Index: sys/compat/linux/linux.h
===================================================================
--- sys/compat/linux/linux.h
+++ sys/compat/linux/linux.h
@@ -197,5 +197,6 @@
 #define	BITMAP_1t1_LINUX(_name)	BITMAP_EASY_LINUX(_name, LINUX_##_name)
 
 int bsd_to_linux_errno(int error);
+void linux_check_errtbl(void);
 
 #endif /* _LINUX_MI_H_ */
Index: sys/compat/linux/linux_common.c
===================================================================
--- sys/compat/linux/linux_common.c
+++ sys/compat/linux/linux_common.c
@@ -67,6 +67,9 @@
 
 	switch(type) {
 	case MOD_LOAD:
+#ifdef INVARIANTS
+		linux_check_errtbl();
+#endif
 		linux_dev_shm_create();
 		linux_osd_jail_register();
 		linux_exit_tag = EVENTHANDLER_REGISTER(process_exit,
Index: sys/compat/linux/linux_errno.h
===================================================================
--- /dev/null
+++ sys/compat/linux/linux_errno.h
@@ -0,0 +1,184 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ *
+ * Copyright (c) 2020 The FreeBSD Foundation
+ * All rights reserved.
+ *
+ * This software was developed by Edward Tomasz Napierala under sponsorship
+ * from the FreeBSD Foundation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef _LINUX_ERRNO_H_
+#define _LINUX_ERRNO_H_
+
+#define	LINUX_EPERM		1
+#define	LINUX_ENOENT		2
+#define	LINUX_ESRCH		3
+#define	LINUX_EINTR		4
+#define	LINUX_EIO		5
+#define	LINUX_ENXIO		6
+#define	LINUX_E2BIG		7
+#define	LINUX_ENOEXEC		8
+#define	LINUX_EBADF		9
+
+#define	LINUX_ECHILD		10
+#define	LINUX_EAGAIN		11
+#define	LINUX_ENOMEM		12
+#define	LINUX_EACCES		13
+#define	LINUX_EFAULT		14
+#define	LINUX_ENOTBLK		15
+#define	LINUX_EBUSY		16
+#define	LINUX_EEXIST		17
+#define	LINUX_EXDEV		18
+#define	LINUX_ENODEV		19
+
+#define	LINUX_ENOTDIR		20
+#define	LINUX_EISDIR		21
+#define	LINUX_EINVAL		22
+#define	LINUX_ENFILE		23
+#define	LINUX_EMFILE		24
+#define	LINUX_ENOTTY		25
+#define	LINUX_ETXTBSY		26
+#define	LINUX_EFBIG		27
+#define	LINUX_ENOSPC		28
+#define	LINUX_ESPIPE		29
+
+#define	LINUX_EROFS		30
+#define	LINUX_EMLINK		31
+#define	LINUX_EPIPE		32
+#define	LINUX_EDOM		33
+#define	LINUX_ERANGE		34
+#define	LINUX_EDEADLK		35
+#define	LINUX_ENAMETOOLONG	36
+#define	LINUX_ENOLCK		37
+#define	LINUX_ENOSYS		38
+#define	LINUX_ENOTEMPTY		39
+
+#define	LINUX_ELOOP		40
+#define	LINUX_ESEEMSUNUSED	41 /* XXX */
+#define	LINUX_ENOMSG		42
+#define	LINUX_EIDRM		43
+#define	LINUX_ECHRNG		44
+#define	LINUX_EL2NSYNC		45
+#define	LINUX_EL3HLT		46
+#define	LINUX_EL3RST		47
+#define	LINUX_ELNRNG		48
+#define	LINUX_EUNATCH		49
+
+#define	LINUX_ENOCSI		50
+#define	LINUX_L2HLT		51
+#define	LINUX_EBADE		52
+#define	LINUX_EBADR		53
+#define	LINUX_EXFULL		54
+#define	LINUX_ENOANO		55
+#define	LINUX_EBADRQC		56
+#define	LINUX_EBADSLT		57
+#define	LINUX_EALSOUNUSED	58 /* XXX */
+#define	LINUX_EBFONT		59
+
+#define	LINUX_ENOSTR		60
+#define	LINUX_ENODATA		61
+#define	LINUX_ENOTIME		62
+#define	LINUX_ENOSR		63
+#define	LINUX_ENONET		64
+#define	LINUX_ENOPKG		65
+#define	LINUX_EREMOTE		66
+#define	LINUX_ENOLINK		67
+#define	LINUX_EADV		68
+#define	LINUX_ESRMNT		69
+
+#define	LINUX_ECOMM		70
+#define	LINUX_EPROTO		71
+#define	LINUX_EMULTIHOP		72
+#define	LINUX_EDOTDOT		73
+#define	LINUX_EBADMSG		74
+#define	LINUX_EOVERFLOW		75
+#define	LINUX_ENOTUNIQ		76
+#define	LINUX_EBADFD		77
+#define	LINUX_EREMCHG		78
+#define	LINUX_ELIBACC		79
+
+#define	LINUX_ELIBBAD		80
+#define	LINUX_ELIBSCN		81
+#define	LINUX_ELIBMAX		82
+#define	LINUX_ELIBEXEC		83
+#define	LINUX_EILSEQ		84
+#define	LINUX_ERESTART		85
+#define	LINUX_ESTRPIPE		86
+#define	LINUX_EUSERS		87
+#define	LINUX_ENOTSOCK		88
+#define	LINUX_EDESTADDRREQ	89
+
+#define	LINUX_EMSGSIZE		90
+#define	LINUX_EPROTOTYPE	91
+#define	LINUX_ENOPROTOOPT	92
+#define	LINUX_EPROTONOTSUPPORT	93
+#define	LINUX_ESOCKNOTSUPPORT	94
+#define	LINUX_EOPNOTSUPPORT	95
+#define	LINUX_EPFNOTSUPPORT	96
+#define	LINUX_EAFNOTSUPPORT	97
+#define	LINUX_EADDRINUSE	98
+#define	LINUX_EADDRNOTAVAIL	99
+
+#define	LINUX_ENETDOWN		100
+#define	LINUX_ENETUNREACH	101
+#define	LINUX_ENETRESET		102
+#define	LINUX_ECONNABORTED	103
+#define	LINUX_ECONNRESET	104
+#define	LINUX_ENOBUFS		105
+#define	LINUX_EISCONN		106
+#define	LINUX_ENOTCONN		107
+#define	LINUX_ESHUTDOWN		108
+#define	LINUX_ETOOMANYREFS	109
+
+#define	LINUX_ETIMEDOUT		110
+#define	LINUX_ECONNREFUSED	111
+#define	LINUX_EHOSTDOWN		112
+#define	LINUX_EHOSTUNREACH	113
+#define	LINUX_EALREADY		114
+#define	LINUX_EINPROGRESS	115
+#define	LINUX_ESTALE		116
+#define	LINUX_EUCLEAN		117
+#define	LINUX_ENOTNAM		118
+#define	LINUX_ENAVAIL		119
+
+#define	LINUX_EISNAM		120
+#define	LINUX_EREMOTEIO		121
+#define	LINUX_EDQUOT		122
+#define	LINUX_ENOMEDIUM		123
+#define	LINUX_EMEDIUMTYPE	124
+#define	LINUX_ECANCELED		125
+#define	LINUX_ENOKEY		126
+#define	LINUX_EKEYEXPIRED	127
+#define	LINUX_EKEYREVOKED	128
+#define	LINUX_EKEYREJECTED	129
+
+#define	LINUX_EOWNERDEAD	130
+#define	LINUX_ENOTRECOVERABLE	131
+#define	LINUX_ERFKILL		132
+#define	LINUX_EHWPOISON		133
+
+#endif /* _LINUX_ERRNO_H_ */
Index: sys/compat/linux/linux_errno.c
===================================================================
--- sys/compat/linux/linux_errno.c
+++ sys/compat/linux/linux_errno.c
@@ -8,6 +8,7 @@
 #include <sys/systm.h>
 
 #include <compat/linux/linux.h>
+#include <compat/linux/linux_errno.h>
 #include <compat/linux/linux_errno.inc>
 
 int
@@ -19,3 +20,16 @@
 
 	return (linux_errtbl[error]);
 }
+
+#ifdef INVARIANTS
+void
+linux_check_errtbl(void)
+{
+	int i;
+
+	for (i = 1; i < sizeof(linux_errtbl); i++) {
+		KASSERT(linux_errtbl[i] != 0,
+		    ("%s: linux_errtbl[%d] == 0", __func__, i));
+	}
+}
+#endif
Index: sys/compat/linux/linux_errno.inc
===================================================================
--- sys/compat/linux/linux_errno.inc
+++ sys/compat/linux/linux_errno.inc
@@ -36,113 +36,123 @@
  *            include/uapi/asm-generic/errno.h
  */
 const int linux_errtbl[ELAST + 1] = {
-	-0,
-	-1,
-	-2,
-	-3,
-	-4,
-	-5,
-	-6,
-	-7,
-	-8,
-	-9,
+	/* [0, 9] */
+	[0] = -0,
+	[EPERM] = -LINUX_EPERM,
+	[ENOENT] = -LINUX_ENOENT,
+	[ESRCH] = -LINUX_ESRCH,
+	[EINTR] = -LINUX_EINTR,
+	[EIO] = -LINUX_EIO,
+	[ENXIO] = -LINUX_ENXIO,
+	[E2BIG] = -LINUX_E2BIG,
+	[ENOEXEC] = -LINUX_ENOEXEC,
+	[EBADF] = -LINUX_EBADF,
 
-	-10,
-	-35,	/* EDEADLK */
-	-12,
-	-13,
-	-14,
-	-15,
-	-16,
-	-17,
-	-18,
-	-19,
+	/* [10, 19] */
+	[ECHILD] = -LINUX_ECHILD,
+	[EDEADLK] = -LINUX_EDEADLK,
+	[ENOMEM] = -LINUX_ENOMEM,
+	[EACCES] = -LINUX_EACCES,
+	[EFAULT] = -LINUX_EFAULT,
+	[ENOTBLK] = -LINUX_ENOTBLK,
+	[EBUSY] = -LINUX_EBUSY,
+	[EEXIST] = -LINUX_EEXIST,
+	[EXDEV] = -LINUX_EXDEV,
+	[ENODEV] = -LINUX_ENODEV,
 
-	-20,
-	-21,
-	-22,
-	-23,
-	-24,
-	-25,
-	-26,
-	-27,
-	-28,
-	-29,
+	/* [20, 29] */
+	[ENOTDIR] = -LINUX_ENOTDIR,
+	[EISDIR] = -LINUX_EISDIR,
+	[EINVAL] = -LINUX_EINVAL,
+	[ENFILE] = -LINUX_ENFILE,
+	[EMFILE] = -LINUX_EMFILE,
+	[ENOTTY] = -LINUX_ENOTTY,
+	[ETXTBSY] = -LINUX_ETXTBSY,
+	[EFBIG] = -LINUX_EFBIG,
+	[ENOSPC] = -LINUX_ENOSPC,
+	[ESPIPE] = -LINUX_ESPIPE,
 
-	-30,
-	-31,
-	-32,
-	-33,
-	-34,
-	-11,	/* EAGAIN */
-	-115,
-	-114,
-	-88,
-	-89,
+	/* [30, 39] */
+	[EROFS] = -LINUX_EROFS,
+	[EMLINK] = -LINUX_EMLINK,
+	[EPIPE] = -LINUX_EPIPE,
+	[EDOM] = -LINUX_EDOM,
+	[ERANGE] = -LINUX_ERANGE,
+	[EAGAIN] = -LINUX_EAGAIN,
+	[EINPROGRESS] = -LINUX_EINPROGRESS,
+	[EALREADY] = -LINUX_EALREADY,
+	[ENOTSOCK] = -LINUX_ENOTSOCK,
+	[EDESTADDRREQ] = -LINUX_EDESTADDRREQ,
 
-	-90,
-	-91,
-	-92,
-	-93,
-	-94,
-	-95,
-	-96,
-	-97,
-	-98,
-	-99,
+	/* [40, 49] */
+	[EMSGSIZE] = -LINUX_EMSGSIZE,
+	[EPROTOTYPE] = -LINUX_EPROTOTYPE,
+	[ENOPROTOOPT] = -LINUX_ENOPROTOOPT,
+	[EPROTONOSUPPORT] = -LINUX_EPROTONOTSUPPORT,
+	[ESOCKTNOSUPPORT] = -LINUX_ESOCKNOTSUPPORT,
+	[EOPNOTSUPP] = -LINUX_EOPNOTSUPPORT,
+	[EPFNOSUPPORT] = -LINUX_EPFNOTSUPPORT,
+	[EAFNOSUPPORT] = -LINUX_EAFNOTSUPPORT,
+	[EADDRINUSE] = -LINUX_EADDRINUSE,
+	[EADDRNOTAVAIL] = -LINUX_EADDRNOTAVAIL,
 
-	-100,
-	-101,
-	-102,
-	-103,
-	-104,
-	-105,
-	-106,
-	-107,
-	-108,
-	-109,
+	/* [50, 59] */
+	[ENETDOWN] = -LINUX_ENETDOWN,
+	[ENETUNREACH] = -LINUX_ENETUNREACH,
+	[ENETRESET] = -LINUX_ENETRESET,
+	[ECONNABORTED] = -LINUX_ECONNABORTED,
+	[ECONNRESET] = -LINUX_ECONNRESET,
+	[ENOBUFS] = -LINUX_ENOBUFS,
+	[EISCONN] = -LINUX_EISCONN,
+	[ENOTCONN] = -LINUX_ENOTCONN,
+	[ESHUTDOWN] = -LINUX_ESHUTDOWN,
+	[ETOOMANYREFS] = -LINUX_ETOOMANYREFS,
 
-	-110,
-	-111,
-	-40,
-	-36,
-	-112,
-	-113,
-	-39,
-	-11,
-	-87,
-	-122,
+	/* [60, 69] */
+	[ETIMEDOUT] = -LINUX_ETIMEDOUT,
+	[ECONNREFUSED] = -LINUX_ECONNREFUSED,
+	[ELOOP] = -LINUX_ELOOP,
+	[ENAMETOOLONG] = -LINUX_ENAMETOOLONG,
+	[EHOSTDOWN] = -LINUX_EHOSTDOWN,
+	[EHOSTUNREACH] = -LINUX_EHOSTUNREACH,
+	[ENOTEMPTY] = -LINUX_ENOTEMPTY,
+	[EPROCLIM] = -LINUX_EAGAIN,	/* EPROCLIM -> EAGAIN, XXX */
+	[EUSERS] = -LINUX_EUSERS,
+	[EDQUOT] = -LINUX_EDQUOT,
 
-	-116,
-	-66,
-	-6,	/* EBADRPC -> ENXIO */
-	-6,	/* ERPCMISMATCH -> ENXIO */
-	-6,	/* EPROGUNAVAIL -> ENXIO */
-	-6,	/* EPROGMISMATCH -> ENXIO */
-	-6,	/* EPROCUNAVAIL -> ENXIO */
-	-37,
-	-38,
-	-9,
+	/* [70, 79] */
+	[ESTALE] = -LINUX_ESTALE,
+	[EREMOTE] = -LINUX_EREMOTE,
+	[EBADRPC] = -LINUX_ENXIO,	/* EBADRPC -> ENXIO */
+	[ERPCMISMATCH] = -LINUX_ENXIO,	/* ERPCMISMATCH -> ENXIO */
+	[EPROGUNAVAIL] = -LINUX_ENXIO,	/* EPROGUNAVAIL -> ENXIO */
+	[EPROGMISMATCH] = -LINUX_ENXIO,	/* EPROGMISMATCH -> ENXIO */
+	[EPROCUNAVAIL] = -LINUX_ENXIO,	/* EPROCUNAVAIL -> ENXIO */
+	[ENOLCK] = -LINUX_ENOLCK,
+	[ENOSYS] = -LINUX_ENOSYS,
+	[EFTYPE] = -LINUX_EBADF,	/* EFTYPE -> EBADF */
 
-	-6,	/* EAUTH -> ENXIO */
-	-6,	/* ENEEDAUTH -> ENXIO */
-	-43,
-	-42,
-	-75,
-	-125,
-	-84,
-	-61,
-	-22,	/* EDOOFUS -> EINVAL */
-	-74,
+	/* [80, 89] */
+	[EAUTH] = -LINUX_ENXIO,		/* EAUTH -> ENXIO */
+	[ENEEDAUTH] = -LINUX_ENXIO,	/* ENEEDAUTH -> ENXIO */
+	[EIDRM] = -LINUX_EIDRM,
+	[ENOMSG] = -LINUX_ENOMSG,
+	[EOVERFLOW] = -LINUX_EOVERFLOW,
+	[ECANCELED] = -LINUX_ECANCELED,
+	[EILSEQ] = -LINUX_EILSEQ,
+	[ENOATTR] = -LINUX_ENODATA,	/* ENOATTR -> ENODATA */
+	[EDOOFUS] = -LINUX_EINVAL,	/* EDOOFUS -> EINVAL */
+	[EBADMSG] = -LINUX_EBADMSG,
 
-	-72,
-	-67,
-	-71,
-	-1,	/* ENOTCAPABLE -> EPERM */
-	-1,	/* ECAPMODE -> EPERM */
-	-131,	/* ENOTRECOVERABLE */
-	-130,	/* EOWNERDEAD */
-	-22,	/* EINTEGRITY -> EINVAL */
+	/* [90, 99] */
+	[EMULTIHOP] = -LINUX_EMULTIHOP,
+	[ENOLINK] = -LINUX_ENOLINK,
+	[EPROTO] = -LINUX_EPROTO,
+	[ENOTCAPABLE] = -LINUX_EPERM,	/* ENOTCAPABLE -> EPERM */
+	[ECAPMODE] = -LINUX_EPERM,	/* ECAPMODE -> EPERM */
+	[ENOTRECOVERABLE] = -LINUX_ENOTRECOVERABLE,
+	[EOWNERDEAD] = -LINUX_EOWNERDEAD,
+	[EINTEGRITY] = -LINUX_EINVAL,	/* EINTEGRITY -> EINVAL */
 };
 
 _Static_assert(ELAST == 97,