Merge branch 'next' (accumulated 3.16 merge window patches) into master

Now that 3.15 is released, this merges the 'next' branch into 'master',
bringing us to the normal situation where my 'master' branch is the
merge window.

* accumulated work in next: (6809 commits)
  ufs: sb mutex merge + mutex_destroy
  powerpc: update comments for generic idle conversion
  cris: update comments for generic idle conversion
  idle: remove cpu_idle() forward declarations
  nbd: zero from and len fields in NBD_CMD_DISCONNECT.
  mm: convert some level-less printks to pr_*
  MAINTAINERS: adi-buildroot-devel is moderated
  MAINTAINERS: add linux-api for review of API/ABI changes
  mm/kmemleak-test.c: use pr_fmt for logging
  fs/dlm/debug_fs.c: replace seq_printf by seq_puts
  fs/dlm/lockspace.c: convert simple_str to kstr
  fs/dlm/config.c: convert simple_str to kstr
  mm: mark remap_file_pages() syscall as deprecated
  mm: memcontrol: remove unnecessary memcg argument from soft limit functions
  mm: memcontrol: clean up memcg zoneinfo lookup
  mm/memblock.c: call kmemleak directly from memblock_(alloc|free)
  mm/mempool.c: update the kmemleak stack trace for mempool allocations
  lib/radix-tree.c: update the kmemleak stack trace for radix tree allocations
  mm: introduce kmemleak_update_trace()
  mm/kmemleak.c: use %u to print ->checksum
  ...

1 files changed, 85 insertions, 18 deletions

diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 74f5b580fe3..db19e3e2aa4 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -173,6 +173,13 @@ extern int no_unaligned_warning;
 #endif
 
 #ifdef CONFIG_PROC_SYSCTL
+
+#define SYSCTL_WRITES_LEGACY	-1
+#define SYSCTL_WRITES_WARN	 0
+#define SYSCTL_WRITES_STRICT	 1
+
+static int sysctl_writes_strict = SYSCTL_WRITES_WARN;
+
 static int proc_do_cad_pid(struct ctl_table *table, int write,
 		  void __user *buffer, size_t *lenp, loff_t *ppos);
 static int proc_taint(struct ctl_table *table, int write,
@@ -195,7 +202,7 @@ static int proc_dostring_coredump(struct ctl_table *table, int write,
 /* Note: sysrq code uses it's own private copy */
 static int __sysrq_enabled = CONFIG_MAGIC_SYSRQ_DEFAULT_ENABLE;
 
-static int sysrq_sysctl_handler(ctl_table *table, int write,
+static int sysrq_sysctl_handler(struct ctl_table *table, int write,
 				void __user *buffer, size_t *lenp,
 				loff_t *ppos)
 {
@@ -495,6 +502,15 @@ static struct ctl_table kern_table[] = {
 		.mode		= 0644,
 		.proc_handler	= proc_taint,
 	},
+	{
+		.procname	= "sysctl_writes_strict",
+		.data		= &sysctl_writes_strict,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= &neg_one,
+		.extra2		= &one,
+	},
 #endif
 #ifdef CONFIG_LATENCYTOP
 	{
@@ -643,7 +659,7 @@ static struct ctl_table kern_table[] = {
 		.extra2		= &one,
 	},
 #endif
-
+#ifdef CONFIG_UEVENT_HELPER
 	{
 		.procname	= "hotplug",
 		.data		= &uevent_helper,
@@ -651,7 +667,7 @@ static struct ctl_table kern_table[] = {
 		.mode		= 0644,
 		.proc_handler	= proc_dostring,
 	},
-
+#endif
 #ifdef CONFIG_CHR_DEV_SG
 	{
 		.procname	= "sg-big-buff",
@@ -1418,8 +1434,13 @@ static struct ctl_table vm_table[] = {
    (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
 	{
 		.procname	= "vdso_enabled",
+#ifdef CONFIG_X86_32
+		.data		= &vdso32_enabled,
+		.maxlen		= sizeof(vdso32_enabled),
+#else
 		.data		= &vdso_enabled,
 		.maxlen		= sizeof(vdso_enabled),
+#endif
 		.mode		= 0644,
 		.proc_handler	= proc_dointvec,
 		.extra1		= &zero,
@@ -1698,8 +1719,8 @@ int __init sysctl_init(void)
 
 #ifdef CONFIG_PROC_SYSCTL
 
-static int _proc_do_string(void* data, int maxlen, int write,
-			   void __user *buffer,
+static int _proc_do_string(char *data, int maxlen, int write,
+			   char __user *buffer,
 			   size_t *lenp, loff_t *ppos)
 {
 	size_t len;
@@ -1712,21 +1733,30 @@ static int _proc_do_string(void* data, int maxlen, int write,
 	}
 
 	if (write) {
-		len = 0;
+		if (sysctl_writes_strict == SYSCTL_WRITES_STRICT) {
+			/* Only continue writes not past the end of buffer. */
+			len = strlen(data);
+			if (len > maxlen - 1)
+				len = maxlen - 1;
+
+			if (*ppos > len)
+				return 0;
+			len = *ppos;
+		} else {
+			/* Start writing from beginning of buffer. */
+			len = 0;
+		}
+
+		*ppos += *lenp;
 		p = buffer;
-		while (len < *lenp) {
+		while ((p - buffer) < *lenp && len < maxlen - 1) {
 			if (get_user(c, p++))
 				return -EFAULT;
 			if (c == 0 || c == '\n')
 				break;
-			len++;
+			data[len++] = c;
 		}
-		if (len >= maxlen)
-			len = maxlen-1;
-		if(copy_from_user(data, buffer, len))
-			return -EFAULT;
-		((char *) data)[len] = 0;
-		*ppos += *lenp;
+		data[len] = 0;
 	} else {
 		len = strlen(data);
 		if (len > maxlen)
@@ -1743,10 +1773,10 @@ static int _proc_do_string(void* data, int maxlen, int write,
 		if (len > *lenp)
 			len = *lenp;
 		if (len)
-			if(copy_to_user(buffer, data, len))
+			if (copy_to_user(buffer, data, len))
 				return -EFAULT;
 		if (len < *lenp) {
-			if(put_user('\n', ((char __user *) buffer) + len))
+			if (put_user('\n', buffer + len))
 				return -EFAULT;
 			len++;
 		}
@@ -1756,6 +1786,14 @@ static int _proc_do_string(void* data, int maxlen, int write,
 	return 0;
 }
 
+static void warn_sysctl_write(struct ctl_table *table)
+{
+	pr_warn_once("%s wrote to %s when file position was not 0!\n"
+		"This will not be supported in the future. To silence this\n"
+		"warning, set kernel.sysctl_writes_strict = -1\n",
+		current->comm, table->procname);
+}
+
 /**
  * proc_dostring - read a string sysctl
  * @table: the sysctl table
@@ -1776,8 +1814,11 @@ static int _proc_do_string(void* data, int maxlen, int write,
 int proc_dostring(struct ctl_table *table, int write,
 		  void __user *buffer, size_t *lenp, loff_t *ppos)
 {
-	return _proc_do_string(table->data, table->maxlen, write,
-			       buffer, lenp, ppos);
+	if (write && *ppos && sysctl_writes_strict == SYSCTL_WRITES_WARN)
+		warn_sysctl_write(table);
+
+	return _proc_do_string((char *)(table->data), table->maxlen, write,
+			       (char __user *)buffer, lenp, ppos);
 }
 
 static size_t proc_skip_spaces(char **buf)
@@ -1951,6 +1992,18 @@ static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
 		conv = do_proc_dointvec_conv;
 
 	if (write) {
+		if (*ppos) {
+			switch (sysctl_writes_strict) {
+			case SYSCTL_WRITES_STRICT:
+				goto out;
+			case SYSCTL_WRITES_WARN:
+				warn_sysctl_write(table);
+				break;
+			default:
+				break;
+			}
+		}
+
 		if (left > PAGE_SIZE - 1)
 			left = PAGE_SIZE - 1;
 		page = __get_free_page(GFP_TEMPORARY);
@@ -2008,6 +2061,7 @@ free:
 			return err ? : -EINVAL;
 	}
 	*lenp -= left;
+out:
 	*ppos += *lenp;
 	return err;
 }
@@ -2200,6 +2254,18 @@ static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int
 	left = *lenp;
 
 	if (write) {
+		if (*ppos) {
+			switch (sysctl_writes_strict) {
+			case SYSCTL_WRITES_STRICT:
+				goto out;
+			case SYSCTL_WRITES_WARN:
+				warn_sysctl_write(table);
+				break;
+			default:
+				break;
+			}
+		}
+
 		if (left > PAGE_SIZE - 1)
 			left = PAGE_SIZE - 1;
 		page = __get_free_page(GFP_TEMPORARY);
@@ -2255,6 +2321,7 @@ free:
 			return err ? : -EINVAL;
 	}
 	*lenp -= left;
+out:
 	*ppos += *lenp;
 	return err;
 }