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, 502 insertions, 0 deletions

diff --git a/fs/adfs/super.c b/fs/adfs/super.c
new file mode 100644
index 000000000..a4cd0a515
--- /dev/null
+++ b/fs/adfs/super.c
@@ -0,0 +1,502 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  linux/fs/adfs/super.c
+ *
+ *  Copyright (C) 1997-1999 Russell King
+ */
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/fs_parser.h>
+#include <linux/fs_context.h>
+#include <linux/mount.h>
+#include <linux/seq_file.h>
+#include <linux/slab.h>
+#include <linux/statfs.h>
+#include <linux/user_namespace.h>
+#include <linux/blkdev.h>
+#include "adfs.h"
+#include "dir_f.h"
+#include "dir_fplus.h"
+
+#define ADFS_SB_FLAGS SB_NOATIME
+
+#define ADFS_DEFAULT_OWNER_MASK S_IRWXU
+#define ADFS_DEFAULT_OTHER_MASK (S_IRWXG | S_IRWXO)
+
+void __adfs_error(struct super_block *sb, const char *function, const char *fmt, ...)
+{
+	struct va_format vaf;
+	va_list args;
+
+	va_start(args, fmt);
+	vaf.fmt = fmt;
+	vaf.va = &args;
+
+	printk(KERN_CRIT "ADFS-fs error (device %s)%s%s: %pV\n",
+		sb->s_id, function ? ": " : "",
+		function ? function : "", &vaf);
+
+	va_end(args);
+}
+
+void adfs_msg(struct super_block *sb, const char *pfx, const char *fmt, ...)
+{
+	struct va_format vaf;
+	va_list args;
+
+	va_start(args, fmt);
+	vaf.fmt = fmt;
+	vaf.va = &args;
+	printk("%sADFS-fs (%s): %pV\n", pfx, sb->s_id, &vaf);
+	va_end(args);
+}
+
+static int adfs_checkdiscrecord(struct adfs_discrecord *dr)
+{
+	unsigned int max_idlen;
+	int i;
+
+	/* sector size must be 256, 512 or 1024 bytes */
+	if (dr->log2secsize != 8 &&
+	    dr->log2secsize != 9 &&
+	    dr->log2secsize != 10)
+		return 1;
+
+	/* idlen must be at least log2secsize + 3 */
+	if (dr->idlen < dr->log2secsize + 3)
+		return 1;
+
+	/* we cannot have such a large disc that we
+	 * are unable to represent sector offsets in
+	 * 32 bits.  This works out at 2.0 TB.
+	 */
+	if (le32_to_cpu(dr->disc_size_high) >> dr->log2secsize)
+		return 1;
+
+	/*
+	 * Maximum idlen is limited to 16 bits for new directories by
+	 * the three-byte storage of an indirect disc address.  For
+	 * big directories, idlen must be no greater than 19 v2 [1.0]
+	 */
+	max_idlen = dr->format_version ? 19 : 16;
+	if (dr->idlen > max_idlen)
+		return 1;
+
+	/* reserved bytes should be zero */
+	for (i = 0; i < sizeof(dr->unused52); i++)
+		if (dr->unused52[i] != 0)
+			return 1;
+
+	return 0;
+}
+
+static void adfs_put_super(struct super_block *sb)
+{
+	struct adfs_sb_info *asb = ADFS_SB(sb);
+
+	adfs_free_map(sb);
+	kfree_rcu(asb, rcu);
+}
+
+static int adfs_show_options(struct seq_file *seq, struct dentry *root)
+{
+	struct adfs_sb_info *asb = ADFS_SB(root->d_sb);
+
+	if (!uid_eq(asb->s_uid, GLOBAL_ROOT_UID))
+		seq_printf(seq, ",uid=%u", from_kuid_munged(&init_user_ns, asb->s_uid));
+	if (!gid_eq(asb->s_gid, GLOBAL_ROOT_GID))
+		seq_printf(seq, ",gid=%u", from_kgid_munged(&init_user_ns, asb->s_gid));
+	if (asb->s_owner_mask != ADFS_DEFAULT_OWNER_MASK)
+		seq_printf(seq, ",ownmask=%o", asb->s_owner_mask);
+	if (asb->s_other_mask != ADFS_DEFAULT_OTHER_MASK)
+		seq_printf(seq, ",othmask=%o", asb->s_other_mask);
+	if (asb->s_ftsuffix != 0)
+		seq_printf(seq, ",ftsuffix=%u", asb->s_ftsuffix);
+
+	return 0;
+}
+
+enum {Opt_uid, Opt_gid, Opt_ownmask, Opt_othmask, Opt_ftsuffix};
+
+static const struct fs_parameter_spec adfs_param_spec[] = {
+	fsparam_uid	("uid",		Opt_uid),
+	fsparam_gid	("gid",		Opt_gid),
+	fsparam_u32oct	("ownmask",	Opt_ownmask),
+	fsparam_u32oct	("othmask",	Opt_othmask),
+	fsparam_u32	("ftsuffix",	Opt_ftsuffix),
+	{}
+};
+
+static int adfs_parse_param(struct fs_context *fc, struct fs_parameter *param)
+{
+	struct adfs_sb_info *asb = fc->s_fs_info;
+	struct fs_parse_result result;
+	int opt;
+
+	opt = fs_parse(fc, adfs_param_spec, param, &result);
+	if (opt < 0)
+		return opt;
+
+	switch (opt) {
+	case Opt_uid:
+		asb->s_uid = result.uid;
+		break;
+	case Opt_gid:
+		asb->s_gid = result.gid;
+		break;
+	case Opt_ownmask:
+		asb->s_owner_mask = result.uint_32;
+		break;
+	case Opt_othmask:
+		asb->s_other_mask = result.uint_32;
+		break;
+	case Opt_ftsuffix:
+		asb->s_ftsuffix = result.uint_32;
+		break;
+	default:
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static int adfs_reconfigure(struct fs_context *fc)
+{
+	struct adfs_sb_info *new_asb = fc->s_fs_info;
+	struct adfs_sb_info *asb = ADFS_SB(fc->root->d_sb);
+
+	sync_filesystem(fc->root->d_sb);
+	fc->sb_flags |= ADFS_SB_FLAGS;
+
+	/* Structure copy newly parsed options */
+	*asb = *new_asb;
+
+	return 0;
+}
+
+static int adfs_statfs(struct dentry *dentry, struct kstatfs *buf)
+{
+	struct super_block *sb = dentry->d_sb;
+	struct adfs_sb_info *sbi = ADFS_SB(sb);
+	u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
+
+	adfs_map_statfs(sb, buf);
+
+	buf->f_type    = ADFS_SUPER_MAGIC;
+	buf->f_namelen = sbi->s_namelen;
+	buf->f_bsize   = sb->s_blocksize;
+	buf->f_ffree   = (long)(buf->f_bfree * buf->f_files) / (long)buf->f_blocks;
+	buf->f_fsid    = u64_to_fsid(id);
+
+	return 0;
+}
+
+static struct kmem_cache *adfs_inode_cachep;
+
+static struct inode *adfs_alloc_inode(struct super_block *sb)
+{
+	struct adfs_inode_info *ei;
+	ei = alloc_inode_sb(sb, adfs_inode_cachep, GFP_KERNEL);
+	if (!ei)
+		return NULL;
+	return &ei->vfs_inode;
+}
+
+static void adfs_free_inode(struct inode *inode)
+{
+	kmem_cache_free(adfs_inode_cachep, ADFS_I(inode));
+}
+
+static int adfs_drop_inode(struct inode *inode)
+{
+	/* always drop inodes if we are read-only */
+	return !IS_ENABLED(CONFIG_ADFS_FS_RW) || IS_RDONLY(inode);
+}
+
+static void init_once(void *foo)
+{
+	struct adfs_inode_info *ei = (struct adfs_inode_info *) foo;
+
+	inode_init_once(&ei->vfs_inode);
+}
+
+static int __init init_inodecache(void)
+{
+	adfs_inode_cachep = kmem_cache_create("adfs_inode_cache",
+					     sizeof(struct adfs_inode_info),
+					     0, (SLAB_RECLAIM_ACCOUNT|
+						SLAB_ACCOUNT),
+					     init_once);
+	if (adfs_inode_cachep == NULL)
+		return -ENOMEM;
+	return 0;
+}
+
+static void destroy_inodecache(void)
+{
+	/*
+	 * Make sure all delayed rcu free inodes are flushed before we
+	 * destroy cache.
+	 */
+	rcu_barrier();
+	kmem_cache_destroy(adfs_inode_cachep);
+}
+
+static const struct super_operations adfs_sops = {
+	.alloc_inode	= adfs_alloc_inode,
+	.free_inode	= adfs_free_inode,
+	.drop_inode	= adfs_drop_inode,
+	.write_inode	= adfs_write_inode,
+	.put_super	= adfs_put_super,
+	.statfs		= adfs_statfs,
+	.show_options	= adfs_show_options,
+};
+
+static int adfs_probe(struct super_block *sb, unsigned int offset, int silent,
+		      int (*validate)(struct super_block *sb,
+				      struct buffer_head *bh,
+				      struct adfs_discrecord **bhp))
+{
+	struct adfs_sb_info *asb = ADFS_SB(sb);
+	struct adfs_discrecord *dr;
+	struct buffer_head *bh;
+	unsigned int blocksize = BLOCK_SIZE;
+	int ret, try;
+
+	for (try = 0; try < 2; try++) {
+		/* try to set the requested block size */
+		if (sb->s_blocksize != blocksize &&
+		    !sb_set_blocksize(sb, blocksize)) {
+			if (!silent)
+				adfs_msg(sb, KERN_ERR,
+					 "error: unsupported blocksize");
+			return -EINVAL;
+		}
+
+		/* read the buffer */
+		bh = sb_bread(sb, offset >> sb->s_blocksize_bits);
+		if (!bh) {
+			adfs_msg(sb, KERN_ERR,
+				 "error: unable to read block %u, try %d",
+				 offset >> sb->s_blocksize_bits, try);
+			return -EIO;
+		}
+
+		/* validate it */
+		ret = validate(sb, bh, &dr);
+		if (ret) {
+			brelse(bh);
+			return ret;
+		}
+
+		/* does the block size match the filesystem block size? */
+		blocksize = 1 << dr->log2secsize;
+		if (sb->s_blocksize == blocksize) {
+			asb->s_map = adfs_read_map(sb, dr);
+			brelse(bh);
+			return PTR_ERR_OR_ZERO(asb->s_map);
+		}
+
+		brelse(bh);
+	}
+
+	return -EIO;
+}
+
+static int adfs_validate_bblk(struct super_block *sb, struct buffer_head *bh,
+			      struct adfs_discrecord **drp)
+{
+	struct adfs_discrecord *dr;
+	unsigned char *b_data;
+
+	b_data = bh->b_data + (ADFS_DISCRECORD % sb->s_blocksize);
+	if (adfs_checkbblk(b_data))
+		return -EILSEQ;
+
+	/* Do some sanity checks on the ADFS disc record */
+	dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET);
+	if (adfs_checkdiscrecord(dr))
+		return -EILSEQ;
+
+	if ((dr->nzones | dr->nzones_high << 8) == 0)
+		return -EILSEQ;
+
+	*drp = dr;
+	return 0;
+}
+
+static int adfs_validate_dr0(struct super_block *sb, struct buffer_head *bh,
+			      struct adfs_discrecord **drp)
+{
+	struct adfs_discrecord *dr;
+
+	/* Do some sanity checks on the ADFS disc record */
+	dr = (struct adfs_discrecord *)(bh->b_data + 4);
+	if (adfs_checkdiscrecord(dr) || dr->nzones_high || dr->nzones != 1)
+		return -EILSEQ;
+
+	*drp = dr;
+	return 0;
+}
+
+static int adfs_fill_super(struct super_block *sb, struct fs_context *fc)
+{
+	struct adfs_discrecord *dr;
+	struct object_info root_obj;
+	struct adfs_sb_info *asb = sb->s_fs_info;
+	struct inode *root;
+	int ret = -EINVAL;
+	int silent = fc->sb_flags & SB_SILENT;
+
+	sb->s_flags |= ADFS_SB_FLAGS;
+
+	sb->s_fs_info = asb;
+	sb->s_magic = ADFS_SUPER_MAGIC;
+	sb->s_time_gran = 10000000;
+
+	/* Try to probe the filesystem boot block */
+	ret = adfs_probe(sb, ADFS_DISCRECORD, 1, adfs_validate_bblk);
+	if (ret == -EILSEQ)
+		ret = adfs_probe(sb, 0, silent, adfs_validate_dr0);
+	if (ret == -EILSEQ) {
+		if (!silent)
+			adfs_msg(sb, KERN_ERR,
+				 "error: can't find an ADFS filesystem on dev %s.",
+				 sb->s_id);
+		ret = -EINVAL;
+	}
+	if (ret)
+		goto error;
+
+	/* set up enough so that we can read an inode */
+	sb->s_op = &adfs_sops;
+
+	dr = adfs_map_discrecord(asb->s_map);
+
+	root_obj.parent_id = root_obj.indaddr = le32_to_cpu(dr->root);
+	root_obj.name_len  = 0;
+	/* Set root object date as 01 Jan 1987 00:00:00 */
+	root_obj.loadaddr  = 0xfff0003f;
+	root_obj.execaddr  = 0xec22c000;
+	root_obj.size	   = ADFS_NEWDIR_SIZE;
+	root_obj.attr	   = ADFS_NDA_DIRECTORY   | ADFS_NDA_OWNER_READ |
+			     ADFS_NDA_OWNER_WRITE | ADFS_NDA_PUBLIC_READ;
+
+	/*
+	 * If this is a F+ disk with variable length directories,
+	 * get the root_size from the disc record.
+	 */
+	if (dr->format_version) {
+		root_obj.size = le32_to_cpu(dr->root_size);
+		asb->s_dir     = &adfs_fplus_dir_ops;
+		asb->s_namelen = ADFS_FPLUS_NAME_LEN;
+	} else {
+		asb->s_dir     = &adfs_f_dir_ops;
+		asb->s_namelen = ADFS_F_NAME_LEN;
+	}
+	/*
+	 * ,xyz hex filetype suffix may be added by driver
+	 * to files that have valid RISC OS filetype
+	 */
+	if (asb->s_ftsuffix)
+		asb->s_namelen += 4;
+
+	set_default_d_op(sb, &adfs_dentry_operations);
+	root = adfs_iget(sb, &root_obj);
+	sb->s_root = d_make_root(root);
+	if (!sb->s_root) {
+		adfs_free_map(sb);
+		adfs_error(sb, "get root inode failed\n");
+		ret = -EIO;
+		goto error;
+	}
+	return 0;
+
+error:
+	sb->s_fs_info = NULL;
+	kfree(asb);
+	return ret;
+}
+
+static int adfs_get_tree(struct fs_context *fc)
+{
+	return get_tree_bdev(fc, adfs_fill_super);
+}
+
+static void adfs_free_fc(struct fs_context *fc)
+{
+	struct adfs_context *asb = fc->s_fs_info;
+
+	kfree(asb);
+}
+
+static const struct fs_context_operations adfs_context_ops = {
+	.parse_param	= adfs_parse_param,
+	.get_tree	= adfs_get_tree,
+	.reconfigure	= adfs_reconfigure,
+	.free		= adfs_free_fc,
+};
+
+static int adfs_init_fs_context(struct fs_context *fc)
+{
+	struct adfs_sb_info *asb;
+
+	asb = kzalloc_obj(struct adfs_sb_info);
+	if (!asb)
+		return -ENOMEM;
+
+	if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
+		struct super_block *sb = fc->root->d_sb;
+		struct adfs_sb_info *old_asb = ADFS_SB(sb);
+
+		/* structure copy existing options before parsing */
+		*asb = *old_asb;
+	} else {
+		/* set default options */
+		asb->s_uid = GLOBAL_ROOT_UID;
+		asb->s_gid = GLOBAL_ROOT_GID;
+		asb->s_owner_mask = ADFS_DEFAULT_OWNER_MASK;
+		asb->s_other_mask = ADFS_DEFAULT_OTHER_MASK;
+		asb->s_ftsuffix = 0;
+	}
+
+	fc->ops = &adfs_context_ops;
+	fc->s_fs_info = asb;
+
+	return 0;
+}
+
+static struct file_system_type adfs_fs_type = {
+	.owner		= THIS_MODULE,
+	.name		= "adfs",
+	.kill_sb	= kill_block_super,
+	.fs_flags	= FS_REQUIRES_DEV,
+	.init_fs_context = adfs_init_fs_context,
+	.parameters	= adfs_param_spec,
+};
+MODULE_ALIAS_FS("adfs");
+
+static int __init init_adfs_fs(void)
+{
+	int err = init_inodecache();
+	if (err)
+		goto out1;
+	err = register_filesystem(&adfs_fs_type);
+	if (err)
+		goto out;
+	return 0;
+out:
+	destroy_inodecache();
+out1:
+	return err;
+}
+
+static void __exit exit_adfs_fs(void)
+{
+	unregister_filesystem(&adfs_fs_type);
+	destroy_inodecache();
+}
+
+module_init(init_adfs_fs)
+module_exit(exit_adfs_fs)
+MODULE_DESCRIPTION("Acorn Disc Filing System");
+MODULE_LICENSE("GPL");