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, 484 insertions, 0 deletions

diff --git a/fs/xfs/xfs_itable.c b/fs/xfs/xfs_itable.c
new file mode 100644
index 000000000..159295c63
--- /dev/null
+++ b/fs/xfs/xfs_itable.c
@@ -0,0 +1,484 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc.
+ * All Rights Reserved.
+ */
+#include "xfs_platform.h"
+#include "xfs_fs.h"
+#include "xfs_shared.h"
+#include "xfs_format.h"
+#include "xfs_log_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_mount.h"
+#include "xfs_inode.h"
+#include "xfs_btree.h"
+#include "xfs_ialloc.h"
+#include "xfs_ialloc_btree.h"
+#include "xfs_iwalk.h"
+#include "xfs_itable.h"
+#include "xfs_error.h"
+#include "xfs_icache.h"
+#include "xfs_health.h"
+#include "xfs_trans.h"
+
+/*
+ * Bulk Stat
+ * =========
+ *
+ * Use the inode walking functions to fill out struct xfs_bulkstat for every
+ * allocated inode, then pass the stat information to some externally provided
+ * iteration function.
+ */
+
+struct xfs_bstat_chunk {
+	bulkstat_one_fmt_pf	formatter;
+	struct xfs_ibulk	*breq;
+	struct xfs_bulkstat	*buf;
+};
+
+static inline bool
+want_metadir_file(
+	struct xfs_inode	*ip,
+	struct xfs_ibulk	*breq)
+{
+	return xfs_is_metadir_inode(ip) && (breq->flags & XFS_IBULK_METADIR);
+}
+
+/*
+ * Fill out the bulkstat info for a single inode and report it somewhere.
+ *
+ * bc->breq->lastino is effectively the inode cursor as we walk through the
+ * filesystem.  Therefore, we update it any time we need to move the cursor
+ * forward, regardless of whether or not we're sending any bstat information
+ * back to userspace.  If the inode is internal metadata or, has been freed
+ * out from under us, we just simply keep going.
+ *
+ * However, if any other type of error happens we want to stop right where we
+ * are so that userspace will call back with exact number of the bad inode and
+ * we can send back an error code.
+ *
+ * Note that if the formatter tells us there's no space left in the buffer we
+ * move the cursor forward and abort the walk.
+ */
+STATIC int
+xfs_bulkstat_one_int(
+	struct xfs_mount	*mp,
+	struct mnt_idmap	*idmap,
+	struct xfs_trans	*tp,
+	xfs_ino_t		ino,
+	struct xfs_bstat_chunk	*bc)
+{
+	struct user_namespace	*sb_userns = mp->m_super->s_user_ns;
+	struct xfs_inode	*ip;		/* incore inode pointer */
+	struct inode		*inode;
+	struct xfs_bulkstat	*buf = bc->buf;
+	xfs_extnum_t		nextents;
+	int			error = -EINVAL;
+	vfsuid_t		vfsuid;
+	vfsgid_t		vfsgid;
+
+	error = xfs_iget(mp, tp, ino,
+			 (XFS_IGET_DONTCACHE | XFS_IGET_UNTRUSTED),
+			 XFS_ILOCK_SHARED, &ip);
+	if (error == -ENOENT || error == -EINVAL)
+		goto out_advance;
+	if (error)
+		goto out;
+
+	/* Reload the incore unlinked list to avoid failure in inodegc. */
+	if (xfs_inode_unlinked_incomplete(ip)) {
+		error = xfs_inode_reload_unlinked_bucket(tp, ip);
+		if (error) {
+			xfs_iunlock(ip, XFS_ILOCK_SHARED);
+			xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
+			xfs_irele(ip);
+			return error;
+		}
+	}
+
+	ASSERT(ip != NULL);
+	ASSERT(ip->i_imap.im_agbno != 0);
+	inode = VFS_I(ip);
+	vfsuid = i_uid_into_vfsuid(idmap, inode);
+	vfsgid = i_gid_into_vfsgid(idmap, inode);
+
+	/*
+	 * If caller wants files from the metadata directories, push out the
+	 * bare minimum information for enabling scrub.
+	 */
+	if (want_metadir_file(ip, bc->breq)) {
+		memset(buf, 0, sizeof(*buf));
+		buf->bs_ino = ino;
+		buf->bs_gen = inode->i_generation;
+		buf->bs_mode = inode->i_mode & S_IFMT;
+		xfs_bulkstat_health(ip, buf);
+		buf->bs_version = XFS_BULKSTAT_VERSION_V5;
+		xfs_iunlock(ip, XFS_ILOCK_SHARED);
+		xfs_irele(ip);
+
+		error = bc->formatter(bc->breq, buf);
+		if (!error || error == -ECANCELED)
+			goto out_advance;
+		goto out;
+	}
+
+	/* If this is a private inode, don't leak its details to userspace. */
+	if (IS_PRIVATE(inode) || xfs_is_sb_inum(mp, ino)) {
+		xfs_iunlock(ip, XFS_ILOCK_SHARED);
+		xfs_irele(ip);
+		error = -EINVAL;
+		goto out_advance;
+	}
+
+	/* xfs_iget returns the following without needing
+	 * further change.
+	 */
+	buf->bs_projectid = ip->i_projid;
+	buf->bs_ino = ino;
+	buf->bs_uid = from_kuid(sb_userns, vfsuid_into_kuid(vfsuid));
+	buf->bs_gid = from_kgid(sb_userns, vfsgid_into_kgid(vfsgid));
+	buf->bs_size = ip->i_disk_size;
+
+	buf->bs_nlink = inode->i_nlink;
+	buf->bs_atime = inode_get_atime_sec(inode);
+	buf->bs_atime_nsec = inode_get_atime_nsec(inode);
+	buf->bs_mtime = inode_get_mtime_sec(inode);
+	buf->bs_mtime_nsec = inode_get_mtime_nsec(inode);
+	buf->bs_ctime = inode_get_ctime_sec(inode);
+	buf->bs_ctime_nsec = inode_get_ctime_nsec(inode);
+	buf->bs_gen = inode->i_generation;
+	buf->bs_mode = inode->i_mode;
+
+	buf->bs_xflags = xfs_ip2xflags(ip);
+	buf->bs_extsize_blks = ip->i_extsize;
+
+	nextents = xfs_ifork_nextents(&ip->i_df);
+	if (!(bc->breq->flags & XFS_IBULK_NREXT64))
+		buf->bs_extents = min(nextents, XFS_MAX_EXTCNT_DATA_FORK_SMALL);
+	else
+		buf->bs_extents64 = nextents;
+
+	xfs_bulkstat_health(ip, buf);
+	buf->bs_aextents = xfs_ifork_nextents(&ip->i_af);
+	buf->bs_forkoff = xfs_inode_fork_boff(ip);
+	buf->bs_version = XFS_BULKSTAT_VERSION_V5;
+
+	if (xfs_has_v3inodes(mp)) {
+		buf->bs_btime = ip->i_crtime.tv_sec;
+		buf->bs_btime_nsec = ip->i_crtime.tv_nsec;
+		if (ip->i_diflags2 & XFS_DIFLAG2_COWEXTSIZE)
+			buf->bs_cowextsize_blks = ip->i_cowextsize;
+	}
+
+	switch (ip->i_df.if_format) {
+	case XFS_DINODE_FMT_DEV:
+		buf->bs_rdev = sysv_encode_dev(inode->i_rdev);
+		buf->bs_blksize = BLKDEV_IOSIZE;
+		buf->bs_blocks = 0;
+		break;
+	case XFS_DINODE_FMT_LOCAL:
+		buf->bs_rdev = 0;
+		buf->bs_blksize = mp->m_sb.sb_blocksize;
+		buf->bs_blocks = 0;
+		break;
+	case XFS_DINODE_FMT_EXTENTS:
+	case XFS_DINODE_FMT_BTREE:
+		buf->bs_rdev = 0;
+		buf->bs_blksize = mp->m_sb.sb_blocksize;
+		buf->bs_blocks = ip->i_nblocks + ip->i_delayed_blks;
+		break;
+	}
+	xfs_iunlock(ip, XFS_ILOCK_SHARED);
+	xfs_irele(ip);
+
+	error = bc->formatter(bc->breq, buf);
+	if (error == -ECANCELED)
+		goto out_advance;
+	if (error)
+		goto out;
+
+out_advance:
+	/*
+	 * Advance the cursor to the inode that comes after the one we just
+	 * looked at.  We want the caller to move along if the bulkstat
+	 * information was copied successfully; if we tried to grab the inode
+	 * but it's no longer allocated; or if it's internal metadata.
+	 */
+	bc->breq->startino = ino + 1;
+out:
+	return error;
+}
+
+/* Bulkstat a single inode. */
+int
+xfs_bulkstat_one(
+	struct xfs_ibulk	*breq,
+	bulkstat_one_fmt_pf	formatter)
+{
+	struct xfs_bstat_chunk	bc = {
+		.formatter	= formatter,
+		.breq		= breq,
+	};
+	struct xfs_trans	*tp;
+	int			error;
+
+	if (breq->idmap != &nop_mnt_idmap) {
+		xfs_warn_ratelimited(breq->mp,
+			"bulkstat not supported inside of idmapped mounts.");
+		return -EINVAL;
+	}
+
+	ASSERT(breq->icount == 1);
+
+	bc.buf = kzalloc_obj(struct xfs_bulkstat,
+			     GFP_KERNEL | __GFP_RETRY_MAYFAIL);
+	if (!bc.buf)
+		return -ENOMEM;
+
+	/*
+	 * Grab an empty transaction so that we can use its recursive buffer
+	 * locking abilities to detect cycles in the inobt without deadlocking.
+	 */
+	tp = xfs_trans_alloc_empty(breq->mp);
+	error = xfs_bulkstat_one_int(breq->mp, breq->idmap, tp,
+			breq->startino, &bc);
+	xfs_trans_cancel(tp);
+	kfree(bc.buf);
+
+	/*
+	 * If we reported one inode to userspace then we abort because we hit
+	 * the end of the buffer.  Don't leak that back to userspace.
+	 */
+	if (error == -ECANCELED)
+		error = 0;
+
+	return error;
+}
+
+static int
+xfs_bulkstat_iwalk(
+	struct xfs_mount	*mp,
+	struct xfs_trans	*tp,
+	xfs_ino_t		ino,
+	void			*data)
+{
+	struct xfs_bstat_chunk	*bc = data;
+	int			error;
+
+	error = xfs_bulkstat_one_int(mp, bc->breq->idmap, tp, ino, data);
+	/* bulkstat just skips over missing inodes */
+	if (error == -ENOENT || error == -EINVAL)
+		return 0;
+	return error;
+}
+
+/*
+ * Check the incoming lastino parameter.
+ *
+ * We allow any inode value that could map to physical space inside the
+ * filesystem because if there are no inodes there, bulkstat moves on to the
+ * next chunk.  In other words, the magic agino value of zero takes us to the
+ * first chunk in the AG, and an agino value past the end of the AG takes us to
+ * the first chunk in the next AG.
+ *
+ * Therefore we can end early if the requested inode is beyond the end of the
+ * filesystem or doesn't map properly.
+ */
+static inline bool
+xfs_bulkstat_already_done(
+	struct xfs_mount	*mp,
+	xfs_ino_t		startino)
+{
+	xfs_agnumber_t		agno = XFS_INO_TO_AGNO(mp, startino);
+	xfs_agino_t		agino = XFS_INO_TO_AGINO(mp, startino);
+
+	return agno >= mp->m_sb.sb_agcount ||
+	       startino != XFS_AGINO_TO_INO(mp, agno, agino);
+}
+
+/* Return stat information in bulk (by-inode) for the filesystem. */
+int
+xfs_bulkstat(
+	struct xfs_ibulk	*breq,
+	bulkstat_one_fmt_pf	formatter)
+{
+	struct xfs_bstat_chunk	bc = {
+		.formatter	= formatter,
+		.breq		= breq,
+	};
+	struct xfs_trans	*tp;
+	int			error;
+
+	if (breq->idmap != &nop_mnt_idmap) {
+		xfs_warn_ratelimited(breq->mp,
+			"bulkstat not supported inside of idmapped mounts.");
+		return -EINVAL;
+	}
+	if (xfs_bulkstat_already_done(breq->mp, breq->startino))
+		return 0;
+
+	bc.buf = kzalloc_obj(struct xfs_bulkstat,
+			     GFP_KERNEL | __GFP_RETRY_MAYFAIL);
+	if (!bc.buf)
+		return -ENOMEM;
+
+	/*
+	 * Grab an empty transaction so that we can use its recursive buffer
+	 * locking abilities to detect cycles in the inobt without deadlocking.
+	 */
+	tp = xfs_trans_alloc_empty(breq->mp);
+	error = xfs_iwalk(breq->mp, tp, breq->startino, breq->iwalk_flags,
+			xfs_bulkstat_iwalk, breq->icount, &bc);
+	xfs_trans_cancel(tp);
+	kfree(bc.buf);
+
+	/*
+	 * We found some inodes, so clear the error status and return them.
+	 * The lastino pointer will point directly at the inode that triggered
+	 * any error that occurred, so on the next call the error will be
+	 * triggered again and propagated to userspace as there will be no
+	 * formatted inodes in the buffer.
+	 */
+	if (breq->ocount > 0)
+		error = 0;
+
+	return error;
+}
+
+/* Convert bulkstat (v5) to bstat (v1). */
+void
+xfs_bulkstat_to_bstat(
+	struct xfs_mount		*mp,
+	struct xfs_bstat		*bs1,
+	const struct xfs_bulkstat	*bstat)
+{
+	/* memset is needed here because of padding holes in the structure. */
+	memset(bs1, 0, sizeof(struct xfs_bstat));
+	bs1->bs_ino = bstat->bs_ino;
+	bs1->bs_mode = bstat->bs_mode;
+	bs1->bs_nlink = bstat->bs_nlink;
+	bs1->bs_uid = bstat->bs_uid;
+	bs1->bs_gid = bstat->bs_gid;
+	bs1->bs_rdev = bstat->bs_rdev;
+	bs1->bs_blksize = bstat->bs_blksize;
+	bs1->bs_size = bstat->bs_size;
+	bs1->bs_atime.tv_sec = bstat->bs_atime;
+	bs1->bs_mtime.tv_sec = bstat->bs_mtime;
+	bs1->bs_ctime.tv_sec = bstat->bs_ctime;
+	bs1->bs_atime.tv_nsec = bstat->bs_atime_nsec;
+	bs1->bs_mtime.tv_nsec = bstat->bs_mtime_nsec;
+	bs1->bs_ctime.tv_nsec = bstat->bs_ctime_nsec;
+	bs1->bs_blocks = bstat->bs_blocks;
+	bs1->bs_xflags = bstat->bs_xflags;
+	bs1->bs_extsize = XFS_FSB_TO_B(mp, bstat->bs_extsize_blks);
+	bs1->bs_extents = bstat->bs_extents;
+	bs1->bs_gen = bstat->bs_gen;
+	bs1->bs_projid_lo = bstat->bs_projectid & 0xFFFF;
+	bs1->bs_forkoff = bstat->bs_forkoff;
+	bs1->bs_projid_hi = bstat->bs_projectid >> 16;
+	bs1->bs_sick = bstat->bs_sick;
+	bs1->bs_checked = bstat->bs_checked;
+	bs1->bs_cowextsize = XFS_FSB_TO_B(mp, bstat->bs_cowextsize_blks);
+	bs1->bs_dmevmask = 0;
+	bs1->bs_dmstate = 0;
+	bs1->bs_aextents = bstat->bs_aextents;
+}
+
+struct xfs_inumbers_chunk {
+	inumbers_fmt_pf		formatter;
+	struct xfs_ibulk	*breq;
+};
+
+/*
+ * INUMBERS
+ * ========
+ * This is how we export inode btree records to userspace, so that XFS tools
+ * can figure out where inodes are allocated.
+ */
+
+/*
+ * Format the inode group structure and report it somewhere.
+ *
+ * Similar to xfs_bulkstat_one_int, lastino is the inode cursor as we walk
+ * through the filesystem so we move it forward unless there was a runtime
+ * error.  If the formatter tells us the buffer is now full we also move the
+ * cursor forward and abort the walk.
+ */
+STATIC int
+xfs_inumbers_walk(
+	struct xfs_mount	*mp,
+	struct xfs_trans	*tp,
+	xfs_agnumber_t		agno,
+	const struct xfs_inobt_rec_incore *irec,
+	void			*data)
+{
+	struct xfs_inumbers	inogrp = {
+		.xi_startino	= XFS_AGINO_TO_INO(mp, agno, irec->ir_startino),
+		.xi_alloccount	= irec->ir_count - irec->ir_freecount,
+		.xi_allocmask	= ~irec->ir_free,
+		.xi_version	= XFS_INUMBERS_VERSION_V5,
+	};
+	struct xfs_inumbers_chunk *ic = data;
+	int			error;
+
+	error = ic->formatter(ic->breq, &inogrp);
+	if (error && error != -ECANCELED)
+		return error;
+
+	ic->breq->startino = XFS_AGINO_TO_INO(mp, agno, irec->ir_startino) +
+			XFS_INODES_PER_CHUNK;
+	return error;
+}
+
+/*
+ * Return inode number table for the filesystem.
+ */
+int
+xfs_inumbers(
+	struct xfs_ibulk	*breq,
+	inumbers_fmt_pf		formatter)
+{
+	struct xfs_inumbers_chunk ic = {
+		.formatter	= formatter,
+		.breq		= breq,
+	};
+	struct xfs_trans	*tp;
+	int			error = 0;
+
+	if (xfs_bulkstat_already_done(breq->mp, breq->startino))
+		return 0;
+
+	/*
+	 * Grab an empty transaction so that we can use its recursive buffer
+	 * locking abilities to detect cycles in the inobt without deadlocking.
+	 */
+	tp = xfs_trans_alloc_empty(breq->mp);
+	error = xfs_inobt_walk(breq->mp, tp, breq->startino, breq->iwalk_flags,
+			xfs_inumbers_walk, breq->icount, &ic);
+	xfs_trans_cancel(tp);
+
+	/*
+	 * We found some inode groups, so clear the error status and return
+	 * them.  The lastino pointer will point directly at the inode that
+	 * triggered any error that occurred, so on the next call the error
+	 * will be triggered again and propagated to userspace as there will be
+	 * no formatted inode groups in the buffer.
+	 */
+	if (breq->ocount > 0)
+		error = 0;
+
+	return error;
+}
+
+/* Convert an inumbers (v5) struct to a inogrp (v1) struct. */
+void
+xfs_inumbers_to_inogrp(
+	struct xfs_inogrp		*ig1,
+	const struct xfs_inumbers	*ig)
+{
+	/* memset is needed here because of padding holes in the structure. */
+	memset(ig1, 0, sizeof(struct xfs_inogrp));
+	ig1->xi_startino = ig->xi_startino;
+	ig1->xi_alloccount = ig->xi_alloccount;
+	ig1->xi_allocmask = ig->xi_allocmask;
+}