diff --git a/lib/libcam/cam_cdbparse.3 b/lib/libcam/cam_cdbparse.3
index 8379899dbb5c..1b9fb02feee2 100644
--- a/lib/libcam/cam_cdbparse.3
+++ b/lib/libcam/cam_cdbparse.3
@@ -88,7 +88,7 @@
 .Fa "u_int32_t flags"
 .Fa "int retry_count"
 .Fa "int timeout"
-.Fa "char *cmd_spec"
+.Fa "const char *cmd_spec"
 .Fa "..."
 .Fc
 .Ft int
@@ -99,20 +99,20 @@
 .Fa "u_int32_t flags"
 .Fa "int retry_count"
 .Fa "int timeout"
-.Fa "char *cmd_spec"
+.Fa "const char *cmd_spec"
 .Fa "int (*arg_get)(void *hook, char *field_name)"
 .Fa "void *gethook"
 .Fc
 .Ft int
 .Fo csio_decode
 .Fa "struct ccb_scsiio *csio"
-.Fa "char *fmt"
+.Fa "const char *fmt"
 .Fa "..."
 .Fc
 .Ft int
 .Fo csio_decode_visit
 .Fa "struct ccb_scsiio *csio"
-.Fa "char *fmt"
+.Fa "const char *fmt"
 .Fa "void (*arg_put)(void *hook"
 .Fa "int letter"
 .Fa "void *val"
@@ -124,27 +124,27 @@
 .Fo buff_decode
 .Fa "u_int8_t *buff"
 .Fa "size_t len"
-.Fa "char *fmt"
+.Fa "const char *fmt"
 .Fa "..."
 .Fc
 .Ft int
 .Fo buff_decode_visit
 .Fa "u_int8_t *buff"
 .Fa "size_t len"
-.Fa "char *fmt"
+.Fa "const char *fmt"
 .Fa "void (*arg_put)(void *, int, void *, int, char *)"
 .Fa "void *puthook"
 .Fc
 .Ft int
 .Fo csio_encode
 .Fa "struct ccb_scsiio *csio"
-.Fa "char *fmt"
+.Fa "const char *fmt"
 .Fa "..."
 .Fc
 .Ft int
 .Fo csio_encode_visit
 .Fa "struct ccb_scsiio *csio"
-.Fa "char *fmt"
+.Fa "const char *fmt"
 .Fa "int (*arg_get)(void *hook, char *field_name)"
 .Fa "void *gethook"
 .Fc
@@ -152,7 +152,7 @@
 .Fo buff_encode_visit
 .Fa "u_int8_t *buff"
 .Fa "size_t len"
-.Fa "char *fmt"
+.Fa "const char *fmt"
 .Fa "int (*arg_get)(void *hook, char *field_name)"
 .Fa "void *gethook"
 .Fc
diff --git a/lib/libcam/camlib.h b/lib/libcam/camlib.h
index 8d1823a7c0b9..46affd619619 100644
--- a/lib/libcam/camlib.h
+++ b/lib/libcam/camlib.h
@@ -150,27 +150,30 @@ int			cam_get_device(const char *path, char *dev_name,
 /*
  * Buffer encoding/decoding routines, from the old SCSI library.
  */
-int csio_decode(struct ccb_scsiio *csio, char *fmt, ...) __printflike(2, 3);
-int csio_decode_visit(struct ccb_scsiio *csio, char *fmt,
+int csio_decode(struct ccb_scsiio *csio, const char *fmt, ...)
+		__printflike(2, 3);
+int csio_decode_visit(struct ccb_scsiio *csio, const char *fmt,
 		      void (*arg_put)(void *, int, void *, int, char *),
 		      void *puthook);
-int buff_decode(u_int8_t *buff, size_t len, char *fmt, ...) __printflike(3, 4);
-int buff_decode_visit(u_int8_t *buff, size_t len, char *fmt,
+int buff_decode(u_int8_t *buff, size_t len, const char *fmt, ...)
+		__printflike(3, 4);
+int buff_decode_visit(u_int8_t *buff, size_t len, const char *fmt,
 		      void (*arg_put)(void *, int, void *, int, char *),
 		      void *puthook);
 int csio_build(struct ccb_scsiio *csio, u_int8_t *data_ptr,
 	       u_int32_t dxfer_len, u_int32_t flags, int retry_count,
-	       int timeout, char *cmd_spec, ...);
+	       int timeout, const char *cmd_spec, ...);
 int csio_build_visit(struct ccb_scsiio *csio, u_int8_t *data_ptr,
 		     u_int32_t dxfer_len, u_int32_t flags, int retry_count,
-		     int timeout, char *cmd_spec,
+		     int timeout, const char *cmd_spec,
 		     int (*arg_get)(void *hook, char *field_name),
 		     void *gethook);
-int csio_encode(struct ccb_scsiio *csio, char *fmt, ...) __printflike(2, 3);
-int buff_encode_visit(u_int8_t *buff, size_t len, char *fmt,
+int csio_encode(struct ccb_scsiio *csio, const char *fmt, ...)
+		__printflike(2, 3);
+int buff_encode_visit(u_int8_t *buff, size_t len, const char *fmt,
 		      int (*arg_get)(void *hook, char *field_name),
 		      void *gethook);
-int csio_encode_visit(struct ccb_scsiio *csio, char *fmt,
+int csio_encode_visit(struct ccb_scsiio *csio, const char *fmt,
 		      int (*arg_get)(void *hook, char *field_name),
 		      void *gethook);
 __END_DECLS
diff --git a/lib/libcam/scsi_cmdparse.c b/lib/libcam/scsi_cmdparse.c
index e853f2d531ca..f0cb724bb664 100644
--- a/lib/libcam/scsi_cmdparse.c
+++ b/lib/libcam/scsi_cmdparse.c
@@ -100,7 +100,7 @@ __FBSDID("$FreeBSD$");
 static int
 do_buff_decode(u_int8_t *databuf, size_t len,
 	       void (*arg_put)(void *, int , void *, int, char *),
-	       void *puthook, char *fmt, va_list ap)
+	       void *puthook, const char *fmt, va_list ap)
 {
 	int assigned = 0;
 	int width;
@@ -111,6 +111,7 @@ do_buff_decode(u_int8_t *databuf, size_t len,
 				   0x1f, 0x3f, 0x7f, 0xff};
 	int value;
 	u_char *base = databuf;
+	char *intendp;
 	char letter;
 	char field_name[80];
 
@@ -178,7 +179,8 @@ do_buff_decode(u_int8_t *databuf, size_t len,
 		case 't':	/* Bit (field) */
 		case 'b':	/* Bits */
 			fmt++;
-			width = strtol(fmt, &fmt, 10);
+			width = strtol(fmt, &intendp, 10);
+			fmt = intendp;
 			if (width > 8)
 				done = 1;
 			else {
@@ -203,7 +205,8 @@ do_buff_decode(u_int8_t *databuf, size_t len,
 		case 'i':	/* Integral values */
 			shift = 0;
 			fmt++;
-			width = strtol(fmt, &fmt, 10);
+			width = strtol(fmt, &intendp, 10);
+			fmt = intendp;
 			switch(width) {
 			case 1:
 				ARG_PUT(*databuf);
@@ -241,7 +244,8 @@ do_buff_decode(u_int8_t *databuf, size_t len,
 					   spaces  */
 			shift = 0;
 			fmt++;
-			width = strtol(fmt, &fmt, 10);
+			width = strtol(fmt, &intendp, 10);
+			fmt = intendp;
 			if (!suppress) {
 				if (arg_put)
 					(*arg_put)(puthook,
@@ -283,8 +287,10 @@ do_buff_decode(u_int8_t *databuf, size_t len,
 				 */
 				width = (arg_put) ? 0 : va_arg(ap, int);
 				fmt++;
-			} else
-				width = strtol(fmt, &fmt, 10);
+			} else {
+				width = strtol(fmt, &intendp, 10);
+				fmt = intendp;
+			}
 
 			if (plus)
 				databuf += width;	/* Relative seek */
@@ -341,10 +347,11 @@ do_buff_decode(u_int8_t *databuf, size_t len,
  */
 
 static int
-next_field(char **pp, char *fmt, int *width_p, int *value_p, char *name,
+next_field(const char **pp, char *fmt, int *width_p, int *value_p, char *name,
 	   int n_name, int *error_p, int *suppress_p)
 {
-	char *p = *pp;
+	const char *p = *pp;
+	char *intendp;
 
 	int something = 0;
 
@@ -404,7 +411,8 @@ next_field(char **pp, char *fmt, int *width_p, int *value_p, char *name,
 				suppress = 1;
 			} else if (isxdigit(*p)) {
 				something = 1;
-				value = strtol(p, &p, 16);
+				value = strtol(p, &intendp, 16);
+				p = intendp;
 				state = START_FIELD;
 			} else if (tolower(*p) == 'v') {
 				p++;
@@ -421,7 +429,8 @@ next_field(char **pp, char *fmt, int *width_p, int *value_p, char *name,
 
 				*fmt = 'i';
 				field_size = 8;
-				field_width = strtol(p, &p, 10);
+				field_width = strtol(p, &intendp, 10);
+				p = intendp;
 				state = DONE;
 
 			} else if (tolower(*p) == 't') {
@@ -436,7 +445,8 @@ next_field(char **pp, char *fmt, int *width_p, int *value_p, char *name,
 
 				*fmt = 'b';
 				field_size = 1;
-				field_width = strtol(p, &p, 10);
+				field_width = strtol(p, &intendp, 10);
+				p = intendp;
 				state = DONE;
 			} else if (tolower(*p) == 's') {
 				/* Seek */
@@ -448,7 +458,8 @@ next_field(char **pp, char *fmt, int *width_p, int *value_p, char *name,
 					value = *value_p;
 				} else {
 					something = 1;
-					value = strtol(p, &p, 0);
+					value = strtol(p, &intendp, 0);
+					p = intendp;
 				}
 				state = DONE;
 			} else {
@@ -473,7 +484,8 @@ next_field(char **pp, char *fmt, int *width_p, int *value_p, char *name,
 			if (isdigit(*p)) {
 				*fmt = 'b';
 				field_size = 1;
-				field_width = strtol(p, &p, 10);
+				field_width = strtol(p, &intendp, 10);
+				p = intendp;
 				state = DONE;
 			} else if (*p == 'i') {
 
@@ -482,7 +494,8 @@ next_field(char **pp, char *fmt, int *width_p, int *value_p, char *name,
 
 				*fmt = 'i';
 				field_size = 8;
-				field_width = strtol(p, &p, 10);
+				field_width = strtol(p, &intendp, 10);
+				p = intendp;
 				state = DONE;
 			} else if (*p == 'b') {
 
@@ -491,7 +504,8 @@ next_field(char **pp, char *fmt, int *width_p, int *value_p, char *name,
 
 				*fmt = 'b';
 				field_size = 1;
-				field_width = strtol(p, &p, 10);
+				field_width = strtol(p, &intendp, 10);
+				p = intendp;
 				state = DONE;
 			} else {
 				fprintf(stderr, "Invalid startfield %c "
@@ -522,7 +536,8 @@ next_field(char **pp, char *fmt, int *width_p, int *value_p, char *name,
 
 static int
 do_encode(u_char *buff, size_t vec_max, size_t *used,
-	  int (*arg_get)(void *, char *), void *gethook, char *fmt, va_list ap)
+	  int (*arg_get)(void *, char *), void *gethook, const char *fmt,
+	  va_list ap)
 {
 	int ind;
 	int shift;
@@ -642,7 +657,7 @@ do_encode(u_char *buff, size_t vec_max, size_t *used,
 }
 
 int
-csio_decode(struct ccb_scsiio *csio, char *fmt, ...)
+csio_decode(struct ccb_scsiio *csio, const char *fmt, ...)
 {
 	va_list ap;
 
@@ -653,7 +668,7 @@ csio_decode(struct ccb_scsiio *csio, char *fmt, ...)
 }
 
 int
-csio_decode_visit(struct ccb_scsiio *csio, char *fmt,
+csio_decode_visit(struct ccb_scsiio *csio, const char *fmt,
 		  void (*arg_put)(void *, int, void *, int, char *),
 		  void *puthook)
 {
@@ -673,7 +688,7 @@ csio_decode_visit(struct ccb_scsiio *csio, char *fmt,
 }
 
 int
-buff_decode(u_int8_t *buff, size_t len, char *fmt, ...)
+buff_decode(u_int8_t *buff, size_t len, const char *fmt, ...)
 {
 	va_list ap;
 
@@ -683,7 +698,7 @@ buff_decode(u_int8_t *buff, size_t len, char *fmt, ...)
 }
 
 int
-buff_decode_visit(u_int8_t *buff, size_t len, char *fmt,
+buff_decode_visit(u_int8_t *buff, size_t len, const char *fmt,
 		  void (*arg_put)(void *, int, void *, int, char *),
 		  void *puthook)
 {
@@ -707,7 +722,8 @@ buff_decode_visit(u_int8_t *buff, size_t len, char *fmt,
  */
 int
 csio_build(struct ccb_scsiio *csio, u_int8_t *data_ptr, u_int32_t dxfer_len,
-	   u_int32_t flags, int retry_count, int timeout, char *cmd_spec, ...)
+	   u_int32_t flags, int retry_count, int timeout, const char *cmd_spec,
+	   ...)
 {
 	size_t cmdlen;
 	int retval;
@@ -741,7 +757,7 @@ csio_build(struct ccb_scsiio *csio, u_int8_t *data_ptr, u_int32_t dxfer_len,
 int
 csio_build_visit(struct ccb_scsiio *csio, u_int8_t *data_ptr,
 		 u_int32_t dxfer_len, u_int32_t flags, int retry_count,
-		 int timeout, char *cmd_spec,
+		 int timeout, const char *cmd_spec,
 		 int (*arg_get)(void *hook, char *field_name), void *gethook)
 {
 	va_list ap;
@@ -781,7 +797,7 @@ csio_build_visit(struct ccb_scsiio *csio, u_int8_t *data_ptr,
 }
 
 int
-csio_encode(struct ccb_scsiio *csio, char *fmt, ...)
+csio_encode(struct ccb_scsiio *csio, const char *fmt, ...)
 {
 	va_list ap;
 
@@ -794,7 +810,7 @@ csio_encode(struct ccb_scsiio *csio, char *fmt, ...)
 }
 
 int
-buff_encode_visit(u_int8_t *buff, size_t len, char *fmt,
+buff_encode_visit(u_int8_t *buff, size_t len, const char *fmt,
 		  int (*arg_get)(void *hook, char *field_name), void *gethook)
 {
 	va_list ap;
@@ -812,7 +828,7 @@ buff_encode_visit(u_int8_t *buff, size_t len, char *fmt,
 }
 
 int
-csio_encode_visit(struct ccb_scsiio *csio, char *fmt,
+csio_encode_visit(struct ccb_scsiio *csio, const char *fmt,
 		  int (*arg_get)(void *hook, char *field_name), void *gethook)
 {
 	va_list ap;