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>
author: Christoph Hellwig <hch@lst.de> 2020-04-24 08:43:38 +0200
committer: Al Viro <viro@zeniv.linux.org.uk> 2020-04-27 02:07:40 -0400
commit: 32927393dc1ccd60fb2bdc05b9e8e88753761469 (patch)
tree: c488a5564cdde7594c953219a98e22fb4865c812
parent: f461d2dcd511c020a26d4d791fae595c65ed09b6 (diff)
88 files changed, 458 insertions, 653 deletions
diff --git a/arch/arm64/kernel/armv8_deprecated.c b/arch/arm64/kernel/armv8_deprecated.c
index c19aa81ddc8c..7364de008bab 100644
--- a/arch/arm64/kernel/armv8_deprecated.c
+++ b/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;
diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c
index 94289d126993..35cb5e66c504 100644
--- a/arch/arm64/kernel/fpsimd.c
+++ b/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;
diff --git a/arch/mips/lasat/sysctl.c b/arch/mips/lasat/sysctl.c
index e666fe26c50d..2119541a5b8b 100644
--- a/arch/mips/lasat/sysctl.c
+++ b/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;
diff --git a/arch/s390/appldata/appldata_base.c b/arch/s390/appldata/appldata_base.c
index aa738cad1338..d74a4c7d5df6 100644
--- a/arch/s390/appldata/appldata_base.c
+++ b/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;
diff --git a/arch/s390/kernel/debug.c b/arch/s390/kernel/debug.c
index 6d321f5f101d..636446003a06 100644
--- a/arch/s390/kernel/debug.c
+++ b/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);
diff --git a/arch/s390/kernel/topology.c b/arch/s390/kernel/topology.c
index 5f70cefc13e4..332b542548cd 100644
--- a/arch/s390/kernel/topology.c
+++ b/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;
diff --git a/arch/s390/mm/cmm.c b/arch/s390/mm/cmm.c
index ae989b740376..36bce727897b 100644
--- a/arch/s390/mm/cmm.c
+++ b/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;
 	}
diff --git a/arch/x86/kernel/itmt.c b/arch/x86/kernel/itmt.c
index 1cb3ca9bba49..1afbdd1dd777 100644
--- a/arch/x86/kernel/itmt.c
+++ b/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;
diff --git a/drivers/cdrom/cdrom.c b/drivers/cdrom/cdrom.c
index faca0f346fff..e3bbe108eb54 100644
--- a/drivers/cdrom/cdrom.c
+++ b/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;
 	
diff --git a/drivers/char/random.c b/drivers/char/random.c
index 0d10e31fd342..1e0db78b83ba 100644
--- a/drivers/char/random.c
+++ b/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;
diff --git a/drivers/macintosh/mac_hid.c b/drivers/macintosh/mac_hid.c
index 7af0c536d568..28b8581b44dd 100644
--- a/drivers/macintosh/mac_hid.c
+++ b/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;
diff --git a/drivers/parport/procfs.c b/drivers/parport/procfs.c
index 48804049d697..ee7b5daabfd4 100644
--- a/drivers/parport/procfs.c
+++ b/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 }
diff --git a/fs/dcache.c b/fs/dcache.c
index b280e07e162b..8dd4d8d7bd0b 100644
--- a/fs/dcache.c
+++ b/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();
diff --git a/fs/drop_caches.c b/fs/drop_caches.c
index dc1a1d5d825b..f00fcc4a4f72 100644
--- a/fs/drop_caches.c
+++ b/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;
 
diff --git a/fs/file_table.c b/fs/file_table.c
index 30d55c9a1744..3b612535391f 100644
--- a/fs/file_table.c
+++ b/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;
 }
diff --git a/fs/fscache/main.c b/fs/fscache/main.c
index 59c2494efda3..c1e6cc9091aa 100644
--- a/fs/fscache/main.c
+++ b/
author	Christoph Hellwig <hch@lst.de>	2020-04-24 08:43:38 +0200
committer	Al Viro <viro@zeniv.linux.org.uk>	2020-04-27 02:07:40 -0400
commit	32927393dc1ccd60fb2bdc05b9e8e88753761469 (patch)
tree	c488a5564cdde7594c953219a98e22fb4865c812
parent	f461d2dcd511c020a26d4d791fae595c65ed09b6 (diff)