(&ftrace_lock);
-		ret = ftrace_hash_move_and_update_ops(iter->ops, orig_hash,
+		ftrace_hash_move_and_update_ops(iter->ops, orig_hash,
 						      iter->hash, filter_hash);
 		mutex_unlock(&ftrace_lock);
 	} else {
@@ -6884,8 +6883,7 @@ void ftrace_init_trace_array(struct trace_array *tr)
 
 struct ftrace_ops global_ops = {
 	.func			= ftrace_stub,
-	.flags			= FTRACE_OPS_FL_RECURSION_SAFE |
-				  FTRACE_OPS_FL_INITIALIZED |
+	.flags			= FTRACE_OPS_FL_INITIALIZED |
 				  FTRACE_OPS_FL_PID,
 };
 
@@ -6935,12 +6933,13 @@ void ftrace_reset_array_ops(struct trace_array *tr)
 
 static nokprobe_inline void
 __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
-		       struct ftrace_ops *ignored, struct pt_regs *regs)
+		       struct ftrace_ops *ignored, struct ftrace_regs *fregs)
 {
+	struct pt_regs *regs = ftrace_get_regs(fregs);
 	struct ftrace_ops *op;
 	int bit;
 
-	bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX);
+	bit = trace_test_and_set_recursion(ip, parent_ip, TRACE_LIST_START, TRACE_LIST_MAX);
 	if (bit < 0)
 		return;
 
@@ -6969,7 +6968,7 @@ __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
 				pr_warn("op=%p %pS\n", op, op);
 				goto out;
 			}
-			op->func(ip, parent_ip, op, regs);
+			op->func(ip, parent_ip, op, fregs);
 		}
 	} while_for_each_ftrace_op(op);
 out:
@@ -6992,9 +6991,9 @@ out:
  */
 #if ARCH_SUPPORTS_FTRACE_OPS
 static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
-				 struct ftrace_ops *op, struct pt_regs *regs)
+				 struct ftrace_ops *op, struct ftrace_regs *fregs)
 {
-	__ftrace_ops_list_func(ip, parent_ip, NULL, regs);
+	__ftrace_ops_list_func(ip, parent_ip, NULL, fregs);
 }
 NOKPROBE_SYMBOL(ftrace_ops_list_func);
 #else
@@ -7011,18 +7010,18 @@ NOKPROBE_SYMBOL(ftrace_ops_no_ops);
  * this function will be called by the mcount trampoline.
  */
 static void ftrace_ops_assist_func(unsigned long ip, unsigned long parent_ip,
-				   struct ftrace_ops *op, struct pt_regs *regs)
+				   struct ftrace_ops *op, struct ftrace_regs *fregs)
 {
 	int bit;
 
-	bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX);
+	bit = trace_test_and_set_recursion(ip, parent_ip, TRACE_LIST_START, TRACE_LIST_MAX);
 	if (bit < 0)
 		return;
 
 	preempt_disable_notrace();
 
 	if (!(op->flags & FTRACE_OPS_FL_RCU) || rcu_is_watching())
-		op->func(ip, parent_ip, op, regs);
+		op->func(ip, parent_ip, op, fregs);
 
 	preempt_enable_notrace();
 	trace_clear_recursion(bit);
@@ -7043,11 +7042,11 @@ NOKPROBE_SYMBOL(ftrace_ops_assist_func);
 ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops)
 {
 	/*
-	 * If the function does not handle recursion, needs to be RCU safe,
-	 * or does per cpu logic, then we need to call the assist handler.
+	 * If the function does not handle recursion or needs to be RCU safe,
+	 * then we need to call the assist handler.
 	 */
-	if (!(ops->flags & FTRACE_OPS_FL_RECURSION_SAFE) ||
-	    ops->flags & FTRACE_OPS_FL_RCU)
+	if (ops->flags & (FTRACE_OPS_FL_RECURSION |
+			  FTRACE_OPS_FL_RCU))
 		return ftrace_ops_assist_func;
 
 	return ops->func;