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, 481 insertions, 0 deletions

diff --git a/fs/vboxsf/dir.c b/fs/vboxsf/dir.c
new file mode 100644
index 000000000..0b9eab157
--- /dev/null
+++ b/fs/vboxsf/dir.c
@@ -0,0 +1,481 @@
+// SPDX-License-Identifier: MIT
+/*
+ * VirtualBox Guest Shared Folders support: Directory inode and file operations
+ *
+ * Copyright (C) 2006-2018 Oracle Corporation
+ */
+
+#include <linux/namei.h>
+#include <linux/vbox_utils.h>
+#include "vfsmod.h"
+
+static int vboxsf_dir_open(struct inode *inode, struct file *file)
+{
+	struct vboxsf_sbi *sbi = VBOXSF_SBI(inode->i_sb);
+	struct shfl_createparms params = {};
+	struct vboxsf_dir_info *sf_d;
+	int err;
+
+	sf_d = vboxsf_dir_info_alloc();
+	if (!sf_d)
+		return -ENOMEM;
+
+	params.handle = SHFL_HANDLE_NIL;
+	params.create_flags = SHFL_CF_DIRECTORY | SHFL_CF_ACT_OPEN_IF_EXISTS |
+			      SHFL_CF_ACT_FAIL_IF_NEW | SHFL_CF_ACCESS_READ;
+
+	err = vboxsf_create_at_dentry(file_dentry(file), &params);
+	if (err)
+		goto err_free_dir_info;
+
+	if (params.result != SHFL_FILE_EXISTS) {
+		err = -ENOENT;
+		goto err_close;
+	}
+
+	err = vboxsf_dir_read_all(sbi, sf_d, params.handle);
+	if (err)
+		goto err_close;
+
+	vboxsf_close(sbi->root, params.handle);
+	file->private_data = sf_d;
+	return 0;
+
+err_close:
+	vboxsf_close(sbi->root, params.handle);
+err_free_dir_info:
+	vboxsf_dir_info_free(sf_d);
+	return err;
+}
+
+static int vboxsf_dir_release(struct inode *inode, struct file *file)
+{
+	if (file->private_data)
+		vboxsf_dir_info_free(file->private_data);
+
+	return 0;
+}
+
+static unsigned int vboxsf_get_d_type(u32 mode)
+{
+	unsigned int d_type;
+
+	switch (mode & SHFL_TYPE_MASK) {
+	case SHFL_TYPE_FIFO:
+		d_type = DT_FIFO;
+		break;
+	case SHFL_TYPE_DEV_CHAR:
+		d_type = DT_CHR;
+		break;
+	case SHFL_TYPE_DIRECTORY:
+		d_type = DT_DIR;
+		break;
+	case SHFL_TYPE_DEV_BLOCK:
+		d_type = DT_BLK;
+		break;
+	case SHFL_TYPE_FILE:
+		d_type = DT_REG;
+		break;
+	case SHFL_TYPE_SYMLINK:
+		d_type = DT_LNK;
+		break;
+	case SHFL_TYPE_SOCKET:
+		d_type = DT_SOCK;
+		break;
+	case SHFL_TYPE_WHITEOUT:
+		d_type = DT_WHT;
+		break;
+	default:
+		d_type = DT_UNKNOWN;
+		break;
+	}
+	return d_type;
+}
+
+static bool vboxsf_dir_emit(struct file *dir, struct dir_context *ctx)
+{
+	struct vboxsf_sbi *sbi = VBOXSF_SBI(file_inode(dir)->i_sb);
+	struct vboxsf_dir_info *sf_d = dir->private_data;
+	struct shfl_dirinfo *info;
+	struct vboxsf_dir_buf *b;
+	unsigned int d_type;
+	loff_t i, cur = 0;
+	ino_t fake_ino;
+	void *end;
+	int err;
+
+	list_for_each_entry(b, &sf_d->info_list, head) {
+try_next_entry:
+		if (ctx->pos >= cur + b->entries) {
+			cur += b->entries;
+			continue;
+		}
+
+		/*
+		 * Note the vboxsf_dir_info objects we are iterating over here
+		 * are variable sized, so the info pointer may end up being
+		 * unaligned. This is how we get the data from the host.
+		 * Since vboxsf is only supported on x86 machines this is not
+		 * a problem.
+		 */
+		for (i = 0, info = b->buf; i < ctx->pos - cur; i++) {
+			end = &info->name.string.utf8[info->name.size];
+			/* Only happens if the host gives us corrupt data */
+			if (WARN_ON(end > (b->buf + b->used)))
+				return false;
+			info = end;
+		}
+
+		end = &info->name.string.utf8[info->name.size];
+		if (WARN_ON(end > (b->buf + b->used)))
+			return false;
+
+		/* Info now points to the right entry, emit it. */
+		d_type = vboxsf_get_d_type(info->info.attr.mode);
+
+		/*
+		 * On 32-bit systems pos is 64-bit signed, while ino is 32-bit
+		 * unsigned so fake_ino may overflow, check for this.
+		 */
+		if ((ino_t)(ctx->pos + 1) != (u64)(ctx->pos + 1)) {
+			vbg_err("vboxsf: fake ino overflow, truncating dir\n");
+			return false;
+		}
+		fake_ino = ctx->pos + 1;
+
+		if (sbi->nls) {
+			char d_name[NAME_MAX];
+
+			err = vboxsf_nlscpy(sbi, d_name, NAME_MAX,
+					    info->name.string.utf8,
+					    info->name.length);
+			if (err) {
+				/* skip erroneous entry and proceed */
+				ctx->pos += 1;
+				goto try_next_entry;
+			}
+
+			return dir_emit(ctx, d_name, strlen(d_name),
+					fake_ino, d_type);
+		}
+
+		return dir_emit(ctx, info->name.string.utf8, info->name.length,
+				fake_ino, d_type);
+	}
+
+	return false;
+}
+
+static int vboxsf_dir_iterate(struct file *dir, struct dir_context *ctx)
+{
+	bool emitted;
+
+	do {
+		emitted = vboxsf_dir_emit(dir, ctx);
+		if (emitted)
+			ctx->pos += 1;
+	} while (emitted);
+
+	return 0;
+}
+
+WRAP_DIR_ITER(vboxsf_dir_iterate) // FIXME!
+const struct file_operations vboxsf_dir_fops = {
+	.open = vboxsf_dir_open,
+	.iterate_shared = shared_vboxsf_dir_iterate,
+	.release = vboxsf_dir_release,
+	.read = generic_read_dir,
+	.llseek = generic_file_llseek,
+};
+
+/*
+ * This is called during name resolution/lookup to check if the @dentry in
+ * the cache is still valid. the job is handled by vboxsf_inode_revalidate.
+ */
+static int vboxsf_dentry_revalidate(struct inode *dir, const struct qstr *name,
+				    struct dentry *dentry, unsigned int flags)
+{
+	if (flags & LOOKUP_RCU)
+		return -ECHILD;
+
+	if (d_really_is_positive(dentry))
+		return vboxsf_inode_revalidate(dentry) == 0;
+	else
+		return vboxsf_stat_dentry(dentry, NULL) == -ENOENT;
+}
+
+const struct dentry_operations vboxsf_dentry_ops = {
+	.d_revalidate = vboxsf_dentry_revalidate
+};
+
+/* iops */
+
+static struct dentry *vboxsf_dir_lookup(struct inode *parent,
+					struct dentry *dentry,
+					unsigned int flags)
+{
+	struct vboxsf_sbi *sbi = VBOXSF_SBI(parent->i_sb);
+	struct shfl_fsobjinfo fsinfo;
+	struct inode *inode;
+	int err;
+
+	dentry->d_time = jiffies;
+
+	err = vboxsf_stat_dentry(dentry, &fsinfo);
+	if (err) {
+		inode = (err == -ENOENT) ? NULL : ERR_PTR(err);
+	} else {
+		inode = vboxsf_new_inode(parent->i_sb);
+		if (!IS_ERR(inode))
+			vboxsf_init_inode(sbi, inode, &fsinfo, false);
+	}
+
+	return d_splice_alias(inode, dentry);
+}
+
+static int vboxsf_dir_instantiate(struct inode *parent, struct dentry *dentry,
+				  struct shfl_fsobjinfo *info)
+{
+	struct vboxsf_sbi *sbi = VBOXSF_SBI(parent->i_sb);
+	struct vboxsf_inode *sf_i;
+	struct inode *inode;
+
+	inode = vboxsf_new_inode(parent->i_sb);
+	if (IS_ERR(inode))
+		return PTR_ERR(inode);
+
+	sf_i = VBOXSF_I(inode);
+	/* The host may have given us different attr then requested */
+	sf_i->force_restat = 1;
+	vboxsf_init_inode(sbi, inode, info, false);
+
+	d_instantiate(dentry, inode);
+
+	return 0;
+}
+
+static int vboxsf_dir_create(struct inode *parent, struct dentry *dentry,
+			     umode_t mode, bool is_dir, bool excl, u64 *handle_ret)
+{
+	struct vboxsf_inode *sf_parent_i = VBOXSF_I(parent);
+	struct vboxsf_sbi *sbi = VBOXSF_SBI(parent->i_sb);
+	struct shfl_createparms params = {};
+	int err;
+
+	params.handle = SHFL_HANDLE_NIL;
+	params.create_flags = SHFL_CF_ACT_CREATE_IF_NEW | SHFL_CF_ACCESS_READWRITE;
+	if (is_dir)
+		params.create_flags |= SHFL_CF_DIRECTORY;
+	if (excl)
+		params.create_flags |= SHFL_CF_ACT_FAIL_IF_EXISTS;
+
+	params.info.attr.mode = (mode & 0777) |
+				(is_dir ? SHFL_TYPE_DIRECTORY : SHFL_TYPE_FILE);
+	params.info.attr.additional = SHFLFSOBJATTRADD_NOTHING;
+
+	err = vboxsf_create_at_dentry(dentry, &params);
+	if (err)
+		return err;
+
+	if (params.result != SHFL_FILE_CREATED)
+		return -EPERM;
+
+	err = vboxsf_dir_instantiate(parent, dentry, &params.info);
+	if (err)
+		goto out;
+
+	/* parent directory access/change time changed */
+	sf_parent_i->force_restat = 1;
+
+out:
+	if (err == 0 && handle_ret)
+		*handle_ret = params.handle;
+	else
+		vboxsf_close(sbi->root, params.handle);
+
+	return err;
+}
+
+static int vboxsf_dir_mkfile(struct mnt_idmap *idmap,
+			     struct inode *parent, struct dentry *dentry,
+			     umode_t mode)
+{
+	return vboxsf_dir_create(parent, dentry, mode, false, true, NULL);
+}
+
+static struct dentry *vboxsf_dir_mkdir(struct mnt_idmap *idmap,
+				       struct inode *parent, struct dentry *dentry,
+				       umode_t mode)
+{
+	return ERR_PTR(vboxsf_dir_create(parent, dentry, mode, true, true, NULL));
+}
+
+static int vboxsf_dir_atomic_open(struct inode *parent, struct dentry *dentry,
+				  struct file *file, unsigned int flags, umode_t mode)
+{
+	struct vboxsf_sbi *sbi = VBOXSF_SBI(parent->i_sb);
+	struct vboxsf_handle *sf_handle;
+	u64 handle;
+	int err;
+
+	if (d_in_lookup(dentry)) {
+		struct dentry *res = vboxsf_dir_lookup(parent, dentry, 0);
+		if (res || d_really_is_positive(dentry))
+			return finish_no_open(file, res);
+	}
+
+	/* Only creates */
+	if (!(flags & O_CREAT))
+		return finish_no_open(file, NULL);
+
+	err = vboxsf_dir_create(parent, dentry, mode, false, flags & O_EXCL, &handle);
+	if (err)
+		return err;
+
+	sf_handle = vboxsf_create_sf_handle(d_inode(dentry), handle, SHFL_CF_ACCESS_READWRITE);
+	if (IS_ERR(sf_handle)) {
+		vboxsf_close(sbi->root, handle);
+		return PTR_ERR(sf_handle);
+	}
+
+	err = finish_open(file, dentry, generic_file_open);
+	if (err) {
+		/* This also closes the handle passed to vboxsf_create_sf_handle() */
+		vboxsf_release_sf_handle(d_inode(dentry), sf_handle);
+		return err;
+	}
+
+	file->private_data = sf_handle;
+	file->f_mode |= FMODE_CREATED;
+	return 0;
+}
+
+static int vboxsf_dir_unlink(struct inode *parent, struct dentry *dentry)
+{
+	struct vboxsf_sbi *sbi = VBOXSF_SBI(parent->i_sb);
+	struct vboxsf_inode *sf_parent_i = VBOXSF_I(parent);
+	struct inode *inode = d_inode(dentry);
+	struct shfl_string *path;
+	u32 flags;
+	int err;
+
+	if (S_ISDIR(inode->i_mode))
+		flags = SHFL_REMOVE_DIR;
+	else
+		flags = SHFL_REMOVE_FILE;
+
+	if (S_ISLNK(inode->i_mode))
+		flags |= SHFL_REMOVE_SYMLINK;
+
+	path = vboxsf_path_from_dentry(sbi, dentry);
+	if (IS_ERR(path))
+		return PTR_ERR(path);
+
+	err = vboxsf_remove(sbi->root, path, flags);
+	__putname(path);
+	if (err)
+		return err;
+
+	/* parent directory access/change time changed */
+	sf_parent_i->force_restat = 1;
+
+	return 0;
+}
+
+static int vboxsf_dir_rename(struct mnt_idmap *idmap,
+			     struct inode *old_parent,
+			     struct dentry *old_dentry,
+			     struct inode *new_parent,
+			     struct dentry *new_dentry,
+			     unsigned int flags)
+{
+	struct vboxsf_sbi *sbi = VBOXSF_SBI(old_parent->i_sb);
+	struct vboxsf_inode *sf_old_parent_i = VBOXSF_I(old_parent);
+	struct vboxsf_inode *sf_new_parent_i = VBOXSF_I(new_parent);
+	u32 shfl_flags = SHFL_RENAME_FILE | SHFL_RENAME_REPLACE_IF_EXISTS;
+	struct shfl_string *old_path, *new_path;
+	int err;
+
+	if (flags)
+		return -EINVAL;
+
+	old_path = vboxsf_path_from_dentry(sbi, old_dentry);
+	if (IS_ERR(old_path))
+		return PTR_ERR(old_path);
+
+	new_path = vboxsf_path_from_dentry(sbi, new_dentry);
+	if (IS_ERR(new_path)) {
+		err = PTR_ERR(new_path);
+		goto err_put_old_path;
+	}
+
+	if (d_inode(old_dentry)->i_mode & S_IFDIR)
+		shfl_flags = 0;
+
+	err = vboxsf_rename(sbi->root, old_path, new_path, shfl_flags);
+	if (err == 0) {
+		/* parent directories access/change time changed */
+		sf_new_parent_i->force_restat = 1;
+		sf_old_parent_i->force_restat = 1;
+	}
+
+	__putname(new_path);
+err_put_old_path:
+	__putname(old_path);
+	return err;
+}
+
+static int vboxsf_dir_symlink(struct mnt_idmap *idmap,
+			      struct inode *parent, struct dentry *dentry,
+			      const char *symname)
+{
+	struct vboxsf_inode *sf_parent_i = VBOXSF_I(parent);
+	struct vboxsf_sbi *sbi = VBOXSF_SBI(parent->i_sb);
+	int symname_size = strlen(symname) + 1;
+	struct shfl_string *path, *ssymname;
+	struct shfl_fsobjinfo info;
+	int err;
+
+	path = vboxsf_path_from_dentry(sbi, dentry);
+	if (IS_ERR(path))
+		return PTR_ERR(path);
+
+	ssymname = kmalloc(SHFLSTRING_HEADER_SIZE + symname_size, GFP_KERNEL);
+	if (!ssymname) {
+		__putname(path);
+		return -ENOMEM;
+	}
+	ssymname->length = symname_size - 1;
+	ssymname->size = symname_size;
+	memcpy(ssymname->string.utf8, symname, symname_size);
+
+	err = vboxsf_symlink(sbi->root, path, ssymname, &info);
+	kfree(ssymname);
+	__putname(path);
+	if (err) {
+		/* -EROFS means symlinks are note support -> -EPERM */
+		return (err == -EROFS) ? -EPERM : err;
+	}
+
+	err = vboxsf_dir_instantiate(parent, dentry, &info);
+	if (err)
+		return err;
+
+	/* parent directory access/change time changed */
+	sf_parent_i->force_restat = 1;
+	return 0;
+}
+
+const struct inode_operations vboxsf_dir_iops = {
+	.lookup  = vboxsf_dir_lookup,
+	.create  = vboxsf_dir_mkfile,
+	.mkdir   = vboxsf_dir_mkdir,
+	.atomic_open = vboxsf_dir_atomic_open,
+	.rmdir   = vboxsf_dir_unlink,
+	.unlink  = vboxsf_dir_unlink,
+	.rename  = vboxsf_dir_rename,
+	.symlink = vboxsf_dir_symlink,
+	.getattr = vboxsf_getattr,
+	.setattr = vboxsf_setattr,
+	.fileattr_get = vboxsf_fileattr_get,
+};