Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted

Pull I3C updates from Alexandre Belloni:
 "A new driver this cycle, for the AMD AXI I3C controller.

  There are also new features such as IBI wakeup support, SETAASA device
  discovery and ACPI support for the the DAA methods, meaning we can now
  communicate with the SPD devices on DDR5 modules.

  New driver:
   - AMD AXI I3C master controller

  Subsystem:
   - I3C Common Command Code (CCC) handling improvements, especially
     around GET CCCs
   - SETAASA device discovery support
   - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as
     well as I2C devices on I3C bus
   - IBI-based wakeup support

  Drivers:
   - dw: SETAASA support
   - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C
     controller support, PIO queue management support for HCI v1.2
   - renesas: improve suspend to RAM support, add runtime PM support"

* tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits)
  i3c: dw: reduce do_daa time if there's no client
  i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller
  i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2
  i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode
  i3c: dw: rename "pclk" to "apb" to match dt-binding
  i3c: dw: make struct dw_i3c_cmd smaller
  i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding
  i3c: renesas: Don't register devices when ENTDAA times out
  i3c: master: dw-i3c-master: fix OD timing for first broadcast
  i3c: mipi-i3c-hci: Advertise IBI wakeup capability
  i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev()
  i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI
  i3c: master: Reject IBI requests from non-IBI-capable devices
  i3c: master: Add helper to query bus wakeup requirements
  i3c: master: Report wakeup events for IBIs
  i3c: master: Support IBI-based wakeup capability
  i3c: master: Fix potential UAF in i3c_device_match()
  i3c: master: Fix potential UAF in i3c_device_uevent()
  i3c: Make dev->desc locking assumptions explicit
  i3c: master: Fix use-after-free of master->this
  ...

2 files changed, 580 insertions, 0 deletions

diff --git a/fs/devpts/Makefile b/fs/devpts/Makefile
new file mode 100644
index 000000000..66064c8fc
--- /dev/null
+++ b/fs/devpts/Makefile
@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Makefile for the Linux /dev/pts virtual filesystem.
+#
+
+obj-$(CONFIG_UNIX98_PTYS)		+= devpts.o
+
+devpts-$(CONFIG_UNIX98_PTYS)		:= inode.o
diff --git a/fs/devpts/inode.c b/fs/devpts/inode.c
new file mode 100644
index 000000000..9844dcf35
--- /dev/null
+++ b/fs/devpts/inode.c
@@ -0,0 +1,572 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* -*- linux-c -*- --------------------------------------------------------- *
+ *
+ * linux/fs/devpts/inode.c
+ *
+ *  Copyright 1998-2004 H. Peter Anvin -- All Rights Reserved
+ *
+ * ------------------------------------------------------------------------- */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/fs.h>
+#include <linux/fs_context.h>
+#include <linux/fs_parser.h>
+#include <linux/sched.h>
+#include <linux/namei.h>
+#include <linux/slab.h>
+#include <linux/mount.h>
+#include <linux/tty.h>
+#include <linux/mutex.h>
+#include <linux/magic.h>
+#include <linux/idr.h>
+#include <linux/devpts_fs.h>
+#include <linux/fsnotify.h>
+#include <linux/seq_file.h>
+
+#define DEVPTS_DEFAULT_MODE 0600
+/*
+ * ptmx is a new node in /dev/pts and will be unused in legacy (single-
+ * instance) mode. To prevent surprises in user space, set permissions of
+ * ptmx to 0. Use 'chmod' or remount with '-o ptmxmode' to set meaningful
+ * permissions.
+ */
+#define DEVPTS_DEFAULT_PTMX_MODE 0000
+#define PTMX_MINOR	2
+
+/*
+ * sysctl support for setting limits on the number of Unix98 ptys allocated.
+ * Otherwise one can eat up all kernel memory by opening /dev/ptmx repeatedly.
+ */
+static int pty_limit = NR_UNIX98_PTY_DEFAULT;
+static int pty_reserve = NR_UNIX98_PTY_RESERVE;
+static int pty_limit_min;
+static int pty_limit_max = INT_MAX;
+static atomic_t pty_count = ATOMIC_INIT(0);
+
+static const struct ctl_table pty_table[] = {
+	{
+		.procname	= "max",
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.data		= &pty_limit,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= &pty_limit_min,
+		.extra2		= &pty_limit_max,
+	}, {
+		.procname	= "reserve",
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.data		= &pty_reserve,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= &pty_limit_min,
+		.extra2		= &pty_limit_max,
+	}, {
+		.procname	= "nr",
+		.maxlen		= sizeof(int),
+		.mode		= 0444,
+		.data		= &pty_count,
+		.proc_handler	= proc_dointvec,
+	},
+};
+
+struct pts_mount_opts {
+	int setuid;
+	int setgid;
+	kuid_t   uid;
+	kgid_t   gid;
+	umode_t mode;
+	umode_t ptmxmode;
+	int reserve;
+	int max;
+};
+
+enum {
+	Opt_uid, Opt_gid, Opt_mode, Opt_ptmxmode, Opt_newinstance,  Opt_max,
+	Opt_err
+};
+
+static const struct fs_parameter_spec devpts_param_specs[] = {
+	fsparam_gid	("gid",		Opt_gid),
+	fsparam_s32	("max",		Opt_max),
+	fsparam_u32oct	("mode",	Opt_mode),
+	fsparam_flag	("newinstance",	Opt_newinstance),
+	fsparam_u32oct	("ptmxmode",	Opt_ptmxmode),
+	fsparam_uid	("uid",		Opt_uid),
+	{}
+};
+
+struct pts_fs_info {
+	struct ida allocated_ptys;
+	struct pts_mount_opts mount_opts;
+	struct super_block *sb;
+	struct inode *ptmx_inode; // borrowed
+};
+
+static inline struct pts_fs_info *DEVPTS_SB(struct super_block *sb)
+{
+	return sb->s_fs_info;
+}
+
+static int devpts_ptmx_path(struct path *path)
+{
+	struct super_block *sb;
+	int err;
+
+	/* Is a devpts filesystem at "pts" in the same directory? */
+	err = path_pts(path);
+	if (err)
+		return err;
+
+	/* Is the path the root of a devpts filesystem? */
+	sb = path->mnt->mnt_sb;
+	if ((sb->s_magic != DEVPTS_SUPER_MAGIC) ||
+	    (path->mnt->mnt_root != sb->s_root))
+		return -ENODEV;
+
+	return 0;
+}
+
+/*
+ * Try to find a suitable devpts filesystem. We support the following
+ * scenarios:
+ * - The ptmx device node is located in the same directory as the devpts
+ *   mount where the pts device nodes are located.
+ *   This is e.g. the case when calling open on the /dev/pts/ptmx device
+ *   node when the devpts filesystem is mounted at /dev/pts.
+ * - The ptmx device node is located outside the devpts filesystem mount
+ *   where the pts device nodes are located. For example, the ptmx device
+ *   is a symlink, separate device node, or bind-mount.
+ *   A supported scenario is bind-mounting /dev/pts/ptmx to /dev/ptmx and
+ *   then calling open on /dev/ptmx. In this case a suitable pts
+ *   subdirectory can be found in the common parent directory /dev of the
+ *   devpts mount and the ptmx bind-mount, after resolving the /dev/ptmx
+ *   bind-mount.
+ *   If no suitable pts subdirectory can be found this function will fail.
+ *   This is e.g. the case when bind-mounting /dev/pts/ptmx to /ptmx.
+ */
+struct vfsmount *devpts_mntget(struct file *filp, struct pts_fs_info *fsi)
+{
+	struct path path;
+	int err = 0;
+
+	path = filp->f_path;
+	path_get(&path);
+
+	/* Walk upward while the start point is a bind mount of
+	 * a single file.
+	 */
+	while (path.mnt->mnt_root == path.dentry)
+		if (follow_up(&path) == 0)
+			break;
+
+	/* devpts_ptmx_path() finds a devpts fs or returns an error. */
+	if ((path.mnt->mnt_sb->s_magic != DEVPTS_SUPER_MAGIC) ||
+	    (DEVPTS_SB(path.mnt->mnt_sb) != fsi))
+		err = devpts_ptmx_path(&path);
+	dput(path.dentry);
+	if (!err) {
+		if (DEVPTS_SB(path.mnt->mnt_sb) == fsi)
+			return path.mnt;
+
+		err = -ENODEV;
+	}
+
+	mntput(path.mnt);
+	return ERR_PTR(err);
+}
+
+struct pts_fs_info *devpts_acquire(struct file *filp)
+{
+	struct pts_fs_info *result;
+	struct path path;
+	struct super_block *sb;
+
+	path = filp->f_path;
+	path_get(&path);
+
+	/* Has the devpts filesystem already been found? */
+	if (path.mnt->mnt_sb->s_magic != DEVPTS_SUPER_MAGIC) {
+		int err;
+
+		err = devpts_ptmx_path(&path);
+		if (err) {
+			result = ERR_PTR(err);
+			goto out;
+		}
+	}
+
+	/*
+	 * pty code needs to hold extra references in case of last /dev/tty close
+	 */
+	sb = path.mnt->mnt_sb;
+	atomic_inc(&sb->s_active);
+	result = DEVPTS_SB(sb);
+
+out:
+	path_put(&path);
+	return result;
+}
+
+void devpts_release(struct pts_fs_info *fsi)
+{
+	deactivate_super(fsi->sb);
+}
+
+/*
+ * devpts_parse_param - Parse mount parameters
+ */
+static int devpts_parse_param(struct fs_context *fc, struct fs_parameter *param)
+{
+	struct pts_fs_info *fsi = fc->s_fs_info;
+	struct pts_mount_opts *opts = &fsi->mount_opts;
+	struct fs_parse_result result;
+	int opt;
+
+	opt = fs_parse(fc, devpts_param_specs, param, &result);
+	if (opt < 0)
+		return opt;
+
+	switch (opt) {
+	case Opt_uid:
+		opts->uid = result.uid;
+		opts->setuid = 1;
+		break;
+	case Opt_gid:
+		opts->gid = result.gid;
+		opts->setgid = 1;
+		break;
+	case Opt_mode:
+		opts->mode = result.uint_32 & S_IALLUGO;
+		break;
+	case Opt_ptmxmode:
+		opts->ptmxmode = result.uint_32 & S_IALLUGO;
+		break;
+	case Opt_newinstance:
+		break;
+	case Opt_max:
+		if (result.uint_32 > NR_UNIX98_PTY_MAX)
+			return invalf(fc, "max out of range");
+		opts->max = result.uint_32;
+		break;
+	}
+
+	return 0;
+}
+
+static int mknod_ptmx(struct super_block *sb, struct fs_context *fc)
+{
+	int mode;
+	struct dentry *dentry;
+	struct inode *inode;
+	struct dentry *root = sb->s_root;
+	struct pts_fs_info *fsi = DEVPTS_SB(sb);
+	struct pts_mount_opts *opts = &fsi->mount_opts;
+	kuid_t ptmx_uid = current_fsuid();
+	kgid_t ptmx_gid = current_fsgid();
+
+	dentry = simple_start_creating(root, "ptmx");
+	if (IS_ERR(dentry)) {
+		pr_err("Unable to alloc dentry for ptmx node\n");
+		return PTR_ERR(dentry);
+	}
+
+	/*
+	 * Create a new 'ptmx' node in this mount of devpts.
+	 */
+	inode = new_inode(sb);
+	if (!inode) {
+		simple_done_creating(dentry);
+		pr_err("Unable to alloc inode for ptmx node\n");
+		return -ENOMEM;
+	}
+
+	inode->i_ino = 2;
+	simple_inode_init_ts(inode);
+
+	mode = S_IFCHR|opts->ptmxmode;
+	init_special_inode(inode, mode, MKDEV(TTYAUX_MAJOR, 2));
+	inode->i_uid = ptmx_uid;
+	inode->i_gid = ptmx_gid;
+	fsi->ptmx_inode = inode;
+
+	d_make_persistent(dentry, inode);
+
+	simple_done_creating(dentry);
+
+	return 0;
+}
+
+static void update_ptmx_mode(struct pts_fs_info *fsi)
+{
+	fsi->ptmx_inode->i_mode = S_IFCHR|fsi->mount_opts.ptmxmode;
+}
+
+static int devpts_reconfigure(struct fs_context *fc)
+{
+	struct pts_fs_info *fsi = DEVPTS_SB(fc->root->d_sb);
+	struct pts_fs_info *new = fc->s_fs_info;
+
+	/* Apply the revised options.  We don't want to change ->reserve.
+	 * Ideally, we'd update each option conditionally on it having been
+	 * explicitly changed, but the default is to reset everything so that
+	 * would break UAPI...
+	 */
+	fsi->mount_opts.setuid		= new->mount_opts.setuid;
+	fsi->mount_opts.setgid		= new->mount_opts.setgid;
+	fsi->mount_opts.uid		= new->mount_opts.uid;
+	fsi->mount_opts.gid		= new->mount_opts.gid;
+	fsi->mount_opts.mode		= new->mount_opts.mode;
+	fsi->mount_opts.ptmxmode	= new->mount_opts.ptmxmode;
+	fsi->mount_opts.max		= new->mount_opts.max;
+
+	/*
+	 * parse_mount_options() restores options to default values
+	 * before parsing and may have changed ptmxmode. So, update the
+	 * mode in the inode too. Bogus options don't fail the remount,
+	 * so do this even on error return.
+	 */
+	update_ptmx_mode(fsi);
+
+	return 0;
+}
+
+static int devpts_show_options(struct seq_file *seq, struct dentry *root)
+{
+	struct pts_fs_info *fsi = DEVPTS_SB(root->d_sb);
+	struct pts_mount_opts *opts = &fsi->mount_opts;
+
+	if (opts->setuid)
+		seq_printf(seq, ",uid=%u",
+			   from_kuid_munged(&init_user_ns, opts->uid));
+	if (opts->setgid)
+		seq_printf(seq, ",gid=%u",
+			   from_kgid_munged(&init_user_ns, opts->gid));
+	seq_printf(seq, ",mode=%03o", opts->mode);
+	seq_printf(seq, ",ptmxmode=%03o", opts->ptmxmode);
+	if (opts->max < NR_UNIX98_PTY_MAX)
+		seq_printf(seq, ",max=%d", opts->max);
+
+	return 0;
+}
+
+static const struct super_operations devpts_sops = {
+	.statfs		= simple_statfs,
+	.show_options	= devpts_show_options,
+};
+
+static int devpts_fill_super(struct super_block *s, struct fs_context *fc)
+{
+	struct pts_fs_info *fsi = DEVPTS_SB(s);
+	struct inode *inode;
+
+	s->s_iflags &= ~SB_I_NODEV;
+	s->s_blocksize = 1024;
+	s->s_blocksize_bits = 10;
+	s->s_magic = DEVPTS_SUPER_MAGIC;
+	s->s_op = &devpts_sops;
+	s->s_d_flags = DCACHE_DONTCACHE;
+	s->s_time_gran = 1;
+	fsi->sb = s;
+
+	inode = new_inode(s);
+	if (!inode)
+		return -ENOMEM;
+	inode->i_ino = 1;
+	simple_inode_init_ts(inode);
+	inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO | S_IWUSR;
+	inode->i_op = &simple_dir_inode_operations;
+	inode->i_fop = &simple_dir_operations;
+	set_nlink(inode, 2);
+
+	s->s_root = d_make_root(inode);
+	if (!s->s_root) {
+		pr_err("get root dentry failed\n");
+		return -ENOMEM;
+	}
+
+	return mknod_ptmx(s, fc);
+}
+
+/*
+ * devpts_get_tree()
+ *
+ *     Mount a new (private) instance of devpts.  PTYs created in this
+ *     instance are independent of the PTYs in other devpts instances.
+ */
+static int devpts_get_tree(struct fs_context *fc)
+{
+	return get_tree_nodev(fc, devpts_fill_super);
+}
+
+static void devpts_free_fc(struct fs_context *fc)
+{
+	kfree(fc->s_fs_info);
+}
+
+static const struct fs_context_operations devpts_context_ops = {
+	.free		= devpts_free_fc,
+	.parse_param	= devpts_parse_param,
+	.get_tree	= devpts_get_tree,
+	.reconfigure	= devpts_reconfigure,
+};
+
+/*
+ * Set up the filesystem mount context.
+ */
+static int devpts_init_fs_context(struct fs_context *fc)
+{
+	struct pts_fs_info *fsi;
+
+	fsi = kzalloc_obj(struct pts_fs_info);
+	if (!fsi)
+		return -ENOMEM;
+
+	ida_init(&fsi->allocated_ptys);
+	fsi->mount_opts.uid     = GLOBAL_ROOT_UID;
+	fsi->mount_opts.gid     = GLOBAL_ROOT_GID;
+	fsi->mount_opts.mode    = DEVPTS_DEFAULT_MODE;
+	fsi->mount_opts.ptmxmode = DEVPTS_DEFAULT_PTMX_MODE;
+	fsi->mount_opts.max     = NR_UNIX98_PTY_MAX;
+
+	if (fc->purpose == FS_CONTEXT_FOR_MOUNT &&
+	    current->nsproxy->mnt_ns == init_task.nsproxy->mnt_ns)
+		fsi->mount_opts.reserve = true;
+
+	fc->s_fs_info = fsi;
+	fc->ops = &devpts_context_ops;
+	return 0;
+}
+
+static void devpts_kill_sb(struct super_block *sb)
+{
+	struct pts_fs_info *fsi = DEVPTS_SB(sb);
+
+	if (fsi)
+		ida_destroy(&fsi->allocated_ptys);
+	kfree(fsi);
+	kill_anon_super(sb);
+}
+
+static struct file_system_type devpts_fs_type = {
+	.name		= "devpts",
+	.init_fs_context = devpts_init_fs_context,
+	.parameters	= devpts_param_specs,
+	.kill_sb	= devpts_kill_sb,
+	.fs_flags	= FS_USERNS_MOUNT,
+};
+
+/*
+ * The normal naming convention is simply /dev/pts/<number>; this conforms
+ * to the System V naming convention
+ */
+
+int devpts_new_index(struct pts_fs_info *fsi)
+{
+	int index = -ENOSPC;
+
+	if (atomic_inc_return(&pty_count) >= (pty_limit -
+			  (fsi->mount_opts.reserve ? 0 : pty_reserve)))
+		goto out;
+
+	index = ida_alloc_max(&fsi->allocated_ptys, fsi->mount_opts.max - 1,
+			GFP_KERNEL);
+
+out:
+	if (index < 0)
+		atomic_dec(&pty_count);
+	return index;
+}
+
+void devpts_kill_index(struct pts_fs_info *fsi, int idx)
+{
+	ida_free(&fsi->allocated_ptys, idx);
+	atomic_dec(&pty_count);
+}
+
+/**
+ * devpts_pty_new -- create a new inode in /dev/pts/
+ * @fsi: Filesystem info for this instance.
+ * @index: used as a name of the node
+ * @priv: what's given back by devpts_get_priv
+ *
+ * The dentry for the created inode is returned.
+ * Remove it from /dev/pts/ with devpts_pty_kill().
+ */
+struct dentry *devpts_pty_new(struct pts_fs_info *fsi, int index, void *priv)
+{
+	struct dentry *dentry;
+	struct super_block *sb = fsi->sb;
+	struct inode *inode;
+	struct dentry *root;
+	struct pts_mount_opts *opts;
+	char s[12];
+
+	root = sb->s_root;
+	opts = &fsi->mount_opts;
+
+	inode = new_inode(sb);
+	if (!inode)
+		return ERR_PTR(-ENOMEM);
+
+	inode->i_ino = index + 3;
+	inode->i_uid = opts->setuid ? opts->uid : current_fsuid();
+	inode->i_gid = opts->setgid ? opts->gid : current_fsgid();
+	simple_inode_init_ts(inode);
+	init_special_inode(inode, S_IFCHR|opts->mode, MKDEV(UNIX98_PTY_SLAVE_MAJOR, index));
+
+	sprintf(s, "%d", index);
+
+	dentry = d_alloc_name(root, s);
+	if (!dentry) {
+		iput(inode);
+		return ERR_PTR(-ENOMEM);
+	}
+	dentry->d_fsdata = priv;
+	d_make_persistent(dentry, inode);
+	fsnotify_create(d_inode(root), dentry);
+	dput(dentry);
+	return dentry; // borrowed
+}
+
+/**
+ * devpts_get_priv -- get private data for a slave
+ * @dentry: dentry of the slave
+ *
+ * Returns whatever was passed as priv in devpts_pty_new for a given inode.
+ */
+void *devpts_get_priv(struct dentry *dentry)
+{
+	if (dentry->d_sb->s_magic != DEVPTS_SUPER_MAGIC)
+		return NULL;
+	return dentry->d_fsdata;
+}
+
+/**
+ * devpts_pty_kill -- remove inode form /dev/pts/
+ * @dentry: dentry of the slave to be removed
+ *
+ * This is an inverse operation of devpts_pty_new.
+ */
+void devpts_pty_kill(struct dentry *dentry)
+{
+	WARN_ON_ONCE(dentry->d_sb->s_magic != DEVPTS_SUPER_MAGIC);
+
+	dentry->d_fsdata = NULL;
+	drop_nlink(dentry->d_inode);
+	d_drop(dentry);
+	fsnotify_unlink(d_inode(dentry->d_parent), dentry);
+	d_make_discardable(dentry);
+}
+
+static int __init init_devpts_fs(void)
+{
+	int err = register_filesystem(&devpts_fs_type);
+	if (!err) {
+		register_sysctl("kernel/pty", pty_table);
+	}
+	return err;
+}
+module_init(init_devpts_fs)