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, 355 insertions, 0 deletions

diff --git a/fs/ufs/ialloc.c b/fs/ufs/ialloc.c
new file mode 100644
index 000000000..8e51f4630
--- /dev/null
+++ b/fs/ufs/ialloc.c
@@ -0,0 +1,355 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/fs/ufs/ialloc.c
+ *
+ * Copyright (c) 1998
+ * Daniel Pirkl <daniel.pirkl@email.cz>
+ * Charles University, Faculty of Mathematics and Physics
+ *
+ *  from
+ *
+ *  linux/fs/ext2/ialloc.c
+ *
+ * Copyright (C) 1992, 1993, 1994, 1995
+ * Remy Card (card@masi.ibp.fr)
+ * Laboratoire MASI - Institut Blaise Pascal
+ * Universite Pierre et Marie Curie (Paris VI)
+ *
+ *  BSD ufs-inspired inode and directory allocation by 
+ *  Stephen Tweedie (sct@dcs.ed.ac.uk), 1993
+ *  Big-endian to little-endian byte-swapping/bitmaps by
+ *        David S. Miller (davem@caip.rutgers.edu), 1995
+ *
+ * UFS2 write support added by
+ * Evgeniy Dushistov <dushistov@mail.ru>, 2007
+ */
+
+#include <linux/fs.h>
+#include <linux/time.h>
+#include <linux/stat.h>
+#include <linux/string.h>
+#include <linux/buffer_head.h>
+#include <linux/sched.h>
+#include <linux/bitops.h>
+#include <asm/byteorder.h>
+
+#include "ufs_fs.h"
+#include "ufs.h"
+#include "swab.h"
+#include "util.h"
+
+/*
+ * NOTE! When we get the inode, we're the only people
+ * that have access to it, and as such there are no
+ * race conditions we have to worry about. The inode
+ * is not on the hash-lists, and it cannot be reached
+ * through the filesystem because the directory entry
+ * has been deleted earlier.
+ *
+ * HOWEVER: we must make sure that we get no aliases,
+ * which means that we have to call "clear_inode()"
+ * _before_ we mark the inode not in use in the inode
+ * bitmaps. Otherwise a newly created file might use
+ * the same inode number (not actually the same pointer
+ * though), and then we'd have two inodes sharing the
+ * same inode number and space on the harddisk.
+ */
+void ufs_free_inode (struct inode * inode)
+{
+	struct super_block * sb;
+	struct ufs_sb_private_info * uspi;
+	struct ufs_cg_private_info * ucpi;
+	struct ufs_cylinder_group * ucg;
+	int is_directory;
+	unsigned ino, cg, bit;
+	
+	UFSD("ENTER, ino %llu\n", inode->i_ino);
+
+	sb = inode->i_sb;
+	uspi = UFS_SB(sb)->s_uspi;
+	
+	ino = inode->i_ino;
+
+	mutex_lock(&UFS_SB(sb)->s_lock);
+
+	if (!((ino > 1) && (ino < (uspi->s_ncg * uspi->s_ipg )))) {
+		ufs_warning(sb, "ufs_free_inode", "reserved inode or nonexistent inode %u\n", ino);
+		mutex_unlock(&UFS_SB(sb)->s_lock);
+		return;
+	}
+	
+	cg = ufs_inotocg (ino);
+	bit = ufs_inotocgoff (ino);
+	ucpi = ufs_load_cylinder (sb, cg);
+	if (!ucpi) {
+		mutex_unlock(&UFS_SB(sb)->s_lock);
+		return;
+	}
+	ucg = ubh_get_ucg(UCPI_UBH(ucpi));
+	if (!ufs_cg_chkmagic(sb, ucg))
+		ufs_panic (sb, "ufs_free_fragments", "internal error, bad cg magic number");
+
+	ucg->cg_time = ufs_get_seconds(sb);
+
+	is_directory = S_ISDIR(inode->i_mode);
+
+	if (ubh_isclr (UCPI_UBH(ucpi), ucpi->c_iusedoff, bit))
+		ufs_error(sb, "ufs_free_inode", "bit already cleared for inode %u", ino);
+	else {
+		ubh_clrbit (UCPI_UBH(ucpi), ucpi->c_iusedoff, bit);
+		if (ino < ucpi->c_irotor)
+			ucpi->c_irotor = ino;
+		fs32_add(sb, &ucg->cg_cs.cs_nifree, 1);
+		uspi->cs_total.cs_nifree++;
+		fs32_add(sb, &UFS_SB(sb)->fs_cs(cg).cs_nifree, 1);
+
+		if (is_directory) {
+			fs32_sub(sb, &ucg->cg_cs.cs_ndir, 1);
+			uspi->cs_total.cs_ndir--;
+			fs32_sub(sb, &UFS_SB(sb)->fs_cs(cg).cs_ndir, 1);
+		}
+	}
+
+	ubh_mark_buffer_dirty (USPI_UBH(uspi));
+	ubh_mark_buffer_dirty (UCPI_UBH(ucpi));
+	if (sb->s_flags & SB_SYNCHRONOUS)
+		ubh_sync_block(UCPI_UBH(ucpi));
+	
+	ufs_mark_sb_dirty(sb);
+	mutex_unlock(&UFS_SB(sb)->s_lock);
+	UFSD("EXIT\n");
+}
+
+/*
+ * Nullify new chunk of inodes,
+ * BSD people also set ui_gen field of inode
+ * during nullification, but we not care about
+ * that because of linux ufs do not support NFS
+ */
+static void ufs2_init_inodes_chunk(struct super_block *sb,
+				   struct ufs_cg_private_info *ucpi,
+				   struct ufs_cylinder_group *ucg)
+{
+	struct buffer_head *bh;
+	struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi;
+	sector_t beg = uspi->s_sbbase +
+		ufs_inotofsba(ucpi->c_cgx * uspi->s_ipg +
+			      fs32_to_cpu(sb, ucg->cg_u.cg_u2.cg_initediblk));
+	sector_t end = beg + uspi->s_fpb;
+
+	UFSD("ENTER cgno %d\n", ucpi->c_cgx);
+
+	for (; beg < end; ++beg) {
+		bh = sb_getblk(sb, beg);
+		lock_buffer(bh);
+		memset(bh->b_data, 0, sb->s_blocksize);
+		set_buffer_uptodate(bh);
+		mark_buffer_dirty(bh);
+		unlock_buffer(bh);
+		if (sb->s_flags & SB_SYNCHRONOUS)
+			sync_dirty_buffer(bh);
+		brelse(bh);
+	}
+
+	fs32_add(sb, &ucg->cg_u.cg_u2.cg_initediblk, uspi->s_inopb);
+	ubh_mark_buffer_dirty(UCPI_UBH(ucpi));
+	if (sb->s_flags & SB_SYNCHRONOUS)
+		ubh_sync_block(UCPI_UBH(ucpi));
+
+	UFSD("EXIT\n");
+}
+
+/*
+ * There are two policies for allocating an inode.  If the new inode is
+ * a directory, then a forward search is made for a block group with both
+ * free space and a low directory-to-inode ratio; if that fails, then of
+ * the groups with above-average free space, that group with the fewest
+ * directories already is chosen.
+ *
+ * For other inodes, search forward from the parent directory's block
+ * group to find a free inode.
+ */
+struct inode *ufs_new_inode(struct inode *dir, umode_t mode)
+{
+	struct super_block * sb;
+	struct ufs_sb_info * sbi;
+	struct ufs_sb_private_info * uspi;
+	struct ufs_cg_private_info * ucpi;
+	struct ufs_cylinder_group * ucg;
+	struct inode * inode;
+	struct timespec64 ts;
+	unsigned cg, bit, i, j, start;
+	struct ufs_inode_info *ufsi;
+	int err = -ENOSPC;
+
+	UFSD("ENTER\n");
+	
+	/* Cannot create files in a deleted directory */
+	if (!dir || !dir->i_nlink)
+		return ERR_PTR(-EPERM);
+	sb = dir->i_sb;
+	inode = new_inode(sb);
+	if (!inode)
+		return ERR_PTR(-ENOMEM);
+	ufsi = UFS_I(inode);
+	sbi = UFS_SB(sb);
+	uspi = sbi->s_uspi;
+
+	mutex_lock(&sbi->s_lock);
+
+	/*
+	 * Try to place the inode in its parent directory
+	 */
+	i = ufs_inotocg(dir->i_ino);
+	if (sbi->fs_cs(i).cs_nifree) {
+		cg = i;
+		goto cg_found;
+	}
+
+	/*
+	 * Use a quadratic hash to find a group with a free inode
+	 */
+	for ( j = 1; j < uspi->s_ncg; j <<= 1 ) {
+		i += j;
+		if (i >= uspi->s_ncg)
+			i -= uspi->s_ncg;
+		if (sbi->fs_cs(i).cs_nifree) {
+			cg = i;
+			goto cg_found;
+		}
+	}
+
+	/*
+	 * That failed: try linear search for a free inode
+	 */
+	i = ufs_inotocg(dir->i_ino) + 1;
+	for (j = 2; j < uspi->s_ncg; j++) {
+		i++;
+		if (i >= uspi->s_ncg)
+			i = 0;
+		if (sbi->fs_cs(i).cs_nifree) {
+			cg = i;
+			goto cg_found;
+		}
+	}
+
+	goto failed;
+
+cg_found:
+	ucpi = ufs_load_cylinder (sb, cg);
+	if (!ucpi) {
+		err = -EIO;
+		goto failed;
+	}
+	ucg = ubh_get_ucg(UCPI_UBH(ucpi));
+	if (!ufs_cg_chkmagic(sb, ucg)) 
+		ufs_panic (sb, "ufs_new_inode", "internal error, bad cg magic number");
+
+	start = ucpi->c_irotor;
+	bit = ubh_find_next_zero_bit (UCPI_UBH(ucpi), ucpi->c_iusedoff, uspi->s_ipg, start);
+	if (!(bit < uspi->s_ipg)) {
+		bit = ubh_find_first_zero_bit (UCPI_UBH(ucpi), ucpi->c_iusedoff, start);
+		if (!(bit < start)) {
+			ufs_error (sb, "ufs_new_inode",
+			    "cylinder group %u corrupted - error in inode bitmap\n", cg);
+			err = -EIO;
+			goto failed;
+		}
+	}
+	UFSD("start = %u, bit = %u, ipg = %u\n", start, bit, uspi->s_ipg);
+	if (ubh_isclr (UCPI_UBH(ucpi), ucpi->c_iusedoff, bit))
+		ubh_setbit (UCPI_UBH(ucpi), ucpi->c_iusedoff, bit);
+	else {
+		ufs_panic (sb, "ufs_new_inode", "internal error");
+		err = -EIO;
+		goto failed;
+	}
+
+	if (uspi->fs_magic == UFS2_MAGIC) {
+		u32 initediblk = fs32_to_cpu(sb, ucg->cg_u.cg_u2.cg_initediblk);
+
+		if (bit + uspi->s_inopb > initediblk &&
+		    initediblk < fs32_to_cpu(sb, ucg->cg_u.cg_u2.cg_niblk))
+			ufs2_init_inodes_chunk(sb, ucpi, ucg);
+	}
+
+	fs32_sub(sb, &ucg->cg_cs.cs_nifree, 1);
+	uspi->cs_total.cs_nifree--;
+	fs32_sub(sb, &sbi->fs_cs(cg).cs_nifree, 1);
+	
+	if (S_ISDIR(mode)) {
+		fs32_add(sb, &ucg->cg_cs.cs_ndir, 1);
+		uspi->cs_total.cs_ndir++;
+		fs32_add(sb, &sbi->fs_cs(cg).cs_ndir, 1);
+	}
+	ubh_mark_buffer_dirty (USPI_UBH(uspi));
+	ubh_mark_buffer_dirty (UCPI_UBH(ucpi));
+	if (sb->s_flags & SB_SYNCHRONOUS)
+		ubh_sync_block(UCPI_UBH(ucpi));
+	ufs_mark_sb_dirty(sb);
+
+	inode->i_ino = cg * uspi->s_ipg + bit;
+	inode_init_owner(&nop_mnt_idmap, inode, dir, mode);
+	inode->i_blocks = 0;
+	inode->i_generation = 0;
+	simple_inode_init_ts(inode);
+	ufsi->i_flags = UFS_I(dir)->i_flags;
+	ufsi->i_lastfrag = 0;
+	ufsi->i_shadow = 0;
+	ufsi->i_osync = 0;
+	ufsi->i_oeftflag = 0;
+	ufsi->i_dir_start_lookup = 0;
+	memset(&ufsi->i_u1, 0, sizeof(ufsi->i_u1));
+	if (insert_inode_locked(inode) < 0) {
+		err = -EIO;
+		goto failed;
+	}
+	mark_inode_dirty(inode);
+
+	if (uspi->fs_magic == UFS2_MAGIC) {
+		struct buffer_head *bh;
+		struct ufs2_inode *ufs2_inode;
+
+		/*
+		 * setup birth date, we do it here because of there is no sense
+		 * to hold it in struct ufs_inode_info, and lose 64 bit
+		 */
+		bh = sb_bread(sb, uspi->s_sbbase + ufs_inotofsba(inode->i_ino));
+		if (!bh) {
+			ufs_warning(sb, "ufs_read_inode",
+				    "unable to read inode %llu\n",
+				    inode->i_ino);
+			err = -EIO;
+			goto fail_remove_inode;
+		}
+		lock_buffer(bh);
+		ufs2_inode = (struct ufs2_inode *)bh->b_data;
+		ufs2_inode += ufs_inotofsbo(inode->i_ino);
+		ktime_get_real_ts64(&ts);
+		ufs2_inode->ui_birthtime = cpu_to_fs64(sb, ts.tv_sec);
+		ufs2_inode->ui_birthnsec = cpu_to_fs32(sb, ts.tv_nsec);
+		mark_buffer_dirty(bh);
+		unlock_buffer(bh);
+		if (sb->s_flags & SB_SYNCHRONOUS)
+			sync_dirty_buffer(bh);
+		brelse(bh);
+	}
+	mutex_unlock(&sbi->s_lock);
+
+	UFSD("allocating inode %llu\n", inode->i_ino);
+	UFSD("EXIT\n");
+	return inode;
+
+fail_remove_inode:
+	mutex_unlock(&sbi->s_lock);
+	clear_nlink(inode);
+	discard_new_inode(inode);
+	UFSD("EXIT (FAILED): err %d\n", err);
+	return ERR_PTR(err);
+failed:
+	mutex_unlock(&sbi->s_lock);
+	make_bad_inode(inode);
+	iput (inode);
+	UFSD("EXIT (FAILED): err %d\n", err);
+	return ERR_PTR(err);
+}