Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull misc vfs updates from Al Viro:
 "All kinds of stuff.  That probably should've been 5 or 6 separate
  branches, but by the time I'd realized how large and mixed that bag
  had become it had been too close to -final to play with rebasing.

  Some fs/namei.c cleanups there, memdup_user_nul() introduction and
  switching open-coded instances, burying long-dead code, whack-a-mole
  of various kinds, several new helpers for ->llseek(), assorted
  cleanups and fixes from various people, etc.

  One piece probably deserves special mention - Neil's
  lookup_one_len_unlocked().  Similar to lookup_one_len(), but gets
  called without ->i_mutex and tries to avoid ever taking it.  That, of
  course, means that it's not useful for any directory modifications,
  but things like getting inode attributes in nfds readdirplus are fine
  with that.  I really should've asked for moratorium on lookup-related
  changes this cycle, but since I hadn't done that early enough...  I
  *am* asking for that for the coming cycle, though - I'm going to try
  and get conversion of i_mutex to rwsem with ->lookup() done under lock
  taken shared.

  There will be a patch closer to the end of the window, along the lines
  of the one Linus had posted last May - mechanical conversion of
  ->i_mutex accesses to inode_lock()/inode_unlock()/inode_trylock()/
  inode_is_locked()/inode_lock_nested().  To quote Linus back then:

    -----
    |    This is an automated patch using
    |
    |        sed 's/mutex_lock(&\(.*\)->i_mutex)/inode_lock(\1)/'
    |        sed 's/mutex_unlock(&\(.*\)->i_mutex)/inode_unlock(\1)/'
    |        sed 's/mutex_lock_nested(&\(.*\)->i_mutex,[     ]*I_MUTEX_\([A-Z0-9_]*\))/inode_lock_nested(\1, I_MUTEX_\2)/'
    |        sed 's/mutex_is_locked(&\(.*\)->i_mutex)/inode_is_locked(\1)/'
    |        sed 's/mutex_trylock(&\(.*\)->i_mutex)/inode_trylock(\1)/'
    |
    |    with a very few manual fixups
    -----

  I'm going to send that once the ->i_mutex-affecting stuff in -next
  gets mostly merged (or when Linus says he's about to stop taking
  merges)"

* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits)
  nfsd: don't hold i_mutex over userspace upcalls
  fs:affs:Replace time_t with time64_t
  fs/9p: use fscache mutex rather than spinlock
  proc: add a reschedule point in proc_readfd_common()
  logfs: constify logfs_block_ops structures
  fcntl: allow to set O_DIRECT flag on pipe
  fs: __generic_file_splice_read retry lookup on AOP_TRUNCATED_PAGE
  fs: xattr: Use kvfree()
  [s390] page_to_phys() always returns a multiple of PAGE_SIZE
  nbd: use ->compat_ioctl()
  fs: use block_device name vsprintf helper
  lib/vsprintf: add %*pg format specifier
  fs: use gendisk->disk_name where possible
  poll: plug an unused argument to do_poll
  amdkfd: don't open-code memdup_user()
  cdrom: don't open-code memdup_user()
  rsxx: don't open-code memdup_user()
  mtip32xx: don't open-code memdup_user()
  [um] mconsole: don't open-code memdup_user_nul()
  [um] hostaudio: don't open-code memdup_user()
  ...

5 files changed, 51 insertions, 104 deletions

diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index dc6858d6639e..5faf89ac9ec0 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -2047,9 +2047,8 @@ static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
 		  void *data)
 {
 	int *i, vleft, first = 1, err = 0;
-	unsigned long page = 0;
 	size_t left;
-	char *kbuf;
+	char *kbuf = NULL, *p;
 	
 	if (!tbl_data || !table->maxlen || !*lenp || (*ppos && !write)) {
 		*lenp = 0;
@@ -2078,15 +2077,9 @@ static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
 
 		if (left > PAGE_SIZE - 1)
 			left = PAGE_SIZE - 1;
-		page = __get_free_page(GFP_TEMPORARY);
-		kbuf = (char *) page;
-		if (!kbuf)
-			return -ENOMEM;
-		if (copy_from_user(kbuf, buffer, left)) {
-			err = -EFAULT;
-			goto free;
-		}
-		kbuf[left] = 0;
+		p = kbuf = memdup_user_nul(buffer, left);
+		if (IS_ERR(kbuf))
+			return PTR_ERR(kbuf);
 	}
 
 	for (; left && vleft--; i++, first=0) {
@@ -2094,11 +2087,11 @@ static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
 		bool neg;
 
 		if (write) {
-			left -= proc_skip_spaces(&kbuf);
+			left -= proc_skip_spaces(&p);
 
 			if (!left)
 				break;
-			err = proc_get_long(&kbuf, &left, &lval, &neg,
+			err = proc_get_long(&p, &left, &lval, &neg,
 					     proc_wspace_sep,
 					     sizeof(proc_wspace_sep), NULL);
 			if (err)
@@ -2125,10 +2118,9 @@ static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
 	if (!write && !first && left && !err)
 		err = proc_put_char(&buffer, &left, '\n');
 	if (write && !err && left)
-		left -= proc_skip_spaces(&kbuf);
-free:
+		left -= proc_skip_spaces(&p);
 	if (write) {
-		free_page(page);
+		kfree(kbuf);
 		if (first)
 			return err ? : -EINVAL;
 	}
@@ -2310,9 +2302,8 @@ static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int
 {
 	unsigned long *i, *min, *max;
 	int vleft, first = 1, err = 0;
-	unsigned long page = 0;
 	size_t left;
-	char *kbuf;
+	char *kbuf = NULL, *p;
 
 	if (!data || !table->maxlen || !*lenp || (*ppos && !write)) {
 		*lenp = 0;
@@ -2340,15 +2331,9 @@ static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int
 
 		if (left > PAGE_SIZE - 1)
 			left = PAGE_SIZE - 1;
-		page = __get_free_page(GFP_TEMPORARY);
-		kbuf = (char *) page;
-		if (!kbuf)
-			return -ENOMEM;
-		if (copy_from_user(kbuf, buffer, left)) {
-			err = -EFAULT;
-			goto free;
-		}
-		kbuf[left] = 0;
+		p = kbuf = memdup_user_nul(buffer, left);
+		if (IS_ERR(kbuf))
+			return PTR_ERR(kbuf);
 	}
 
 	for (; left && vleft--; i++, first = 0) {
@@ -2357,9 +2342,9 @@ static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int
 		if (write) {
 			bool neg;
 
-			left -= proc_skip_spaces(&kbuf);
+			left -= proc_skip_spaces(&p);
 
-			err = proc_get_long(&kbuf, &left, &val, &neg,
+			err = proc_get_long(&p, &left, &val, &neg,
 					     proc_wspace_sep,
 					     sizeof(proc_wspace_sep), NULL);
 			if (err)
@@ -2385,10 +2370,9 @@ static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int
 	if (!write && !first && left && !err)
 		err = proc_put_char(&buffer, &left, '\n');
 	if (write && !err)
-		left -= proc_skip_spaces(&kbuf);
-free:
+		left -= proc_skip_spaces(&p);
 	if (write) {
-		free_page(page);
+		kfree(kbuf);
 		if (first)
 			return err ? : -EINVAL;
 	}
@@ -2650,34 +2634,27 @@ int proc_do_large_bitmap(struct ctl_table *table, int write,
 	}
 
 	if (write) {
-		unsigned long page = 0;
-		char *kbuf;
+		char *kbuf, *p;
 
 		if (left > PAGE_SIZE - 1)
 			left = PAGE_SIZE - 1;
 
-		page = __get_free_page(GFP_TEMPORARY);
-		kbuf = (char *) page;
-		if (!kbuf)
-			return -ENOMEM;
-		if (copy_from_user(kbuf, buffer, left)) {
-			free_page(page);
-			return -EFAULT;
-                }
-		kbuf[left] = 0;
+		p = kbuf = memdup_user_nul(buffer, left);
+		if (IS_ERR(kbuf))
+			return PTR_ERR(kbuf);
 
 		tmp_bitmap = kzalloc(BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long),
 				     GFP_KERNEL);
 		if (!tmp_bitmap) {
-			free_page(page);
+			kfree(kbuf);
 			return -ENOMEM;
 		}
-		proc_skip_char(&kbuf, &left, '\n');
+		proc_skip_char(&p, &left, '\n');
 		while (!err && left) {
 			unsigned long val_a, val_b;
 			bool neg;
 
-			err = proc_get_long(&kbuf, &left, &val_a, &neg, tr_a,
+			err = proc_get_long(&p, &left, &val_a, &neg, tr_a,
 					     sizeof(tr_a), &c);
 			if (err)
 				break;
@@ -2688,12 +2665,12 @@ int proc_do_large_bitmap(struct ctl_table *table, int write,
 
 			val_b = val_a;
 			if (left) {
-				kbuf++;
+				p++;
 				left--;
 			}
 
 			if (c == '-') {
-				err = proc_get_long(&kbuf, &left, &val_b,
+				err = proc_get_long(&p, &left, &val_b,
 						     &neg, tr_b, sizeof(tr_b),
 						     &c);
 				if (err)
@@ -2704,16 +2681,16 @@ int proc_do_large_bitmap(struct ctl_table *table, int write,
 					break;
 				}
 				if (left) {
-					kbuf++;
+					p++;
 					left--;
 				}
 			}
 
 			bitmap_set(tmp_bitmap, val_a, val_b - val_a + 1);
 			first = 0;
-			proc_skip_char(&kbuf, &left, '\n');
+			proc_skip_char(&p, &left, '\n');
 		}
-		free_page(page);
+		kfree(kbuf);
 	} else {
 		unsigned long bit_a, bit_b = 0;
 
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index a990824c8604..2aeb6ffc0a1e 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -349,16 +349,10 @@ static ssize_t blk_msg_write(struct file *filp, const char __user *buffer,
 	if (count >= BLK_TN_MAX_MSG)
 		return -EINVAL;
 
-	msg = kmalloc(count + 1, GFP_KERNEL);
-	if (msg == NULL)
-		return -ENOMEM;
-
-	if (copy_from_user(msg, buffer, count)) {
-		kfree(msg);
-		return -EFAULT;
-	}
+	msg = memdup_user_nul(buffer, count);
+	if (IS_ERR(msg))
+		return PTR_ERR(msg);
 
-	msg[count] = '\0';
 	bt = filp->private_data;
 	__trace_note_message(bt, "%s", msg);
 	kfree(msg);
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 4f6ef6912e00..f333e57c4614 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -1340,15 +1340,9 @@ event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
 	if (cnt >= PAGE_SIZE)
 		return -EINVAL;
 
-	buf = (char *)__get_free_page(GFP_TEMPORARY);
-	if (!buf)
-		return -ENOMEM;
-
-	if (copy_from_user(buf, ubuf, cnt)) {
-		free_page((unsigned long) buf);
-		return -EFAULT;
-	}
-	buf[cnt] = '\0';
+	buf = memdup_user_nul(ubuf, cnt);
+	if (IS_ERR(buf))
+		return PTR_ERR(buf);
 
 	mutex_lock(&event_mutex);
 	file = event_file_data(filp);
@@ -1356,7 +1350,7 @@ event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
 		err = apply_event_filter(file, buf);
 	mutex_unlock(&event_mutex);
 
-	free_page((unsigned long) buf);
+	kfree(buf);
 	if (err < 0)
 		return err;
 
@@ -1507,18 +1501,12 @@ subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
 	if (cnt >= PAGE_SIZE)
 		return -EINVAL;
 
-	buf = (char *)__get_free_page(GFP_TEMPORARY);
-	if (!buf)
-		return -ENOMEM;
-
-	if (copy_from_user(buf, ubuf, cnt)) {
-		free_page((unsigned long) buf);
-		return -EFAULT;
-	}
-	buf[cnt] = '\0';
+	buf = memdup_user_nul(ubuf, cnt);
+	if (IS_ERR(buf))
+		return PTR_ERR(buf);
 
 	err = apply_subsystem_event_filter(dir, buf);
-	free_page((unsigned long) buf);
+	kfree(buf);
 	if (err < 0)
 		return err;
 
diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c
index 42a4009fd75a..4b5e8ed68d77 100644
--- a/kernel/trace/trace_events_trigger.c
+++ b/kernel/trace/trace_events_trigger.c
@@ -237,28 +237,23 @@ static ssize_t event_trigger_regex_write(struct file *file,
 	if (cnt >= PAGE_SIZE)
 		return -EINVAL;
 
-	buf = (char *)__get_free_page(GFP_TEMPORARY);
-	if (!buf)
-		return -ENOMEM;
+	buf = memdup_user_nul(ubuf, cnt);
+	if (IS_ERR(buf))
+		return PTR_ERR(buf);
 
-	if (copy_from_user(buf, ubuf, cnt)) {
-		free_page((unsigned long)buf);
-		return -EFAULT;
-	}
-	buf[cnt] = '\0';
 	strim(buf);
 
 	mutex_lock(&event_mutex);
 	event_file = event_file_data(file);
 	if (unlikely(!event_file)) {
 		mutex_unlock(&event_mutex);
-		free_page((unsigned long)buf);
+		kfree(buf);
 		return -ENODEV;
 	}
 	ret = trigger_process_regex(event_file, buf);
 	mutex_unlock(&event_mutex);
 
-	free_page((unsigned long)buf);
+	kfree(buf);
 	if (ret < 0)
 		goto out;
 
diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c
index 88fefa68c516..9bafc211930c 100644
--- a/kernel/user_namespace.c
+++ b/kernel/user_namespace.c
@@ -602,8 +602,7 @@ static ssize_t map_write(struct file *file, const char __user *buf,
 	struct uid_gid_map new_map;
 	unsigned idx;
 	struct uid_gid_extent *extent = NULL;
-	unsigned long page = 0;
-	char *kbuf, *pos, *next_line;
+	char *kbuf = NULL, *pos, *next_line;
 	ssize_t ret = -EINVAL;
 
 	/*
@@ -638,23 +637,18 @@ static ssize_t map_write(struct file *file, const char __user *buf,
 	if (cap_valid(cap_setid) && !file_ns_capable(file, ns, CAP_SYS_ADMIN))
 		goto out;
 
-	/* Get a buffer */
-	ret = -ENOMEM;
-	page = __get_free_page(GFP_TEMPORARY);
-	kbuf = (char *) page;
-	if (!page)
-		goto out;
-
 	/* Only allow < page size writes at the beginning of the file */
 	ret = -EINVAL;
 	if ((*ppos != 0) || (count >= PAGE_SIZE))
 		goto out;
 
 	/* Slurp in the user data */
-	ret = -EFAULT;
-	if (copy_from_user(kbuf, buf, count))
+	kbuf = memdup_user_nul(buf, count);
+	if (IS_ERR(kbuf)) {
+		ret = PTR_ERR(kbuf);
+		kbuf = NULL;
 		goto out;
-	kbuf[count] = '\0';
+	}
 
 	/* Parse the user data */
 	ret = -EINVAL;
@@ -756,8 +750,7 @@ static ssize_t map_write(struct file *file, const char __user *buf,
 	ret = count;
 out:
 	mutex_unlock(&userns_state_mutex);
-	if (page)
-		free_page(page);
+	kfree(kbuf);
 	return ret;
 }