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, 402 insertions, 0 deletions

diff --git a/fs/coda/inode.c b/fs/coda/inode.c
new file mode 100644
index 000000000..40b43866e
--- /dev/null
+++ b/fs/coda/inode.c
@@ -0,0 +1,402 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Super block/filesystem wide operations
+ *
+ * Copyright (C) 1996 Peter J. Braam <braam@maths.ox.ac.uk> and 
+ * Michael Callahan <callahan@maths.ox.ac.uk> 
+ * 
+ * Rewritten for Linux 2.1.  Peter Braam <braam@cs.cmu.edu>
+ * Copyright (C) Carnegie Mellon University
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/stat.h>
+#include <linux/errno.h>
+#include <linux/unistd.h>
+#include <linux/mutex.h>
+#include <linux/spinlock.h>
+#include <linux/file.h>
+#include <linux/vfs.h>
+#include <linux/slab.h>
+#include <linux/pid_namespace.h>
+#include <linux/uaccess.h>
+#include <linux/fs.h>
+#include <linux/fs_context.h>
+#include <linux/fs_parser.h>
+#include <linux/vmalloc.h>
+
+#include <linux/coda.h>
+#include "coda_psdev.h"
+#include "coda_linux.h"
+#include "coda_cache.h"
+
+#include "coda_int.h"
+
+/* VFS super_block ops */
+static void coda_evict_inode(struct inode *);
+static void coda_put_super(struct super_block *);
+static int coda_statfs(struct dentry *dentry, struct kstatfs *buf);
+
+static struct kmem_cache * coda_inode_cachep;
+
+static struct inode *coda_alloc_inode(struct super_block *sb)
+{
+	struct coda_inode_info *ei;
+	ei = alloc_inode_sb(sb, coda_inode_cachep, GFP_KERNEL);
+	if (!ei)
+		return NULL;
+	memset(&ei->c_fid, 0, sizeof(struct CodaFid));
+	ei->c_flags = 0;
+	ei->c_uid = GLOBAL_ROOT_UID;
+	ei->c_cached_perm = 0;
+	spin_lock_init(&ei->c_lock);
+	return &ei->vfs_inode;
+}
+
+static void coda_free_inode(struct inode *inode)
+{
+	kmem_cache_free(coda_inode_cachep, ITOC(inode));
+}
+
+static void init_once(void *foo)
+{
+	struct coda_inode_info *ei = (struct coda_inode_info *) foo;
+
+	inode_init_once(&ei->vfs_inode);
+}
+
+int __init coda_init_inodecache(void)
+{
+	coda_inode_cachep = kmem_cache_create("coda_inode_cache",
+				sizeof(struct coda_inode_info), 0,
+				SLAB_RECLAIM_ACCOUNT | SLAB_ACCOUNT,
+				init_once);
+	if (coda_inode_cachep == NULL)
+		return -ENOMEM;
+	return 0;
+}
+
+void coda_destroy_inodecache(void)
+{
+	/*
+	 * Make sure all delayed rcu free inodes are flushed before we
+	 * destroy cache.
+	 */
+	rcu_barrier();
+	kmem_cache_destroy(coda_inode_cachep);
+}
+
+static int coda_reconfigure(struct fs_context *fc)
+{
+	sync_filesystem(fc->root->d_sb);
+	fc->sb_flags |= SB_NOATIME;
+	return 0;
+}
+
+/* exported operations */
+static const struct super_operations coda_super_operations =
+{
+	.alloc_inode	= coda_alloc_inode,
+	.free_inode	= coda_free_inode,
+	.evict_inode	= coda_evict_inode,
+	.put_super	= coda_put_super,
+	.statfs		= coda_statfs,
+};
+
+struct coda_fs_context {
+	int	idx;
+};
+
+enum {
+	Opt_fd,
+};
+
+static const struct fs_parameter_spec coda_param_specs[] = {
+	fsparam_fd	("fd",	Opt_fd),
+	{}
+};
+
+static int coda_set_idx(struct fs_context *fc, struct file *file)
+{
+	struct coda_fs_context *ctx = fc->fs_private;
+	struct inode *inode;
+	int idx;
+
+	inode = file_inode(file);
+	if (!S_ISCHR(inode->i_mode) || imajor(inode) != CODA_PSDEV_MAJOR) {
+		return invalf(fc, "coda: Not coda psdev");
+	}
+	idx = iminor(inode);
+	if (idx < 0 || idx >= MAX_CODADEVS)
+		return invalf(fc, "coda: Bad minor number");
+	ctx->idx = idx;
+	return 0;
+}
+
+static int coda_parse_fd(struct fs_context *fc, struct fs_parameter *param,
+			 struct fs_parse_result *result)
+{
+	struct file *file;
+	int err;
+
+	if (param->type == fs_value_is_file) {
+		file = param->file;
+		param->file = NULL;
+	} else {
+		file = fget(result->uint_32);
+	}
+	if (!file)
+		return -EBADF;
+
+	err = coda_set_idx(fc, file);
+	fput(file);
+	return err;
+}
+
+static int coda_parse_param(struct fs_context *fc, struct fs_parameter *param)
+{
+	struct fs_parse_result result;
+	int opt;
+
+	opt = fs_parse(fc, coda_param_specs, param, &result);
+	if (opt < 0)
+		return opt;
+
+	switch (opt) {
+	case Opt_fd:
+		return coda_parse_fd(fc, param, &result);
+	}
+
+	return 0;
+}
+
+/*
+ * Parse coda's binary mount data form.  We ignore any errors and go with index
+ * 0 if we get one for backward compatibility.
+ */
+static int coda_parse_monolithic(struct fs_context *fc, void *_data)
+{
+	struct file *file;
+	struct coda_mount_data *data = _data;
+
+	if (!data)
+		return invalf(fc, "coda: Bad mount data");
+
+	if (data->version != CODA_MOUNT_VERSION)
+		return invalf(fc, "coda: Bad mount version");
+
+	file = fget(data->fd);
+	if (file) {
+		coda_set_idx(fc, file);
+		fput(file);
+	}
+	return 0;
+}
+
+static int coda_fill_super(struct super_block *sb, struct fs_context *fc)
+{
+	struct coda_fs_context *ctx = fc->fs_private;
+	struct inode *root = NULL;
+	struct venus_comm *vc;
+	struct CodaFid fid;
+	int error;
+
+	infof(fc, "coda: device index: %i\n", ctx->idx);
+
+	vc = &coda_comms[ctx->idx];
+	mutex_lock(&vc->vc_mutex);
+
+	if (!vc->vc_inuse) {
+		errorf(fc, "coda: No pseudo device");
+		error = -EINVAL;
+		goto unlock_out;
+	}
+
+	if (vc->vc_sb) {
+		errorf(fc, "coda: Device already mounted");
+		error = -EBUSY;
+		goto unlock_out;
+	}
+
+	vc->vc_sb = sb;
+	mutex_unlock(&vc->vc_mutex);
+
+	sb->s_fs_info = vc;
+	sb->s_flags |= SB_NOATIME;
+	sb->s_blocksize = 4096;	/* XXXXX  what do we put here?? */
+	sb->s_blocksize_bits = 12;
+	sb->s_magic = CODA_SUPER_MAGIC;
+	sb->s_op = &coda_super_operations;
+	set_default_d_op(sb, &coda_dentry_operations);
+	sb->s_time_gran = 1;
+	sb->s_time_min = S64_MIN;
+	sb->s_time_max = S64_MAX;
+
+	error = super_setup_bdi(sb);
+	if (error)
+		goto error;
+
+	/* get root fid from Venus: this needs the root inode */
+	error = venus_rootfid(sb, &fid);
+	if ( error ) {
+		pr_warn("%s: coda_get_rootfid failed with %d\n",
+			__func__, error);
+		goto error;
+	}
+	pr_info("%s: rootfid is %s\n", __func__, coda_f2s(&fid));
+	
+	/* make root inode */
+        root = coda_cnode_make(&fid, sb);
+        if (IS_ERR(root)) {
+		error = PTR_ERR(root);
+		pr_warn("Failure of coda_cnode_make for root: error %d\n",
+			error);
+		goto error;
+	} 
+
+	pr_info("%s: rootinode is %llu dev %s\n",
+		__func__, root->i_ino, root->i_sb->s_id);
+	sb->s_root = d_make_root(root);
+	if (!sb->s_root) {
+		error = -EINVAL;
+		goto error;
+	}
+	return 0;
+
+error:
+	mutex_lock(&vc->vc_mutex);
+	vc->vc_sb = NULL;
+	sb->s_fs_info = NULL;
+unlock_out:
+	mutex_unlock(&vc->vc_mutex);
+	return error;
+}
+
+static void coda_put_super(struct super_block *sb)
+{
+	struct venus_comm *vcp = coda_vcp(sb);
+	mutex_lock(&vcp->vc_mutex);
+	vcp->vc_sb = NULL;
+	sb->s_fs_info = NULL;
+	mutex_unlock(&vcp->vc_mutex);
+	mutex_destroy(&vcp->vc_mutex);
+
+	pr_info("Bye bye.\n");
+}
+
+static void coda_evict_inode(struct inode *inode)
+{
+	truncate_inode_pages_final(&inode->i_data);
+	clear_inode(inode);
+	coda_cache_clear_inode(inode);
+}
+
+int coda_getattr(struct mnt_idmap *idmap, const struct path *path,
+		 struct kstat *stat, u32 request_mask, unsigned int flags)
+{
+	int err = coda_revalidate_inode(d_inode(path->dentry));
+	if (!err)
+		generic_fillattr(&nop_mnt_idmap, request_mask,
+				 d_inode(path->dentry), stat);
+	return err;
+}
+
+int coda_setattr(struct mnt_idmap *idmap, struct dentry *de,
+		 struct iattr *iattr)
+{
+	struct inode *inode = d_inode(de);
+	struct coda_vattr vattr;
+	int error;
+
+	memset(&vattr, 0, sizeof(vattr)); 
+
+	inode_set_ctime_current(inode);
+	coda_iattr_to_vattr(iattr, &vattr);
+	vattr.va_type = C_VNON; /* cannot set type */
+
+	/* Venus is responsible for truncating the container-file!!! */
+	error = venus_setattr(inode->i_sb, coda_i2f(inode), &vattr);
+
+	if (!error) {
+	        coda_vattr_to_iattr(inode, &vattr); 
+		coda_cache_clear_inode(inode);
+	}
+	return error;
+}
+
+const struct inode_operations coda_file_inode_operations = {
+	.permission	= coda_permission,
+	.getattr	= coda_getattr,
+	.setattr	= coda_setattr,
+};
+
+static int coda_statfs(struct dentry *dentry, struct kstatfs *buf)
+{
+	int error;
+	
+	error = venus_statfs(dentry, buf);
+
+	if (error) {
+		/* fake something like AFS does */
+		buf->f_blocks = 9000000;
+		buf->f_bfree  = 9000000;
+		buf->f_bavail = 9000000;
+		buf->f_files  = 9000000;
+		buf->f_ffree  = 9000000;
+	}
+
+	/* and fill in the rest */
+	buf->f_type = CODA_SUPER_MAGIC;
+	buf->f_bsize = 4096;
+	buf->f_namelen = CODA_MAXNAMLEN;
+
+	return 0; 
+}
+
+static int coda_get_tree(struct fs_context *fc)
+{
+	if (task_active_pid_ns(current) != &init_pid_ns)
+		return -EINVAL;
+
+	return get_tree_nodev(fc, coda_fill_super);
+}
+
+static void coda_free_fc(struct fs_context *fc)
+{
+	kfree(fc->fs_private);
+}
+
+static const struct fs_context_operations coda_context_ops = {
+	.free		= coda_free_fc,
+	.parse_param	= coda_parse_param,
+	.parse_monolithic = coda_parse_monolithic,
+	.get_tree	= coda_get_tree,
+	.reconfigure	= coda_reconfigure,
+};
+
+static int coda_init_fs_context(struct fs_context *fc)
+{
+	struct coda_fs_context *ctx;
+
+	ctx = kzalloc_obj(struct coda_fs_context);
+	if (!ctx)
+		return -ENOMEM;
+
+	fc->fs_private = ctx;
+	fc->ops = &coda_context_ops;
+	return 0;
+}
+
+struct file_system_type coda_fs_type = {
+	.owner		= THIS_MODULE,
+	.name		= "coda",
+	.init_fs_context = coda_init_fs_context,
+	.parameters	= coda_param_specs,
+	.kill_sb	= kill_anon_super,
+	.fs_flags	= FS_BINARY_MOUNTDATA,
+};
+MODULE_ALIAS_FS("coda");
+