Commit 594d2815 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'trace-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace 

Pull tracing updates from Steven Rostedt:

 - Remove unused ftrace_direct_funcs variables

 - Fix a possible NULL pointer dereference race in eventfs

 - Update do_div() usage in trace event benchmark test

 - Speedup direct function registration with asynchronous RCU callback.

   The synchronization was done in the registration code and this caused
   delays when registering direct callbacks. Move the freeing to a
   call_rcu() that will prevent delaying of the registering.

 - Replace simple_strtoul() usage with kstrtoul()

* tag 'trace-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  eventfs: Fix a possible null pointer dereference in eventfs_find_events()
  ftrace: Fix possible use-after-free issue in ftrace_location()
  ftrace: Remove unused global 'ftrace_direct_func_count'
  ftrace: Remove unused list 'ftrace_direct_funcs'
  tracing: Improve benchmark test performance by using do_div()
  ftrace: Use asynchronous grace period for register_ftrace_direct()
  ftrace: Replaces simple_strtoul in ftrace
parents 70a66320 d4e9a968

fs/tracefs/event_inode.c

+3 −4
Original line number Diff line number Diff line
@@ -345,10 +345,9 @@ static struct eventfs_inode *eventfs_find_events(struct dentry *dentry) 
		 * If the ei is being freed, the ownership of the children

		 * doesn't matter.

		 */

		if (ei->is_freed) {

			ei = NULL;

			break;

		}

		if (ei->is_freed)

			return NULL;



		// Walk upwards until you find the events inode

	} while (!ei->is_events);

include/linux/ftrace.h

+0 −3
Original line number Diff line number Diff line
@@ -83,7 +83,6 @@ static inline void early_trace_init(void) { } 


struct module;

struct ftrace_hash;

struct ftrace_direct_func;



#if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_MODULES) && \

	defined(CONFIG_DYNAMIC_FTRACE)
@@ -414,7 +413,6 @@ struct ftrace_func_entry { 
};



#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS

extern int ftrace_direct_func_count;

unsigned long ftrace_find_rec_direct(unsigned long ip);

int register_ftrace_direct(struct ftrace_ops *ops, unsigned long addr);

int unregister_ftrace_direct(struct ftrace_ops *ops, unsigned long addr,
@@ -426,7 +424,6 @@ void ftrace_stub_direct_tramp(void); 


#else

struct ftrace_ops;

# define ftrace_direct_func_count 0

static inline unsigned long ftrace_find_rec_direct(unsigned long ip)

{

	return 0;

kernel/trace/fgraph.c

+0 −11
Original line number Diff line number Diff line
@@ -125,17 +125,6 @@ int function_graph_enter(unsigned long ret, unsigned long func, 
{

	struct ftrace_graph_ent trace;



#ifndef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS

	/*

	 * Skip graph tracing if the return location is served by direct trampoline,

	 * since call sequence and return addresses are unpredictable anyway.

	 * Ex: BPF trampoline may call original function and may skip frame

	 * depending on type of BPF programs attached.

	 */

	if (ftrace_direct_func_count &&

	    ftrace_find_rec_direct(ret - MCOUNT_INSN_SIZE))

		return -EBUSY;

#endif

	trace.func = func;

	trace.depth = ++current->curr_ret_depth;

kernel/trace/ftrace.c

+35 −33
Original line number Diff line number Diff line
@@ -1595,12 +1595,15 @@ static struct dyn_ftrace *lookup_rec(unsigned long start, unsigned long end) 
unsigned long ftrace_location_range(unsigned long start, unsigned long end)

{

	struct dyn_ftrace *rec;

	unsigned long ip = 0;



	rcu_read_lock();

	rec = lookup_rec(start, end);

	if (rec)

		return rec->ip;

		ip = rec->ip;

	rcu_read_unlock();



	return 0;

	return ip;

}



/**
@@ -1614,25 +1617,22 @@ unsigned long ftrace_location_range(unsigned long start, unsigned long end) 
 */

unsigned long ftrace_location(unsigned long ip)

{

	struct dyn_ftrace *rec;

	unsigned long loc;

	unsigned long offset;

	unsigned long size;



	rec = lookup_rec(ip, ip);

	if (!rec) {

	loc = ftrace_location_range(ip, ip);

	if (!loc) {

		if (!kallsyms_lookup_size_offset(ip, &size, &offset))

			goto out;



		/* map sym+0 to __fentry__ */

		if (!offset)

			rec = lookup_rec(ip, ip + size - 1);

			loc = ftrace_location_range(ip, ip + size - 1);

	}



	if (rec)

		return rec->ip;



out:

	return 0;

	return loc;

}



/**
@@ -2538,7 +2538,6 @@ ftrace_find_unique_ops(struct dyn_ftrace *rec) 
/* Protected by rcu_tasks for reading, and direct_mutex for writing */

static struct ftrace_hash __rcu *direct_functions = EMPTY_HASH;

static DEFINE_MUTEX(direct_mutex);

int ftrace_direct_func_count;



/*

 * Search the direct_functions hash to see if the given instruction pointer
@@ -4201,12 +4200,12 @@ static int 
add_rec_by_index(struct ftrace_hash *hash, struct ftrace_glob *func_g,

		 int clear_filter)

{

	long index = simple_strtoul(func_g->search, NULL, 0);

	long index;

	struct ftrace_page *pg;

	struct dyn_ftrace *rec;



	/* The index starts at 1 */

	if (--index < 0)

	if (kstrtoul(func_g->search, 0, &index) || --index < 0)

		return 0;



	do_for_each_ftrace_rec(pg, rec) {
@@ -5317,14 +5316,6 @@ ftrace_set_addr(struct ftrace_ops *ops, unsigned long *ips, unsigned int cnt, 


#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS



struct ftrace_direct_func {

	struct list_head	next;

	unsigned long		addr;

	int			count;

};



static LIST_HEAD(ftrace_direct_funcs);



static int register_ftrace_function_nolock(struct ftrace_ops *ops);



/*
@@ -5365,6 +5356,13 @@ static void remove_direct_functions_hash(struct ftrace_hash *hash, unsigned long 
	}

}



static void register_ftrace_direct_cb(struct rcu_head *rhp)

{

	struct ftrace_hash *fhp = container_of(rhp, struct ftrace_hash, rcu);



	free_ftrace_hash(fhp);

}



/**

 * register_ftrace_direct - Call a custom trampoline directly

 * for multiple functions registered in @ops
@@ -5463,10 +5461,8 @@ int register_ftrace_direct(struct ftrace_ops *ops, unsigned long addr) 
 out_unlock:

	mutex_unlock(&direct_mutex);



	if (free_hash && free_hash != EMPTY_HASH) {

		synchronize_rcu_tasks();

		free_ftrace_hash(free_hash);

	}

	if (free_hash && free_hash != EMPTY_HASH)

		call_rcu_tasks(&free_hash->rcu, register_ftrace_direct_cb);



	if (new_hash)

		free_ftrace_hash(new_hash);
@@ -5816,9 +5812,8 @@ __setup("ftrace_graph_notrace=", set_graph_notrace_function); 


static int __init set_graph_max_depth_function(char *str)

{

	if (!str)

	if (!str || kstrtouint(str, 0, &fgraph_max_depth))

		return 0;

	fgraph_max_depth = simple_strtoul(str, NULL, 0);

	return 1;

}

__setup("ftrace_graph_max_depth=", set_graph_max_depth_function);
@@ -6595,6 +6590,8 @@ static int ftrace_process_locs(struct module *mod, 
	/* We should have used all pages unless we skipped some */

	if (pg_unuse) {

		WARN_ON(!skipped);

		/* Need to synchronize with ftrace_location_range() */

		synchronize_rcu();

		ftrace_free_pages(pg_unuse);

	}

	return ret;
@@ -6808,6 +6805,9 @@ void ftrace_release_mod(struct module *mod) 
 out_unlock:

	mutex_unlock(&ftrace_lock);



	/* Need to synchronize with ftrace_location_range() */

	if (tmp_page)

		synchronize_rcu();

	for (pg = tmp_page; pg; pg = tmp_page) {



		/* Needs to be called outside of ftrace_lock */
@@ -7141,6 +7141,7 @@ void ftrace_free_mem(struct module *mod, void *start_ptr, void *end_ptr) 
	unsigned long start = (unsigned long)(start_ptr);

	unsigned long end = (unsigned long)(end_ptr);

	struct ftrace_page **last_pg = &ftrace_pages_start;

	struct ftrace_page *tmp_page = NULL;

	struct ftrace_page *pg;

	struct dyn_ftrace *rec;

	struct dyn_ftrace key;
@@ -7182,12 +7183,8 @@ void ftrace_free_mem(struct module *mod, void *start_ptr, void *end_ptr) 
		ftrace_update_tot_cnt--;

		if (!pg->index) {

			*last_pg = pg->next;

			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->next = tmp_page;

			tmp_page = pg;

			pg = container_of(last_pg, struct ftrace_page, next);

			if (!(*last_pg))

				ftrace_pages = pg;
@@ -7204,6 +7201,11 @@ void ftrace_free_mem(struct module *mod, void *start_ptr, void *end_ptr) 
		clear_func_from_hashes(func);

		kfree(func);

	}

	/* Need to synchronize with ftrace_location_range() */

	if (tmp_page) {

		synchronize_rcu();

		ftrace_free_pages(tmp_page);

	}

}



void __init ftrace_free_init_mem(void)

kernel/trace/trace_benchmark.c

+1 −1
Original line number Diff line number Diff line
@@ -104,7 +104,7 @@ static void trace_do_benchmark(void) 
		stddev = 0;



	delta = bm_total;

	delta = div64_u64(delta, bm_cnt);

	do_div(delta, (u32)bm_cnt);

	avg = delta;



	if (stddev > 0) {