[PATCH AUTOSEL 4.9 01/17] bfs: add sanity check at bfs_fill_super()

[PATCH AUTOSEL 4.9 01/17] bfs: add sanity check at bfs_fill_super()

[Sasha Levin]

From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>

[ Upstream commit 9f2df09a33aa2c76ce6385d382693f98d7f2f07e ]

syzbot is reporting too large memory allocation at bfs_fill_super() [1].
Since file system image is corrupted such that bfs_sb->s_start == 0,
bfs_fill_super() is trying to allocate 8MB of continuous memory. Fix
this by adding a sanity check on bfs_sb->s_start, __GFP_NOWARN and
printf().

[1] https://syzkaller.appspot.com/bug?id=16a87c236b951351374a84c8a32f40edbc034e96

Link: http://lkml.kernel.org/r/1525862104-3407-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reported-by: syzbot <syzbot+71c6b5d68e91149fc8a4@syzkaller.appspotmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Tigran Aivazian <aivazian.tigran@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/bfs/inode.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/fs/bfs/inode.c b/fs/bfs/inode.c
index 1e5c896f6b79..0acb83efedea 100644
--- a/fs/bfs/inode.c
+++ b/fs/bfs/inode.c
@@ -350,7 +350,8 @@ static int bfs_fill_super(struct super_block *s, void *data, int silent)
 
 	s->s_magic = BFS_MAGIC;
 
-	if (le32_to_cpu(bfs_sb->s_start) > le32_to_cpu(bfs_sb->s_end)) {
+	if (le32_to_cpu(bfs_sb->s_start) > le32_to_cpu(bfs_sb->s_end) ||
+	    le32_to_cpu(bfs_sb->s_start) < BFS_BSIZE) {
 		printf("Superblock is corrupted\n");
 		goto out1;
 	}
@@ -359,9 +360,11 @@ static int bfs_fill_super(struct super_block *s, void *data, int silent)
 					sizeof(struct bfs_inode)
 					+ BFS_ROOT_INO - 1;
 	imap_len = (info->si_lasti / 8) + 1;
-	info->si_imap = kzalloc(imap_len, GFP_KERNEL);
-	if (!info->si_imap)
+	info->si_imap = kzalloc(imap_len, GFP_KERNEL | __GFP_NOWARN);
+	if (!info->si_imap) {
+		printf("Cannot allocate %u bytes\n", imap_len);
 		goto out1;
+	}
 	for (i = 0; i < BFS_ROOT_INO; i++)
 		set_bit(i, info->si_imap);
 
-- 
2.17.1

[PATCH AUTOSEL 4.9 02/17] cifs: don't dereference smb_file_target before null check

[Sasha Levin]

From: Colin Ian King <colin.king@canonical.com>

[ Upstream commit 8c6c9bed8773375b1d54ccca2911ec892c59db5d ]

There is a null check on dst_file->private data which suggests
it can be potentially null. However, before this check, pointer
smb_file_target is derived from dst_file->private and dereferenced
in the call to tlink_tcon, hence there is a potential null pointer
deference.

Fix this by assigning smb_file_target and target_tcon after the
null pointer sanity checks.

Detected by CoverityScan, CID#1475302 ("Dereference before null check")

Fixes: 04b38d601239 ("vfs: pull btrfs clone API to vfs layer")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/cifs/cifsfs.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index 87658f63b374..be84d49f2406 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -927,8 +927,8 @@ static int cifs_clone_file_range(struct file *src_file, loff_t off,
 	struct inode *src_inode = file_inode(src_file);
 	struct inode *target_inode = file_inode(dst_file);
 	struct cifsFileInfo *smb_file_src = src_file->private_data;
-	struct cifsFileInfo *smb_file_target = dst_file->private_data;
-	struct cifs_tcon *target_tcon = tlink_tcon(smb_file_target->tlink);
+	struct cifsFileInfo *smb_file_target;
+	struct cifs_tcon *target_tcon;
 	unsigned int xid;
 	int rc;
 
@@ -942,6 +942,9 @@ static int cifs_clone_file_range(struct file *src_file, loff_t off,
 		goto out;
 	}
 
+	smb_file_target = dst_file->private_data;
+	target_tcon = tlink_tcon(smb_file_target->tlink);
+
 	/*
 	 * Note: cifs case is easier than btrfs since server responsible for
 	 * checks for proper open modes and file type and if it wants
-- 
2.17.1

[PATCH AUTOSEL 4.9 03/17] mm/memory_hotplug: make add_memory() take the device_hotplug_lock

[Sasha Levin]

From: David Hildenbrand <david@redhat.com>

[ Upstream commit 8df1d0e4a265f25dc1e7e7624ccdbcb4a6630c89 ]

add_memory() currently does not take the device_hotplug_lock, however
is aleady called under the lock from
	arch/powerpc/platforms/pseries/hotplug-memory.c
	drivers/acpi/acpi_memhotplug.c
to synchronize against CPU hot-remove and similar.

In general, we should hold the device_hotplug_lock when adding memory to
synchronize against online/offline request (e.g.  from user space) - which
already resulted in lock inversions due to device_lock() and
mem_hotplug_lock - see 30467e0b3be ("mm, hotplug: fix concurrent memory
hot-add deadlock").  add_memory()/add_memory_resource() will create memory
block devices, so this really feels like the right thing to do.

Holding the device_hotplug_lock makes sure that a memory block device
can really only be accessed (e.g. via .online/.state) from user space,
once the memory has been fully added to the system.

The lock is not held yet in
	drivers/xen/balloon.c
	arch/powerpc/platforms/powernv/memtrace.c
	drivers/s390/char/sclp_cmd.c
	drivers/hv/hv_balloon.c
So, let's either use the locked variants or take the lock.

Don't export add_memory_resource(), as it once was exported to be used by
XEN, which is never built as a module.  If somebody requires it, we also
have to export a locked variant (as device_hotplug_lock is never
exported).

Link: http://lkml.kernel.org/r/20180925091457.28651-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Pavel Tatashin <pavel.tatashin@microsoft.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Rashmica Gupta <rashmica.g@gmail.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Len Brown <lenb@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Cc: John Allen <jallen@linux.vnet.ibm.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mathieu Malaterre <malat@debian.org>
Cc: Pavel Tatashin <pavel.tatashin@microsoft.com>
Cc: YASUAKI ISHIMATSU <yasu.isimatu@gmail.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Michael Neuling <mikey@neuling.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 .../platforms/pseries/hotplug-memory.c        |  2 +-
 drivers/acpi/acpi_memhotplug.c                |  2 +-
 drivers/base/memory.c                         |  9 ++++++--
 drivers/xen/balloon.c                         |  3 +++
 include/linux/memory_hotplug.h                |  1 +
 mm/memory_hotplug.c                           | 22 ++++++++++++++++---
 6 files changed, 32 insertions(+), 7 deletions(-)

diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c b/arch/powerpc/platforms/pseries/hotplug-memory.c
index c0a0947f43bb..656bbbd731d0 100644
--- a/arch/powerpc/platforms/pseries/hotplug-memory.c
+++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
@@ -616,7 +616,7 @@ static int dlpar_add_lmb(struct of_drconf_cell *lmb)
 	nid = memory_add_physaddr_to_nid(lmb->base_addr);
 
 	/* Add the memory */
-	rc = add_memory(nid, lmb->base_addr, block_sz);
+	rc = __add_memory(nid, lmb->base_addr, block_sz);
 	if (rc) {
 		dlpar_remove_device_tree_lmb(lmb);
 		dlpar_release_drc(lmb->drc_index);
diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c
index 6b0d3ef7309c..2ccfbb61ca89 100644
--- a/drivers/acpi/acpi_memhotplug.c
+++ b/drivers/acpi/acpi_memhotplug.c
@@ -228,7 +228,7 @@ static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
 		if (node < 0)
 			node = memory_add_physaddr_to_nid(info->start_addr);
 
-		result = add_memory(node, info->start_addr, info->length);
+		result = __add_memory(node, info->start_addr, info->length);
 
 		/*
 		 * If the memory block has been used by the kernel, add_memory()
diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index c5cdd190b781..9f96f1b43c15 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -500,15 +500,20 @@ memory_probe_store(struct device *dev, struct device_attribute *attr,
 	if (phys_addr & ((pages_per_block << PAGE_SHIFT) - 1))
 		return -EINVAL;
 
+	ret = lock_device_hotplug_sysfs();
+	if (ret)
+		goto out;
+
 	nid = memory_add_physaddr_to_nid(phys_addr);
-	ret = add_memory(nid, phys_addr,
-			 MIN_MEMORY_BLOCK_SIZE * sections_per_block);
+	ret = __add_memory(nid, phys_addr,
+			   MIN_MEMORY_BLOCK_SIZE * sections_per_block);
 
 	if (ret)
 		goto out;
 
 	ret = count;
 out:
+	unlock_device_hotplug();
 	return ret;
 }
 
diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c
index e4db19e88ab1..a10c64fee9ac 100644
--- a/drivers/xen/balloon.c
+++ b/drivers/xen/balloon.c
@@ -358,7 +358,10 @@ static enum bp_state reserve_additional_memory(void)
 	 * callers drop the mutex before trying again.
 	 */
 	mutex_unlock(&balloon_mutex);
+	/* add_memory_resource() requires the device_hotplug lock */
+	lock_device_hotplug();
 	rc = add_memory_resource(nid, resource, memhp_auto_online);
+	unlock_device_hotplug();
 	mutex_lock(&balloon_mutex);
 
 	if (rc) {
diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
index 134a2f69c21a..9469eef30095 100644
--- a/include/linux/memory_hotplug.h
+++ b/include/linux/memory_hotplug.h
@@ -272,6 +272,7 @@ static inline void remove_memory(int nid, u64 start, u64 size) {}
 
 extern int walk_memory_range(unsigned long start_pfn, unsigned long end_pfn,
 		void *arg, int (*func)(struct memory_block *, void *));
+extern int __add_memory(int nid, u64 start, u64 size);
 extern int add_memory(int nid, u64 start, u64 size);
 extern int add_memory_resource(int nid, struct resource *resource, bool online);
 extern int zone_for_memory(int nid, u64 start, u64 size, int zone_default,
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 0f962cc3f1bf..1e8ba77f642d 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1339,7 +1339,12 @@ static int online_memory_block(struct memory_block *mem, void *arg)
 	return memory_block_change_state(mem, MEM_ONLINE, MEM_OFFLINE);
 }
 
-/* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */
+/*
+ * NOTE: The caller must call lock_device_hotplug() to serialize hotplug
+ * and online/offline operations (triggered e.g. by sysfs).
+ *
+ * we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG
+ */
 int __ref add_memory_resource(int nid, struct resource *res, bool online)
 {
 	u64 start, size;
@@ -1417,9 +1422,9 @@ int __ref add_memory_resource(int nid, struct resource *res, bool online)
 	mem_hotplug_done();
 	return ret;
 }
-EXPORT_SYMBOL_GPL(add_memory_resource);
 
-int __ref add_memory(int nid, u64 start, u64 size)
+/* requires device_hotplug_lock, see add_memory_resource() */
+int __ref __add_memory(int nid, u64 start, u64 size)
 {
 	struct resource *res;
 	int ret;
@@ -1433,6 +1438,17 @@ int __ref add_memory(int nid, u64 start, u64 size)
 		release_memory_resource(res);
 	return ret;
 }
+
+int add_memory(int nid, u64 start, u64 size)
+{
+	int rc;
+
+	lock_device_hotplug();
+	rc = __add_memory(nid, start, size);
+	unlock_device_hotplug();
+
+	return rc;
+}
 EXPORT_SYMBOL_GPL(add_memory);
 
 #ifdef CONFIG_MEMORY_HOTREMOVE
-- 
2.17.1

[PATCH AUTOSEL 4.9 04/17] reiserfs: propagate errors from fill_with_dentries() properly

[Sasha Levin]

From: Jann Horn <jannh@google.com>

[ Upstream commit b10298d56c9623f9b173f19959732d3184b35f4f ]

fill_with_dentries() failed to propagate errors up to
reiserfs_for_each_xattr() properly.  Plumb them through.

Note that reiserfs_for_each_xattr() is only used by
reiserfs_delete_xattrs() and reiserfs_chown_xattrs().  The result of
reiserfs_delete_xattrs() is discarded anyway, the only difference there is
whether a warning is printed to dmesg.  The result of
reiserfs_chown_xattrs() does matter because it can block chowning of the
file to which the xattrs belong; but either way, the resulting state can
have misaligned ownership, so my patch doesn't improve things greatly.

Credit for making me look at this code goes to Al Viro, who pointed out
that the ->actor calling convention is suboptimal and should be changed.

Link: http://lkml.kernel.org/r/20180802163335.83312-1-jannh@google.com
Signed-off-by: Jann Horn <jannh@google.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Jeff Mahoney <jeffm@suse.com>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/reiserfs/xattr.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/fs/reiserfs/xattr.c b/fs/reiserfs/xattr.c
index 06a9fae202a7..9e313fc7fdc7 100644
--- a/fs/reiserfs/xattr.c
+++ b/fs/reiserfs/xattr.c
@@ -184,6 +184,7 @@ struct reiserfs_dentry_buf {
 	struct dir_context ctx;
 	struct dentry *xadir;
 	int count;
+	int err;
 	struct dentry *dentries[8];
 };
 
@@ -206,6 +207,7 @@ fill_with_dentries(struct dir_context *ctx, const char *name, int namelen,
 
 	dentry = lookup_one_len(name, dbuf->xadir, namelen);
 	if (IS_ERR(dentry)) {
+		dbuf->err = PTR_ERR(dentry);
 		return PTR_ERR(dentry);
 	} else if (d_really_is_negative(dentry)) {
 		/* A directory entry exists, but no file? */
@@ -214,6 +216,7 @@ fill_with_dentries(struct dir_context *ctx, const char *name, int namelen,
 			       "not found for file %pd.\n",
 			       dentry, dbuf->xadir);
 		dput(dentry);
+		dbuf->err = -EIO;
 		return -EIO;
 	}
 
@@ -261,6 +264,10 @@ static int reiserfs_for_each_xattr(struct inode *inode,
 		err = reiserfs_readdir_inode(d_inode(dir), &buf.ctx);
 		if (err)
 			break;
+		if (buf.err) {
+			err = buf.err;
+			break;
+		}
 		if (!buf.count)
 			break;
 		for (i = 0; !err && i < buf.count && buf.dentries[i]; i++) {
-- 
2.17.1

[PATCH AUTOSEL 4.9 05/17] hfs: prevent btree data loss on root split

[Sasha Levin]

From: Ernesto A. Fernández <ernesto.mnd.fernandez@gmail.com>

[ Upstream commit d057c036672f33d43a5f7344acbb08cf3a8a0c09 ]

This bug is triggered whenever hfs_brec_update_parent() needs to split
the root node.  The height of the btree is not increased, which leaves
the new node orphaned and its records lost.  It is not possible for this
to happen on a valid hfs filesystem because the index nodes have fixed
length keys.

For reasons I ignore, the hfs module does have support for a number of
hfsplus features.  A corrupt btree header may report variable length
keys and trigger this bug, so it's better to fix it.

Link: http://lkml.kernel.org/r/9750b1415685c4adca10766895f6d5ef12babdb0.1535682463.git.ernesto.mnd.fernandez@gmail.com
Signed-off-by: Ernesto A. Fernández <ernesto.mnd.fernandez@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/hfs/brec.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/fs/hfs/brec.c b/fs/hfs/brec.c
index 2a6f3c67cb3f..2e713673df42 100644
--- a/fs/hfs/brec.c
+++ b/fs/hfs/brec.c
@@ -424,6 +424,10 @@ static int hfs_brec_update_parent(struct hfs_find_data *fd)
 	if (new_node) {
 		__be32 cnid;
 
+		if (!new_node->parent) {
+			hfs_btree_inc_height(tree);
+			new_node->parent = tree->root;
+		}
 		fd->bnode = hfs_bnode_find(tree, new_node->parent);
 		/* create index key and entry */
 		hfs_bnode_read_key(new_node, fd->search_key, 14);
-- 
2.17.1

[PATCH AUTOSEL 4.9 06/17] hfsplus: prevent btree data loss on root split

[Sasha Levin]

From: Ernesto A. Fernández <ernesto.mnd.fernandez@gmail.com>

[ Upstream commit 0a3021d4f5295aa073c7bf5c5e4de60a2e292578 ]

Creating, renaming or deleting a file may cause catalog corruption and
data loss.  This bug is randomly triggered by xfstests generic/027, but
here is a faster reproducer:

  truncate -s 50M fs.iso
  mkfs.hfsplus fs.iso
  mount fs.iso /mnt
  i=100
  while [ $i -le 150 ]; do
    touch /mnt/$i &>/dev/null
    ((++i))
  done
  i=100
  while [ $i -le 150 ]; do
    mv /mnt/$i /mnt/$(perl -e "print $i x82") &>/dev/null
    ((++i))
  done
  umount /mnt
  fsck.hfsplus -n fs.iso

The bug is triggered whenever hfs_brec_update_parent() needs to split the
root node.  The height of the btree is not increased, which leaves the new
node orphaned and its records lost.

Link: http://lkml.kernel.org/r/26d882184fc43043a810114258f45277752186c7.1535682461.git.ernesto.mnd.fernandez@gmail.com
Signed-off-by: Ernesto A. Fernández <ernesto.mnd.fernandez@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/hfsplus/brec.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/fs/hfsplus/brec.c b/fs/hfsplus/brec.c
index 754fdf8c6356..1002a0c08319 100644
--- a/fs/hfsplus/brec.c
+++ b/fs/hfsplus/brec.c
@@ -427,6 +427,10 @@ static int hfs_brec_update_parent(struct hfs_find_data *fd)
 	if (new_node) {
 		__be32 cnid;
 
+		if (!new_node->parent) {
+			hfs_btree_inc_height(tree);
+			new_node->parent = tree->root;
+		}
 		fd->bnode = hfs_bnode_find(tree, new_node->parent);
 		/* create index key and entry */
 		hfs_bnode_read_key(new_node, fd->search_key, 14);
-- 
2.17.1

[PATCH AUTOSEL 4.9 07/17] um: Give start_idle_thread() a return code

[Sasha Levin]

From: Richard Weinberger <richard@nod.at>

[ Upstream commit 7ff1e34bbdc15acab823b1ee4240e94623d50ee8 ]

Fixes:
arch/um/os-Linux/skas/process.c:613:1: warning: control reaches end of
non-void function [-Wreturn-type]

longjmp() never returns but gcc still warns that the end of the function
can be reached.
Add a return code and debug aid to detect this impossible case.

Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/um/os-Linux/skas/process.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/um/os-Linux/skas/process.c b/arch/um/os-Linux/skas/process.c
index 23025d645160..0a99d4515065 100644
--- a/arch/um/os-Linux/skas/process.c
+++ b/arch/um/os-Linux/skas/process.c
@@ -578,6 +578,11 @@ int start_idle_thread(void *stack, jmp_buf *switch_buf)
 		fatal_sigsegv();
 	}
 	longjmp(*switch_buf, 1);
+
+	/* unreachable */
+	printk(UM_KERN_ERR "impossible long jump!");
+	fatal_sigsegv();
+	return 0;
 }
 
 void initial_thread_cb_skas(void (*proc)(void *), void *arg)
-- 
2.17.1

[PATCH AUTOSEL 4.9 08/17] drm/edid: Add 6 bpc quirk for BOE panel.

[Sasha Levin]

From: "Lee, Shawn C" <shawn.c.lee@intel.com>

[ Upstream commit 922dceff8dc1fb4dafc9af78139ba65671408103 ]

BOE panel (ID: 0x0771) that reports "DFP 1.x compliant TMDS".
But it's 6bpc panel only instead of 8 bpc.

Add panel ID to edid quirk list and set 6 bpc as default to
work around this issue.

Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Gustavo Padovan <gustavo@padovan.org>
Cc: Cooper Chiou <cooper.chiou@intel.com>
Signed-off-by: Lee, Shawn C <shawn.c.lee@intel.com>>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/1540792173-7288-1-git-send-email-shawn.c.lee@intel.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/gpu/drm/drm_edid.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 83d2f43b5a2f..c93dcfedc219 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -116,6 +116,9 @@ static const struct edid_quirk {
 	/* SDC panel of Lenovo B50-80 reports 8 bpc, but is a 6 bpc panel */
 	{ "SDC", 0x3652, EDID_QUIRK_FORCE_6BPC },
 
+	/* BOE model 0x0771 reports 8 bpc, but is a 6 bpc panel */
+	{ "BOE", 0x0771, EDID_QUIRK_FORCE_6BPC },
+
 	/* Belinea 10 15 55 */
 	{ "MAX", 1516, EDID_QUIRK_PREFER_LARGE_60 },
 	{ "MAX", 0x77e, EDID_QUIRK_PREFER_LARGE_60 },
-- 
2.17.1

Re: [PATCH AUTOSEL 4.9 08/17] drm/edid: Add 6 bpc quirk for BOE panel.

[Daniel Vetter]

On Tue, Nov 13, 2018 at 12:52:14AM -0500, Sasha Levin wrote:
> From: "Lee, Shawn C" <shawn.c.lee@intel.com>
> 
> [ Upstream commit 922dceff8dc1fb4dafc9af78139ba65671408103 ]
> 
> BOE panel (ID: 0x0771) that reports "DFP 1.x compliant TMDS".
> But it's 6bpc panel only instead of 8 bpc.
> 
> Add panel ID to edid quirk list and set 6 bpc as default to
> work around this issue.
> 
> Cc: Jani Nikula <jani.nikula@intel.com>
> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
> Cc: Gustavo Padovan <gustavo@padovan.org>
> Cc: Cooper Chiou <cooper.chiou@intel.com>
> Signed-off-by: Lee, Shawn C <shawn.c.lee@intel.com>>
> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
> Link: https://patchwork.freedesktop.org/patch/msgid/1540792173-7288-1-git-send-email-shawn.c.lee@intel.com
> Signed-off-by: Sasha Levin <sashal@kernel.org>

Given that I'm not a fan of AUTOSEL at all: This one here is correctly
cherry-picked for stable, ack.
-Daniel

> ---
>  drivers/gpu/drm/drm_edid.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
> index 83d2f43b5a2f..c93dcfedc219 100644
> --- a/drivers/gpu/drm/drm_edid.c
> +++ b/drivers/gpu/drm/drm_edid.c
> @@ -116,6 +116,9 @@ static const struct edid_quirk {
>  	/* SDC panel of Lenovo B50-80 reports 8 bpc, but is a 6 bpc panel */
>  	{ "SDC", 0x3652, EDID_QUIRK_FORCE_6BPC },
>  
> +	/* BOE model 0x0771 reports 8 bpc, but is a 6 bpc panel */
> +	{ "BOE", 0x0771, EDID_QUIRK_FORCE_6BPC },
> +
>  	/* Belinea 10 15 55 */
>  	{ "MAX", 1516, EDID_QUIRK_PREFER_LARGE_60 },
>  	{ "MAX", 0x77e, EDID_QUIRK_PREFER_LARGE_60 },
> -- 
> 2.17.1
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

Re: [PATCH AUTOSEL 4.9 08/17] drm/edid: Add 6 bpc quirk for BOE panel.

[Daniel Vetter]

On Wed, Nov 21, 2018 at 10:31 AM Daniel Vetter <daniel@ffwll.ch> wrote:
>
> On Tue, Nov 13, 2018 at 12:52:14AM -0500, Sasha Levin wrote:
> > From: "Lee, Shawn C" <shawn.c.lee@intel.com>
> >
> > [ Upstream commit 922dceff8dc1fb4dafc9af78139ba65671408103 ]
> >
> > BOE panel (ID: 0x0771) that reports "DFP 1.x compliant TMDS".
> > But it's 6bpc panel only instead of 8 bpc.
> >
> > Add panel ID to edid quirk list and set 6 bpc as default to
> > work around this issue.
> >
> > Cc: Jani Nikula <jani.nikula@intel.com>
> > Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
> > Cc: Gustavo Padovan <gustavo@padovan.org>
> > Cc: Cooper Chiou <cooper.chiou@intel.com>
> > Signed-off-by: Lee, Shawn C <shawn.c.lee@intel.com>>
> > Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
> > Link: https://patchwork.freedesktop.org/patch/msgid/1540792173-7288-1-git-send-email-shawn.c.lee@intel.com
> > Signed-off-by: Sasha Levin <sashal@kernel.org>
>
> Given that I'm not a fan of AUTOSEL at all: This one here is correctly
> cherry-picked for stable, ack.

An idea that just crossed my mind: Could we integrate this into 0day
and suggest cc: stable before the patch even gets merged? Or is the
heuristics not good enough for that kind of automation?
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch

Re: [PATCH AUTOSEL 4.9 08/17] drm/edid: Add 6 bpc quirk for BOE panel.

[Sasha Levin]

On Wed, Nov 21, 2018 at 10:33:18AM +0100, Daniel Vetter wrote:
>On Wed, Nov 21, 2018 at 10:31 AM Daniel Vetter <daniel@ffwll.ch> wrote:
>>
>> On Tue, Nov 13, 2018 at 12:52:14AM -0500, Sasha Levin wrote:
>> > From: "Lee, Shawn C" <shawn.c.lee@intel.com>
>> >
>> > [ Upstream commit 922dceff8dc1fb4dafc9af78139ba65671408103 ]
>> >
>> > BOE panel (ID: 0x0771) that reports "DFP 1.x compliant TMDS".
>> > But it's 6bpc panel only instead of 8 bpc.
>> >
>> > Add panel ID to edid quirk list and set 6 bpc as default to
>> > work around this issue.
>> >
>> > Cc: Jani Nikula <jani.nikula@intel.com>
>> > Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
>> > Cc: Gustavo Padovan <gustavo@padovan.org>
>> > Cc: Cooper Chiou <cooper.chiou@intel.com>
>> > Signed-off-by: Lee, Shawn C <shawn.c.lee@intel.com>>
>> > Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
>> > Link: https://patchwork.freedesktop.org/patch/msgid/1540792173-7288-1-git-send-email-shawn.c.lee@intel.com
>> > Signed-off-by: Sasha Levin <sashal@kernel.org>
>>
>> Given that I'm not a fan of AUTOSEL at all: This one here is correctly
>> cherry-picked for stable, ack.
>
>An idea that just crossed my mind: Could we integrate this into 0day
>and suggest cc: stable before the patch even gets merged? Or is the
>heuristics not good enough for that kind of automation?

Yes! I've actually tried it before but it seemed that the response rate
was quite low (even for commits that are obviously stable material) so I
turned it off to avoid spamming too much.

If you'd like to be the guinea pig for this, I could enable it for
drivers/gpu/drm/i915/ which I currently completely ignore. If at any
point you want it back off that's easy to do.

If this works well we can extend it to more subsystems where maintainers
might find it useful.

--
Thanks,
Sasha

[PATCH AUTOSEL 4.9 09/17] platform/x86: intel_telemetry: report debugfs failure

[Sasha Levin]

From: Rajneesh Bhardwaj <rajneesh.bhardwaj@linux.intel.com>

[ Upstream commit 8d98b1ef368feeb7720b8b9b6f3bd93f2ad892bc ]

On some Goldmont based systems such as ASRock J3455M the BIOS may not
enable the IPC1 device that provides access to the PMC and PUNIT. In
such scenarios, the IOSS and PSS resources from the platform device can
not be obtained and result in a invalid telemetry_plt_config which is an
internal data structure that holds platform config and is maintained by
the telemetry platform driver.

This is also applicable to the platforms where the BIOS supports IPC1
device under debug configurations but IPC1 is disabled by user or the
policy.

This change allows user to know the reason for not seeing entries under
/sys/kernel/debug/telemetry/* when there is no apparent failure at boot.

Cc: Matt Turner <matt.turner@intel.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Souvik Kumar Chakravarty <souvik.k.chakravarty@intel.com>
Cc: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@intel.com>

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=198779
Acked-by: Matt Turner <matt.turner@intel.com>
Signed-off-by: Rajneesh Bhardwaj <rajneesh.bhardwaj@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/platform/x86/intel_telemetry_debugfs.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/platform/x86/intel_telemetry_debugfs.c b/drivers/platform/x86/intel_telemetry_debugfs.c
index ef29f18b1951..4069433a0ec6 100644
--- a/drivers/platform/x86/intel_telemetry_debugfs.c
+++ b/drivers/platform/x86/intel_telemetry_debugfs.c
@@ -953,12 +953,16 @@ static int __init telemetry_debugfs_init(void)
 	debugfs_conf = (struct telemetry_debugfs_conf *)id->driver_data;
 
 	err = telemetry_pltconfig_valid();
-	if (err < 0)
+	if (err < 0) {
+		pr_info("Invalid pltconfig, ensure IPC1 device is enabled in BIOS\n");
 		return -ENODEV;
+	}
 
 	err = telemetry_debugfs_check_evts();
-	if (err < 0)
+	if (err < 0) {
+		pr_info("telemetry_debugfs_check_evts failed\n");
 		return -EINVAL;
+	}
 
 
 #ifdef CONFIG_PM_SLEEP
-- 
2.17.1

[PATCH AUTOSEL 4.9 10/17] clk: fixed-rate: fix of_node_get-put imbalance

[Sasha Levin]

From: Alan Tull <atull@kernel.org>

[ Upstream commit 52091c256bdcad0d01e2852a63f19cd2cce6af96 ]

When the fixed rate clock is created by devicetree,
of_clk_add_provider is called.  Add a call to
of_clk_del_provider in the remove function to balance
it out.

Signed-off-by: Alan Tull <atull@kernel.org>
Fixes: 435779fe1336 ("clk: fixed-rate: Convert into a module platform driver")
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/clk/clk-fixed-rate.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/clk/clk-fixed-rate.c b/drivers/clk/clk-fixed-rate.c
index b5c46b3f8764..6d6475c32ee5 100644
--- a/drivers/clk/clk-fixed-rate.c
+++ b/drivers/clk/clk-fixed-rate.c
@@ -200,6 +200,7 @@ static int of_fixed_clk_remove(struct platform_device *pdev)
 {
 	struct clk *clk = platform_get_drvdata(pdev);
 
+	of_clk_del_provider(pdev->dev.of_node);
 	clk_unregister_fixed_rate(clk);
 
 	return 0;
-- 
2.17.1

[PATCH AUTOSEL 4.9 11/17] fs/exofs: fix potential memory leak in mount option parsing

[Sasha Levin]

From: Chengguang Xu <cgxu519@gmx.com>

[ Upstream commit 515f1867addaba49c1c6ac73abfaffbc192c1db4 ]

There are some cases can cause memory leak when parsing
option 'osdname'.

Signed-off-by: Chengguang Xu <cgxu519@gmx.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/exofs/super.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/fs/exofs/super.c b/fs/exofs/super.c
index 1076a4233b39..0c48138486dc 100644
--- a/fs/exofs/super.c
+++ b/fs/exofs/super.c
@@ -100,6 +100,7 @@ static int parse_options(char *options, struct exofs_mountopt *opts)
 		token = match_token(p, tokens, args);
 		switch (token) {
 		case Opt_name:
+			kfree(opts->dev_name);
 			opts->dev_name = match_strdup(&args[0]);
 			if (unlikely(!opts->dev_name)) {
 				EXOFS_ERR("Error allocating dev_name");
@@ -868,8 +869,10 @@ static struct dentry *exofs_mount(struct file_system_type *type,
 	int ret;
 
 	ret = parse_options(data, &opts);
-	if (ret)
+	if (ret) {
+		kfree(opts.dev_name);
 		return ERR_PTR(ret);
+	}
 
 	if (!opts.dev_name)
 		opts.dev_name = dev_name;
-- 
2.17.1

[PATCH AUTOSEL 4.9 12/17] clk: samsung: exynos5420: Enable PERIS clocks for suspend

[Sasha Levin]

From: Marek Szyprowski <m.szyprowski@samsung.com>

[ Upstream commit b33228029d842269e17bba591609e83ed422005d ]

Ensure that clocks for core SoC modules (including TZPC0..9 modules)
are enabled for suspend/resume cycle. This fixes suspend/resume
support on Exynos5422-based Odroid XU3/XU4 boards.

Suggested-by: Joonyoung Shim <jy0922.shim@samsung.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Sylwester Nawrocki <snawrocki@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/clk/samsung/clk-exynos5420.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/clk/samsung/clk-exynos5420.c b/drivers/clk/samsung/clk-exynos5420.c
index 07fb667e258f..13c09a740840 100644
--- a/drivers/clk/samsung/clk-exynos5420.c
+++ b/drivers/clk/samsung/clk-exynos5420.c
@@ -280,6 +280,7 @@ static const struct samsung_clk_reg_dump exynos5420_set_clksrc[] = {
 	{ .offset = GATE_BUS_TOP,		.value = 0xffffffff, },
 	{ .offset = GATE_BUS_DISP1,		.value = 0xffffffff, },
 	{ .offset = GATE_IP_PERIC,		.value = 0xffffffff, },
+	{ .offset = GATE_IP_PERIS,		.value = 0xffffffff, },
 };
 
 static int exynos5420_clk_suspend(void)
-- 
2.17.1

[PATCH AUTOSEL 4.9 13/17] platform/x86: acerhdf: Add BIOS entry for Gateway LT31 v1.3307

[Sasha Levin]

From: Paul Gortmaker <paul.gortmaker@windriver.com>

[ Upstream commit 684238d79ad85c5e19a71bb5818e77e329912fbc ]

To fix:

  acerhdf: unknown (unsupported) BIOS version Gateway  /LT31   /v1.3307 , please report, aborting!

As can be seen in the context, the BIOS registers haven't changed in
the previous versions, so the assumption is they won't have changed
in this last update for this somewhat older platform either.

Cc: Peter Feuerer <peter@piie.net>
Cc: Darren Hart <dvhart@infradead.org>
Cc: Andy Shevchenko <andy@infradead.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Peter Feuerer <peter@piie.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/platform/x86/acerhdf.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/platform/x86/acerhdf.c b/drivers/platform/x86/acerhdf.c
index 2acdb0d6ea89..a0533e4e52d7 100644
--- a/drivers/platform/x86/acerhdf.c
+++ b/drivers/platform/x86/acerhdf.c
@@ -233,6 +233,7 @@ static const struct bios_settings bios_tbl[] = {
 	{"Gateway", "LT31",   "v1.3201",  0x55, 0x58, {0x9e, 0x00}, 0},
 	{"Gateway", "LT31",   "v1.3302",  0x55, 0x58, {0x9e, 0x00}, 0},
 	{"Gateway", "LT31",   "v1.3303t", 0x55, 0x58, {0x9e, 0x00}, 0},
+	{"Gateway", "LT31",   "v1.3307",  0x55, 0x58, {0x9e, 0x00}, 0},
 	/* Packard Bell */
 	{"Packard Bell", "DOA150",  "v0.3104",  0x55, 0x58, {0x21, 0x00}, 0},
 	{"Packard Bell", "DOA150",  "v0.3105",  0x55, 0x58, {0x20, 0x00}, 0},
-- 
2.17.1

[PATCH AUTOSEL 4.9 14/17] arm64: percpu: Initialize ret in the default case

[Sasha Levin]

From: Nathan Chancellor <natechancellor@gmail.com>

[ Upstream commit b5bb425871186303e6936fa2581521bdd1964a58 ]

Clang warns that if the default case is taken, ret will be
uninitialized.

./arch/arm64/include/asm/percpu.h:196:2: warning: variable 'ret' is used
uninitialized whenever switch default is taken
[-Wsometimes-uninitialized]
        default:
        ^~~~~~~
./arch/arm64/include/asm/percpu.h:200:9: note: uninitialized use occurs
here
        return ret;
               ^~~
./arch/arm64/include/asm/percpu.h:157:19: note: initialize the variable
'ret' to silence this warning
        unsigned long ret, loop;
                         ^
                          = 0

This warning appears several times while building the erofs filesystem.
While it's not strictly wrong, the BUILD_BUG will prevent this from
becoming a true problem. Initialize ret to 0 in the default case right
before the BUILD_BUG to silence all of these warnings.

Reported-by: Prasad Sodagudi <psodagud@codeaurora.org>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/arm64/include/asm/percpu.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/arm64/include/asm/percpu.h b/arch/arm64/include/asm/percpu.h
index 0d551576eb57..4724b8f0b625 100644
--- a/arch/arm64/include/asm/percpu.h
+++ b/arch/arm64/include/asm/percpu.h
@@ -92,6 +92,7 @@ static inline unsigned long __percpu_##op(void *ptr,			\
 		: [val] "Ir" (val));					\
 		break;							\
 	default:							\
+		ret = 0;						\
 		BUILD_BUG();						\
 	}								\
 									\
@@ -121,6 +122,7 @@ static inline unsigned long __percpu_read(void *ptr, int size)
 		ret = ACCESS_ONCE(*(u64 *)ptr);
 		break;
 	default:
+		ret = 0;
 		BUILD_BUG();
 	}
 
@@ -190,6 +192,7 @@ static inline unsigned long __percpu_xchg(void *ptr, unsigned long val,
 		: [val] "r" (val));
 		break;
 	default:
+		ret = 0;
 		BUILD_BUG();
 	}
 
-- 
2.17.1

[PATCH AUTOSEL 4.9 15/17] mm/vmstat.c: assert that vmstat_text is in sync with stat_items_size

[Sasha Levin]

From: Jann Horn <jannh@google.com>

[ Upstream commit f0ecf25a093fc0589f0a6bc4c1ea068bbb67d220 ]

Having two gigantic arrays that must manually be kept in sync, including
ifdefs, isn't exactly robust.  To make it easier to catch such issues in
the future, add a BUILD_BUG_ON().

Link: http://lkml.kernel.org/r/20181001143138.95119-3-jannh@google.com
Signed-off-by: Jann Horn <jannh@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Roman Gushchin <guro@fb.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Kemi Wang <kemi.wang@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 mm/vmstat.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/mm/vmstat.c b/mm/vmstat.c
index 5e6a4d76659d..2bab38d5570c 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -1484,6 +1484,8 @@ static void *vmstat_start(struct seq_file *m, loff_t *pos)
 	stat_items_size += sizeof(struct vm_event_state);
 #endif
 
+	BUILD_BUG_ON(stat_items_size !=
+		     ARRAY_SIZE(vmstat_text) * sizeof(unsigned long));
 	v = kmalloc(stat_items_size, GFP_KERNEL);
 	m->private = v;
 	if (!v)
-- 
2.17.1

[PATCH AUTOSEL 4.9 16/17] userfaultfd: allow get_mempolicy(MPOL_F_NODE|MPOL_F_ADDR) to trigger userfaults

[Sasha Levin]

From: Andrea Arcangeli <aarcange@redhat.com>

[ Upstream commit 3b9aadf7278d16d7bed4d5d808501065f70898d8 ]

get_mempolicy(MPOL_F_NODE|MPOL_F_ADDR) called a get_user_pages that would
not be waiting for userfaults before failing and it would hit on a SIGBUS
instead.  Using get_user_pages_locked/unlocked instead will allow
get_mempolicy to allow userfaults to resolve the fault and fill the hole,
before grabbing the node id of the page.

If the user calls get_mempolicy() with MPOL_F_ADDR | MPOL_F_NODE for an
address inside an area managed by uffd and there is no page at that
address, the page allocation from within get_mempolicy() will fail
because get_user_pages() does not allow for page fault retry required
for uffd; the user will get SIGBUS.

With this patch, the page fault will be resolved by the uffd and the
get_mempolicy() will continue normally.

Background:

Via code review, previously the syscall would have returned -EFAULT
(vm_fault_to_errno), now it will block and wait for an userfault (if
it's waken before the fault is resolved it'll still -EFAULT).

This way get_mempolicy will give a chance to an "unaware" app to be
compliant with userfaults.

The reason this visible change is that becoming "userfault compliant"
cannot regress anything: all other syscalls including read(2)/write(2)
had to become "userfault compliant" long time ago (that's one of the
things userfaultfd can do that PROT_NONE and trapping segfaults can't).

So this is just one more syscall that become "userfault compliant" like
all other major ones already were.

This has been happening on virtio-bridge dpdk process which just called
get_mempolicy on the guest space post live migration, but before the
memory had a chance to be migrated to destination.

I didn't run an strace to be able to show the -EFAULT going away, but
I've the confirmation of the below debug aid information (only visible
with CONFIG_DEBUG_VM=y) going away with the patch:

    [20116.371461] FAULT_FLAG_ALLOW_RETRY missing 0
    [20116.371464] CPU: 1 PID: 13381 Comm: vhost-events Not tainted 4.17.12-200.fc28.x86_64 #1
    [20116.371465] Hardware name: LENOVO 20FAS2BN0A/20FAS2BN0A, BIOS N1CET54W (1.22 ) 02/10/2017
    [20116.371466] Call Trace:
    [20116.371473]  dump_stack+0x5c/0x80
    [20116.371476]  handle_userfault.cold.37+0x1b/0x22
    [20116.371479]  ? remove_wait_queue+0x20/0x60
    [20116.371481]  ? poll_freewait+0x45/0xa0
    [20116.371483]  ? do_sys_poll+0x31c/0x520
    [20116.371485]  ? radix_tree_lookup_slot+0x1e/0x50
    [20116.371488]  shmem_getpage_gfp+0xce7/0xe50
    [20116.371491]  ? page_add_file_rmap+0x1a/0x2c0
    [20116.371493]  shmem_fault+0x78/0x1e0
    [20116.371495]  ? filemap_map_pages+0x3a1/0x450
    [20116.371498]  __do_fault+0x1f/0xc0
    [20116.371500]  __handle_mm_fault+0xe2e/0x12f0
    [20116.371502]  handle_mm_fault+0xda/0x200
    [20116.371504]  __get_user_pages+0x238/0x790
    [20116.371506]  get_user_pages+0x3e/0x50
    [20116.371510]  kernel_get_mempolicy+0x40b/0x700
    [20116.371512]  ? vfs_write+0x170/0x1a0
    [20116.371515]  __x64_sys_get_mempolicy+0x21/0x30
    [20116.371517]  do_syscall_64+0x5b/0x160
    [20116.371520]  entry_SYSCALL_64_after_hwframe+0x44/0xa9

The above harmless debug message (not a kernel crash, just a
dump_stack()) is shown with CONFIG_DEBUG_VM=y to more quickly identify
and improve kernel spots that may have to become "userfaultfd
compliant" like this one (without having to run an strace and search
for syscall misbehavior).  Spots like the above are more closer to a
kernel bug for the non-cooperative usages that Mike focuses on, than
for for dpdk qemu-cooperative usages that reproduced it, but it's still
nicer to get this fixed for dpdk too.

The part of the patch that caused me to think is only the
implementation issue of mpol_get, but it looks like it should work safe
no matter the kind of mempolicy structure that is (the default static
policy also starts at 1 so it'll go to 2 and back to 1 without crashing
everything at 0).

[rppt@linux.vnet.ibm.com: changelog addition]
  http://lkml.kernel.org/r/20180904073718.GA26916@rapoport-lnx
Link: http://lkml.kernel.org/r/20180831214848.23676-1-aarcange@redhat.com
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Reported-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Tested-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 mm/mempolicy.c | 24 +++++++++++++++++++-----
 1 file changed, 19 insertions(+), 5 deletions(-)

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 69c4a0c92ebb..625122adefe0 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -845,16 +845,19 @@ static void get_policy_nodemask(struct mempolicy *p, nodemask_t *nodes)
 	}
 }
 
-static int lookup_node(unsigned long addr)
+static int lookup_node(struct mm_struct *mm, unsigned long addr)
 {
 	struct page *p;
 	int err;
 
-	err = get_user_pages(addr & PAGE_MASK, 1, 0, &p, NULL);
+	int locked = 1;
+	err = get_user_pages_locked(addr & PAGE_MASK, 1, 0, &p, &locked);
 	if (err >= 0) {
 		err = page_to_nid(p);
 		put_page(p);
 	}
+	if (locked)
+		up_read(&mm->mmap_sem);
 	return err;
 }
 
@@ -865,7 +868,7 @@ static long do_get_mempolicy(int *policy, nodemask_t *nmask,
 	int err;
 	struct mm_struct *mm = current->mm;
 	struct vm_area_struct *vma = NULL;
-	struct mempolicy *pol = current->mempolicy;
+	struct mempolicy *pol = current->mempolicy, *pol_refcount = NULL;
 
 	if (flags &
 		~(unsigned long)(MPOL_F_NODE|MPOL_F_ADDR|MPOL_F_MEMS_ALLOWED))
@@ -905,7 +908,16 @@ static long do_get_mempolicy(int *policy, nodemask_t *nmask,
 
 	if (flags & MPOL_F_NODE) {
 		if (flags & MPOL_F_ADDR) {
-			err = lookup_node(addr);
+			/*
+			 * Take a refcount on the mpol, lookup_node()
+			 * wil drop the mmap_sem, so after calling
+			 * lookup_node() only "pol" remains valid, "vma"
+			 * is stale.
+			 */
+			pol_refcount = pol;
+			vma = NULL;
+			mpol_get(pol);
+			err = lookup_node(mm, addr);
 			if (err < 0)
 				goto out;
 			*policy = err;
@@ -940,7 +952,9 @@ static long do_get_mempolicy(int *policy, nodemask_t *nmask,
  out:
 	mpol_cond_put(pol);
 	if (vma)
-		up_read(&current->mm->mmap_sem);
+		up_read(&mm->mmap_sem);
+	if (pol_refcount)
+		mpol_put(pol_refcount);
 	return err;
 }
 
-- 
2.17.1

[PATCH AUTOSEL 4.9 17/17] mm: don't warn about large allocations for slab

[Sasha Levin]

From: Dmitry Vyukov <dvyukov@google.com>

[ Upstream commit 61448479a9f2c954cde0cfe778cb6bec5d0a748d ]

Slub does not call kmalloc_slab() for sizes > KMALLOC_MAX_CACHE_SIZE,
instead it falls back to kmalloc_large().

For slab KMALLOC_MAX_CACHE_SIZE == KMALLOC_MAX_SIZE and it calls
kmalloc_slab() for all allocations relying on NULL return value for
over-sized allocations.

This inconsistency leads to unwanted warnings from kmalloc_slab() for
over-sized allocations for slab.  Returning NULL for failed allocations is
the expected behavior.

Make slub and slab code consistent by checking size >
KMALLOC_MAX_CACHE_SIZE in slab before calling kmalloc_slab().

While we are here also fix the check in kmalloc_slab().  We should check
against KMALLOC_MAX_CACHE_SIZE rather than KMALLOC_MAX_SIZE.  It all kinda
worked because for slab the constants are the same, and slub always checks
the size against KMALLOC_MAX_CACHE_SIZE before kmalloc_slab().  But if we
get there with size > KMALLOC_MAX_CACHE_SIZE anyhow bad things will
happen.  For example, in case of a newly introduced bug in slub code.

Also move the check in kmalloc_slab() from function entry to the size >
192 case.  This partially compensates for the additional check in slab
code and makes slub code a bit faster (at least theoretically).

Also drop __GFP_NOWARN in the warning check.  This warning means a bug in
slab code itself, user-passed flags have nothing to do with it.

Nothing of this affects slob.

Link: http://lkml.kernel.org/r/20180927171502.226522-1-dvyukov@gmail.com
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Reported-by: syzbot+87829a10073277282ad1@syzkaller.appspotmail.com
Reported-by: syzbot+ef4e8fc3a06e9019bb40@syzkaller.appspotmail.com
Reported-by: syzbot+6e438f4036df52cbb863@syzkaller.appspotmail.com
Reported-by: syzbot+8574471d8734457d98aa@syzkaller.appspotmail.com
Reported-by: syzbot+af1504df0807a083dbd9@syzkaller.appspotmail.com
Acked-by: Christoph Lameter <cl@linux.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 mm/slab.c        |  4 ++++
 mm/slab_common.c | 12 ++++++------
 2 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/mm/slab.c b/mm/slab.c
index c59844dbd034..263dcda6897b 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -3690,6 +3690,8 @@ __do_kmalloc_node(size_t size, gfp_t flags, int node, unsigned long caller)
 	struct kmem_cache *cachep;
 	void *ret;
 
+	if (unlikely(size > KMALLOC_MAX_CACHE_SIZE))
+		return NULL;
 	cachep = kmalloc_slab(size, flags);
 	if (unlikely(ZERO_OR_NULL_PTR(cachep)))
 		return cachep;
@@ -3725,6 +3727,8 @@ static __always_inline void *__do_kmalloc(size_t size, gfp_t flags,
 	struct kmem_cache *cachep;
 	void *ret;
 
+	if (unlikely(size > KMALLOC_MAX_CACHE_SIZE))
+		return NULL;
 	cachep = kmalloc_slab(size, flags);
 	if (unlikely(ZERO_OR_NULL_PTR(cachep)))
 		return cachep;
diff --git a/mm/slab_common.c b/mm/slab_common.c
index 622f6b6ae844..13f1926f8fcd 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -883,18 +883,18 @@ struct kmem_cache *kmalloc_slab(size_t size, gfp_t flags)
 {
 	int index;
 
-	if (unlikely(size > KMALLOC_MAX_SIZE)) {
-		WARN_ON_ONCE(!(flags & __GFP_NOWARN));
-		return NULL;
-	}
-
 	if (size <= 192) {
 		if (!size)
 			return ZERO_SIZE_PTR;
 
 		index = size_index[size_index_elem(size)];
-	} else
+	} else {
+		if (unlikely(size > KMALLOC_MAX_CACHE_SIZE)) {
+			WARN_ON(1);
+			return NULL;
+		}
 		index = fls(size - 1);
+	}
 
 #ifdef CONFIG_ZONE_DMA
 	if (unlikely((flags & GFP_DMA)))
-- 
2.17.1