Commit 257dcf29 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'trace-v5.16-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace 

Pull tracing fixes from Steven Rostedt:
 "Tracing, ftrace and tracefs fixes:

   - Have tracefs honor the gid mount option

   - Have new files in tracefs inherit the parent ownership

   - Have direct_ops unregister when it has no more functions

   - Properly clean up the ops when unregistering multi direct ops

   - Add a sample module to test the multiple direct ops

   - Fix memory leak in error path of __create_synth_event()"

* tag 'trace-v5.16-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Fix possible memory leak in __create_synth_event() error path
  ftrace/samples: Add module to test multi direct modify interface
  ftrace: Add cleanup to unregister_ftrace_direct_multi
  ftrace: Use direct_ops hash in unregister_ftrace_direct
  tracefs: Set all files to the same group ownership as the mount option
  tracefs: Have new files inherit the ownership of their parent
parents 0d21e668 c24be24a

fs/tracefs/inode.c

+76 −0
Original line number Diff line number Diff line
@@ -161,6 +161,77 @@ struct tracefs_fs_info { 
	struct tracefs_mount_opts mount_opts;

};



static void change_gid(struct dentry *dentry, kgid_t gid)

{

	if (!dentry->d_inode)

		return;

	dentry->d_inode->i_gid = gid;

}



/*

 * Taken from d_walk, but without he need for handling renames.

 * Nothing can be renamed while walking the list, as tracefs

 * does not support renames. This is only called when mounting

 * or remounting the file system, to set all the files to

 * the given gid.

 */

static void set_gid(struct dentry *parent, kgid_t gid)

{

	struct dentry *this_parent;

	struct list_head *next;



	this_parent = parent;

	spin_lock(&this_parent->d_lock);



	change_gid(this_parent, gid);

repeat:

	next = this_parent->d_subdirs.next;

resume:

	while (next != &this_parent->d_subdirs) {

		struct list_head *tmp = next;

		struct dentry *dentry = list_entry(tmp, struct dentry, d_child);

		next = tmp->next;



		spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);



		change_gid(dentry, gid);



		if (!list_empty(&dentry->d_subdirs)) {

			spin_unlock(&this_parent->d_lock);

			spin_release(&dentry->d_lock.dep_map, _RET_IP_);

			this_parent = dentry;

			spin_acquire(&this_parent->d_lock.dep_map, 0, 1, _RET_IP_);

			goto repeat;

		}

		spin_unlock(&dentry->d_lock);

	}

	/*

	 * All done at this level ... ascend and resume the search.

	 */

	rcu_read_lock();

ascend:

	if (this_parent != parent) {

		struct dentry *child = this_parent;

		this_parent = child->d_parent;



		spin_unlock(&child->d_lock);

		spin_lock(&this_parent->d_lock);



		/* go into the first sibling still alive */

		do {

			next = child->d_child.next;

			if (next == &this_parent->d_subdirs)

				goto ascend;

			child = list_entry(next, struct dentry, d_child);

		} while (unlikely(child->d_flags & DCACHE_DENTRY_KILLED));

		rcu_read_unlock();

		goto resume;

	}

	rcu_read_unlock();

	spin_unlock(&this_parent->d_lock);

	return;

}



static int tracefs_parse_options(char *data, struct tracefs_mount_opts *opts)

{

	substring_t args[MAX_OPT_ARGS];
@@ -193,6 +264,7 @@ static int tracefs_parse_options(char *data, struct tracefs_mount_opts *opts) 
			if (!gid_valid(gid))

				return -EINVAL;

			opts->gid = gid;

			set_gid(tracefs_mount->mnt_root, gid);

			break;

		case Opt_mode:

			if (match_octal(&args[0], &option))
@@ -414,6 +486,8 @@ struct dentry *tracefs_create_file(const char *name, umode_t mode, 
	inode->i_mode = mode;

	inode->i_fop = fops ? fops : &tracefs_file_operations;

	inode->i_private = data;

	inode->i_uid = d_inode(dentry->d_parent)->i_uid;

	inode->i_gid = d_inode(dentry->d_parent)->i_gid;

	d_instantiate(dentry, inode);

	fsnotify_create(dentry->d_parent->d_inode, dentry);

	return end_creating(dentry);
@@ -436,6 +510,8 @@ static struct dentry *__create_dir(const char *name, struct dentry *parent, 
	inode->i_mode = S_IFDIR | S_IRWXU | S_IRUSR| S_IRGRP | S_IXUSR | S_IXGRP;

	inode->i_op = ops;

	inode->i_fop = &simple_dir_operations;

	inode->i_uid = d_inode(dentry->d_parent)->i_uid;

	inode->i_gid = d_inode(dentry->d_parent)->i_gid;



	/* directory inodes start off with i_nlink == 2 (for "." entry) */

	inc_nlink(inode);

kernel/trace/ftrace.c

+7 −1
Original line number Diff line number Diff line
@@ -5217,6 +5217,7 @@ int unregister_ftrace_direct(unsigned long ip, unsigned long addr) 
{

	struct ftrace_direct_func *direct;

	struct ftrace_func_entry *entry;

	struct ftrace_hash *hash;

	int ret = -ENODEV;



	mutex_lock(&direct_mutex);
@@ -5225,7 +5226,8 @@ int unregister_ftrace_direct(unsigned long ip, unsigned long addr) 
	if (!entry)

		goto out_unlock;



	if (direct_functions->count == 1)

	hash = direct_ops.func_hash->filter_hash;

	if (hash->count == 1)

		unregister_ftrace_function(&direct_ops);



	ret = ftrace_set_filter_ip(&direct_ops, ip, 1, 0);
@@ -5540,6 +5542,10 @@ int unregister_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr) 
	err = unregister_ftrace_function(ops);

	remove_direct_functions_hash(hash, addr);

	mutex_unlock(&direct_mutex);



	/* cleanup for possible another register call */

	ops->func = NULL;

	ops->trampoline = 0;

	return err;

}

EXPORT_SYMBOL_GPL(unregister_ftrace_direct_multi);

kernel/trace/trace_events_synth.c

+6 −5
Original line number Diff line number Diff line
@@ -1237,9 +1237,8 @@ static int __create_synth_event(const char *name, const char *raw_fields) 
						  argv + consumed, &consumed,

						  &field_version);

			if (IS_ERR(field)) {

				argv_free(argv);

				ret = PTR_ERR(field);

				goto err;

				goto err_free_arg;

			}



			/*
@@ -1262,18 +1261,19 @@ static int __create_synth_event(const char *name, const char *raw_fields) 
			if (cmd_version > 1 && n_fields_this_loop >= 1) {

				synth_err(SYNTH_ERR_INVALID_CMD, errpos(field_str));

				ret = -EINVAL;

				goto err;

				goto err_free_arg;

			}



			fields[n_fields++] = field;

			if (n_fields == SYNTH_FIELDS_MAX) {

				synth_err(SYNTH_ERR_TOO_MANY_FIELDS, 0);

				ret = -EINVAL;

				goto err;

				goto err_free_arg;

			}



			n_fields_this_loop++;

		}

		argv_free(argv);



		if (consumed < argc) {

			synth_err(SYNTH_ERR_INVALID_CMD, 0);
@@ -1281,7 +1281,6 @@ static int __create_synth_event(const char *name, const char *raw_fields) 
			goto err;

		}



		argv_free(argv);

	}



	if (n_fields == 0) {
@@ -1307,6 +1306,8 @@ static int __create_synth_event(const char *name, const char *raw_fields) 
	kfree(saved_fields);



	return ret;

 err_free_arg:

	argv_free(argv);

 err:

	for (i = 0; i < n_fields; i++)

		free_synth_field(fields[i]);

samples/ftrace/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -4,6 +4,7 @@ obj-$(CONFIG_SAMPLE_FTRACE_DIRECT) += ftrace-direct.o 
obj-$(CONFIG_SAMPLE_FTRACE_DIRECT) += ftrace-direct-too.o

obj-$(CONFIG_SAMPLE_FTRACE_DIRECT) += ftrace-direct-modify.o

obj-$(CONFIG_SAMPLE_FTRACE_DIRECT_MULTI) += ftrace-direct-multi.o

obj-$(CONFIG_SAMPLE_FTRACE_DIRECT_MULTI) += ftrace-direct-multi-modify.o



CFLAGS_sample-trace-array.o := -I$(src)

obj-$(CONFIG_SAMPLE_TRACE_ARRAY) += sample-trace-array.o

samples/ftrace/ftrace-direct-multi-modify.c

0 → 100644
+152 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0-only

#include <linux/module.h>

#include <linux/kthread.h>

#include <linux/ftrace.h>

#include <asm/asm-offsets.h>



void my_direct_func1(unsigned long ip)

{

	trace_printk("my direct func1 ip %lx\n", ip);

}



void my_direct_func2(unsigned long ip)

{

	trace_printk("my direct func2 ip %lx\n", ip);

}



extern void my_tramp1(void *);

extern void my_tramp2(void *);



#ifdef CONFIG_X86_64



asm (

"	.pushsection    .text, \"ax\", @progbits\n"

"	.type		my_tramp1, @function\n"

"	.globl		my_tramp1\n"

"   my_tramp1:"

"	pushq %rbp\n"

"	movq %rsp, %rbp\n"

"	pushq %rdi\n"

"	movq 8(%rbp), %rdi\n"

"	call my_direct_func1\n"

"	popq %rdi\n"

"	leave\n"

"	ret\n"

"	.size		my_tramp1, .-my_tramp1\n"

"	.type		my_tramp2, @function\n"

"\n"

"	.globl		my_tramp2\n"

"   my_tramp2:"

"	pushq %rbp\n"

"	movq %rsp, %rbp\n"

"	pushq %rdi\n"

"	movq 8(%rbp), %rdi\n"

"	call my_direct_func2\n"

"	popq %rdi\n"

"	leave\n"

"	ret\n"

"	.size		my_tramp2, .-my_tramp2\n"

"	.popsection\n"

);



#endif /* CONFIG_X86_64 */



#ifdef CONFIG_S390



asm (

"       .pushsection    .text, \"ax\", @progbits\n"

"       .type           my_tramp1, @function\n"

"       .globl          my_tramp1\n"

"   my_tramp1:"

"       lgr             %r1,%r15\n"

"       stmg            %r0,%r5,"__stringify(__SF_GPRS)"(%r15)\n"

"       stg             %r14,"__stringify(__SF_GPRS+8*8)"(%r15)\n"

"       aghi            %r15,"__stringify(-STACK_FRAME_OVERHEAD)"\n"

"       stg             %r1,"__stringify(__SF_BACKCHAIN)"(%r15)\n"

"       lgr             %r2,%r0\n"

"       brasl           %r14,my_direct_func1\n"

"       aghi            %r15,"__stringify(STACK_FRAME_OVERHEAD)"\n"

"       lmg             %r0,%r5,"__stringify(__SF_GPRS)"(%r15)\n"

"       lg              %r14,"__stringify(__SF_GPRS+8*8)"(%r15)\n"

"       lgr             %r1,%r0\n"

"       br              %r1\n"

"       .size           my_tramp1, .-my_tramp1\n"

"\n"

"       .type           my_tramp2, @function\n"

"       .globl          my_tramp2\n"

"   my_tramp2:"

"       lgr             %r1,%r15\n"

"       stmg            %r0,%r5,"__stringify(__SF_GPRS)"(%r15)\n"

"       stg             %r14,"__stringify(__SF_GPRS+8*8)"(%r15)\n"

"       aghi            %r15,"__stringify(-STACK_FRAME_OVERHEAD)"\n"

"       stg             %r1,"__stringify(__SF_BACKCHAIN)"(%r15)\n"

"       lgr             %r2,%r0\n"

"       brasl           %r14,my_direct_func2\n"

"       aghi            %r15,"__stringify(STACK_FRAME_OVERHEAD)"\n"

"       lmg             %r0,%r5,"__stringify(__SF_GPRS)"(%r15)\n"

"       lg              %r14,"__stringify(__SF_GPRS+8*8)"(%r15)\n"

"       lgr             %r1,%r0\n"

"       br              %r1\n"

"       .size           my_tramp2, .-my_tramp2\n"

"       .popsection\n"

);



#endif /* CONFIG_S390 */



static unsigned long my_tramp = (unsigned long)my_tramp1;

static unsigned long tramps[2] = {

	(unsigned long)my_tramp1,

	(unsigned long)my_tramp2,

};



static struct ftrace_ops direct;



static int simple_thread(void *arg)

{

	static int t;

	int ret = 0;



	while (!kthread_should_stop()) {

		set_current_state(TASK_INTERRUPTIBLE);

		schedule_timeout(2 * HZ);



		if (ret)

			continue;

		t ^= 1;

		ret = modify_ftrace_direct_multi(&direct, tramps[t]);

		if (!ret)

			my_tramp = tramps[t];

		WARN_ON_ONCE(ret);

	}



	return 0;

}



static struct task_struct *simple_tsk;



static int __init ftrace_direct_multi_init(void)

{

	int ret;



	ftrace_set_filter_ip(&direct, (unsigned long) wake_up_process, 0, 0);

	ftrace_set_filter_ip(&direct, (unsigned long) schedule, 0, 0);



	ret = register_ftrace_direct_multi(&direct, my_tramp);



	if (!ret)

		simple_tsk = kthread_run(simple_thread, NULL, "event-sample-fn");

	return ret;

}



static void __exit ftrace_direct_multi_exit(void)

{

	kthread_stop(simple_tsk);

	unregister_ftrace_direct_multi(&direct, my_tramp);

}



module_init(ftrace_direct_multi_init);

module_exit(ftrace_direct_multi_exit);



MODULE_AUTHOR("Jiri Olsa");

MODULE_DESCRIPTION("Example use case of using modify_ftrace_direct_multi()");

MODULE_LICENSE("GPL");