Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 443 insertions, 0 deletions

diff --git a/fs/jffs2/super.c b/fs/jffs2/super.c
new file mode 100644
index 000000000..81396a092
--- /dev/null
+++ b/fs/jffs2/super.c
@@ -0,0 +1,443 @@
+/*
+ * JFFS2 -- Journalling Flash File System, Version 2.
+ *
+ * Copyright © 2001-2007 Red Hat, Inc.
+ *
+ * Created by David Woodhouse <dwmw2@infradead.org>
+ *
+ * For licensing information, see the file 'LICENCE' in this directory.
+ *
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/fs.h>
+#include <linux/err.h>
+#include <linux/mount.h>
+#include <linux/fs_context.h>
+#include <linux/fs_parser.h>
+#include <linux/jffs2.h>
+#include <linux/pagemap.h>
+#include <linux/mtd/super.h>
+#include <linux/ctype.h>
+#include <linux/namei.h>
+#include <linux/seq_file.h>
+#include <linux/exportfs.h>
+#include "compr.h"
+#include "nodelist.h"
+
+static void jffs2_put_super(struct super_block *);
+
+static struct kmem_cache *jffs2_inode_cachep;
+
+static struct inode *jffs2_alloc_inode(struct super_block *sb)
+{
+	struct jffs2_inode_info *f;
+
+	f = alloc_inode_sb(sb, jffs2_inode_cachep, GFP_KERNEL);
+	if (!f)
+		return NULL;
+	return &f->vfs_inode;
+}
+
+static void jffs2_free_inode(struct inode *inode)
+{
+	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
+
+	kfree(f->target);
+	kmem_cache_free(jffs2_inode_cachep, f);
+}
+
+static void jffs2_i_init_once(void *foo)
+{
+	struct jffs2_inode_info *f = foo;
+
+	mutex_init(&f->sem);
+	f->target = NULL;
+	inode_init_once(&f->vfs_inode);
+}
+
+static const char *jffs2_compr_name(unsigned int compr)
+{
+	switch (compr) {
+	case JFFS2_COMPR_MODE_NONE:
+		return "none";
+#ifdef CONFIG_JFFS2_LZO
+	case JFFS2_COMPR_MODE_FORCELZO:
+		return "lzo";
+#endif
+#ifdef CONFIG_JFFS2_ZLIB
+	case JFFS2_COMPR_MODE_FORCEZLIB:
+		return "zlib";
+#endif
+	default:
+		/* should never happen; programmer error */
+		WARN_ON(1);
+		return "";
+	}
+}
+
+static int jffs2_show_options(struct seq_file *s, struct dentry *root)
+{
+	struct jffs2_sb_info *c = JFFS2_SB_INFO(root->d_sb);
+	struct jffs2_mount_opts *opts = &c->mount_opts;
+
+	if (opts->override_compr)
+		seq_printf(s, ",compr=%s", jffs2_compr_name(opts->compr));
+	if (opts->set_rp_size)
+		seq_printf(s, ",rp_size=%u", opts->rp_size / 1024);
+
+	return 0;
+}
+
+static int jffs2_sync_fs(struct super_block *sb, int wait)
+{
+	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
+
+#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
+	if (jffs2_is_writebuffered(c))
+		cancel_delayed_work_sync(&c->wbuf_dwork);
+#endif
+
+	mutex_lock(&c->alloc_sem);
+	jffs2_flush_wbuf_pad(c);
+	mutex_unlock(&c->alloc_sem);
+	return 0;
+}
+
+static struct inode *jffs2_nfs_get_inode(struct super_block *sb, uint64_t ino,
+					 uint32_t generation)
+{
+	/* We don't care about i_generation. We'll destroy the flash
+	   before we start re-using inode numbers anyway. And even
+	   if that wasn't true, we'd have other problems...*/
+	return jffs2_iget(sb, ino);
+}
+
+static struct dentry *jffs2_fh_to_dentry(struct super_block *sb, struct fid *fid,
+					 int fh_len, int fh_type)
+{
+        return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
+                                    jffs2_nfs_get_inode);
+}
+
+static struct dentry *jffs2_fh_to_parent(struct super_block *sb, struct fid *fid,
+					 int fh_len, int fh_type)
+{
+        return generic_fh_to_parent(sb, fid, fh_len, fh_type,
+                                    jffs2_nfs_get_inode);
+}
+
+static struct dentry *jffs2_get_parent(struct dentry *child)
+{
+	struct jffs2_inode_info *f;
+	uint32_t pino;
+
+	BUG_ON(!d_is_dir(child));
+
+	f = JFFS2_INODE_INFO(d_inode(child));
+
+	pino = f->inocache->pino_nlink;
+
+	JFFS2_DEBUG("Parent of directory ino #%u is #%u\n",
+		    f->inocache->ino, pino);
+
+	return d_obtain_alias(jffs2_iget(child->d_sb, pino));
+}
+
+static const struct export_operations jffs2_export_ops = {
+	.encode_fh = generic_encode_ino32_fh,
+	.get_parent = jffs2_get_parent,
+	.fh_to_dentry = jffs2_fh_to_dentry,
+	.fh_to_parent = jffs2_fh_to_parent,
+};
+
+/*
+ * JFFS2 mount options.
+ *
+ * Opt_source: The source device
+ * Opt_override_compr: override default compressor
+ * Opt_rp_size: size of reserved pool in KiB
+ */
+enum {
+	Opt_override_compr,
+	Opt_rp_size,
+};
+
+static const struct constant_table jffs2_param_compr[] = {
+	{"none",	JFFS2_COMPR_MODE_NONE },
+#ifdef CONFIG_JFFS2_LZO
+	{"lzo",		JFFS2_COMPR_MODE_FORCELZO },
+#endif
+#ifdef CONFIG_JFFS2_ZLIB
+	{"zlib",	JFFS2_COMPR_MODE_FORCEZLIB },
+#endif
+	{}
+};
+
+static const struct fs_parameter_spec jffs2_fs_parameters[] = {
+	fsparam_enum	("compr",	Opt_override_compr, jffs2_param_compr),
+	fsparam_u32	("rp_size",	Opt_rp_size),
+	{}
+};
+
+static int jffs2_parse_param(struct fs_context *fc, struct fs_parameter *param)
+{
+	struct fs_parse_result result;
+	struct jffs2_sb_info *c = fc->s_fs_info;
+	int opt;
+
+	opt = fs_parse(fc, jffs2_fs_parameters, param, &result);
+	if (opt < 0)
+		return opt;
+
+	switch (opt) {
+	case Opt_override_compr:
+		c->mount_opts.compr = result.uint_32;
+		c->mount_opts.override_compr = true;
+		break;
+	case Opt_rp_size:
+		if (result.uint_32 > UINT_MAX / 1024)
+			return invalf(fc, "jffs2: rp_size unrepresentable");
+		c->mount_opts.rp_size = result.uint_32 * 1024;
+		c->mount_opts.set_rp_size = true;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static inline void jffs2_update_mount_opts(struct fs_context *fc)
+{
+	struct jffs2_sb_info *new_c = fc->s_fs_info;
+	struct jffs2_sb_info *c = JFFS2_SB_INFO(fc->root->d_sb);
+
+	mutex_lock(&c->alloc_sem);
+	if (new_c->mount_opts.override_compr) {
+		c->mount_opts.override_compr = new_c->mount_opts.override_compr;
+		c->mount_opts.compr = new_c->mount_opts.compr;
+	}
+	if (new_c->mount_opts.set_rp_size) {
+		c->mount_opts.set_rp_size = new_c->mount_opts.set_rp_size;
+		c->mount_opts.rp_size = new_c->mount_opts.rp_size;
+	}
+	mutex_unlock(&c->alloc_sem);
+}
+
+static int jffs2_reconfigure(struct fs_context *fc)
+{
+	struct super_block *sb = fc->root->d_sb;
+
+	sync_filesystem(sb);
+	jffs2_update_mount_opts(fc);
+
+	return jffs2_do_remount_fs(sb, fc);
+}
+
+static const struct super_operations jffs2_super_operations =
+{
+	.alloc_inode =	jffs2_alloc_inode,
+	.free_inode =	jffs2_free_inode,
+	.put_super =	jffs2_put_super,
+	.statfs =	jffs2_statfs,
+	.evict_inode =	jffs2_evict_inode,
+	.dirty_inode =	jffs2_dirty_inode,
+	.show_options =	jffs2_show_options,
+	.sync_fs =	jffs2_sync_fs,
+};
+
+/*
+ * fill in the superblock
+ */
+static int jffs2_fill_super(struct super_block *sb, struct fs_context *fc)
+{
+	struct jffs2_sb_info *c = sb->s_fs_info;
+
+	jffs2_dbg(1, "jffs2_get_sb_mtd():"
+		  " New superblock for device %d (\"%s\")\n",
+		  sb->s_mtd->index, sb->s_mtd->name);
+
+	c->mtd = sb->s_mtd;
+	c->os_priv = sb;
+
+	if (c->mount_opts.rp_size > c->mtd->size)
+		return invalf(fc, "jffs2: Too large reserve pool specified, max is %llu KB",
+			      c->mtd->size / 1024);
+
+	/* Initialize JFFS2 superblock locks, the further initialization will
+	 * be done later */
+	mutex_init(&c->alloc_sem);
+	mutex_init(&c->erase_free_sem);
+	init_waitqueue_head(&c->erase_wait);
+	init_waitqueue_head(&c->inocache_wq);
+	spin_lock_init(&c->erase_completion_lock);
+	spin_lock_init(&c->inocache_lock);
+
+	sb->s_op = &jffs2_super_operations;
+	sb->s_export_op = &jffs2_export_ops;
+	sb->s_flags = sb->s_flags | SB_NOATIME;
+	sb->s_xattr = jffs2_xattr_handlers;
+#ifdef CONFIG_JFFS2_FS_POSIX_ACL
+	sb->s_flags |= SB_POSIXACL;
+#endif
+	return jffs2_do_fill_super(sb, fc);
+}
+
+static int jffs2_get_tree(struct fs_context *fc)
+{
+	return get_tree_mtd(fc, jffs2_fill_super);
+}
+
+static void jffs2_free_fc(struct fs_context *fc)
+{
+	kfree(fc->s_fs_info);
+}
+
+static const struct fs_context_operations jffs2_context_ops = {
+	.free		= jffs2_free_fc,
+	.parse_param	= jffs2_parse_param,
+	.get_tree	= jffs2_get_tree,
+	.reconfigure	= jffs2_reconfigure,
+};
+
+static int jffs2_init_fs_context(struct fs_context *fc)
+{
+	struct jffs2_sb_info *ctx;
+
+	ctx = kzalloc_obj(struct jffs2_sb_info);
+	if (!ctx)
+		return -ENOMEM;
+
+	fc->s_fs_info = ctx;
+	fc->ops = &jffs2_context_ops;
+	return 0;
+}
+
+static void jffs2_put_super (struct super_block *sb)
+{
+	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
+
+	jffs2_dbg(2, "%s()\n", __func__);
+
+	mutex_lock(&c->alloc_sem);
+	jffs2_flush_wbuf_pad(c);
+	mutex_unlock(&c->alloc_sem);
+
+	jffs2_sum_exit(c);
+
+	jffs2_free_ino_caches(c);
+	jffs2_free_raw_node_refs(c);
+	kvfree(c->blocks);
+	jffs2_flash_cleanup(c);
+	kfree(c->inocache_list);
+	jffs2_clear_xattr_subsystem(c);
+	mtd_sync(c->mtd);
+	jffs2_dbg(1, "%s(): returning\n", __func__);
+}
+
+static void jffs2_kill_sb(struct super_block *sb)
+{
+	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
+	if (c && !sb_rdonly(sb))
+		jffs2_stop_garbage_collect_thread(c);
+	kill_mtd_super(sb);
+	kfree(c);
+}
+
+static struct file_system_type jffs2_fs_type = {
+	.owner =	THIS_MODULE,
+	.name =		"jffs2",
+	.init_fs_context = jffs2_init_fs_context,
+	.parameters =	jffs2_fs_parameters,
+	.kill_sb =	jffs2_kill_sb,
+};
+MODULE_ALIAS_FS("jffs2");
+
+static int __init init_jffs2_fs(void)
+{
+	int ret;
+
+	/* Paranoia checks for on-medium structures. If we ask GCC
+	   to pack them with __attribute__((packed)) then it _also_
+	   assumes that they're not aligned -- so it emits crappy
+	   code on some architectures. Ideally we want an attribute
+	   which means just 'no padding', without the alignment
+	   thing. But GCC doesn't have that -- we have to just
+	   hope the structs are the right sizes, instead. */
+	BUILD_BUG_ON(sizeof(struct jffs2_unknown_node) != 12);
+	BUILD_BUG_ON(sizeof(struct jffs2_raw_dirent) != 40);
+	BUILD_BUG_ON(sizeof(struct jffs2_raw_inode) != 68);
+	BUILD_BUG_ON(sizeof(struct jffs2_raw_summary) != 32);
+
+	pr_info("version 2.2."
+#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
+	       " (NAND)"
+#endif
+#ifdef CONFIG_JFFS2_SUMMARY
+	       " (SUMMARY) "
+#endif
+	       " © 2001-2006 Red Hat, Inc.\n");
+
+	jffs2_inode_cachep = kmem_cache_create("jffs2_i",
+					     sizeof(struct jffs2_inode_info),
+					     0, (SLAB_RECLAIM_ACCOUNT|
+						SLAB_ACCOUNT),
+					     jffs2_i_init_once);
+	if (!jffs2_inode_cachep) {
+		pr_err("error: Failed to initialise inode cache\n");
+		return -ENOMEM;
+	}
+	ret = jffs2_compressors_init();
+	if (ret) {
+		pr_err("error: Failed to initialise compressors\n");
+		goto out;
+	}
+	ret = jffs2_create_slab_caches();
+	if (ret) {
+		pr_err("error: Failed to initialise slab caches\n");
+		goto out_compressors;
+	}
+	ret = register_filesystem(&jffs2_fs_type);
+	if (ret) {
+		pr_err("error: Failed to register filesystem\n");
+		goto out_slab;
+	}
+	return 0;
+
+ out_slab:
+	jffs2_destroy_slab_caches();
+ out_compressors:
+	jffs2_compressors_exit();
+ out:
+	kmem_cache_destroy(jffs2_inode_cachep);
+	return ret;
+}
+
+static void __exit exit_jffs2_fs(void)
+{
+	unregister_filesystem(&jffs2_fs_type);
+	jffs2_destroy_slab_caches();
+	jffs2_compressors_exit();
+
+	/*
+	 * Make sure all delayed rcu free inodes are flushed before we
+	 * destroy cache.
+	 */
+	rcu_barrier();
+	kmem_cache_destroy(jffs2_inode_cachep);
+}
+
+module_init(init_jffs2_fs);
+module_exit(exit_jffs2_fs);
+
+MODULE_DESCRIPTION("The Journalling Flash File System, v2");
+MODULE_AUTHOR("Red Hat, Inc.");
+MODULE_LICENSE("GPL"); // Actually dual-licensed, but it doesn't matter for
+		       // the sake of this tag. It's Free Software.