diff --git a/sys/amd64/amd64/elf_machdep.c b/sys/amd64/amd64/elf_machdep.c
index 7c43f26c28bf..f70d86ed1a9a 100644
--- a/sys/amd64/amd64/elf_machdep.c
+++ b/sys/amd64/amd64/elf_machdep.c
@@ -52,7 +52,6 @@ __FBSDID("$FreeBSD$");
 struct sysentvec elf64_freebsd_sysvec = {
 	.sv_size	= SYS_MAXSYSCALL,
 	.sv_table	= sysent,
-	.sv_mask	= 0,
 	.sv_errsize	= 0,
 	.sv_errtbl	= NULL,
 	.sv_transtrap	= NULL,
diff --git a/sys/amd64/amd64/trap.c b/sys/amd64/amd64/trap.c
index 7a0973025296..91090043bcf3 100644
--- a/sys/amd64/amd64/trap.c
+++ b/sys/amd64/amd64/trap.c
@@ -991,8 +991,6 @@ cpu_fetch_syscall_args_fallback(struct thread *td, struct syscall_args *sa)
 		reg++;
 		regcnt--;
 	}
- 	if (p->p_sysent->sv_mask)
- 		sa->code &= p->p_sysent->sv_mask;
 
  	if (sa->code >= p->p_sysent->sv_size)
  		sa->callp = &p->p_sysent->sv_table[0];
@@ -1040,9 +1038,6 @@ cpu_fetch_syscall_args(struct thread *td)
 	sa->narg = sa->callp->sy_narg;
 	KASSERT(sa->narg <= nitems(sa->args), ("Too many syscall arguments!"));
 
-	if (p->p_sysent->sv_mask)
-		sa->code &= p->p_sysent->sv_mask;
-
 	if (__predict_false(sa->narg > NARGREGS))
 		return (cpu_fetch_syscall_args_fallback(td, sa));
 
diff --git a/sys/amd64/conf/NOTES b/sys/amd64/conf/NOTES
index 4367b0358210..c6a538de8307 100644
--- a/sys/amd64/conf/NOTES
+++ b/sys/amd64/conf/NOTES
@@ -612,9 +612,6 @@ options 	EFIRT
 # Enable 32-bit runtime support for FreeBSD/i386 binaries.
 options 	COMPAT_FREEBSD32
 
-# Enable iBCS2 runtime support for SCO and ISC binaries
-#XXX#options 	IBCS2
-
 # Emulate spx device for client side of SVR3 local X interface
 #XXX#options 	SPX_HACK
 
diff --git a/sys/amd64/ia32/ia32_syscall.c b/sys/amd64/ia32/ia32_syscall.c
index 2ea7eb84951f..0b0ba742eb3f 100644
--- a/sys/amd64/ia32/ia32_syscall.c
+++ b/sys/amd64/ia32/ia32_syscall.c
@@ -177,8 +177,6 @@ ia32_fetch_syscall_args(struct thread *td)
 		sa->code = tmp;
 		params += sizeof(quad_t);
 	}
- 	if (p->p_sysent->sv_mask)
- 		sa->code &= p->p_sysent->sv_mask;
  	if (sa->code >= p->p_sysent->sv_size)
  		sa->callp = &p->p_sysent->sv_table[0];
   	else
diff --git a/sys/amd64/linux/linux_sysvec.c b/sys/amd64/linux/linux_sysvec.c
index afa06bb415c2..271e86260aee 100644
--- a/sys/amd64/linux/linux_sysvec.c
+++ b/sys/amd64/linux/linux_sysvec.c
@@ -711,7 +711,6 @@ linux_vsyscall(struct thread *td)
 struct sysentvec elf_linux_sysvec = {
 	.sv_size	= LINUX_SYS_MAXSYSCALL,
 	.sv_table	= linux_sysent,
-	.sv_mask	= 0,
 	.sv_errsize	= ELAST + 1,
 	.sv_errtbl	= linux_errtbl,
 	.sv_transtrap	= linux_translate_traps,
diff --git a/sys/amd64/linux32/linux32_sysvec.c b/sys/amd64/linux32/linux32_sysvec.c
index bcaa0cd45459..d91a5836d5c6 100644
--- a/sys/amd64/linux32/linux32_sysvec.c
+++ b/sys/amd64/linux32/linux32_sysvec.c
@@ -909,7 +909,6 @@ linux32_fixlimit(struct rlimit *rl, int which)
 struct sysentvec elf_linux_sysvec = {
 	.sv_size	= LINUX32_SYS_MAXSYSCALL,
 	.sv_table	= linux32_sysent,
-	.sv_mask	= 0,
 	.sv_errsize	= ELAST + 1,
 	.sv_errtbl	= linux_errtbl,
 	.sv_transtrap	= linux_translate_traps,
diff --git a/sys/arm/arm/elf_machdep.c b/sys/arm/arm/elf_machdep.c
index 3ab3eb90f121..acfa1e6649f1 100644
--- a/sys/arm/arm/elf_machdep.c
+++ b/sys/arm/arm/elf_machdep.c
@@ -59,7 +59,6 @@ u_long elf_hwcap2;
 struct sysentvec elf32_freebsd_sysvec = {
 	.sv_size	= SYS_MAXSYSCALL,
 	.sv_table	= sysent,
-	.sv_mask	= 0,
 	.sv_errsize	= 0,
 	.sv_errtbl	= NULL,
 	.sv_transtrap	= NULL,
diff --git a/sys/arm/arm/syscall.c b/sys/arm/arm/syscall.c
index 8c33fff30a19..21a88e9c6c69 100644
--- a/sys/arm/arm/syscall.c
+++ b/sys/arm/arm/syscall.c
@@ -118,8 +118,6 @@ cpu_fetch_syscall_args(struct thread *td)
 		ap += 2;
 	}
 	p = td->td_proc;
-	if (p->p_sysent->sv_mask)
-		sa->code &= p->p_sysent->sv_mask;
 	if (sa->code >= p->p_sysent->sv_size)
 		sa->callp = &p->p_sysent->sv_table[0];
 	else
diff --git a/sys/arm/arm/vm_machdep.c b/sys/arm/arm/vm_machdep.c
index febb6de09bee..31527619a610 100644
--- a/sys/arm/arm/vm_machdep.c
+++ b/sys/arm/arm/vm_machdep.c
@@ -190,8 +190,6 @@ cpu_set_syscall_retval(struct thread *td, int error)
 	if (call == SYS___syscall) {
 		register_t *ap = &frame->tf_r0;
 		register_t code = ap[_QUAD_LOWWORD];
-		if (td->td_proc->p_sysent->sv_mask)
-			code &= td->td_proc->p_sysent->sv_mask;
 		fixup = (code != SYS_lseek);
 	}
 #endif
diff --git a/sys/arm64/arm64/elf_machdep.c b/sys/arm64/arm64/elf_machdep.c
index ae62b36ca793..ab46995dd119 100644
--- a/sys/arm64/arm64/elf_machdep.c
+++ b/sys/arm64/arm64/elf_machdep.c
@@ -58,7 +58,6 @@ __FBSDID("$FreeBSD$");
 static struct sysentvec elf64_freebsd_sysvec = {
 	.sv_size	= SYS_MAXSYSCALL,
 	.sv_table	= sysent,
-	.sv_mask	= 0,
 	.sv_errsize	= 0,
 	.sv_errtbl	= NULL,
 	.sv_transtrap	= NULL,
diff --git a/sys/arm64/arm64/trap.c b/sys/arm64/arm64/trap.c
index bb5924336b58..8de175fb3875 100644
--- a/sys/arm64/arm64/trap.c
+++ b/sys/arm64/arm64/trap.c
@@ -115,8 +115,6 @@ cpu_fetch_syscall_args(struct thread *td)
 		nap--;
 	}
 
-	if (p->p_sysent->sv_mask)
-		sa->code &= p->p_sysent->sv_mask;
 	if (sa->code >= p->p_sysent->sv_size)
 		sa->callp = &p->p_sysent->sv_table[0];
 	else
diff --git a/sys/arm64/linux/linux_sysvec.c b/sys/arm64/linux/linux_sysvec.c
index 0cbfd322de9f..8b197cc59d32 100644
--- a/sys/arm64/linux/linux_sysvec.c
+++ b/sys/arm64/linux/linux_sysvec.c
@@ -124,8 +124,6 @@ linux_fetch_syscall_args(struct thread *td)
 
 	sa->code = td->td_frame->tf_x[8];
 	/* LINUXTODO: generic syscall? */
-	if (p->p_sysent->sv_mask)
-		sa->code &= p->p_sysent->sv_mask;
 	if (sa->code >= p->p_sysent->sv_size)
 		sa->callp = &p->p_sysent->sv_table[0];
 	else
@@ -364,7 +362,6 @@ linux_vsyscall(struct thread *td)
 struct sysentvec elf_linux_sysvec = {
 	.sv_size	= LINUX_SYS_MAXSYSCALL,
 	.sv_table	= linux_sysent,
-	.sv_mask	= 0,
 	.sv_errsize	= ELAST + 1,
 	.sv_errtbl	= linux_errtbl,
 	.sv_transtrap	= linux_translate_traps,
diff --git a/sys/compat/ia32/ia32_sysvec.c b/sys/compat/ia32/ia32_sysvec.c
index 91a2acf329fd..606525146412 100644
--- a/sys/compat/ia32/ia32_sysvec.c
+++ b/sys/compat/ia32/ia32_sysvec.c
@@ -98,7 +98,6 @@ SYSCTL_ULONG(_compat_ia32, OID_AUTO, maxvmem, CTLFLAG_RWTUN, &ia32_maxvmem, 0, "
 struct sysentvec ia32_freebsd_sysvec = {
 	.sv_size	= FREEBSD32_SYS_MAXSYSCALL,
 	.sv_table	= freebsd32_sysent,
-	.sv_mask	= 0,
 	.sv_errsize	= 0,
 	.sv_errtbl	= NULL,
 	.sv_transtrap	= NULL,
diff --git a/sys/conf/files.i386 b/sys/conf/files.i386
index 08d987586a74..c7531cc9c1e0 100644
--- a/sys/conf/files.i386
+++ b/sys/conf/files.i386
@@ -508,25 +508,6 @@ i386/i386/trap.c		standard
 i386/i386/uio_machdep.c		standard
 i386/i386/vm86.c		standard
 i386/i386/vm_machdep.c		standard
-i386/ibcs2/ibcs2_errno.c	optional ibcs2
-i386/ibcs2/ibcs2_fcntl.c	optional ibcs2
-i386/ibcs2/ibcs2_ioctl.c	optional ibcs2
-i386/ibcs2/ibcs2_ipc.c		optional ibcs2
-i386/ibcs2/ibcs2_isc.c		optional ibcs2
-i386/ibcs2/ibcs2_isc_sysent.c	optional ibcs2
-i386/ibcs2/ibcs2_misc.c		optional ibcs2
-i386/ibcs2/ibcs2_msg.c		optional ibcs2
-i386/ibcs2/ibcs2_other.c	optional ibcs2
-i386/ibcs2/ibcs2_signal.c	optional ibcs2
-i386/ibcs2/ibcs2_socksys.c	optional ibcs2
-i386/ibcs2/ibcs2_stat.c		optional ibcs2
-i386/ibcs2/ibcs2_sysent.c	optional ibcs2
-i386/ibcs2/ibcs2_sysi86.c	optional ibcs2
-i386/ibcs2/ibcs2_sysvec.c	optional ibcs2
-i386/ibcs2/ibcs2_util.c		optional ibcs2
-i386/ibcs2/ibcs2_xenix.c	optional ibcs2
-i386/ibcs2/ibcs2_xenix_sysent.c	optional ibcs2
-i386/ibcs2/imgact_coff.c	optional ibcs2
 i386/linux/imgact_linux.c	optional compat_linux
 i386/linux/linux_copyout.c	optional compat_linux
 i386/linux/linux_dummy.c	optional compat_linux
diff --git a/sys/conf/options.amd64 b/sys/conf/options.amd64
index 1edb70164a8f..8939ddaf6246 100644
--- a/sys/conf/options.amd64
+++ b/sys/conf/options.amd64
@@ -16,7 +16,6 @@ PV_STATS		opt_pmap.h
 # (see src/sys/conf/options), except for broken debugging options.
 COMPAT_AOUT		opt_dontuse.h
 COMPAT_FREEBSD32	opt_global.h
-#IBCS2			opt_dontuse.h
 #COMPAT_LINUX		opt_dontuse.h
 COMPAT_LINUX32		opt_compat.h
 LINPROCFS		opt_dontuse.h
diff --git a/sys/conf/options.i386 b/sys/conf/options.i386
index 83298bad651a..8c96ff40c558 100644
--- a/sys/conf/options.i386
+++ b/sys/conf/options.i386
@@ -22,7 +22,6 @@ PV_STATS		opt_pmap.h
 # they are handled like options for static filesystems
 # (see src/sys/conf/options), except for broken debugging options.
 COMPAT_AOUT		opt_dontuse.h
-IBCS2			opt_dontuse.h
 COMPAT_LINUX		opt_dontuse.h
 LINPROCFS		opt_dontuse.h
 LINSYSFS		opt_dontuse.h
diff --git a/sys/i386/Makefile b/sys/i386/Makefile
index f6ecf7fa2fd7..fe6ac2bf41d9 100644
--- a/sys/i386/Makefile
+++ b/sys/i386/Makefile
@@ -14,7 +14,7 @@ all:
 	@echo "make links or tags only"
 
 # Directories in which to place i386 tags links
-DI386=	apm i386 ibcs2 include isa linux
+DI386=	apm i386 include isa linux
 
 links::
 	-for i in ${COMMDIR1}; do \
@@ -25,9 +25,9 @@ links::
 	    (cd $$i && { rm -f tags; ln -s ../tags tags; }) done
 
 SI386=	${SYS}/i386/acpica/*.[ch] ${SYS}/i386/bios/*.[ch] \
-	${SYS}/i386/i386/*.[ch] ${SYS}/i386/ibcs2/*.[ch] \
-	${SYS}/i386/include/*.[ch] ${SYS}/i386/isa/*.[ch] \
-	${SYS}/i386/linux/*.[ch] ${SYS}/i386/pci/*.[ch]
+	${SYS}/i386/i386/*.[ch] ${SYS}/i386/include/*.[ch] \
+	${SYS}/i386/isa/*.[ch] ${SYS}/i386/linux/*.[ch] \
+	${SYS}/i386/pci/*.[ch]
 AI386=	${SYS}/i386/i386/*.s
 
 tags::
diff --git a/sys/i386/conf/NOTES b/sys/i386/conf/NOTES
index fb70ea0d22c3..8ae4d95d45fb 100644
--- a/sys/i386/conf/NOTES
+++ b/sys/i386/conf/NOTES
@@ -885,9 +885,6 @@ options 	NKPT=31
 #####################################################################
 # ABI Emulation
 
-# Enable iBCS2 runtime support for SCO and ISC binaries
-#options 	IBCS2
-
 # Emulate spx device for client side of SVR3 local X interface
 options 	SPX_HACK
 
diff --git a/sys/i386/i386/elf_machdep.c b/sys/i386/i386/elf_machdep.c
index bd07bbc1cc86..59c192f59231 100644
--- a/sys/i386/i386/elf_machdep.c
+++ b/sys/i386/i386/elf_machdep.c
@@ -54,7 +54,6 @@ __FBSDID("$FreeBSD$");
 struct sysentvec elf32_freebsd_sysvec = {
 	.sv_size	= SYS_MAXSYSCALL,
 	.sv_table	= sysent,
-	.sv_mask	= 0,
 	.sv_errsize	= 0,
 	.sv_errtbl	= NULL,
 	.sv_transtrap	= NULL,
diff --git a/sys/i386/i386/trap.c b/sys/i386/i386/trap.c
index a81ec6ee89d1..f260469e4eb9 100644
--- a/sys/i386/i386/trap.c
+++ b/sys/i386/i386/trap.c
@@ -1095,8 +1095,6 @@ cpu_fetch_syscall_args(struct thread *td)
 		params += sizeof(quad_t);
 	}
 
- 	if (p->p_sysent->sv_mask)
- 		sa->code &= p->p_sysent->sv_mask;
  	if (sa->code >= p->p_sysent->sv_size)
  		sa->callp = &p->p_sysent->sv_table[0];
   	else
diff --git a/sys/i386/linux/linux_sysvec.c b/sys/i386/linux/linux_sysvec.c
index d379a6e8f848..f3c4dd158730 100644
--- a/sys/i386/linux/linux_sysvec.c
+++ b/sys/i386/linux/linux_sysvec.c
@@ -850,7 +850,6 @@ linux_get_machine(const char **dst)
 struct sysentvec linux_sysvec = {
 	.sv_size	= LINUX_SYS_MAXSYSCALL,
 	.sv_table	= linux_sysent,
-	.sv_mask	= 0,
 	.sv_errsize	= ELAST + 1,
 	.sv_errtbl	= linux_errtbl,
 	.sv_transtrap	= linux_translate_traps,
@@ -887,7 +886,6 @@ INIT_SYSENTVEC(aout_sysvec, &linux_sysvec);
 struct sysentvec elf_linux_sysvec = {
 	.sv_size	= LINUX_SYS_MAXSYSCALL,
 	.sv_table	= linux_sysent,
-	.sv_mask	= 0,
 	.sv_errsize	= ELAST + 1,
 	.sv_errtbl	= linux_errtbl,
 	.sv_transtrap	= linux_translate_traps,
diff --git a/sys/kern/imgact_aout.c b/sys/kern/imgact_aout.c
index fe893241a4e0..35993f4d4ccd 100644
--- a/sys/kern/imgact_aout.c
+++ b/sys/kern/imgact_aout.c
@@ -76,7 +76,6 @@ static int	aout_fixup(register_t **stack_base, struct image_params *imgp);
 struct sysentvec aout_sysvec = {
 	.sv_size	= SYS_MAXSYSCALL,
 	.sv_table	= sysent,
-	.sv_mask	= 0,
 	.sv_errsize	= 0,
 	.sv_errtbl	= NULL,
 	.sv_transtrap	= NULL,
@@ -119,7 +118,6 @@ extern u_long ia32_maxssiz;
 struct sysentvec aout_sysvec = {
 	.sv_size	= FREEBSD32_SYS_MAXSYSCALL,
 	.sv_table	= freebsd32_sysent,
-	.sv_mask	= 0,
 	.sv_errsize	= 0,
 	.sv_errtbl	= NULL,
 	.sv_transtrap	= NULL,
diff --git a/sys/kern/init_main.c b/sys/kern/init_main.c
index 39c6b7f65178..22aaa2eee9fe 100644
--- a/sys/kern/init_main.c
+++ b/sys/kern/init_main.c
@@ -401,7 +401,6 @@ null_set_syscall_retval(struct thread *td __unused, int error __unused)
 struct sysentvec null_sysvec = {
 	.sv_size	= 0,
 	.sv_table	= NULL,
-	.sv_mask	= 0,
 	.sv_errsize	= 0,
 	.sv_errtbl	= NULL,
 	.sv_transtrap	= NULL,
diff --git a/sys/kern/makesyscalls.sh b/sys/kern/makesyscalls.sh
index 0e95a79c7bad..c794a5e87fbc 100644
--- a/sys/kern/makesyscalls.sh
+++ b/sys/kern/makesyscalls.sh
@@ -526,8 +526,8 @@ sed -e '
 		if (!flag("NOPROTO") && !flag("NODEF")) {
 			if (funcname == "nosys" || funcname == "lkmnosys" ||
 			    funcname == "sysarch" || funcname ~ /^freebsd/ || 
-			    funcname ~ /^linux/ || funcname ~ /^ibcs2/ ||
-			    funcname ~ /^xenix/ || funcname ~ /^cloudabi/) {
+			    funcname ~ /^linux/ || funcname ~ /^xenix/ ||
+			    funcname ~ /^cloudabi/) {
 				printf("%s\t%s(struct thread *, struct %s *)",
 				    rettype, funcname, argalias) > sysdcl
 			} else {
@@ -546,8 +546,8 @@ sed -e '
 		} else {
 			if (funcname == "nosys" || funcname == "sysarch" || 
 			    funcname == "lkmnosys" || funcname ~ /^freebsd/ ||
-			    funcname ~ /^linux/ || funcname ~ /^ibcs2/ ||
-			    funcname ~ /^xenix/ || funcname ~ /^cloudabi/) {
+			    funcname ~ /^linux/ || funcname ~ /^xenix/ ||
+			    funcname ~ /^cloudabi/) {
 				printf("%s, %s, NULL, 0, 0, %s, %s },", funcname, auditev, flags, thr_flag) > sysent
 				column = column + length(funcname) + length(auditev) + length(flags) + 3 
 			} else {
diff --git a/sys/mips/mips/elf_machdep.c b/sys/mips/mips/elf_machdep.c
index d5e92afa0d6d..e8791f821a62 100644
--- a/sys/mips/mips/elf_machdep.c
+++ b/sys/mips/mips/elf_machdep.c
@@ -55,7 +55,6 @@ __FBSDID("$FreeBSD$");
 struct sysentvec elf64_freebsd_sysvec = {
 	.sv_size	= SYS_MAXSYSCALL,
 	.sv_table	= sysent,
-	.sv_mask	= 0,
 	.sv_errsize	= 0,
 	.sv_errtbl	= NULL,
 	.sv_transtrap	= NULL,
@@ -111,7 +110,6 @@ elf64_dump_thread(struct thread *td __unused, void *dst __unused,
 struct sysentvec elf32_freebsd_sysvec = {
 	.sv_size	= SYS_MAXSYSCALL,
 	.sv_table	= sysent,
-	.sv_mask	= 0,
 	.sv_errsize	= 0,
 	.sv_errtbl	= NULL,
 	.sv_transtrap	= NULL,
diff --git a/sys/mips/mips/freebsd32_machdep.c b/sys/mips/mips/freebsd32_machdep.c
index 0c32cb65fbef..7ca31cd517cd 100644
--- a/sys/mips/mips/freebsd32_machdep.c
+++ b/sys/mips/mips/freebsd32_machdep.c
@@ -77,7 +77,6 @@ extern const char *freebsd32_syscallnames[];
 struct sysentvec elf32_freebsd_sysvec = {
 	.sv_size	= SYS_MAXSYSCALL,
 	.sv_table	= freebsd32_sysent,
-	.sv_mask	= 0,
 	.sv_errsize	= 0,
 	.sv_errtbl	= NULL,
 	.sv_transtrap	= NULL,
diff --git a/sys/mips/mips/trap.c b/sys/mips/mips/trap.c
index 042b6450b2e1..55beb0a24b39 100644
--- a/sys/mips/mips/trap.c
+++ b/sys/mips/mips/trap.c
@@ -442,8 +442,6 @@ cpu_fetch_syscall_args(struct thread *td)
 	 * XXX
 	 * Shouldn't this go before switching on the code?
 	 */
-	if (se->sv_mask)
-		sa->code &= se->sv_mask;
 
 	if (sa->code >= se->sv_size)
 		sa->callp = &se->sv_table[0];
diff --git a/sys/powerpc/powerpc/elf32_machdep.c b/sys/powerpc/powerpc/elf32_machdep.c
index 1a0d096d7f97..18ae37318fdd 100644
--- a/sys/powerpc/powerpc/elf32_machdep.c
+++ b/sys/powerpc/powerpc/elf32_machdep.c
@@ -83,7 +83,6 @@ struct sysentvec elf32_freebsd_sysvec = {
 #else
 	.sv_table	= sysent,
 #endif
-	.sv_mask	= 0,
 	.sv_errsize	= 0,
 	.sv_errtbl	= NULL,
 	.sv_transtrap	= NULL,
diff --git a/sys/powerpc/powerpc/elf64_machdep.c b/sys/powerpc/powerpc/elf64_machdep.c
index 9fd0964dc108..70e5cecdcbfa 100644
--- a/sys/powerpc/powerpc/elf64_machdep.c
+++ b/sys/powerpc/powerpc/elf64_machdep.c
@@ -58,7 +58,6 @@ static void exec_setregs_funcdesc(struct thread *td, struct image_params *imgp,
 struct sysentvec elf64_freebsd_sysvec_v1 = {
 	.sv_size	= SYS_MAXSYSCALL,
 	.sv_table	= sysent,
-	.sv_mask	= 0,
 	.sv_errsize	= 0,
 	.sv_errtbl	= NULL,
 	.sv_transtrap	= NULL,
@@ -97,7 +96,6 @@ INIT_SYSENTVEC(elf64_sysvec_v1, &elf64_freebsd_sysvec_v1);
 struct sysentvec elf64_freebsd_sysvec_v2 = {
 	.sv_size	= SYS_MAXSYSCALL,
 	.sv_table	= sysent,
-	.sv_mask	= 0,
 	.sv_errsize	= 0,
 	.sv_errtbl	= NULL,
 	.sv_transtrap	= NULL,
diff --git a/sys/powerpc/powerpc/exec_machdep.c b/sys/powerpc/powerpc/exec_machdep.c
index c506373ed5b5..4cb9fb8bbae5 100644
--- a/sys/powerpc/powerpc/exec_machdep.c
+++ b/sys/powerpc/powerpc/exec_machdep.c
@@ -867,8 +867,6 @@ cpu_set_syscall_retval(struct thread *td, int error)
 	if (tf->fixreg[0] == SYS___syscall &&
 	    (SV_PROC_FLAG(p, SV_ILP32))) {
 		int code = tf->fixreg[FIRSTARG + 1];
-		if (p->p_sysent->sv_mask)
-			code &= p->p_sysent->sv_mask;
 		fixup = (
 #if defined(COMPAT_FREEBSD6) && defined(SYS_freebsd6_lseek)
 		    code != SYS_freebsd6_lseek &&
diff --git a/sys/powerpc/powerpc/trap.c b/sys/powerpc/powerpc/trap.c
index 04decf3387ac..5133d3449267 100644
--- a/sys/powerpc/powerpc/trap.c
+++ b/sys/powerpc/powerpc/trap.c
@@ -622,8 +622,6 @@ cpu_fetch_syscall_args(struct thread *td)
 		}
 	}
 
- 	if (p->p_sysent->sv_mask)
-		sa->code &= p->p_sysent->sv_mask;
 	if (sa->code >= p->p_sysent->sv_size)
 		sa->callp = &p->p_sysent->sv_table[0];
 	else
diff --git a/sys/riscv/riscv/elf_machdep.c b/sys/riscv/riscv/elf_machdep.c
index a6909f59da47..909c91c67a71 100644
--- a/sys/riscv/riscv/elf_machdep.c
+++ b/sys/riscv/riscv/elf_machdep.c
@@ -61,7 +61,6 @@ __FBSDID("$FreeBSD$");
 struct sysentvec elf64_freebsd_sysvec = {
 	.sv_size	= SYS_MAXSYSCALL,
 	.sv_table	= sysent,
-	.sv_mask	= 0,
 	.sv_errsize	= 0,
 	.sv_errtbl	= NULL,
 	.sv_transtrap	= NULL,
diff --git a/sys/riscv/riscv/trap.c b/sys/riscv/riscv/trap.c
index 1a17bc316610..712b284fa99a 100644
--- a/sys/riscv/riscv/trap.c
+++ b/sys/riscv/riscv/trap.c
@@ -111,8 +111,6 @@ cpu_fetch_syscall_args(struct thread *td)
 		nap--;
 	}
 
-	if (p->p_sysent->sv_mask)
-		sa->code &= p->p_sysent->sv_mask;
 	if (sa->code >= p->p_sysent->sv_size)
 		sa->callp = &p->p_sysent->sv_table[0];
 	else
diff --git a/sys/sparc64/sparc64/elf_machdep.c b/sys/sparc64/sparc64/elf_machdep.c
index 0eaeff8f8103..1fbd09fa945e 100644
--- a/sys/sparc64/sparc64/elf_machdep.c
+++ b/sys/sparc64/sparc64/elf_machdep.c
@@ -59,7 +59,6 @@ __FBSDID("$FreeBSD$");
 static struct sysentvec elf64_freebsd_sysvec = {
 	.sv_size	= SYS_MAXSYSCALL,
 	.sv_table	= sysent,
-	.sv_mask	= 0,
 	.sv_errsize	= 0,
 	.sv_errtbl	= NULL,
 	.sv_transtrap	= NULL,
diff --git a/sys/sparc64/sparc64/trap.c b/sys/sparc64/sparc64/trap.c
index 39ff59e9310f..81c48b7699fd 100644
--- a/sys/sparc64/sparc64/trap.c
+++ b/sys/sparc64/sparc64/trap.c
@@ -558,8 +558,6 @@ cpu_fetch_syscall_args(struct thread *td)
 		regcnt--;
 	}
 
-	if (p->p_sysent->sv_mask)
-		sa->code &= p->p_sysent->sv_mask;
 	if (sa->code >= p->p_sysent->sv_size)
 		sa->callp = &p->p_sysent->sv_table[0];
 	else
diff --git a/sys/sys/sysent.h b/sys/sys/sysent.h
index 3938a8ab0e95..434b69b2f4e3 100644
--- a/sys/sys/sysent.h
+++ b/sys/sys/sysent.h
@@ -95,7 +95,6 @@ struct vnode;
 struct sysentvec {
 	int		sv_size;	/* number of entries */
 	struct sysent	*sv_table;	/* pointer to sysent */
-	u_int		sv_mask;	/* optional mask to index */
 	int		sv_errsize;	/* size of errno translation table */
 	const int 	*sv_errtbl;	/* errno translation table */
 	int		(*sv_transtrap)(int, int);