sysctl: pass kernel pointers to ->proc_handler

Instead of having all the sysctl handlers deal with user pointers, which
is rather hairy in terms of the BPF interaction, copy the input to and
from  userspace in common code.  This also means that the strings are
always NUL-terminated by the common code, making the API a little bit
safer.

As most handler just pass through the data to one of the common handlers
a lot of the changes are mechnical.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

arch/arm64/kernel/armv8_deprecated.c

@@ -203,7 +203,7 @@ static void __init register_insn_emulation(struct insn_emulation_ops *ops)
 }
 
 static int emulation_proc_handler(struct ctl_table *table, int write,
-				  void __user *buffer, size_t *lenp,
+				  void *buffer, size_t *lenp,
 				  loff_t *ppos)
 {
 	int ret = 0;

arch/arm64/kernel/fpsimd.c

@@ -341,8 +341,7 @@ static unsigned int find_supported_vector_length(unsigned int vl)
 #ifdef CONFIG_SYSCTL
 
 static int sve_proc_do_default_vl(struct ctl_table *table, int write,
-				  void __user *buffer, size_t *lenp,
-				  loff_t *ppos)
+				  void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int ret;
 	int vl = sve_default_vl;

arch/mips/lasat/sysctl.c

@@ -95,16 +95,15 @@ int proc_lasat_ip(struct ctl_table *table, int write,
 		len = 0;
 		p = buffer;
 		while (len < *lenp) {
-			if (get_user(c, p++))
-				return -EFAULT;
+			c = *p;
+			p++;
 			if (c == 0 || c == '\n')
 				break;
 			len++;
 		}
 		if (len >= sizeof(ipbuf)-1)
 			len = sizeof(ipbuf) - 1;
-		if (copy_from_user(ipbuf, buffer, len))
-			return -EFAULT;
+		memcpy(ipbuf, buffer, len);
 		ipbuf[len] = 0;
 		*ppos += *lenp;
 		/* Now see if we can convert it to a valid IP */
@@ -122,11 +121,9 @@ int proc_lasat_ip(struct ctl_table *table, int write,
 		if (len > *lenp)
 			len = *lenp;
 		if (len)
-			if (copy_to_user(buffer, ipbuf, len))
-				return -EFAULT;
+			memcpy(buffer, ipbuf, len);
 		if (len < *lenp) {
-			if (put_user('\n', ((char *) buffer) + len))
-				return -EFAULT;
+			*((char *)buffer + len) = '\n';
 			len++;
 		}
 		*lenp = len;

arch/s390/appldata/appldata_base.c

@@ -51,10 +51,9 @@ static struct platform_device *appldata_pdev;
  */
 static const char appldata_proc_name[APPLDATA_PROC_NAME_LENGTH] = "appldata";
 static int appldata_timer_handler(struct ctl_table *ctl, int write,
-				  void __user *buffer, size_t *lenp, loff_t *ppos);
+				  void *buffer, size_t *lenp, loff_t *ppos);
 static int appldata_interval_handler(struct ctl_table *ctl, int write,
-					 void __user *buffer,
-					 size_t *lenp, loff_t *ppos);
+				     void *buffer, size_t *lenp, loff_t *ppos);
 
 static struct ctl_table_header *appldata_sysctl_header;
 static struct ctl_table appldata_table[] = {
@@ -217,7 +216,7 @@ static void __appldata_vtimer_setup(int cmd)
  */
 static int
 appldata_timer_handler(struct ctl_table *ctl, int write,
-			   void __user *buffer, size_t *lenp, loff_t *ppos)
+			   void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int timer_active = appldata_timer_active;
 	int rc;
@@ -250,7 +249,7 @@ appldata_timer_handler(struct ctl_table *ctl, int write,
  */
 static int
 appldata_interval_handler(struct ctl_table *ctl, int write,
-			   void __user *buffer, size_t *lenp, loff_t *ppos)
+			   void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int interval = appldata_interval;
 	int rc;
@@ -280,7 +279,7 @@ appldata_interval_handler(struct ctl_table *ctl, int write,
  */
 static int
 appldata_generic_handler(struct ctl_table *ctl, int write,
-			   void __user *buffer, size_t *lenp, loff_t *ppos)
+			   void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct appldata_ops *ops = NULL, *tmp_ops;
 	struct list_head *lh;

arch/s390/kernel/debug.c

@@ -867,7 +867,7 @@ static int debug_active = 1;
  * if debug_active is already off
  */
 static int s390dbf_procactive(struct ctl_table *table, int write,
-			      void __user *buffer, size_t *lenp, loff_t *ppos)
+			      void *buffer, size_t *lenp, loff_t *ppos)
 {
 	if (!write || debug_stoppable || !debug_active)
 		return proc_dointvec(table, write, buffer, lenp, ppos);

arch/s390/kernel/topology.c

@@ -594,7 +594,7 @@ static int __init topology_setup(char *str)
 early_param("topology", topology_setup);
 
 static int topology_ctl_handler(struct ctl_table *ctl, int write,
-				void __user *buffer, size_t *lenp, loff_t *ppos)
+				void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int enabled = topology_is_enabled();
 	int new_mode;

arch/s390/mm/cmm.c

@@ -245,7 +245,7 @@ static int cmm_skip_blanks(char *cp, char **endp)
 }
 
 static int cmm_pages_handler(struct ctl_table *ctl, int write,
-			     void __user *buffer, size_t *lenp, loff_t *ppos)
+			     void *buffer, size_t *lenp, loff_t *ppos)
 {
 	long nr = cmm_get_pages();
 	struct ctl_table ctl_entry = {
@@ -264,7 +264,7 @@ static int cmm_pages_handler(struct ctl_table *ctl, int write,
 }
 
 static int cmm_timed_pages_handler(struct ctl_table *ctl, int write,
-				   void __user *buffer, size_t *lenp,
+				   void *buffer, size_t *lenp,
 				   loff_t *ppos)
 {
 	long nr = cmm_get_timed_pages();
@@ -284,7 +284,7 @@ static int cmm_timed_pages_handler(struct ctl_table *ctl, int write,
 }
 
 static int cmm_timeout_handler(struct ctl_table *ctl, int write,
-			       void __user *buffer, size_t *lenp, loff_t *ppos)
+			       void *buffer, size_t *lenp, loff_t *ppos)
 {
 	char buf[64], *p;
 	long nr, seconds;
@@ -297,8 +297,7 @@ static int cmm_timeout_handler(struct ctl_table *ctl, int write,
 
 	if (write) {
 		len = min(*lenp, sizeof(buf));
-		if (copy_from_user(buf, buffer, len))
-			return -EFAULT;
+		memcpy(buf, buffer, len);
 		buf[len - 1] = '\0';
 		cmm_skip_blanks(buf, &p);
 		nr = simple_strtoul(p, &p, 0);
@@ -311,8 +310,7 @@ static int cmm_timeout_handler(struct ctl_table *ctl, int write,
 			      cmm_timeout_pages, cmm_timeout_seconds);
 		if (len > *lenp)
 			len = *lenp;
-		if (copy_to_user(buffer, buf, len))
-			return -EFAULT;
+		memcpy(buffer, buf, len);
 		*lenp = len;
 		*ppos += len;
 	}

arch/x86/kernel/itmt.c

@@ -39,8 +39,7 @@ static bool __read_mostly sched_itmt_capable;
 unsigned int __read_mostly sysctl_sched_itmt_enabled;
 
 static int sched_itmt_update_handler(struct ctl_table *table, int write,
-				     void __user *buffer, size_t *lenp,
-				     loff_t *ppos)
+				     void *buffer, size_t *lenp, loff_t *ppos)
 {
 	unsigned int old_sysctl;
 	int ret;

drivers/cdrom/cdrom.c

@@ -3631,7 +3631,7 @@ static void cdrom_update_settings(void)
 }
 
 static int cdrom_sysctl_handler(struct ctl_table *ctl, int write,
-				void __user *buffer, size_t *lenp, loff_t *ppos)
+				void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int ret;
 	

drivers/char/random.c

@@ -2057,7 +2057,7 @@ static char sysctl_bootid[16];
  * sysctl system call, as 16 bytes of binary data.
  */
 static int proc_do_uuid(struct ctl_table *table, int write,
-			void __user *buffer, size_t *lenp, loff_t *ppos)
+			void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct ctl_table fake_table;
 	unsigned char buf[64], tmp_uuid[16], *uuid;

drivers/macintosh/mac_hid.c

@@ -183,8 +183,7 @@ static void mac_hid_stop_emulation(void)
 }
 
 static int mac_hid_toggle_emumouse(struct ctl_table *table, int write,
-				   void __user *buffer, size_t *lenp,
-				   loff_t *ppos)
+				   void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int *valp = table->data;
 	int old_val = *valp;

drivers/parport/procfs.c

@@ -34,7 +34,7 @@
 #define PARPORT_MAX_SPINTIME_VALUE 1000
 
 static int do_active_device(struct ctl_table *table, int write,
-		      void __user *result, size_t *lenp, loff_t *ppos)
+		      void *result, size_t *lenp, loff_t *ppos)
 {
 	struct parport *port = (struct parport *)table->extra1;
 	char buffer[256];
@@ -65,13 +65,13 @@ static int do_active_device(struct ctl_table *table, int write,
 		*lenp = len;
 
 	*ppos += len;
-
-	return copy_to_user(result, buffer, len) ? -EFAULT : 0;
+	memcpy(result, buffer, len);
+	return 0;
 }
 
 #ifdef CONFIG_PARPORT_1284
 static int do_autoprobe(struct ctl_table *table, int write,
-			void __user *result, size_t *lenp, loff_t *ppos)
+			void *result, size_t *lenp, loff_t *ppos)
 {
 	struct parport_device_info *info = table->extra2;
 	const char *str;
@@ -108,13 +108,13 @@ static int do_autoprobe(struct ctl_table *table, int write,
 
 	*ppos += len;
 
-	return copy_to_user (result, buffer, len) ? -EFAULT : 0;
+	memcpy(result, buffer, len);
+	return 0;
 }
 #endif /* IEEE1284.3 support. */
 
 static int do_hardware_base_addr(struct ctl_table *table, int write,
-				 void __user *result,
-				 size_t *lenp, loff_t *ppos)
+				 void *result, size_t *lenp, loff_t *ppos)
 {
 	struct parport *port = (struct parport *)table->extra1;
 	char buffer[20];
@@ -136,13 +136,12 @@ static int do_hardware_base_addr(struct ctl_table *table, int write,
 		*lenp = len;
 
 	*ppos += len;
-
-	return copy_to_user(result, buffer, len) ? -EFAULT : 0;
+	memcpy(result, buffer, len);
+	return 0;
 }
 
 static int do_hardware_irq(struct ctl_table *table, int write,
-			   void __user *result,
-			   size_t *lenp, loff_t *ppos)
+			   void *result, size_t *lenp, loff_t *ppos)
 {
 	struct parport *port = (struct parport *)table->extra1;
 	char buffer[20];
@@ -164,13 +163,12 @@ static int do_hardware_irq(struct ctl_table *table, int write,
 		*lenp = len;
 
 	*ppos += len;
-
-	return copy_to_user(result, buffer, len) ? -EFAULT : 0;
+	memcpy(result, buffer, len);
+	return 0;
 }
 
 static int do_hardware_dma(struct ctl_table *table, int write,
-			   void __user *result,
-			   size_t *lenp, loff_t *ppos)
+			   void *result, size_t *lenp, loff_t *ppos)
 {
 	struct parport *port = (struct parport *)table->extra1;
 	char buffer[20];
@@ -192,13 +190,12 @@ static int do_hardware_dma(struct ctl_table *table, int write,
 		*lenp = len;
 
 	*ppos += len;
-
-	return copy_to_user(result, buffer, len) ? -EFAULT : 0;
+	memcpy(result, buffer, len);
+	return 0;
 }
 
 static int do_hardware_modes(struct ctl_table *table, int write,
-			     void __user *result,
-			     size_t *lenp, loff_t *ppos)
+			     void *result, size_t *lenp, loff_t *ppos)
 {
 	struct parport *port = (struct parport *)table->extra1;
 	char buffer[40];
@@ -231,8 +228,8 @@ static int do_hardware_modes(struct ctl_table *table, int write,
 		*lenp = len;
 
 	*ppos += len;
-
-	return copy_to_user(result, buffer, len) ? -EFAULT : 0;
+	memcpy(result, buffer, len);
+	return 0;
 }
 
 #define PARPORT_PORT_DIR(CHILD) { .procname = NULL, .mode = 0555, .child = CHILD }

fs/dcache.c

@@ -165,7 +165,7 @@ static long get_nr_dentry_negative(void)
 	return sum < 0 ? 0 : sum;
 }
 
-int proc_nr_dentry(struct ctl_table *table, int write, void __user *buffer,
+int proc_nr_dentry(struct ctl_table *table, int write, void *buffer,
 		   size_t *lenp, loff_t *ppos)
 {
 	dentry_stat.nr_dentry = get_nr_dentry();

fs/drop_caches.c

@@ -47,7 +47,7 @@ static void drop_pagecache_sb(struct super_block *sb, void *unused)
 }
 
 int drop_caches_sysctl_handler(struct ctl_table *table, int write,
-	void __user *buffer, size_t *length, loff_t *ppos)
+		void *buffer, size_t *length, loff_t *ppos)
 {
 	int ret;
 

fs/file_table.c

@@ -80,14 +80,14 @@ EXPORT_SYMBOL_GPL(get_max_files);
  */
 #if defined(CONFIG_SYSCTL) && defined(CONFIG_PROC_FS)
 int proc_nr_files(struct ctl_table *table, int write,
-                     void __user *buffer, size_t *lenp, loff_t *ppos)
+                     void *buffer, size_t *lenp, loff_t *ppos)
 {
 	files_stat.nr_files = get_nr_files();
 	return proc_doulongvec_minmax(table, write, buffer, lenp, ppos);
 }
 #else
 int proc_nr_files(struct ctl_table *table, int write,
-                     void __user *buffer, size_t *lenp, loff_t *ppos)
+                     void *buffer, size_t *lenp, loff_t *ppos)
 {
 	return -ENOSYS;
 }

fs/fscache/main.c

@@ -51,8 +51,7 @@ static unsigned fscache_op_max_active = 2;
 static struct ctl_table_header *fscache_sysctl_header;
 
 static int fscache_max_active_sysctl(struct ctl_table *table, int write,
-				     void __user *buffer,
-				     size_t *lenp, loff_t *ppos)
+				     void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct workqueue_struct **wqp = table->extra1;
 	unsigned int *datap = table->data;

fs/inode.c

@@ -108,7 +108,7 @@ long get_nr_dirty_inodes(void)
  */
 #ifdef CONFIG_SYSCTL
 int proc_nr_inodes(struct ctl_table *table, int write,
-		   void __user *buffer, size_t *lenp, loff_t *ppos)
+		   void *buffer, size_t *lenp, loff_t *ppos)
 {
 	inodes_stat.nr_inodes = get_nr_inodes();
 	inodes_stat.nr_unused = get_nr_inodes_unused();

fs/proc/proc_sysctl.c

@@ -539,13 +539,13 @@ out:
 	return err;
 }
 
-static ssize_t proc_sys_call_handler(struct file *filp, void __user *buf,
+static ssize_t proc_sys_call_handler(struct file *filp, void __user *ubuf,
 		size_t count, loff_t *ppos, int write)
 {
 	struct inode *inode = file_inode(filp);
 	struct ctl_table_header *head = grab_header(inode);
 	struct ctl_table *table = PROC_I(inode)->sysctl_entry;
-	void *new_buf = NULL;
+	void *kbuf;
 	ssize_t error;
 
 	if (IS_ERR(head))
@@ -564,27 +564,38 @@ static ssize_t proc_sys_call_handler(struct file *filp, void __user *buf,
 	if (!table->proc_handler)
 		goto out;
 
-	error = BPF_CGROUP_RUN_PROG_SYSCTL(head, table, write, buf, &count,
-					   ppos, &new_buf);
-	if (error)
-		goto out;
-
-	/* careful: calling conventions are nasty here */
-	if (new_buf) {
-		mm_segment_t old_fs;
-
-		old_fs = get_fs();
-		set_fs(KERNEL_DS);
-		error = table->proc_handler(table, write, (void __user *)new_buf,
-					    &count, ppos);
-		set_fs(old_fs);
-		kfree(new_buf);
+	if (write) {
+		kbuf = memdup_user_nul(ubuf, count);
+		if (IS_ERR(kbuf)) {
+			error = PTR_ERR(kbuf);
+			goto out;
+		}
 	} else {
-		error = table->proc_handler(table, write, buf, &count, ppos);
+		error = -ENOMEM;
+		kbuf = kzalloc(count, GFP_KERNEL);
+		if (!kbuf)
+			goto out;
 	}
 
-	if (!error)
-		error = count;
+	error = BPF_CGROUP_RUN_PROG_SYSCTL(head, table, write, &kbuf, &count,
+					   ppos);
+	if (error)
+		goto out_free_buf;
+
+	/* careful: calling conventions are nasty here */
+	error = table->proc_handler(table, write, kbuf, &count, ppos);
+	if (error)
+		goto out_free_buf;
+
+	if (!write) {
+		error = -EFAULT;
+		if (copy_to_user(ubuf, kbuf, count))
+			goto out_free_buf;
+	}
+
+	error = count;
+out_free_buf:
+	kfree(kbuf);
 out:
 	sysctl_head_finish(head);
 

fs/quota/dquot.c

@@ -2841,7 +2841,7 @@ const struct quotactl_ops dquot_quotactl_sysfile_ops = {
 EXPORT_SYMBOL(dquot_quotactl_sysfile_ops);
 
 static int do_proc_dqstats(struct ctl_table *table, int write,
-		     void __user *buffer, size_t *lenp, loff_t *ppos)
+		     void *buffer, size_t *lenp, loff_t *ppos)
 {
 	unsigned int type = (unsigned long *)table->data - dqstats.stat;
 	s64 value = percpu_counter_sum(&dqstats.counter[type]);

fs/xfs/xfs_sysctl.c

@@ -13,7 +13,7 @@ STATIC int
 xfs_stats_clear_proc_handler(
 	struct ctl_table	*ctl,
 	int			write,
-	void			__user *buffer,
+	void			*buffer,
 	size_t			*lenp,
 	loff_t			*ppos)
 {
@@ -33,7 +33,7 @@ STATIC int
 xfs_panic_mask_proc_handler(
 	struct ctl_table	*ctl,
 	int			write,
-	void			__user *buffer,
+	void			*buffer,
 	size_t			*lenp,
 	loff_t			*ppos)
 {

include/linux/bpf-cgroup.h

@@ -138,8 +138,7 @@ int __cgroup_bpf_check_dev_permission(short dev_type, u32 major, u32 minor,
 
 int __cgroup_bpf_run_filter_sysctl(struct ctl_table_header *head,
 				   struct ctl_table *table, int write,
-				   void __user *buf, size_t *pcount,
-				   loff_t *ppos, void **new_buf,
+				   void **buf, size_t *pcount, loff_t *ppos,
 				   enum bpf_attach_type type);
 
 int __cgroup_bpf_run_filter_setsockopt(struct sock *sock, int *level,
@@ -302,12 +301,12 @@ int bpf_percpu_cgroup_storage_update(struct bpf_map *map, void *key,
 })
 
 
-#define BPF_CGROUP_RUN_PROG_SYSCTL(head, table, write, buf, count, pos, nbuf)  \
+#define BPF_CGROUP_RUN_PROG_SYSCTL(head, table, write, buf, count, pos)  \
 ({									       \
 	int __ret = 0;							       \
 	if (cgroup_bpf_enabled)						       \
 		__ret = __cgroup_bpf_run_filter_sysctl(head, table, write,     \
-						       buf, count, pos, nbuf,  \
+						       buf, count, pos,        \
 						       BPF_CGROUP_SYSCTL);     \
 	__ret;								       \
 })
@@ -429,7 +428,7 @@ static inline int bpf_percpu_cgroup_storage_update(struct bpf_map *map,
 #define BPF_CGROUP_RUN_PROG_UDP6_RECVMSG_LOCK(sk, uaddr) ({ 0; })
 #define BPF_CGROUP_RUN_PROG_SOCK_OPS(sock_ops) ({ 0; })
 #define BPF_CGROUP_RUN_PROG_DEVICE_CGROUP(type,major,minor,access) ({ 0; })
-#define BPF_CGROUP_RUN_PROG_SYSCTL(head,table,write,buf,count,pos,nbuf) ({ 0; })
+#define BPF_CGROUP_RUN_PROG_SYSCTL(head,table,write,buf,count,pos) ({ 0; })
 #define BPF_CGROUP_GETSOCKOPT_MAX_OPTLEN(optlen) ({ 0; })
 #define BPF_CGROUP_RUN_PROG_GETSOCKOPT(sock, level, optname, optval, \
 				       optlen, max_optlen, retval) ({ retval; })

include/linux/compaction.h

@@ -86,7 +86,7 @@ static inline unsigned long compact_gap(unsigned int order)
 #ifdef CONFIG_COMPACTION
 extern int sysctl_compact_memory;
 extern int sysctl_compaction_handler(struct ctl_table *table, int write,
-			void __user *buffer, size_t *length, loff_t *ppos);
+			void *buffer, size_t *length, loff_t *ppos);
 extern int sysctl_extfrag_threshold;
 extern int sysctl_compact_unevictable_allowed;
 

include/linux/fs.h

@@ -3536,11 +3536,11 @@ ssize_t simple_attr_write(struct file *file, const char __user *buf,
 
 struct ctl_table;
 int proc_nr_files(struct ctl_table *table, int write,
-		  void __user *buffer, size_t *lenp, loff_t *ppos);
+		  void *buffer, size_t *lenp, loff_t *ppos);
 int proc_nr_dentry(struct ctl_table *table, int write,
-		  void __user *buffer, size_t *lenp, loff_t *ppos);
+		  void *buffer, size_t *lenp, loff_t *ppos);
 int proc_nr_inodes(struct ctl_table *table, int write,
-		   void __user *buffer, size_t *lenp, loff_t *ppos);
+		   void *buffer, size_t *lenp, loff_t *ppos);
 int __init get_filesystem_list(char *buf);
 
 #define __FMODE_EXEC		((__force int) FMODE_EXEC)

include/linux/ftrace.h

@@ -1005,8 +1005,7 @@ extern void disable_trace_on_warning(void);
 extern int __disable_trace_on_warning;
 
 int tracepoint_printk_sysctl(struct ctl_table *table, int write,
-			     void __user *buffer, size_t *lenp,
-			     loff_t *ppos);
+			     void *buffer, size_t *lenp, loff_t *ppos);
 
 #else /* CONFIG_TRACING */
 static inline void  disable_trace_on_warning(void) { }

include/linux/hugetlb.h

@@ -105,14 +105,13 @@ struct hugepage_subpool *hugepage_new_subpool(struct hstate *h, long max_hpages,
 void hugepage_put_subpool(struct hugepage_subpool *spool);
 
 void reset_vma_resv_huge_pages(struct vm_area_struct *vma);
-int hugetlb_sysctl_handler(struct ctl_table *, int, void __user *, size_t *, loff_t *);
-int hugetlb_overcommit_handler(struct ctl_table *, int, void __user *, size_t *, loff_t *);
-int hugetlb_treat_movable_handler(struct ctl_table *, int, void __user *, size_t *, loff_t *);
-
-#ifdef CONFIG_NUMA
-int hugetlb_mempolicy_sysctl_handler(struct ctl_table *, int,
-					void __user *, size_t *, loff_t *);
-#endif
+int hugetlb_sysctl_handler(struct ctl_table *, int, void *, size_t *, loff_t *);
+int hugetlb_overcommit_handler(struct ctl_table *, int, void *, size_t *,
+		loff_t *);
+int hugetlb_treat_movable_handler(struct ctl_table *, int, void *, size_t *,
+		loff_t *);
+int hugetlb_mempolicy_sysctl_handler(struct ctl_table *, int, void *, size_t *,
+		loff_t *);
 
 int copy_hugetlb_page_range(struct mm_struct *, struct mm_struct *, struct vm_area_struct *);
 long follow_hugetlb_page(struct mm_struct *, struct vm_area_struct *,

include/linux/kprobes.h

@@ -312,7 +312,7 @@ DEFINE_INSN_CACHE_OPS(optinsn);
 #ifdef CONFIG_SYSCTL
 extern int sysctl_kprobes_optimization;
 extern int proc_kprobes_optimization_handler(struct ctl_table *table,
-					     int write, void __user *buffer,
+					     int write, void *buffer,
 					     size_t *length, loff_t *ppos);
 #endif
 extern void wait_for_kprobe_optimizer(void);

include/linux/latencytop.h

@@ -38,8 +38,8 @@ account_scheduler_latency(struct task_struct *task, int usecs, int inter)
 
 void clear_tsk_latency_tracing(struct task_struct *p);
 
-extern int sysctl_latencytop(struct ctl_table *table, int write,
-			void __user *buffer, size_t *lenp, loff_t *ppos);
+int sysctl_latencytop(struct ctl_table *table, int write, void *buffer,
+		size_t *lenp, loff_t *ppos);
 
 #else
 

include/linux/mm.h

@@ -201,10 +201,10 @@ extern int sysctl_overcommit_memory;
 extern int sysctl_overcommit_ratio;
 extern unsigned long sysctl_overcommit_kbytes;
 
-extern int overcommit_ratio_handler(struct ctl_table *, int, void __user *,
-				    size_t *, loff_t *);
-extern int overcommit_kbytes_handler(struct ctl_table *, int, void __user *,
-				    size_t *, loff_t *);
+int overcommit_ratio_handler(struct ctl_table *, int, void *, size_t *,
+		loff_t *);
+int overcommit_kbytes_handler(struct ctl_table *, int, void *, size_t *,
+		loff_t *);
 
 #define nth_page(page,n) pfn_to_page(page_to_pfn((page)) + (n))
 
@@ -2957,8 +2957,8 @@ extern bool process_shares_mm(struct task_struct *p, struct mm_struct *mm);
 
 #ifdef CONFIG_SYSCTL
 extern int sysctl_drop_caches;
-int drop_caches_sysctl_handler(struct ctl_table *, int,
-					void __user *, size_t *, loff_t *);
+int drop_caches_sysctl_handler(struct ctl_table *, int, void *, size_t *,
+		loff_t *);
 #endif
 
 void drop_slab(void);

include/linux/mmzone.h

@@ -910,22 +910,21 @@ static inline int is_highmem(struct zone *zone)
 /* These two functions are used to setup the per zone pages min values */
 struct ctl_table;
 
-int min_free_kbytes_sysctl_handler(struct ctl_table *, int,
-					void __user *, size_t *, loff_t *);
-int watermark_scale_factor_sysctl_handler(struct ctl_table *, int,
-					void __user *, size_t *, loff_t *);
+int min_free_kbytes_sysctl_handler(struct ctl_table *, int, void *, size_t *,
+		loff_t *);
+int watermark_scale_factor_sysctl_handler(struct ctl_table *, int, void *,
+		size_t *, loff_t *);
 extern int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES];
-int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *, int,
-					void __user *, size_t *, loff_t *);
+int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *, int, void *,
+		size_t *, loff_t *);
 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *, int,
-					void __user *, size_t *, loff_t *);
+		void *, size_t *, loff_t *);
 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *, int,
-			void __user *, size_t *, loff_t *);
+		void *, size_t *, loff_t *);
 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *, int,
-			void __user *, size_t *, loff_t *);
-
-extern int numa_zonelist_order_handler(struct ctl_table *, int,
-			void __user *, size_t *, loff_t *);
+		void *, size_t *, loff_t *);
+int numa_zonelist_order_handler(struct ctl_table *, int,
+		void *, size_t *, loff_t *);
 extern int percpu_pagelist_fraction;
 extern char numa_zonelist_order[];
 #define NUMA_ZONELIST_ORDER_LEN	16

include/linux/nmi.h

@@ -202,16 +202,11 @@ static inline void watchdog_update_hrtimer_threshold(u64 period) { }
 #endif
 
 struct ctl_table;
-extern int proc_watchdog(struct ctl_table *, int ,
-			 void __user *, size_t *, loff_t *);
-extern int proc_nmi_watchdog(struct ctl_table *, int ,
-			     void __user *, size_t *, loff_t *);
-extern int proc_soft_watchdog(struct ctl_table *, int ,
-			      void __user *, size_t *, loff_t *);
-extern int proc_watchdog_thresh(struct ctl_table *, int ,
-				void __user *, size_t *, loff_t *);
-extern int proc_watchdog_cpumask(struct ctl_table *, int,
-				 void __user *, size_t *, loff_t *);
+int proc_watchdog(struct ctl_table *, int, void *, size_t *, loff_t *);
+int proc_nmi_watchdog(struct ctl_table *, int , void *, size_t *, loff_t *);
+int proc_soft_watchdog(struct ctl_table *, int , void *, size_t *, loff_t *);
+int proc_watchdog_thresh(struct ctl_table *, int , void *, size_t *, loff_t *);
+int proc_watchdog_cpumask(struct ctl_table *, int, void *, size_t *, loff_t *);
 
 #ifdef CONFIG_HAVE_ACPI_APEI_NMI
 #include <asm/nmi.h>

include/linux/perf_event.h

@@ -1280,15 +1280,12 @@ extern int sysctl_perf_cpu_time_max_percent;
 
 extern void perf_sample_event_took(u64 sample_len_ns);
 
-extern int perf_proc_update_handler(struct ctl_table *table, int write,
-		void __user *buffer, size_t *lenp,
-		loff_t *ppos);
-extern int perf_cpu_time_max_percent_handler(struct ctl_table *table, int write,
-		void __user *buffer, size_t *lenp,
-		loff_t *ppos);
-
+int perf_proc_update_handler(struct ctl_table *table, int write,
+		void *buffer, size_t *lenp, loff_t *ppos);
+int perf_cpu_time_max_percent_handler(struct ctl_table *table, int write,
+		void *buffer, size_t *lenp, loff_t *ppos);
 int perf_event_max_stack_handler(struct ctl_table *table, int write,
-				 void __user *buffer, size_t *lenp, loff_t *ppos);
+		void *buffer, size_t *lenp, loff_t *ppos);
 
 /* Access to perf_event_open(2) syscall. */
 #define PERF_SECURITY_OPEN		0

include/linux/printk.h

@@ -189,7 +189,7 @@ extern int printk_delay_msec;
 extern int dmesg_restrict;
 
 extern int
-devkmsg_sysctl_set_loglvl(struct ctl_table *table, int write, void __user *buf,
+devkmsg_sysctl_set_loglvl(struct ctl_table *table, int write, void *buf,
 			  size_t *lenp, loff_t *ppos);
 
 extern void wake_up_klogd(void);

include/linux/sched/sysctl.h

@@ -12,9 +12,8 @@ extern unsigned int  sysctl_hung_task_panic;
 extern unsigned long sysctl_hung_task_timeout_secs;
 extern unsigned long sysctl_hung_task_check_interval_secs;
 extern int sysctl_hung_task_warnings;
-extern int proc_dohung_task_timeout_secs(struct ctl_table *table, int write,
-					 void __user *buffer,
-					 size_t *lenp, loff_t *ppos);
+int proc_dohung_task_timeout_secs(struct ctl_table *table, int write,
+		void *buffer, size_t *lenp, loff_t *ppos);
 #else
 /* Avoid need for ifdefs elsewhere in the code */
 enum { sysctl_hung_task_timeout_secs = 0 };
@@ -43,8 +42,7 @@ extern __read_mostly unsigned int sysctl_sched_migration_cost;
 extern __read_mostly unsigned int sysctl_sched_nr_migrate;
 
 int sched_proc_update_handler(struct ctl_table *table, int write,
-		void __user *buffer, size_t *length,
-		loff_t *ppos);
+		void *buffer, size_t *length, loff_t *ppos);
 #endif
 
 /*
@@ -72,33 +70,21 @@ extern unsigned int sysctl_sched_autogroup_enabled;
 extern int sysctl_sched_rr_timeslice;
 extern int sched_rr_timeslice;
 
-extern int sched_rr_handler(struct ctl_table *table, int write,
-		void __user *buffer, size_t *lenp,
-		loff_t *ppos);
-
-extern int sched_rt_handler(struct ctl_table *table, int write,
-		void __user *buffer, size_t *lenp,
-		loff_t *ppos);
-
-#ifdef CONFIG_UCLAMP_TASK
-extern int sysctl_sched_uclamp_handler(struct ctl_table *table, int write,
-				       void __user *buffer, size_t *lenp,
-				       loff_t *ppos);
-#endif
-
-extern int sysctl_numa_balancing(struct ctl_table *table, int write,
-				 void __user *buffer, size_t *lenp,
-				 loff_t *ppos);
-
-extern int sysctl_schedstats(struct ctl_table *table, int write,
-				 void __user *buffer, size_t *lenp,
-				 loff_t *ppos);
+int sched_rr_handler(struct ctl_table *table, int write, void *buffer,
+		size_t *lenp, loff_t *ppos);
+int sched_rt_handler(struct ctl_table *table, int write, void *buffer,
+		size_t *lenp, loff_t *ppos);
+int sysctl_sched_uclamp_handler(struct ctl_table *table, int write,
+		void *buffer, size_t *lenp, loff_t *ppos);
+int sysctl_numa_balancing(struct ctl_table *table, int write, void *buffer,
+		size_t *lenp, loff_t *ppos);
+int sysctl_schedstats(struct ctl_table *table, int write, void *buffer,
+		size_t *lenp, loff_t *ppos);
 
 #if defined(CONFIG_ENERGY_MODEL) && defined(CONFIG_CPU_FREQ_GOV_SCHEDUTIL)
 extern unsigned int sysctl_sched_energy_aware;
-extern int sched_energy_aware_handler(struct ctl_table *table, int write,
-				 void __user *buffer, size_t *lenp,
-				 loff_t *ppos);
+int sched_energy_aware_handler(struct ctl_table *table, int write,
+		void *buffer, size_t *lenp, loff_t *ppos);
 #endif
 
 #endif /* _LINUX_SCHED_SYSCTL_H */

include/linux/security.h

@@ -211,7 +211,7 @@ struct request_sock;
 
 #ifdef CONFIG_MMU
 extern int mmap_min_addr_handler(struct ctl_table *table, int write,
-				 void __user *buffer, size_t *lenp, loff_t *ppos);
+				 void *buffer, size_t *lenp, loff_t *ppos);
 #endif
 
 /* security_inode_init_security callback function to write xattrs */

include/linux/sysctl.h

@@ -44,35 +44,26 @@ struct ctl_dir;
 
 extern const int sysctl_vals[];
 
-typedef int proc_handler (struct ctl_table *ctl, int write,
-			  void __user *buffer, size_t *lenp, loff_t *ppos);
+typedef int proc_handler(struct ctl_table *ctl, int write, void *buffer,
+		size_t *lenp, loff_t *ppos);
 
-extern int proc_dostring(struct ctl_table *, int,
-			 void __user *, size_t *, loff_t *);
-extern int proc_dointvec(struct ctl_table *, int,
-			 void __user *, size_t *, loff_t *);
-extern int proc_douintvec(struct ctl_table *, int,
-			 void __user *, size_t *, loff_t *);
-extern int proc_dointvec_minmax(struct ctl_table *, int,
-				void __user *, size_t *, loff_t *);
-extern int proc_douintvec_minmax(struct ctl_table *table, int write,
-				 void __user *buffer, size_t *lenp,
-				 loff_t *ppos);
-extern int proc_dointvec_jiffies(struct ctl_table *, int,
-				 void __user *, size_t *, loff_t *);
-extern int proc_dointvec_userhz_jiffies(struct ctl_table *, int,
-					void __user *, size_t *, loff_t *);
-extern int proc_dointvec_ms_jiffies(struct ctl_table *, int,
-				    void __user *, size_t *, loff_t *);
-extern int proc_doulongvec_minmax(struct ctl_table *, int,
-				  void __user *, size_t *, loff_t *);
-extern int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int,
-				      void __user *, size_t *, loff_t *);
-extern int proc_do_large_bitmap(struct ctl_table *, int,
-				void __user *, size_t *, loff_t *);
-extern int proc_do_static_key(struct ctl_table *table, int write,
-			      void __user *buffer, size_t *lenp,
-			      loff_t *ppos);
+int proc_dostring(struct ctl_table *, int, void *, size_t *, loff_t *);
+int proc_dointvec(struct ctl_table *, int, void *, size_t *, loff_t *);
+int proc_douintvec(struct ctl_table *, int, void *, size_t *, loff_t *);
+int proc_dointvec_minmax(struct ctl_table *, int, void *, size_t *, loff_t *);
+int proc_douintvec_minmax(struct ctl_table *table, int write, void *buffer,
+		size_t *lenp, loff_t *ppos);
+int proc_dointvec_jiffies(struct ctl_table *, int, void *, size_t *, loff_t *);
+int proc_dointvec_userhz_jiffies(struct ctl_table *, int, void *, size_t *,
+		loff_t *);
+int proc_dointvec_ms_jiffies(struct ctl_table *, int, void *, size_t *,
+		loff_t *);
+int proc_doulongvec_minmax(struct ctl_table *, int, void *, size_t *, loff_t *);
+int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int, void *,
+		size_t *, loff_t *);
+int proc_do_large_bitmap(struct ctl_table *, int, void *, size_t *, loff_t *);
+int proc_do_static_key(struct ctl_table *table, int write, void *buffer,
+		size_t *lenp, loff_t *ppos);
 
 /*
  * Register a set of sysctl names by calling register_sysctl_table
@@ -246,7 +237,7 @@ static inline void setup_sysctl_set(struct ctl_table_set *p,
 
 #endif /* CONFIG_SYSCTL */
 
-int sysctl_max_threads(struct ctl_table *table, int write,
-		       void __user *buffer, size_t *lenp, loff_t *ppos);
+int sysctl_max_threads(struct ctl_table *table, int write, void *buffer,
+		size_t *lenp, loff_t *ppos);
 
 #endif /* _LINUX_SYSCTL_H */

include/linux/timer.h

@@ -201,8 +201,7 @@ struct ctl_table;
 
 extern unsigned int sysctl_timer_migration;
 int timer_migration_handler(struct ctl_table *table, int write,
-			    void __user *buffer, size_t *lenp,
-			    loff_t *ppos);
+			    void *buffer, size_t *lenp, loff_t *ppos);
 #endif
 
 unsigned long __round_jiffies(unsigned long j, int cpu);

include/linux/vmstat.h

@@ -16,8 +16,8 @@ extern int sysctl_stat_interval;
 #define DISABLE_NUMA_STAT   0
 extern int sysctl_vm_numa_stat;
 DECLARE_STATIC_KEY_TRUE(vm_numa_stat_key);
-extern int sysctl_vm_numa_stat_handler(struct ctl_table *table,
-		int write, void __user *buffer, size_t *length, loff_t *ppos);
+int sysctl_vm_numa_stat_handler(struct ctl_table *table, int write,
+		void *buffer, size_t *length, loff_t *ppos);
 #endif
 
 struct reclaim_stat {
@@ -274,8 +274,8 @@ void cpu_vm_stats_fold(int cpu);
 void refresh_zone_stat_thresholds(void);
 
 struct ctl_table;
-int vmstat_refresh(struct ctl_table *, int write,
-		   void __user *buffer, size_t *lenp, loff_t *ppos);
+int vmstat_refresh(struct ctl_table *, int write, void *buffer, size_t *lenp,
+		loff_t *ppos);
 
 void drain_zonestat(struct zone *zone, struct per_cpu_pageset *);
 

include/linux/writeback.h

@@ -362,24 +362,18 @@ extern int vm_highmem_is_dirtyable;
 extern int block_dump;
 extern int laptop_mode;
 
-extern int dirty_background_ratio_handler(struct ctl_table *table, int write,
-		void __user *buffer, size_t *lenp,
-		loff_t *ppos);
-extern int dirty_background_bytes_handler(struct ctl_table *table, int write,
-		void __user *buffer, size_t *lenp,
-		loff_t *ppos);
-extern int dirty_ratio_handler(struct ctl_table *table, int write,
-		void __user *buffer, size_t *lenp,
-		loff_t *ppos);
-extern int dirty_bytes_handler(struct ctl_table *table, int write,
-		void __user *buffer, size_t *lenp,
-		loff_t *ppos);
+int dirty_background_ratio_handler(struct ctl_table *table, int write,
+		void *buffer, size_t *lenp, loff_t *ppos);
+int dirty_background_bytes_handler(struct ctl_table *table, int write,
+		void *buffer, size_t *lenp, loff_t *ppos);
+int dirty_ratio_handler(struct ctl_table *table, int write,
+		void *buffer, size_t *lenp, loff_t *ppos);
+int dirty_bytes_handler(struct ctl_table *table, int write,
+		void *buffer, size_t *lenp, loff_t *ppos);
 int dirtytime_interval_handler(struct ctl_table *table, int write,
-			       void __user *buffer, size_t *lenp, loff_t *ppos);
-
-struct ctl_table;
-int dirty_writeback_centisecs_handler(struct ctl_table *, int,
-				      void __user *, size_t *, loff_t *);
+		void *buffer, size_t *lenp, loff_t *ppos);
+int dirty_writeback_centisecs_handler(struct ctl_table *table, int write,
+		void *buffer, size_t *lenp, loff_t *ppos);
 
 void global_dirty_limits(unsigned long *pbackground, unsigned long *pdirty);
 unsigned long wb_calc_thresh(struct bdi_writeback *wb, unsigned long thresh);

ipc/ipc_sysctl.c

@@ -24,7 +24,7 @@ static void *get_ipc(struct ctl_table *table)
 
 #ifdef CONFIG_PROC_SYSCTL
 static int proc_ipc_dointvec(struct ctl_table *table, int write,
-	void __user *buffer, size_t *lenp, loff_t *ppos)
+		void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct ctl_table ipc_table;
 
@@ -35,7 +35,7 @@ static int proc_ipc_dointvec(struct ctl_table *table, int write,
 }
 
 static int proc_ipc_dointvec_minmax(struct ctl_table *table, int write,
-	void __user *buffer, size_t *lenp, loff_t *ppos)
+		void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct ctl_table ipc_table;
 
@@ -46,7 +46,7 @@ static int proc_ipc_dointvec_minmax(struct ctl_table *table, int write,
 }
 
 static int proc_ipc_dointvec_minmax_orphans(struct ctl_table *table, int write,
-	void __user *buffer, size_t *lenp, loff_t *ppos)
+		void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct ipc_namespace *ns = current->nsproxy->ipc_ns;
 	int err = proc_ipc_dointvec_minmax(table, write, buffer, lenp, ppos);
@@ -59,7 +59,7 @@ static int proc_ipc_dointvec_minmax_orphans(struct ctl_table *table, int write,
 }
 
 static int proc_ipc_doulongvec_minmax(struct ctl_table *table, int write,
-	void __user *buffer, size_t *lenp, loff_t *ppos)
+		void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct ctl_table ipc_table;
 	memcpy(&ipc_table, table, sizeof(ipc_table));
@@ -70,7 +70,7 @@ static int proc_ipc_doulongvec_minmax(struct ctl_table *table, int write,
 }
 
 static int proc_ipc_auto_msgmni(struct ctl_table *table, int write,
-	void __user *buffer, size_t *lenp, loff_t *ppos)
+		void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct ctl_table ipc_table;
 	int dummy = 0;

ipc/mq_sysctl.c

@@ -19,7 +19,7 @@ static void *get_mq(struct ctl_table *table)
 }
 
 static int proc_mq_dointvec(struct ctl_table *table, int write,
-			    void __user *buffer, size_t *lenp, loff_t *ppos)
+			    void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct ctl_table mq_table;
 	memcpy(&mq_table, table, sizeof(mq_table));
@@ -29,7 +29,7 @@ static int proc_mq_dointvec(struct ctl_table *table, int write,
 }
 
 static int proc_mq_dointvec_minmax(struct ctl_table *table, int write,
-	void __user *buffer, size_t *lenp, loff_t *ppos)
+		void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct ctl_table mq_table;
 	memcpy(&mq_table, table, sizeof(mq_table));

kernel/bpf/cgroup.c

@@ -1137,16 +1137,13 @@ const struct bpf_verifier_ops cg_dev_verifier_ops = {
  * @head: sysctl table header
  * @table: sysctl table
  * @write: sysctl is being read (= 0) or written (= 1)
- * @buf: pointer to buffer passed by user space
+ * @buf: pointer to buffer (in and out)
  * @pcount: value-result argument: value is size of buffer pointed to by @buf,
  *	result is size of @new_buf if program set new value, initial value
  *	otherwise
  * @ppos: value-result argument: value is position at which read from or write
  *	to sysctl is happening, result is new position if program overrode it,
  *	initial value otherwise
- * @new_buf: pointer to pointer to new buffer that will be allocated if program
- *	overrides new value provided by user space on sysctl write
- *	NOTE: it's caller responsibility to free *new_buf if it was set
  * @type: type of program to be executed
  *
  * Program is run when sysctl is being accessed, either read or written, and
@@ -1157,8 +1154,7 @@ const struct bpf_verifier_ops cg_dev_verifier_ops = {
  */
 int __cgroup_bpf_run_filter_sysctl(struct ctl_table_header *head,
 				   struct ctl_table *table, int write,
-				   void __user *buf, size_t *pcount,
-				   loff_t *ppos, void **new_buf,
+				   void **buf, size_t *pcount, loff_t *ppos,
 				   enum bpf_attach_type type)
 {
 	struct bpf_sysctl_kern ctx = {
@@ -1173,36 +1169,28 @@ int __cgroup_bpf_run_filter_sysctl(struct ctl_table_header *head,
 		.new_updated = 0,
 	};
 	struct cgroup *cgrp;
+	loff_t pos = 0;
 	int ret;
 
 	ctx.cur_val = kmalloc_track_caller(ctx.cur_len, GFP_KERNEL);
-	if (ctx.cur_val) {
-		mm_segment_t old_fs;
-		loff_t pos = 0;
-
-		old_fs = get_fs();
-		set_fs(KERNEL_DS);
-		if (table->proc_handler(table, 0, (void __user *)ctx.cur_val,
-					&ctx.cur_len, &pos)) {
-			/* Let BPF program decide how to proceed. */
-			ctx.cur_len = 0;
-		}
-		set_fs(old_fs);
-	} else {
+	if (!ctx.cur_val ||
+	    table->proc_handler(table, 0, ctx.cur_val, &ctx.cur_len, &pos)) {
 		/* Let BPF program decide how to proceed. */
 		ctx.cur_len = 0;
 	}
 
-	if (write && buf && *pcount) {
+	if (write && *buf && *pcount) {
 		/* BPF program should be able to override new value with a
 		 * buffer bigger than provided by user.
 		 */
 		ctx.new_val = kmalloc_track_caller(PAGE_SIZE, GFP_KERNEL);
 		ctx.new_len = min_t(size_t, PAGE_SIZE, *pcount);
-		if (!ctx.new_val ||
-		    copy_from_user(ctx.new_val, buf, ctx.new_len))
+		if (ctx.new_val) {
+			memcpy(ctx.new_val, *buf, ctx.new_len);
+		} else {
 			/* Let BPF program decide how to proceed. */
 			ctx.new_len = 0;
+		}
 	}
 
 	rcu_read_lock();
@@ -1213,7 +1201,8 @@ int __cgroup_bpf_run_filter_sysctl(struct ctl_table_header *head,
 	kfree(ctx.cur_val);
 
 	if (ret == 1 && ctx.new_updated) {
-		*new_buf = ctx.new_val;
+		kfree(*buf);
+		*buf = ctx.new_val;
 		*pcount = ctx.new_len;
 	} else {
 		kfree(ctx.new_val);

kernel/events/callchain.c

@@ -236,7 +236,7 @@ exit_put:
  * sysctl_perf_event_max_contexts_per_stack.
  */
 int perf_event_max_stack_handler(struct ctl_table *table, int write,
-				 void __user *buffer, size_t *lenp, loff_t *ppos)
+				 void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int *value = table->data;
 	int new_value = *value, ret;

kernel/events/core.c

@@ -437,8 +437,7 @@ static void update_perf_cpu_limits(void)
 static bool perf_rotate_context(struct perf_cpu_context *cpuctx);
 
 int perf_proc_update_handler(struct ctl_table *table, int write,
-		void __user *buffer, size_t *lenp,
-		loff_t *ppos)
+		void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int ret;
 	int perf_cpu = sysctl_perf_cpu_time_max_percent;
@@ -462,8 +461,7 @@ int perf_proc_update_handler(struct ctl_table *table, int write,
 int sysctl_perf_cpu_time_max_percent __read_mostly = DEFAULT_CPU_TIME_MAX_PERCENT;
 
 int perf_cpu_time_max_percent_handler(struct ctl_table *table, int write,
-				void __user *buffer, size_t *lenp,
-				loff_t *ppos)
+		void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
 

kernel/kprobes.c

@@ -892,7 +892,7 @@ static void unoptimize_all_kprobes(void)
 static DEFINE_MUTEX(kprobe_sysctl_mutex);
 int sysctl_kprobes_optimization;
 int proc_kprobes_optimization_handler(struct ctl_table *table, int write,
-				      void __user *buffer, size_t *length,
+				      void *buffer, size_t *length,
 				      loff_t *ppos)
 {
 	int ret;

kernel/latencytop.c

@@ -269,8 +269,8 @@ static int __init init_lstats_procfs(void)
 	return 0;
 }
 
-int sysctl_latencytop(struct ctl_table *table, int write,
-			void __user *buffer, size_t *lenp, loff_t *ppos)
+int sysctl_latencytop(struct ctl_table *table, int write, void *buffer,
+		size_t *lenp, loff_t *ppos)
 {
 	int err;
 

kernel/pid_namespace.c

@@ -263,7 +263,7 @@ void zap_pid_ns_processes(struct pid_namespace *pid_ns)
 
 #ifdef CONFIG_CHECKPOINT_RESTORE
 static int pid_ns_ctl_handler(struct ctl_table *table, int write,
-		void __user *buffer, size_t *lenp, loff_t *ppos)
+		void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct pid_namespace *pid_ns = task_active_pid_ns(current);
 	struct ctl_table tmp = *table;

kernel/printk/printk.c

@@ -173,7 +173,7 @@ __setup("printk.devkmsg=", control_devkmsg);
 char devkmsg_log_str[DEVKMSG_STR_MAX_SIZE] = "ratelimit";
 
 int devkmsg_sysctl_set_loglvl(struct ctl_table *table, int write,
-			      void __user *buffer, size_t *lenp, loff_t *ppos)
+			      void *buffer, size_t *lenp, loff_t *ppos)
 {
 	char old_str[DEVKMSG_STR_MAX_SIZE];
 	unsigned int old;

kernel/sched/core.c

@@ -1110,8 +1110,7 @@ static void uclamp_update_root_tg(void) { }
 #endif
 
 int sysctl_sched_uclamp_handler(struct ctl_table *table, int write,
-				void __user *buffer, size_t *lenp,
-				loff_t *ppos)
+				void *buffer, size_t *lenp, loff_t *ppos)
 {
 	bool update_root_tg = false;
 	int old_min, old_max;
@@ -2723,7 +2722,7 @@ void set_numabalancing_state(bool enabled)
 
 #ifdef CONFIG_PROC_SYSCTL
 int sysctl_numa_balancing(struct ctl_table *table, int write,
-			 void __user *buffer, size_t *lenp, loff_t *ppos)
+			  void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct ctl_table t;
 	int err;
@@ -2797,8 +2796,8 @@ static void __init init_schedstats(void)
 }
 
 #ifdef CONFIG_PROC_SYSCTL
-int sysctl_schedstats(struct ctl_table *table, int write,
-			 void __user *buffer, size_t *lenp, loff_t *ppos)
+int sysctl_schedstats(struct ctl_table *table, int write, void *buffer,
+		size_t *lenp, loff_t *ppos)
 {
 	struct ctl_table t;
 	int err;

kernel/sched/fair.c

@@ -645,8 +645,7 @@ struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq)
  */
 
 int sched_proc_update_handler(struct ctl_table *table, int write,
-		void __user *buffer, size_t *lenp,
-		loff_t *ppos)
+		void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
 	unsigned int factor = get_update_sysctl_factor();

kernel/sched/rt.c

@@ -2714,9 +2714,8 @@ static void sched_rt_do_global(void)
 	def_rt_bandwidth.rt_period = ns_to_ktime(global_rt_period());
 }
 
-int sched_rt_handler(struct ctl_table *table, int write,
-		void __user *buffer, size_t *lenp,
-		loff_t *ppos)
+int sched_rt_handler(struct ctl_table *table, int write, void *buffer,
+		size_t *lenp, loff_t *ppos)
 {
 	int old_period, old_runtime;
 	static DEFINE_MUTEX(mutex);
@@ -2754,9 +2753,8 @@ undo:
 	return ret;
 }
 
-int sched_rr_handler(struct ctl_table *table, int write,
-		void __user *buffer, size_t *lenp,
-		loff_t *ppos)
+int sched_rr_handler(struct ctl_table *table, int write, void *buffer,
+		size_t *lenp, loff_t *ppos)
 {
 	int ret;
 	static DEFINE_MUTEX(mutex);

kernel/sched/topology.c

@@ -209,7 +209,7 @@ bool sched_energy_update;
 
 #ifdef CONFIG_PROC_SYSCTL
 int sched_energy_aware_handler(struct ctl_table *table, int write,
-			 void __user *buffer, size_t *lenp, loff_t *ppos)
+		void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int ret, state;
 

kernel/seccomp.c

@@ -1776,7 +1776,7 @@ static void audit_actions_logged(u32 actions_logged, u32 old_actions_logged,
 }
 
 static int seccomp_actions_logged_handler(struct ctl_table *ro_table, int write,
-					  void __user *buffer, size_t *lenp,
+					  void *buffer, size_t *lenp,
 					  loff_t *ppos)
 {
 	int ret;

kernel/sysctl.c

@@ -208,12 +208,10 @@ static int max_extfrag_threshold = 1000;
 #ifdef CONFIG_PROC_SYSCTL
 
 static int _proc_do_string(char *data, int maxlen, int write,
-			   char __user *buffer,
-			   size_t *lenp, loff_t *ppos)
+		char *buffer, size_t *lenp, loff_t *ppos)
 {
 	size_t len;
-	char __user *p;
-	char c;
+	char c, *p;
 
 	if (!data || !maxlen || !*lenp) {
 		*lenp = 0;
@@ -238,8 +236,7 @@ static int _proc_do_string(char *data, int maxlen, int write,
 		*ppos += *lenp;
 		p = buffer;
 		while ((p - buffer) < *lenp && len < maxlen - 1) {
-			if (get_user(c, p++))
-				return -EFAULT;
+			c = *(p++);
 			if (c == 0 || c == '\n')
 				break;
 			data[len++] = c;
@@ -261,11 +258,9 @@ static int _proc_do_string(char *data, int maxlen, int write,
 		if (len > *lenp)
 			len = *lenp;
 		if (len)
-			if (copy_to_user(buffer, data, len))
-				return -EFAULT;
+			memcpy(buffer, data, len);
 		if (len < *lenp) {
-			if (put_user('\n', buffer + len))
-				return -EFAULT;
+			buffer[len] = '\n';
 			len++;
 		}
 		*lenp = len;
@@ -326,13 +321,13 @@ static bool proc_first_pos_non_zero_ignore(loff_t *ppos,
  * Returns 0 on success.
  */
 int proc_dostring(struct ctl_table *table, int write,
-		  void __user *buffer, size_t *lenp, loff_t *ppos)
+		  void *buffer, size_t *lenp, loff_t *ppos)
 {
 	if (write)
 		proc_first_pos_non_zero_ignore(ppos, table);
 
-	return _proc_do_string((char *)(table->data), table->maxlen, write,
-			       (char __user *)buffer, lenp, ppos);
+	return _proc_do_string(table->data, table->maxlen, write, buffer, lenp,
+			ppos);
 }
 
 static size_t proc_skip_spaces(char **buf)
@@ -463,11 +458,10 @@ static int proc_get_long(char **buf, size_t *size,
  * @val: the integer to be converted
  * @neg: sign of the number, %TRUE for negative
  *
- * In case of success %0 is returned and @buf and @size are updated with
- * the amount of bytes written.
+ * In case of success @buf and @size are updated with the amount of bytes
+ * written.
  */
-static int proc_put_long(void __user **buf, size_t *size, unsigned long val,
-			  bool neg)
+static void proc_put_long(void **buf, size_t *size, unsigned long val, bool neg)
 {
 	int len;
 	char tmp[TMPBUFLEN], *p = tmp;
@@ -476,24 +470,22 @@ static int proc_put_long(void __user **buf, size_t *size, unsigned long val,
 	len = strlen(tmp);
 	if (len > *size)
 		len = *size;
-	if (copy_to_user(*buf, tmp, len))
-		return -EFAULT;
+	memcpy(*buf, tmp, len);
 	*size -= len;
 	*buf += len;
-	return 0;
 }
 #undef TMPBUFLEN
 
-static int proc_put_char(void __user **buf, size_t *size, char c)
+static void proc_put_char(void **buf, size_t *size, char c)
 {
 	if (*size) {
-		char __user **buffer = (char __user **)buf;
-		if (put_user(c, *buffer))
-			return -EFAULT;
-		(*size)--, (*buffer)++;
+		char **buffer = (char **)buf;
+		**buffer = c;
+
+		(*size)--;
+		(*buffer)++;
 		*buf = *buffer;
 	}
-	return 0;
 }
 
 static int do_proc_dointvec_conv(bool *negp, unsigned long *lvalp,
@@ -541,7 +533,7 @@ static int do_proc_douintvec_conv(unsigned long *lvalp,
 static const char proc_wspace_sep[] = { ' ', '\t', '\n' };
 
 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
-		  int write, void __user *buffer,
+		  int write, void *buffer,
 		  size_t *lenp, loff_t *ppos,
 		  int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
 			      int write, void *data),
@@ -549,7 +541,7 @@ static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
 {
 	int *i, vleft, first = 1, err = 0;
 	size_t left;
-	char *kbuf = NULL, *p;
+	char *p;
 	
 	if (!tbl_data || !table->maxlen || !*lenp || (*ppos && !write)) {
 		*lenp = 0;
@@ -569,9 +561,7 @@ static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
 
 		if (left > PAGE_SIZE - 1)
 			left = PAGE_SIZE - 1;
-		p = kbuf = memdup_user_nul(buffer, left);
-		if (IS_ERR(kbuf))
-			return PTR_ERR(kbuf);
+		p = buffer;
 	}
 
 	for (; left && vleft--; i++, first=0) {
@@ -598,24 +588,17 @@ static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
 				break;
 			}
 			if (!first)
-				err = proc_put_char(&buffer, &left, '\t');
-			if (err)
-				break;
-			err = proc_put_long(&buffer, &left, lval, neg);
-			if (err)
-				break;
+				proc_put_char(&buffer, &left, '\t');
+			proc_put_long(&buffer, &left, lval, neg);
 		}
 	}
 
 	if (!write && !first && left && !err)
-		err = proc_put_char(&buffer, &left, '\n');
+		proc_put_char(&buffer, &left, '\n');
 	if (write && !err && left)
 		left -= proc_skip_spaces(&p);
-	if (write) {
-		kfree(kbuf);
-		if (first)
-			return err ? : -EINVAL;
-	}
+	if (write && first)
+		return err ? : -EINVAL;
 	*lenp -= left;
 out:
 	*ppos += *lenp;
@@ -623,7 +606,7 @@ out:
 }
 
 static int do_proc_dointvec(struct ctl_table *table, int write,
-		  void __user *buffer, size_t *lenp, loff_t *ppos,
+		  void *buffer, size_t *lenp, loff_t *ppos,
 		  int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
 			      int write, void *data),
 		  void *data)
@@ -634,7 +617,7 @@ static int do_proc_dointvec(struct ctl_table *table, int write,
 
 static int do_proc_douintvec_w(unsigned int *tbl_data,
 			       struct ctl_table *table,
-			       void __user *buffer,
+			       void *buffer,
 			       size_t *lenp, loff_t *ppos,
 			       int (*conv)(unsigned long *lvalp,
 					   unsigned int *valp,
@@ -645,7 +628,7 @@ static int do_proc_douintvec_w(unsigned int *tbl_data,
 	int err = 0;
 	size_t left;
 	bool neg;
-	char *kbuf = NULL, *p;
+	char *p = buffer;
 
 	left = *lenp;
 
@@ -655,10 +638,6 @@ static int do_proc_douintvec_w(unsigned int *tbl_data,
 	if (left > PAGE_SIZE - 1)
 		left = PAGE_SIZE - 1;
 
-	p = kbuf = memdup_user_nul(buffer, left);
-	if (IS_ERR(kbuf))
-		return -EINVAL;
-
 	left -= proc_skip_spaces(&p);
 	if (!left) {
 		err = -EINVAL;
@@ -682,7 +661,6 @@ static int do_proc_douintvec_w(unsigned int *tbl_data,
 		left -= proc_skip_spaces(&p);
 
 out_free:
-	kfree(kbuf);
 	if (err)
 		return -EINVAL;
 
@@ -694,7 +672,7 @@ bail_early:
 	return err;
 }
 
-static int do_proc_douintvec_r(unsigned int *tbl_data, void __user *buffer,
+static int do_proc_douintvec_r(unsigned int *tbl_data, void *buffer,
 			       size_t *lenp, loff_t *ppos,
 			       int (*conv)(unsigned long *lvalp,
 					   unsigned int *valp,
@@ -712,11 +690,11 @@ static int do_proc_douintvec_r(unsigned int *tbl_data, void __user *buffer,
 		goto out;
 	}
 
-	err = proc_put_long(&buffer, &left, lval, false);
-	if (err || !left)
+	proc_put_long(&buffer, &left, lval, false);
+	if (!left)
 		goto out;
 
-	err = proc_put_char(&buffer, &left, '\n');
+	proc_put_char(&buffer, &left, '\n');
 
 out:
 	*lenp -= left;
@@ -726,7 +704,7 @@ out:
 }
 
 static int __do_proc_douintvec(void *tbl_data, struct ctl_table *table,
-			       int write, void __user *buffer,
+			       int write, void *buffer,
 			       size_t *lenp, loff_t *ppos,
 			       int (*conv)(unsigned long *lvalp,
 					   unsigned int *valp,
@@ -762,7 +740,7 @@ static int __do_proc_douintvec(void *tbl_data, struct ctl_table *table,
 }
 
 static int do_proc_douintvec(struct ctl_table *table, int write,
-			     void __user *buffer, size_t *lenp, loff_t *ppos,
+			     void *buffer, size_t *lenp, loff_t *ppos,
 			     int (*conv)(unsigned long *lvalp,
 					 unsigned int *valp,
 					 int write, void *data),
@@ -785,16 +763,15 @@ static int do_proc_douintvec(struct ctl_table *table, int write,
  *
  * Returns 0 on success.
  */
-int proc_dointvec(struct ctl_table *table, int write,
-		     void __user *buffer, size_t *lenp, loff_t *ppos)
+int proc_dointvec(struct ctl_table *table, int write, void *buffer,
+		  size_t *lenp, loff_t *ppos)
 {
 	return do_proc_dointvec(table, write, buffer, lenp, ppos, NULL, NULL);
 }
 
 #ifdef CONFIG_COMPACTION
 static int proc_dointvec_minmax_warn_RT_change(struct ctl_table *table,
-					       int write, void __user *buffer,
-					       size_t *lenp, loff_t *ppos)
+		int write, void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int ret, old;
 
@@ -826,8 +803,8 @@ static int proc_dointvec_minmax_warn_RT_change(struct ctl_table *table,
  *
  * Returns 0 on success.
  */
-int proc_douintvec(struct ctl_table *table, int write,
-		     void __user *buffer, size_t *lenp, loff_t *ppos)
+int proc_douintvec(struct ctl_table *table, int write, void *buffer,
+		size_t *lenp, loff_t *ppos)
 {
 	return do_proc_douintvec(table, write, buffer, lenp, ppos,
 				 do_proc_douintvec_conv, NULL);
@@ -838,7 +815,7 @@ int proc_douintvec(struct ctl_table *table, int write,
  * This means we can safely use a temporary.
  */
 static int proc_taint(struct ctl_table *table, int write,
-			       void __user *buffer, size_t *lenp, loff_t *ppos)
+			       void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct ctl_table t;
 	unsigned long tmptaint = get_taint();
@@ -870,7 +847,7 @@ static int proc_taint(struct ctl_table *table, int write,
 
 #ifdef CONFIG_PRINTK
 static int proc_dointvec_minmax_sysadmin(struct ctl_table *table, int write,
-				void __user *buffer, size_t *lenp, loff_t *ppos)
+				void *buffer, size_t *lenp, loff_t *ppos)
 {
 	if (write && !capable(CAP_SYS_ADMIN))
 		return -EPERM;
@@ -936,7 +913,7 @@ static int do_proc_dointvec_minmax_conv(bool *negp, unsigned long *lvalp,
  * Returns 0 on success or -EINVAL on write when the range check fails.
  */
 int proc_dointvec_minmax(struct ctl_table *table, int write,
-		  void __user *buffer, size_t *lenp, loff_t *ppos)
+		  void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct do_proc_dointvec_minmax_conv_param param = {
 		.min = (int *) table->extra1,
@@ -1005,7 +982,7 @@ static int do_proc_douintvec_minmax_conv(unsigned long *lvalp,
  * Returns 0 on success or -ERANGE on write when the range check fails.
  */
 int proc_douintvec_minmax(struct ctl_table *table, int write,
-			  void __user *buffer, size_t *lenp, loff_t *ppos)
+			  void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct do_proc_douintvec_minmax_conv_param param = {
 		.min = (unsigned int *) table->extra1,
@@ -1036,7 +1013,7 @@ static int do_proc_dopipe_max_size_conv(unsigned long *lvalp,
 }
 
 static int proc_dopipe_max_size(struct ctl_table *table, int write,
-				void __user *buffer, size_t *lenp, loff_t *ppos)
+				void *buffer, size_t *lenp, loff_t *ppos)
 {
 	return do_proc_douintvec(table, write, buffer, lenp, ppos,
 				 do_proc_dopipe_max_size_conv, NULL);
@@ -1057,7 +1034,7 @@ static void validate_coredump_safety(void)
 }
 
 static int proc_dointvec_minmax_coredump(struct ctl_table *table, int write,
-		void __user *buffer, size_t *lenp, loff_t *ppos)
+		void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int error = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
 	if (!error)
@@ -1067,7 +1044,7 @@ static int proc_dointvec_minmax_coredump(struct ctl_table *table, int write,
 
 #ifdef CONFIG_COREDUMP
 static int proc_dostring_coredump(struct ctl_table *table, int write,
-		  void __user *buffer, size_t *lenp, loff_t *ppos)
+		  void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int error = proc_dostring(table, write, buffer, lenp, ppos);
 	if (!error)
@@ -1078,7 +1055,7 @@ static int proc_dostring_coredump(struct ctl_table *table, int write,
 
 #ifdef CONFIG_MAGIC_SYSRQ
 static int sysrq_sysctl_handler(struct ctl_table *table, int write,
-				void __user *buffer, size_t *lenp, loff_t *ppos)
+				void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int tmp, ret;
 
@@ -1096,16 +1073,14 @@ static int sysrq_sysctl_handler(struct ctl_table *table, int write,
 }
 #endif
 
-static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
-				     void __user *buffer,
-				     size_t *lenp, loff_t *ppos,
-				     unsigned long convmul,
-				     unsigned long convdiv)
+static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table,
+		int write, void *buffer, size_t *lenp, loff_t *ppos,
+		unsigned long convmul, unsigned long convdiv)
 {
 	unsigned long *i, *min, *max;
 	int vleft, first = 1, err = 0;
 	size_t left;
-	char *kbuf = NULL, *p;
+	char *p;
 
 	if (!data || !table->maxlen || !*lenp || (*ppos && !write)) {
 		*lenp = 0;
@@ -1124,9 +1099,7 @@ static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int
 
 		if (left > PAGE_SIZE - 1)
 			left = PAGE_SIZE - 1;
-		p = kbuf = memdup_user_nul(buffer, left);
-		if (IS_ERR(kbuf))
-			return PTR_ERR(kbuf);
+		p = buffer;
 	}
 
 	for (; left && vleft--; i++, first = 0) {
@@ -1154,26 +1127,18 @@ static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int
 			*i = val;
 		} else {
 			val = convdiv * (*i) / convmul;
-			if (!first) {
-				err = proc_put_char(&buffer, &left, '\t');
-				if (err)
-					break;
-			}
-			err = proc_put_long(&buffer, &left, val, false);
-			if (err)
-				break;
+			if (!first)
+				proc_put_char(&buffer, &left, '\t');
+			proc_put_long(&buffer, &left, val, false);
 		}
 	}
 
 	if (!write && !first && left && !err)
-		err = proc_put_char(&buffer, &left, '\n');
+		proc_put_char(&buffer, &left, '\n');
 	if (write && !err)
 		left -= proc_skip_spaces(&p);
-	if (write) {
-		kfree(kbuf);
-		if (first)
-			return err ? : -EINVAL;
-	}
+	if (write && first)
+		return err ? : -EINVAL;
 	*lenp -= left;
 out:
 	*ppos += *lenp;
@@ -1181,10 +1146,8 @@ out:
 }
 
 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
-				     void __user *buffer,
-				     size_t *lenp, loff_t *ppos,
-				     unsigned long convmul,
-				     unsigned long convdiv)
+		void *buffer, size_t *lenp, loff_t *ppos, unsigned long convmul,
+		unsigned long convdiv)
 {
 	return __do_proc_doulongvec_minmax(table->data, table, write,
 			buffer, lenp, ppos, convmul, convdiv);
@@ -1207,7 +1170,7 @@ static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
  * Returns 0 on success.
  */
 int proc_doulongvec_minmax(struct ctl_table *table, int write,
-			   void __user *buffer, size_t *lenp, loff_t *ppos)
+			   void *buffer, size_t *lenp, loff_t *ppos)
 {
     return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, 1l, 1l);
 }
@@ -1230,8 +1193,7 @@ int proc_doulongvec_minmax(struct ctl_table *table, int write,
  * Returns 0 on success.
  */
 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
-				      void __user *buffer,
-				      size_t *lenp, loff_t *ppos)
+				      void *buffer, size_t *lenp, loff_t *ppos)
 {
     return do_proc_doulongvec_minmax(table, write, buffer,
 				     lenp, ppos, HZ, 1000l);
@@ -1325,7 +1287,7 @@ static int do_proc_dointvec_ms_jiffies_conv(bool *negp, unsigned long *lvalp,
  * Returns 0 on success.
  */
 int proc_dointvec_jiffies(struct ctl_table *table, int write,
-			  void __user *buffer, size_t *lenp, loff_t *ppos)
+			  void *buffer, size_t *lenp, loff_t *ppos)
 {
     return do_proc_dointvec(table,write,buffer,lenp,ppos,
 		    	    do_proc_dointvec_jiffies_conv,NULL);
@@ -1347,7 +1309,7 @@ int proc_dointvec_jiffies(struct ctl_table *table, int write,
  * Returns 0 on success.
  */
 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
-				 void __user *buffer, size_t *lenp, loff_t *ppos)
+				 void *buffer, size_t *lenp, loff_t *ppos)
 {
     return do_proc_dointvec(table,write,buffer,lenp,ppos,
 		    	    do_proc_dointvec_userhz_jiffies_conv,NULL);
@@ -1369,15 +1331,15 @@ int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
  *
  * Returns 0 on success.
  */
-int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
-			     void __user *buffer, size_t *lenp, loff_t *ppos)
+int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, void *buffer,
+		size_t *lenp, loff_t *ppos)
 {
 	return do_proc_dointvec(table, write, buffer, lenp, ppos,
 				do_proc_dointvec_ms_jiffies_conv, NULL);
 }
 
-static int proc_do_cad_pid(struct ctl_table *table, int write,
-			   void __user *buffer, size_t *lenp, loff_t *ppos)
+static int proc_do_cad_pid(struct ctl_table *table, int write, void *buffer,
+		size_t *lenp, loff_t *ppos)
 {
 	struct pid *new_pid;
 	pid_t tmp;
@@ -1416,7 +1378,7 @@ static int proc_do_cad_pid(struct ctl_table *table, int write,
  * Returns 0 on success.
  */
 int proc_do_large_bitmap(struct ctl_table *table, int write,
-			 void __user *buffer, size_t *lenp, loff_t *ppos)
+			 void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int err = 0;
 	bool first = 1;
@@ -1432,7 +1394,7 @@ int proc_do_large_bitmap(struct ctl_table *table, int write,
 	}
 
 	if (write) {
-		char *kbuf, *p;
+		char *p = buffer;
 		size_t skipped = 0;
 
 		if (left > PAGE_SIZE - 1) {
@@ -1441,15 +1403,9 @@ int proc_do_large_bitmap(struct ctl_table *table, int write,
 			skipped = *lenp - left;
 		}
 
-		p = kbuf = memdup_user_nul(buffer, left);
-		if (IS_ERR(kbuf))
-			return PTR_ERR(kbuf);
-
 		tmp_bitmap = bitmap_zalloc(bitmap_len, GFP_KERNEL);
-		if (!tmp_bitmap) {
-			kfree(kbuf);
+		if (!tmp_bitmap)
 			return -ENOMEM;
-		}
 		proc_skip_char(&p, &left, '\n');
 		while (!err && left) {
 			unsigned long val_a, val_b;
@@ -1513,7 +1469,6 @@ int proc_do_large_bitmap(struct ctl_table *table, int write,
 			first = 0;
 			proc_skip_char(&p, &left, '\n');
 		}
-		kfree(kbuf);
 		left += skipped;
 	} else {
 		unsigned long bit_a, bit_b = 0;
@@ -1525,27 +1480,17 @@ int proc_do_large_bitmap(struct ctl_table *table, int write,
 			bit_b = find_next_zero_bit(bitmap, bitmap_len,
 						   bit_a + 1) - 1;
 
-			if (!first) {
-				err = proc_put_char(&buffer, &left, ',');
-				if (err)
-					break;
-			}
-			err = proc_put_long(&buffer, &left, bit_a, false);
-			if (err)
-				break;
+			if (!first)
+				proc_put_char(&buffer, &left, ',');
+			proc_put_long(&buffer, &left, bit_a, false);
 			if (bit_a != bit_b) {
-				err = proc_put_char(&buffer, &left, '-');
-				if (err)
-					break;
-				err = proc_put_long(&buffer, &left, bit_b, false);
-				if (err)
-					break;
+				proc_put_char(&buffer, &left, '-');
+				proc_put_long(&buffer, &left, bit_b, false);
 			}
 
 			first = 0; bit_b++;
 		}
-		if (!err)
-			err = proc_put_char(&buffer, &left, '\n');
+		proc_put_char(&buffer, &left, '\n');
 	}
 
 	if (!err) {
@@ -1566,68 +1511,67 @@ int proc_do_large_bitmap(struct ctl_table *table, int write,
 #else /* CONFIG_PROC_SYSCTL */
 
 int proc_dostring(struct ctl_table *table, int write,
-		  void __user *buffer, size_t *lenp, loff_t *ppos)
+		  void *buffer, size_t *lenp, loff_t *ppos)
 {
 	return -ENOSYS;
 }
 
 int proc_dointvec(struct ctl_table *table, int write,
-		  void __user *buffer, size_t *lenp, loff_t *ppos)
+		  void *buffer, size_t *lenp, loff_t *ppos)
 {
 	return -ENOSYS;
 }
 
 int proc_douintvec(struct ctl_table *table, int write,
-		  void __user *buffer, size_t *lenp, loff_t *ppos)
+		  void *buffer, size_t *lenp, loff_t *ppos)
 {
 	return -ENOSYS;
 }
 
 int proc_dointvec_minmax(struct ctl_table *table, int write,
-		    void __user *buffer, size_t *lenp, loff_t *ppos)
+		    void *buffer, size_t *lenp, loff_t *ppos)
 {
 	return -ENOSYS;
 }
 
 int proc_douintvec_minmax(struct ctl_table *table, int write,
-			  void __user *buffer, size_t *lenp, loff_t *ppos)
+			  void *buffer, size_t *lenp, loff_t *ppos)
 {
 	return -ENOSYS;
 }
 
 int proc_dointvec_jiffies(struct ctl_table *table, int write,
-		    void __user *buffer, size_t *lenp, loff_t *ppos)
+		    void *buffer, size_t *lenp, loff_t *ppos)
 {
 	return -ENOSYS;
 }
 
 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
-		    void __user *buffer, size_t *lenp, loff_t *ppos)
+		    void *buffer, size_t *lenp, loff_t *ppos)
 {
 	return -ENOSYS;
 }
 
 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
-			     void __user *buffer, size_t *lenp, loff_t *ppos)
+			     void *buffer, size_t *lenp, loff_t *ppos)
 {
 	return -ENOSYS;
 }
 
 int proc_doulongvec_minmax(struct ctl_table *table, int write,
-		    void __user *buffer, size_t *lenp, loff_t *ppos)
+		    void *buffer, size_t *lenp, loff_t *ppos)
 {
 	return -ENOSYS;
 }
 
 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
-				      void __user *buffer,
-				      size_t *lenp, loff_t *ppos)
+				      void *buffer, size_t *lenp, loff_t *ppos)
 {
-    return -ENOSYS;
+	return -ENOSYS;
 }
 
 int proc_do_large_bitmap(struct ctl_table *table, int write,
-			 void __user *buffer, size_t *lenp, loff_t *ppos)
+			 void *buffer, size_t *lenp, loff_t *ppos)
 {
 	return -ENOSYS;
 }
@@ -1636,8 +1580,7 @@ int proc_do_large_bitmap(struct ctl_table *table, int write,
 
 #if defined(CONFIG_SYSCTL)
 int proc_do_static_key(struct ctl_table *table, int write,
-		       void __user *buffer, size_t *lenp,
-		       loff_t *ppos)
+		       void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct static_key *key = (struct static_key *)table->data;
 	static DEFINE_MUTEX(static_key_mutex);

kernel/time/timer.c

@@ -249,8 +249,7 @@ void timers_update_nohz(void)
 }
 
 int timer_migration_handler(struct ctl_table *table, int write,
-			    void __user *buffer, size_t *lenp,
-			    loff_t *ppos)
+			    void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int ret;
 

kernel/trace/trace.c

@@ -2661,7 +2661,7 @@ static void output_printk(struct trace_event_buffer *fbuffer)
 }
 
 int tracepoint_printk_sysctl(struct ctl_table *table, int write,
-			     void __user *buffer, size_t *lenp,
+			     void *buffer, size_t *lenp,
 			     loff_t *ppos)
 {
 	int save_tracepoint_printk;

kernel/umh.c

@@ -630,7 +630,7 @@ int call_usermodehelper(const char *path, char **argv, char **envp, int wait)
 EXPORT_SYMBOL(call_usermodehelper);
 
 static int proc_cap_handler(struct ctl_table *table, int write,
-			 void __user *buffer, size_t *lenp, loff_t *ppos)
+			 void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct ctl_table t;
 	unsigned long cap_array[_KERNEL_CAPABILITY_U32S];

kernel/utsname_sysctl.c

@@ -30,7 +30,7 @@ static void *get_uts(struct ctl_table *table)
  *	to observe. Should this be in kernel/sys.c ????
  */
 static int proc_do_uts_string(struct ctl_table *table, int write,
-		  void __user *buffer, size_t *lenp, loff_t *ppos)
+		  void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct ctl_table uts_table;
 	int r;

kernel/watchdog.c

@@ -661,7 +661,7 @@ static void proc_watchdog_update(void)
  * proc_soft_watchdog | soft_watchdog_user_enabled | SOFT_WATCHDOG_ENABLED
  */
 static int proc_watchdog_common(int which, struct ctl_table *table, int write,
-				void __user *buffer, size_t *lenp, loff_t *ppos)
+				void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int err, old, *param = table->data;
 
@@ -688,7 +688,7 @@ static int proc_watchdog_common(int which, struct ctl_table *table, int write,
  * /proc/sys/kernel/watchdog
  */
 int proc_watchdog(struct ctl_table *table, int write,
-		  void __user *buffer, size_t *lenp, loff_t *ppos)
+		  void *buffer, size_t *lenp, loff_t *ppos)
 {
 	return proc_watchdog_common(NMI_WATCHDOG_ENABLED|SOFT_WATCHDOG_ENABLED,
 				    table, write, buffer, lenp, ppos);
@@ -698,7 +698,7 @@ int proc_watchdog(struct ctl_table *table, int write,
  * /proc/sys/kernel/nmi_watchdog
  */
 int proc_nmi_watchdog(struct ctl_table *table, int write,
-		      void __user *buffer, size_t *lenp, loff_t *ppos)
+		      void *buffer, size_t *lenp, loff_t *ppos)
 {
 	if (!nmi_watchdog_available && write)
 		return -ENOTSUPP;
@@ -710,7 +710,7 @@ int proc_nmi_watchdog(struct ctl_table *table, int write,
  * /proc/sys/kernel/soft_watchdog
  */
 int proc_soft_watchdog(struct ctl_table *table, int write,
-			void __user *buffer, size_t *lenp, loff_t *ppos)
+			void *buffer, size_t *lenp, loff_t *ppos)
 {
 	return proc_watchdog_common(SOFT_WATCHDOG_ENABLED,
 				    table, write, buffer, lenp, ppos);
@@ -720,7 +720,7 @@ int proc_soft_watchdog(struct ctl_table *table, int write,
  * /proc/sys/kernel/watchdog_thresh
  */
 int proc_watchdog_thresh(struct ctl_table *table, int write,
-			 void __user *buffer, size_t *lenp, loff_t *ppos)
+			 void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int err, old;
 
@@ -743,7 +743,7 @@ int proc_watchdog_thresh(struct ctl_table *table, int write,
  * been brought online, if desired.
  */
 int proc_watchdog_cpumask(struct ctl_table *table, int write,
-			  void __user *buffer, size_t *lenp, loff_t *ppos)
+			  void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int err;
 

mm/compaction.c

@@ -2463,7 +2463,7 @@ int sysctl_compact_memory;
  * /proc/sys/vm/compact_memory
  */
 int sysctl_compaction_handler(struct ctl_table *table, int write,
-			void __user *buffer, size_t *length, loff_t *ppos)
+			void *buffer, size_t *length, loff_t *ppos)
 {
 	if (write)
 		compact_nodes();

mm/hugetlb.c

@@ -3352,7 +3352,7 @@ static unsigned int cpuset_mems_nr(unsigned int *array)
 #ifdef CONFIG_SYSCTL
 static int hugetlb_sysctl_handler_common(bool obey_mempolicy,
 			 struct ctl_table *table, int write,
-			 void __user *buffer, size_t *length, loff_t *ppos)
+			 void *buffer, size_t *length, loff_t *ppos)
 {
 	struct hstate *h = &default_hstate;
 	unsigned long tmp = h->max_huge_pages;
@@ -3375,7 +3375,7 @@ out:
 }
 
 int hugetlb_sysctl_handler(struct ctl_table *table, int write,
-			  void __user *buffer, size_t *length, loff_t *ppos)
+			  void *buffer, size_t *length, loff_t *ppos)
 {
 
 	return hugetlb_sysctl_handler_common(false, table, write,
@@ -3384,7 +3384,7 @@ int hugetlb_sysctl_handler(struct ctl_table *table, int write,
 
 #ifdef CONFIG_NUMA
 int hugetlb_mempolicy_sysctl_handler(struct ctl_table *table, int write,
-			  void __user *buffer, size_t *length, loff_t *ppos)
+			  void *buffer, size_t *length, loff_t *ppos)
 {
 	return hugetlb_sysctl_handler_common(true, table, write,
 							buffer, length, ppos);
@@ -3392,8 +3392,7 @@ int hugetlb_mempolicy_sysctl_handler(struct ctl_table *table, int write,
 #endif /* CONFIG_NUMA */
 
 int hugetlb_overcommit_handler(struct ctl_table *table, int write,
-			void __user *buffer,
-			size_t *length, loff_t *ppos)
+		void *buffer, size_t *length, loff_t *ppos)
 {
 	struct hstate *h = &default_hstate;
 	unsigned long tmp;

mm/page-writeback.c

@@ -512,8 +512,7 @@ bool node_dirty_ok(struct pglist_data *pgdat)
 }
 
 int dirty_background_ratio_handler(struct ctl_table *table, int write,
-		void __user *buffer, size_t *lenp,
-		loff_t *ppos)
+		void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int ret;
 
@@ -524,8 +523,7 @@ int dirty_background_ratio_handler(struct ctl_table *table, int write,
 }
 
 int dirty_background_bytes_handler(struct ctl_table *table, int write,
-		void __user *buffer, size_t *lenp,
-		loff_t *ppos)
+		void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int ret;
 
@@ -535,9 +533,8 @@ int dirty_background_bytes_handler(struct ctl_table *table, int write,
 	return ret;
 }
 
-int dirty_ratio_handler(struct ctl_table *table, int write,
-		void __user *buffer, size_t *lenp,
-		loff_t *ppos)
+int dirty_ratio_handler(struct ctl_table *table, int write, void *buffer,
+		size_t *lenp, loff_t *ppos)
 {
 	int old_ratio = vm_dirty_ratio;
 	int ret;
@@ -551,8 +548,7 @@ int dirty_ratio_handler(struct ctl_table *table, int write,
 }
 
 int dirty_bytes_handler(struct ctl_table *table, int write,
-		void __user *buffer, size_t *lenp,
-		loff_t *ppos)
+		void *buffer, size_t *lenp, loff_t *ppos)
 {
 	unsigned long old_bytes = vm_dirty_bytes;
 	int ret;
@@ -1972,7 +1968,7 @@ bool wb_over_bg_thresh(struct bdi_writeback *wb)
  * sysctl handler for /proc/sys/vm/dirty_writeback_centisecs
  */
 int dirty_writeback_centisecs_handler(struct ctl_table *table, int write,
-	void __user *buffer, size_t *length, loff_t *ppos)
+		void *buffer, size_t *length, loff_t *ppos)
 {
 	unsigned int old_interval = dirty_writeback_interval;
 	int ret;

mm/page_alloc.c

@@ -5546,21 +5546,11 @@ char numa_zonelist_order[] = "Node";
  * sysctl handler for numa_zonelist_order
  */
 int numa_zonelist_order_handler(struct ctl_table *table, int write,
-		void __user *buffer, size_t *length,
-		loff_t *ppos)
+		void *buffer, size_t *length, loff_t *ppos)
 {
-	char *str;
-	int ret;
-
-	if (!write)
-		return proc_dostring(table, write, buffer, length, ppos);
-	str = memdup_user_nul(buffer, 16);
-	if (IS_ERR(str))
-		return PTR_ERR(str);
-
-	ret = __parse_numa_zonelist_order(str);
-	kfree(str);
-	return ret;
+	if (write)
+		return __parse_numa_zonelist_order(buffer);
+	return proc_dostring(table, write, buffer, length, ppos);
 }
 
 
@@ -7963,7 +7953,7 @@ core_initcall(init_per_zone_wmark_min)
  *	changes.
  */
 int min_free_kbytes_sysctl_handler(struct ctl_table *table, int write,
-	void __user *buffer, size_t *length, loff_t *ppos)
+		void *buffer, size_t *length, loff_t *ppos)
 {
 	int rc;
 
@@ -7979,7 +7969,7 @@ int min_free_kbytes_sysctl_handler(struct ctl_table *table, int write,
 }
 
 int watermark_scale_factor_sysctl_handler(struct ctl_table *table, int write,
-	void __user *buffer, size_t *length, loff_t *ppos)
+		void *buffer, size_t *length, loff_t *ppos)
 {
 	int rc;
 
@@ -8009,7 +7999,7 @@ static void setup_min_unmapped_ratio(void)
 
 
 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *table, int write,
-	void __user *buffer, size_t *length, loff_t *ppos)
+		void *buffer, size_t *length, loff_t *ppos)
 {
 	int rc;
 
@@ -8036,7 +8026,7 @@ static void setup_min_slab_ratio(void)
 }
 
 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *table, int write,
-	void __user *buffer, size_t *length, loff_t *ppos)
+		void *buffer, size_t *length, loff_t *ppos)
 {
 	int rc;
 
@@ -8060,7 +8050,7 @@ int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *table, int write,
  * if in function of the boot time zone sizes.
  */
 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *table, int write,
-	void __user *buffer, size_t *length, loff_t *ppos)
+		void *buffer, size_t *length, loff_t *ppos)
 {
 	proc_dointvec_minmax(table, write, buffer, length, ppos);
 	setup_per_zone_lowmem_reserve();
@@ -8082,7 +8072,7 @@ static void __zone_pcp_update(struct zone *zone)
  * pagelist can have before it gets flushed back to buddy allocator.
  */
 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *table, int write,
-	void __user *buffer, size_t *length, loff_t *ppos)
+		void *buffer, size_t *length, loff_t *ppos)
 {
 	struct zone *zone;
 	int old_percpu_pagelist_fraction;

mm/util.c

@@ -717,9 +717,8 @@ int sysctl_max_map_count __read_mostly = DEFAULT_MAX_MAP_COUNT;
 unsigned long sysctl_user_reserve_kbytes __read_mostly = 1UL << 17; /* 128MB */
 unsigned long sysctl_admin_reserve_kbytes __read_mostly = 1UL << 13; /* 8MB */
 
-int overcommit_ratio_handler(struct ctl_table *table, int write,
-			     void __user *buffer, size_t *lenp,
-			     loff_t *ppos)
+int overcommit_ratio_handler(struct ctl_table *table, int write, void *buffer,
+		size_t *lenp, loff_t *ppos)
 {
 	int ret;
 
@@ -729,9 +728,8 @@ int overcommit_ratio_handler(struct ctl_table *table, int write,
 	return ret;
 }
 
-int overcommit_kbytes_handler(struct ctl_table *table, int write,
-			     void __user *buffer, size_t *lenp,
-			     loff_t *ppos)
+int overcommit_kbytes_handler(struct ctl_table *table, int write, void *buffer,
+		size_t *lenp, loff_t *ppos)
 {
 	int ret;
 

mm/vmstat.c

@@ -76,7 +76,7 @@ static void invalid_numa_statistics(void)
 static DEFINE_MUTEX(vm_numa_stat_lock);
 
 int sysctl_vm_numa_stat_handler(struct ctl_table *table, int write,
-		void __user *buffer, size_t *length, loff_t *ppos)
+		void *buffer, size_t *length, loff_t *ppos)
 {
 	int ret, oldval;
 
@@ -1751,7 +1751,7 @@ static void refresh_vm_stats(struct work_struct *work)
 }
 
 int vmstat_refresh(struct ctl_table *table, int write,
-		   void __user *buffer, size_t *lenp, loff_t *ppos)
+		   void *buffer, size_t *lenp, loff_t *ppos)
 {
 	long val;
 	int err;

net/bridge/br_netfilter_hooks.c

@@ -1027,7 +1027,7 @@ int br_nf_hook_thresh(unsigned int hook, struct net *net,
 #ifdef CONFIG_SYSCTL
 static
 int brnf_sysctl_call_tables(struct ctl_table *ctl, int write,
-			    void __user *buffer, size_t *lenp, loff_t *ppos)
+			    void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int ret;
 

net/core/neighbour.c

@@ -3379,7 +3379,7 @@ EXPORT_SYMBOL(neigh_app_ns);
 static int unres_qlen_max = INT_MAX / SKB_TRUESIZE(ETH_FRAME_LEN);
 
 static int proc_unres_qlen(struct ctl_table *ctl, int write,
-			   void __user *buffer, size_t *lenp, loff_t *ppos)
+			   void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int size, ret;
 	struct ctl_table tmp = *ctl;
@@ -3443,8 +3443,8 @@ static void neigh_proc_update(struct ctl_table *ctl, int write)
 }
 
 static int neigh_proc_dointvec_zero_intmax(struct ctl_table *ctl, int write,
-					   void __user *buffer,
-					   size_t *lenp, loff_t *ppos)
+					   void *buffer, size_t *lenp,
+					   loff_t *ppos)
 {
 	struct ctl_table tmp = *ctl;
 	int ret;
@@ -3457,8 +3457,8 @@ static int neigh_proc_dointvec_zero_intmax(struct ctl_table *ctl, int write,
 	return ret;
 }
 
-int neigh_proc_dointvec(struct ctl_table *ctl, int write,
-			void __user *buffer, size_t *lenp, loff_t *ppos)
+int neigh_proc_dointvec(struct ctl_table *ctl, int write, void *buffer,
+			size_t *lenp, loff_t *ppos)
 {
 	int ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
 
@@ -3467,8 +3467,7 @@ int neigh_proc_dointvec(struct ctl_table *ctl, int write,
 }
 EXPORT_SYMBOL(neigh_proc_dointvec);
 
-int neigh_proc_dointvec_jiffies(struct ctl_table *ctl, int write,
-				void __user *buffer,
+int neigh_proc_dointvec_jiffies(struct ctl_table *ctl, int write, void *buffer,
 				size_t *lenp, loff_t *ppos)
 {
 	int ret = proc_dointvec_jiffies(ctl, write, buffer, lenp, ppos);
@@ -3479,8 +3478,8 @@ int neigh_proc_dointvec_jiffies(struct ctl_table *ctl, int write,
 EXPORT_SYMBOL(neigh_proc_dointvec_jiffies);
 
 static int neigh_proc_dointvec_userhz_jiffies(struct ctl_table *ctl, int write,
-					      void __user *buffer,
-					      size_t *lenp, loff_t *ppos)
+					      void *buffer, size_t *lenp,
+					      loff_t *ppos)
 {
 	int ret = proc_dointvec_userhz_jiffies(ctl, write, buffer, lenp, ppos);
 
@@ -3489,8 +3488,7 @@ static int neigh_proc_dointvec_userhz_jiffies(struct ctl_table *ctl, int write,
 }
 
 int neigh_proc_dointvec_ms_jiffies(struct ctl_table *ctl, int write,
-				   void __user *buffer,
-				   size_t *lenp, loff_t *ppos)
+				   void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int ret = proc_dointvec_ms_jiffies(ctl, write, buffer, lenp, ppos);
 
@@ -3500,8 +3498,8 @@ int neigh_proc_dointvec_ms_jiffies(struct ctl_table *ctl, int write,
 EXPORT_SYMBOL(neigh_proc_dointvec_ms_jiffies);
 
 static int neigh_proc_dointvec_unres_qlen(struct ctl_table *ctl, int write,
-					  void __user *buffer,
-					  size_t *lenp, loff_t *ppos)
+					  void *buffer, size_t *lenp,
+					  loff_t *ppos)
 {
 	int ret = proc_unres_qlen(ctl, write, buffer, lenp, ppos);
 
@@ -3510,8 +3508,8 @@ static int neigh_proc_dointvec_unres_qlen(struct ctl_table *ctl, int write,
 }
 
 static int neigh_proc_base_reachable_time(struct ctl_table *ctl, int write,
-					  void __user *buffer,
-					  size_t *lenp, loff_t *ppos)
+					  void *buffer, size_t *lenp,
+					  loff_t *ppos)
 {
 	struct neigh_parms *p = ctl->extra2;
 	int ret;

net/core/sysctl_net_core.c

@@ -45,7 +45,7 @@ EXPORT_SYMBOL(sysctl_devconf_inherit_init_net);
 
 #ifdef CONFIG_RPS
 static int rps_sock_flow_sysctl(struct ctl_table *table, int write,
-				void __user *buffer, size_t *lenp, loff_t *ppos)
+				void *buffer, size_t *lenp, loff_t *ppos)
 {
 	unsigned int orig_size, size;
 	int ret, i;
@@ -115,8 +115,7 @@ static int rps_sock_flow_sysctl(struct ctl_table *table, int write,
 static DEFINE_MUTEX(flow_limit_update_mutex);
 
 static int flow_limit_cpu_sysctl(struct ctl_table *table, int write,
-				 void __user *buffer, size_t *lenp,
-				 loff_t *ppos)
+				 void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct sd_flow_limit *cur;
 	struct softnet_data *sd;
@@ -180,10 +179,7 @@ write_unlock:
 		}
 		if (len < *lenp)
 			kbuf[len++] = '\n';
-		if (copy_to_user(buffer, kbuf, len)) {
-			ret = -EFAULT;
-			goto done;
-		}
+		memcpy(buffer, kbuf, len);
 		*lenp = len;
 		*ppos += len;
 	}
@@ -194,8 +190,7 @@ done:
 }
 
 static int flow_limit_table_len_sysctl(struct ctl_table *table, int write,
-				       void __user *buffer, size_t *lenp,
-				       loff_t *ppos)
+				       void *buffer, size_t *lenp, loff_t *ppos)
 {
 	unsigned int old, *ptr;
 	int ret;
@@ -217,7 +212,7 @@ static int flow_limit_table_len_sysctl(struct ctl_table *table, int write,
 
 #ifdef CONFIG_NET_SCHED
 static int set_default_qdisc(struct ctl_table *table, int write,
-			     void __user *buffer, size_t *lenp, loff_t *ppos)
+			     void *buffer, size_t *lenp, loff_t *ppos)
 {
 	char id[IFNAMSIZ];
 	struct ctl_table tbl = {
@@ -236,7 +231,7 @@ static int set_default_qdisc(struct ctl_table *table, int write,
 #endif
 
 static int proc_do_dev_weight(struct ctl_table *table, int write,
-			   void __user *buffer, size_t *lenp, loff_t *ppos)
+			   void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int ret;
 
@@ -251,7 +246,7 @@ static int proc_do_dev_weight(struct ctl_table *table, int write,
 }
 
 static int proc_do_rss_key(struct ctl_table *table, int write,
-			   void __user *buffer, size_t *lenp, loff_t *ppos)
+			   void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct ctl_table fake_table;
 	char buf[NETDEV_RSS_KEY_LEN * 3];
@@ -264,7 +259,7 @@ static int proc_do_rss_key(struct ctl_table *table, int write,
 
 #ifdef CONFIG_BPF_JIT
 static int proc_dointvec_minmax_bpf_enable(struct ctl_table *table, int write,
-					   void __user *buffer, size_t *lenp,
+					   void *buffer, size_t *lenp,
 					   loff_t *ppos)
 {
 	int ret, jit_enable = *(int *)table->data;
@@ -291,8 +286,7 @@ static int proc_dointvec_minmax_bpf_enable(struct ctl_table *table, int write,
 # ifdef CONFIG_HAVE_EBPF_JIT
 static int
 proc_dointvec_minmax_bpf_restricted(struct ctl_table *table, int write,
-				    void __user *buffer, size_t *lenp,
-				    loff_t *ppos)
+				    void *buffer, size_t *lenp, loff_t *ppos)
 {
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
@@ -303,8 +297,7 @@ proc_dointvec_minmax_bpf_restricted(struct ctl_table *table, int write,
 
 static int
 proc_dolongvec_minmax_bpf_restricted(struct ctl_table *table, int write,
-				     void __user *buffer, size_t *lenp,
-				     loff_t *ppos)
+				     void *buffer, size_t *lenp, loff_t *ppos)
 {
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;

net/decnet/dn_dev.c

@@ -160,8 +160,8 @@ static int max_t3[] = { 8191 }; /* Must fit in 16 bits when multiplied by BCT3MU
 static int min_priority[1];
 static int max_priority[] = { 127 }; /* From DECnet spec */
 
-static int dn_forwarding_proc(struct ctl_table *, int,
-			void __user *, size_t *, loff_t *);
+static int dn_forwarding_proc(struct ctl_table *, int, void *, size_t *,
+		loff_t *);
 static struct dn_dev_sysctl_table {
 	struct ctl_table_header *sysctl_header;
 	struct ctl_table dn_dev_vars[5];
@@ -245,8 +245,7 @@ static void dn_dev_sysctl_unregister(struct dn_dev_parms *parms)
 }
 
 static int dn_forwarding_proc(struct ctl_table *table, int write,
-				void __user *buffer,
-				size_t *lenp, loff_t *ppos)
+		void *buffer, size_t *lenp, loff_t *ppos)
 {
 #ifdef CONFIG_DECNET_ROUTER
 	struct net_device *dev = table->extra1;

net/decnet/sysctl_net_decnet.c

@@ -134,8 +134,7 @@ static int parse_addr(__le16 *addr, char *str)
 }
 
 static int dn_node_address_handler(struct ctl_table *table, int write,
-				void __user *buffer,
-				size_t *lenp, loff_t *ppos)
+		void *buffer, size_t *lenp, loff_t *ppos)
 {
 	char addr[DN_ASCBUF_LEN];
 	size_t len;
@@ -148,10 +147,7 @@ static int dn_node_address_handler(struct ctl_table *table, int write,
 
 	if (write) {
 		len = (*lenp < DN_ASCBUF_LEN) ? *lenp : (DN_ASCBUF_LEN-1);
-
-		if (copy_from_user(addr, buffer, len))
-			return -EFAULT;
-
+		memcpy(addr, buffer, len);
 		addr[len] = 0;
 		strip_it(addr);
 
@@ -173,11 +169,9 @@ static int dn_node_address_handler(struct ctl_table *table, int write,
 	len = strlen(addr);
 	addr[len++] = '\n';
 
-	if (len > *lenp) len = *lenp;
-
-	if (copy_to_user(buffer, addr, len))
-		return -EFAULT;
-
+	if (len > *lenp)
+		len = *lenp;
+	memcpy(buffer, addr, len);
 	*lenp = len;
 	*ppos += len;
 
@@ -185,8 +179,7 @@ static int dn_node_address_handler(struct ctl_table *table, int write,
 }
 
 static int dn_def_dev_handler(struct ctl_table *table, int write,
-				void __user *buffer,
-				size_t *lenp, loff_t *ppos)
+		void *buffer, size_t *lenp, loff_t *ppos)
 {
 	size_t len;
 	struct net_device *dev;
@@ -201,9 +194,7 @@ static int dn_def_dev_handler(struct ctl_table *table, int write,
 		if (*lenp > 16)
 			return -E2BIG;
 
-		if (copy_from_user(devname, buffer, *lenp))
-			return -EFAULT;
-
+		memcpy(devname, buffer, *lenp);
 		devname[*lenp] = 0;
 		strip_it(devname);
 
@@ -238,9 +229,7 @@ static int dn_def_dev_handler(struct ctl_table *table, int write,
 
 	if (len > *lenp) len = *lenp;
 
-	if (copy_to_user(buffer, devname, len))
-		return -EFAULT;
-
+	memcpy(buffer, devname, len);
 	*lenp = len;
 	*ppos += len;
 

net/ipv4/devinet.c

@@ -2361,8 +2361,7 @@ static int devinet_conf_ifindex(struct net *net, struct ipv4_devconf *cnf)
 }
 
 static int devinet_conf_proc(struct ctl_table *ctl, int write,
-			     void __user *buffer,
-			     size_t *lenp, loff_t *ppos)
+			     void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int old_value = *(int *)ctl->data;
 	int ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
@@ -2414,8 +2413,7 @@ static int devinet_conf_proc(struct ctl_table *ctl, int write,
 }
 
 static int devinet_sysctl_forward(struct ctl_table *ctl, int write,
-				  void __user *buffer,
-				  size_t *lenp, loff_t *ppos)
+				  void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int *valp = ctl->data;
 	int val = *valp;
@@ -2458,8 +2456,7 @@ static int devinet_sysctl_forward(struct ctl_table *ctl, int write,
 }
 
 static int ipv4_doint_and_flush(struct ctl_table *ctl, int write,
-				void __user *buffer,
-				size_t *lenp, loff_t *ppos)
+				void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int *valp = ctl->data;
 	int val = *valp;

net/ipv4/route.c

@@ -3336,8 +3336,7 @@ static int ip_rt_gc_elasticity __read_mostly	= 8;
 static int ip_min_valid_pmtu __read_mostly	= IPV4_MIN_MTU;
 
 static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write,
-					void __user *buffer,
-					size_t *lenp, loff_t *ppos)
+		void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct net *net = (struct net *)__ctl->extra1;
 

net/ipv4/sysctl_net_ipv4.c

@@ -71,8 +71,7 @@ static void set_local_port_range(struct net *net, int range[2])
 
 /* Validate changes from /proc interface. */
 static int ipv4_local_port_range(struct ctl_table *table, int write,
-				 void __user *buffer,
-				 size_t *lenp, loff_t *ppos)
+				 void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct net *net =
 		container_of(table->data, struct net, ipv4.ip_local_ports.range);
@@ -107,7 +106,7 @@ static int ipv4_local_port_range(struct ctl_table *table, int write,
 
 /* Validate changes from /proc interface. */
 static int ipv4_privileged_ports(struct ctl_table *table, int write,
-				void __user *buffer, size_t *lenp, loff_t *ppos)
+				void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct net *net = container_of(table->data, struct net,
 	    ipv4.sysctl_ip_prot_sock);
@@ -168,8 +167,7 @@ static void set_ping_group_range(struct ctl_table *table, kgid_t low, kgid_t hig
 
 /* Validate changes from /proc interface. */
 static int ipv4_ping_group_range(struct ctl_table *table, int write,
-				 void __user *buffer,
-				 size_t *lenp, loff_t *ppos)
+				 void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct user_namespace *user_ns = current_user_ns();
 	int ret;
@@ -204,8 +202,7 @@ static int ipv4_ping_group_range(struct ctl_table *table, int write,
 }
 
 static int ipv4_fwd_update_priority(struct ctl_table *table, int write,
-				    void __user *buffer,
-				    size_t *lenp, loff_t *ppos)
+				    void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct net *net;
 	int ret;
@@ -221,7 +218,7 @@ static int ipv4_fwd_update_priority(struct ctl_table *table, int write,
 }
 
 static int proc_tcp_congestion_control(struct ctl_table *ctl, int write,
-				       void __user *buffer, size_t *lenp, loff_t *ppos)
+				       void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct net *net = container_of(ctl->data, struct net,
 				       ipv4.tcp_congestion_control);
@@ -241,9 +238,8 @@ static int proc_tcp_congestion_control(struct ctl_table *ctl, int write,
 }
 
 static int proc_tcp_available_congestion_control(struct ctl_table *ctl,
-						 int write,
-						 void __user *buffer, size_t *lenp,
-						 loff_t *ppos)
+						 int write, void *buffer,
+						 size_t *lenp, loff_t *ppos)
 {
 	struct ctl_table tbl = { .maxlen = TCP_CA_BUF_MAX, };
 	int ret;
@@ -258,9 +254,8 @@ static int proc_tcp_available_congestion_control(struct ctl_table *ctl,
 }
 
 static int proc_allowed_congestion_control(struct ctl_table *ctl,
-					   int write,
-					   void __user *buffer, size_t *lenp,
-					   loff_t *ppos)
+					   int write, void *buffer,
+					   size_t *lenp, loff_t *ppos)
 {
 	struct ctl_table tbl = { .maxlen = TCP_CA_BUF_MAX };
 	int ret;
@@ -296,8 +291,7 @@ static int sscanf_key(char *buf, __le32 *key)
 }
 
 static int proc_tcp_fastopen_key(struct ctl_table *table, int write,
-				 void __user *buffer, size_t *lenp,
-				 loff_t *ppos)
+				 void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct net *net = container_of(table->data, struct net,
 	    ipv4.sysctl_tcp_fastopen);
@@ -399,7 +393,7 @@ static void proc_configure_early_demux(int enabled, int protocol)
 }
 
 static int proc_tcp_early_demux(struct ctl_table *table, int write,
-				void __user *buffer, size_t *lenp, loff_t *ppos)
+				void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int ret = 0;
 
@@ -415,7 +409,7 @@ static int proc_tcp_early_demux(struct ctl_table *table, int write,
 }
 
 static int proc_udp_early_demux(struct ctl_table *table, int write,
-				void __user *buffer, size_t *lenp, loff_t *ppos)
+				void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int ret = 0;
 
@@ -431,8 +425,7 @@ static int proc_udp_early_demux(struct ctl_table *table, int write,
 }
 
 static int proc_tfo_blackhole_detect_timeout(struct ctl_table *table,
-					     int write,
-					     void __user *buffer,
+					     int write, void *buffer,
 					     size_t *lenp, loff_t *ppos)
 {
 	struct net *net = container_of(table->data, struct net,
@@ -447,8 +440,7 @@ static int proc_tfo_blackhole_detect_timeout(struct ctl_table *table,
 }
 
 static int proc_tcp_available_ulp(struct ctl_table *ctl,
-				  int write,
-				  void __user *buffer, size_t *lenp,
+				  int write, void *buffer, size_t *lenp,
 				  loff_t *ppos)
 {
 	struct ctl_table tbl = { .maxlen = TCP_ULP_BUF_MAX, };
@@ -466,7 +458,7 @@ static int proc_tcp_available_ulp(struct ctl_table *ctl,
 
 #ifdef CONFIG_IP_ROUTE_MULTIPATH
 static int proc_fib_multipath_hash_policy(struct ctl_table *table, int write,
-					  void __user *buffer, size_t *lenp,
+					  void *buffer, size_t *lenp,
 					  loff_t *ppos)
 {
 	struct net *net = container_of(table->data, struct net,

net/ipv6/addrconf.c

@@ -6108,9 +6108,8 @@ static void ipv6_ifa_notify(int event, struct inet6_ifaddr *ifp)
 
 #ifdef CONFIG_SYSCTL
 
-static
-int addrconf_sysctl_forward(struct ctl_table *ctl, int write,
-			   void __user *buffer, size_t *lenp, loff_t *ppos)
+static int addrconf_sysctl_forward(struct ctl_table *ctl, int write,
+		void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int *valp = ctl->data;
 	int val = *valp;
@@ -6134,9 +6133,8 @@ int addrconf_sysctl_forward(struct ctl_table *ctl, int write,
 	return ret;
 }
 
-static
-int addrconf_sysctl_mtu(struct ctl_table *ctl, int write,
-			void __user *buffer, size_t *lenp, loff_t *ppos)
+static int addrconf_sysctl_mtu(struct ctl_table *ctl, int write,
+		void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct inet6_dev *idev = ctl->extra1;
 	int min_mtu = IPV6_MIN_MTU;
@@ -6206,9 +6204,8 @@ static int addrconf_disable_ipv6(struct ctl_table *table, int *p, int newf)
 	return 0;
 }
 
-static
-int addrconf_sysctl_disable(struct ctl_table *ctl, int write,
-			    void __user *buffer, size_t *lenp, loff_t *ppos)
+static int addrconf_sysctl_disable(struct ctl_table *ctl, int write,
+		void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int *valp = ctl->data;
 	int val = *valp;
@@ -6232,9 +6229,8 @@ int addrconf_sysctl_disable(struct ctl_table *ctl, int write,
 	return ret;
 }
 
-static
-int addrconf_sysctl_proxy_ndp(struct ctl_table *ctl, int write,
-			      void __user *buffer, size_t *lenp, loff_t *ppos)
+static int addrconf_sysctl_proxy_ndp(struct ctl_table *ctl, int write,
+		void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int *valp = ctl->data;
 	int ret;
@@ -6275,7 +6271,7 @@ int addrconf_sysctl_proxy_ndp(struct ctl_table *ctl, int write,
 }
 
 static int addrconf_sysctl_addr_gen_mode(struct ctl_table *ctl, int write,
-					 void __user *buffer, size_t *lenp,
+					 void *buffer, size_t *lenp,
 					 loff_t *ppos)
 {
 	int ret = 0;
@@ -6337,7 +6333,7 @@ out:
 }
 
 static int addrconf_sysctl_stable_secret(struct ctl_table *ctl, int write,
-					 void __user *buffer, size_t *lenp,
+					 void *buffer, size_t *lenp,
 					 loff_t *ppos)
 {
 	int err;
@@ -6404,8 +6400,7 @@ out:
 
 static
 int addrconf_sysctl_ignore_routes_with_linkdown(struct ctl_table *ctl,
-						int write,
-						void __user *buffer,
+						int write, void *buffer,
 						size_t *lenp,
 						loff_t *ppos)
 {
@@ -6505,10 +6500,8 @@ int addrconf_disable_policy(struct ctl_table *ctl, int *valp, int val)
 	return 0;
 }
 
-static
-int addrconf_sysctl_disable_policy(struct ctl_table *ctl, int write,
-				   void __user *buffer, size_t *lenp,
-				   loff_t *ppos)
+static int addrconf_sysctl_disable_policy(struct ctl_table *ctl, int write,
+				   void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int *valp = ctl->data;
 	int val = *valp;

net/ipv6/ndisc.c

@@ -1835,7 +1835,8 @@ static void ndisc_warn_deprecated_sysctl(struct ctl_table *ctl,
 	}
 }
 
-int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, void __user *buffer, size_t *lenp, loff_t *ppos)
+int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, void *buffer,
+		size_t *lenp, loff_t *ppos)
 {
 	struct net_device *dev = ctl->extra1;
 	struct inet6_dev *idev;

net/ipv6/route.c

@@ -6088,9 +6088,8 @@ static int rt6_stats_seq_show(struct seq_file *seq, void *v)
 
 #ifdef CONFIG_SYSCTL
 
-static
-int ipv6_sysctl_rtcache_flush(struct ctl_table *ctl, int write,
-			      void __user *buffer, size_t *lenp, loff_t *ppos)
+static int ipv6_sysctl_rtcache_flush(struct ctl_table *ctl, int write,
+			      void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct net *net;
 	int delay;

net/ipv6/sysctl_net_ipv6.c

@@ -26,8 +26,7 @@ static int auto_flowlabels_min;
 static int auto_flowlabels_max = IP6_AUTO_FLOW_LABEL_MAX;
 
 static int proc_rt6_multipath_hash_policy(struct ctl_table *table, int write,
-					  void __user *buffer, size_t *lenp,
-					  loff_t *ppos)
+					  void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct net *net;
 	int ret;

net/mpls/af_mpls.c

@@ -1362,8 +1362,7 @@ done:
 	(&((struct mpls_dev *)0)->field)
 
 static int mpls_conf_proc(struct ctl_table *ctl, int write,
-			  void __user *buffer,
-			  size_t *lenp, loff_t *ppos)
+			  void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int oval = *(int *)ctl->data;
 	int ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
@@ -2594,7 +2593,7 @@ nolabels:
 }
 
 static int mpls_platform_labels(struct ctl_table *table, int write,
-				void __user *buffer, size_t *lenp, loff_t *ppos)
+				void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct net *net = table->data;
 	int platform_labels = net->mpls.platform_labels;

net/netfilter/ipvs/ip_vs_ctl.c

@@ -1736,7 +1736,7 @@ static int three = 3;
 
 static int
 proc_do_defense_mode(struct ctl_table *table, int write,
-		     void __user *buffer, size_t *lenp, loff_t *ppos)
+		     void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct netns_ipvs *ipvs = table->extra2;
 	int *valp = table->data;
@@ -1763,7 +1763,7 @@ proc_do_defense_mode(struct ctl_table *table, int write,
 
 static int
 proc_do_sync_threshold(struct ctl_table *table, int write,
-		       void __user *buffer, size_t *lenp, loff_t *ppos)
+		       void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int *valp = table->data;
 	int val[2];
@@ -1788,7 +1788,7 @@ proc_do_sync_threshold(struct ctl_table *table, int write,
 
 static int
 proc_do_sync_ports(struct ctl_table *table, int write,
-		   void __user *buffer, size_t *lenp, loff_t *ppos)
+		   void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int *valp = table->data;
 	int val = *valp;

net/netfilter/nf_conntrack_standalone.c

@@ -517,7 +517,7 @@ static unsigned int nf_conntrack_htable_size_user __read_mostly;
 
 static int
 nf_conntrack_hash_sysctl(struct ctl_table *table, int write,
-			 void __user *buffer, size_t *lenp, loff_t *ppos)
+			 void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int ret;
 

net/netfilter/nf_log.c

@@ -414,7 +414,7 @@ static struct ctl_table nf_log_sysctl_ftable[] = {
 };
 
 static int nf_log_proc_dostring(struct ctl_table *table, int write,
-			 void __user *buffer, size_t *lenp, loff_t *ppos)
+			 void *buffer, size_t *lenp, loff_t *ppos)
 {
 	const struct nf_logger *logger;
 	char buf[NFLOGGER_NAME_LEN];

net/phonet/sysctl.c

@@ -49,8 +49,7 @@ void phonet_get_local_port_range(int *min, int *max)
 }
 
 static int proc_local_port_range(struct ctl_table *table, int write,
-				void __user *buffer,
-				size_t *lenp, loff_t *ppos)
+				 void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int ret;
 	int range[2] = {local_port_range[0], local_port_range[1]};

net/rds/tcp.c

@@ -62,8 +62,7 @@ static atomic_t rds_tcp_unloading = ATOMIC_INIT(0);
 static struct kmem_cache *rds_tcp_conn_slab;
 
 static int rds_tcp_skbuf_handler(struct ctl_table *ctl, int write,
-				 void __user *buffer, size_t *lenp,
-				 loff_t *fpos);
+				 void *buffer, size_t *lenp, loff_t *fpos);
 
 static int rds_tcp_min_sndbuf = SOCK_MIN_SNDBUF;
 static int rds_tcp_min_rcvbuf = SOCK_MIN_RCVBUF;
@@ -676,8 +675,7 @@ static void rds_tcp_sysctl_reset(struct net *net)
 }
 
 static int rds_tcp_skbuf_handler(struct ctl_table *ctl, int write,
-				 void __user *buffer, size_t *lenp,
-				 loff_t *fpos)
+				 void *buffer, size_t *lenp, loff_t *fpos)
 {
 	struct net *net = current->nsproxy->net_ns;
 	int err;

net/sctp/sysctl.c

@@ -43,20 +43,15 @@ static unsigned long max_autoclose_max =
 	? UINT_MAX : MAX_SCHEDULE_TIMEOUT / HZ;
 
 static int proc_sctp_do_hmac_alg(struct ctl_table *ctl, int write,
-				void __user *buffer, size_t *lenp,
-				loff_t *ppos);
+				 void *buffer, size_t *lenp, loff_t *ppos);
 static int proc_sctp_do_rto_min(struct ctl_table *ctl, int write,
-				void __user *buffer, size_t *lenp,
-				loff_t *ppos);
-static int proc_sctp_do_rto_max(struct ctl_table *ctl, int write,
-				void __user *buffer, size_t *lenp,
-				loff_t *ppos);
+				void *buffer, size_t *lenp, loff_t *ppos);
+static int proc_sctp_do_rto_max(struct ctl_table *ctl, int write, void *buffer,
+				size_t *lenp, loff_t *ppos);
 static int proc_sctp_do_alpha_beta(struct ctl_table *ctl, int write,
-				   void __user *buffer, size_t *lenp,
-				   loff_t *ppos);
+				   void *buffer, size_t *lenp, loff_t *ppos);
 static int proc_sctp_do_auth(struct ctl_table *ctl, int write,
-			     void __user *buffer, size_t *lenp,
-			     loff_t *ppos);
+			     void *buffer, size_t *lenp, loff_t *ppos);
 
 static struct ctl_table sctp_table[] = {
 	{
@@ -343,8 +338,7 @@ static struct ctl_table sctp_net_table[] = {
 };
 
 static int proc_sctp_do_hmac_alg(struct ctl_table *ctl, int write,
-				void __user *buffer, size_t *lenp,
-				loff_t *ppos)
+				 void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct net *net = current->nsproxy->net_ns;
 	struct ctl_table tbl;
@@ -389,8 +383,7 @@ static int proc_sctp_do_hmac_alg(struct ctl_table *ctl, int write,
 }
 
 static int proc_sctp_do_rto_min(struct ctl_table *ctl, int write,
-				void __user *buffer, size_t *lenp,
-				loff_t *ppos)
+				void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct net *net = current->nsproxy->net_ns;
 	unsigned int min = *(unsigned int *) ctl->extra1;
@@ -418,8 +411,7 @@ static int proc_sctp_do_rto_min(struct ctl_table *ctl, int write,
 }
 
 static int proc_sctp_do_rto_max(struct ctl_table *ctl, int write,
-				void __user *buffer, size_t *lenp,
-				loff_t *ppos)
+				void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct net *net = current->nsproxy->net_ns;
 	unsigned int min = *(unsigned int *) ctl->extra1;
@@ -447,8 +439,7 @@ static int proc_sctp_do_rto_max(struct ctl_table *ctl, int write,
 }
 
 static int proc_sctp_do_alpha_beta(struct ctl_table *ctl, int write,
-				   void __user *buffer, size_t *lenp,
-				   loff_t *ppos)
+				   void *buffer, size_t *lenp, loff_t *ppos)
 {
 	if (write)
 		pr_warn_once("Changing rto_alpha or rto_beta may lead to "
@@ -458,8 +449,7 @@ static int proc_sctp_do_alpha_beta(struct ctl_table *ctl, int write,
 }
 
 static int proc_sctp_do_auth(struct ctl_table *ctl, int write,
-			     void __user *buffer, size_t *lenp,
-			     loff_t *ppos)
+			     void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct net *net = current->nsproxy->net_ns;
 	struct ctl_table tbl;

net/sunrpc/sysctl.c

@@ -60,7 +60,7 @@ rpc_unregister_sysctl(void)
 }
 
 static int proc_do_xprt(struct ctl_table *table, int write,
-			void __user *buffer, size_t *lenp, loff_t *ppos)
+			void *buffer, size_t *lenp, loff_t *ppos)
 {
 	char tmpbuf[256];
 	size_t len;
@@ -70,15 +70,15 @@ static int proc_do_xprt(struct ctl_table *table, int write,
 		return 0;
 	}
 	len = svc_print_xprts(tmpbuf, sizeof(tmpbuf));
-	return simple_read_from_buffer(buffer, *lenp, ppos, tmpbuf, len);
+	return memory_read_from_buffer(buffer, *lenp, ppos, tmpbuf, len);
 }
 
 static int
-proc_dodebug(struct ctl_table *table, int write,
-				void __user *buffer, size_t *lenp, loff_t *ppos)
+proc_dodebug(struct ctl_table *table, int write, void *buffer, size_t *lenp,
+	     loff_t *ppos)
 {
-	char		tmpbuf[20], c, *s = NULL;
-	char __user *p;
+	char		tmpbuf[20], *s = NULL;
+	char *p;
 	unsigned int	value;
 	size_t		left, len;
 
@@ -90,18 +90,17 @@ proc_dodebug(struct ctl_table *table, int write,
 	left = *lenp;
 
 	if (write) {
-		if (!access_ok(buffer, left))
-			return -EFAULT;
 		p = buffer;
-		while (left && __get_user(c, p) >= 0 && isspace(c))
-			left--, p++;
+		while (left && isspace(*p)) {
+			left--;
+			p++;
+		}
 		if (!left)
 			goto done;
 
 		if (left > sizeof(tmpbuf) - 1)
 			return -EINVAL;
-		if (copy_from_user(tmpbuf, p, left))
-			return -EFAULT;
+		memcpy(tmpbuf, p, left);
 		tmpbuf[left] = '\0';
 
 		value = simple_strtol(tmpbuf, &s, 0);
@@ -121,11 +120,9 @@ proc_dodebug(struct ctl_table *table, int write,
 		len = sprintf(tmpbuf, "0x%04x", *(unsigned int *) table->data);
 		if (len > left)
 			len = left;
-		if (copy_to_user(buffer, tmpbuf, len))
-			return -EFAULT;
+		memcpy(buffer, tmpbuf, len);
 		if ((left -= len) > 0) {
-			if (put_user('\n', (char __user *)buffer + len))
-				return -EFAULT;
+			*((char *)buffer + len) = '\n';
 			left--;
 		}
 	}

net/sunrpc/xprtrdma/svc_rdma.c

@@ -80,8 +80,7 @@ atomic_t rdma_stat_sq_prod;
  * current value.
  */
 static int read_reset_stat(struct ctl_table *table, int write,
-			   void __user *buffer, size_t *lenp,
-			   loff_t *ppos)
+			   void *buffer, size_t *lenp, loff_t *ppos)
 {
 	atomic_t *stat = (atomic_t *)table->data;
 
@@ -103,8 +102,8 @@ static int read_reset_stat(struct ctl_table *table, int write,
 		len -= *ppos;
 		if (len > *lenp)
 			len = *lenp;
-		if (len && copy_to_user(buffer, str_buf, len))
-			return -EFAULT;
+		if (len)
+			memcpy(buffer, str_buf, len);
 		*lenp = len;
 		*ppos += len;
 	}

security/apparmor/lsm.c

@@ -1696,7 +1696,7 @@ static int __init alloc_buffers(void)
 
 #ifdef CONFIG_SYSCTL
 static int apparmor_dointvec(struct ctl_table *table, int write,
-			     void __user *buffer, size_t *lenp, loff_t *ppos)
+			     void *buffer, size_t *lenp, loff_t *ppos)
 {
 	if (!policy_admin_capable(NULL))
 		return -EPERM;

security/min_addr.c

@@ -30,7 +30,7 @@ static void update_mmap_min_addr(void)
  * calls update_mmap_min_addr() so non MAP_FIXED hints get rounded properly
  */
 int mmap_min_addr_handler(struct ctl_table *table, int write,
-			  void __user *buffer, size_t *lenp, loff_t *ppos)
+			  void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int ret;
 

security/yama/yama_lsm.c

@@ -430,7 +430,7 @@ static struct security_hook_list yama_hooks[] __lsm_ro_after_init = {
 
 #ifdef CONFIG_SYSCTL
 static int yama_dointvec_minmax(struct ctl_table *table, int write,
-				void __user *buffer, size_t *lenp, loff_t *ppos)
+				void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct ctl_table table_copy;