diff --git a/sys/amd64/linux/linux_sysvec.c b/sys/amd64/linux/linux_sysvec.c
--- a/sys/amd64/linux/linux_sysvec.c
+++ b/sys/amd64/linux/linux_sysvec.c
@@ -711,6 +711,8 @@
 	.sv_trap	= linux_vsyscall,
 	.sv_hwcap	= NULL,
 	.sv_hwcap2	= NULL,
+	.sv_hwcap3	= NULL,
+	.sv_hwcap4	= NULL,
 	.sv_onexec	= linux_on_exec_vmspace,
 	.sv_onexit	= linux_on_exit,
 	.sv_ontdexit	= linux_thread_dtor,
diff --git a/sys/amd64/linux32/linux32_sysvec.c b/sys/amd64/linux32/linux32_sysvec.c
--- a/sys/amd64/linux32/linux32_sysvec.c
+++ b/sys/amd64/linux32/linux32_sysvec.c
@@ -811,6 +811,8 @@
 	.sv_trap	= NULL,
 	.sv_hwcap	= NULL,
 	.sv_hwcap2	= NULL,
+	.sv_hwcap3	= NULL,
+	.sv_hwcap4	= NULL,
 	.sv_onexec	= linux_on_exec_vmspace,
 	.sv_onexit	= linux_on_exit,
 	.sv_ontdexit	= linux_thread_dtor,
diff --git a/sys/arm/arm/elf_machdep.c b/sys/arm/arm/elf_machdep.c
--- a/sys/arm/arm/elf_machdep.c
+++ b/sys/arm/arm/elf_machdep.c
@@ -97,6 +97,8 @@
 	.sv_trap	= NULL,
 	.sv_hwcap	= &elf_hwcap,
 	.sv_hwcap2	= &elf_hwcap2,
+	.sv_hwcap3	= NULL,
+	.sv_hwcap4	= NULL,
 	.sv_onexec_old	= exec_onexec_old,
 	.sv_onexit	= exit_onexit,
 	.sv_regset_begin = SET_BEGIN(__elfN(regset)),
diff --git a/sys/arm64/arm64/elf32_machdep.c b/sys/arm64/arm64/elf32_machdep.c
--- a/sys/arm64/arm64/elf32_machdep.c
+++ b/sys/arm64/arm64/elf32_machdep.c
@@ -134,6 +134,8 @@
 	.sv_trap	= NULL,
 	.sv_hwcap	= &elf32_hwcap,
 	.sv_hwcap2	= &elf32_hwcap2,
+	.sv_hwcap3	= NULL,
+	.sv_hwcap4	= NULL,
 	.sv_onexec_old	= exec_onexec_old,
 	.sv_onexit	= exit_onexit,
 	.sv_regset_begin = SET_BEGIN(__elfN(regset)),
diff --git a/sys/arm64/arm64/elf_machdep.c b/sys/arm64/arm64/elf_machdep.c
--- a/sys/arm64/arm64/elf_machdep.c
+++ b/sys/arm64/arm64/elf_machdep.c
@@ -101,6 +101,8 @@
 	.sv_trap	= NULL,
 	.sv_hwcap	= &elf_hwcap,
 	.sv_hwcap2	= &elf_hwcap2,
+	.sv_hwcap3	= NULL,
+	.sv_hwcap4	= NULL,
 	.sv_onexec_old	= exec_onexec_old,
 	.sv_protect	= arm64_exec_protect,
 	.sv_onexit	= exit_onexit,
diff --git a/sys/arm64/linux/linux_sysvec.c b/sys/arm64/linux/linux_sysvec.c
--- a/sys/arm64/linux/linux_sysvec.c
+++ b/sys/arm64/linux/linux_sysvec.c
@@ -458,6 +458,8 @@
 	.sv_trap	= NULL,
 	.sv_hwcap	= &linux_elf_hwcap,
 	.sv_hwcap2	= &linux_elf_hwcap2,
+	.sv_hwcap3	= NULL,
+	.sv_hwcap4	= NULL,
 	.sv_onexec	= linux_on_exec_vmspace,
 	.sv_onexit	= linux_on_exit,
 	.sv_ontdexit	= linux_thread_dtor,
diff --git a/sys/compat/linux/linux_misc.h b/sys/compat/linux/linux_misc.h
--- a/sys/compat/linux/linux_misc.h
+++ b/sys/compat/linux/linux_misc.h
@@ -85,7 +85,9 @@
 					 * differ from AT_PLATFORM.
 					 */
 #define	LINUX_AT_RANDOM		25	/* address of random bytes */
-#define	LINUX_AT_HWCAP2		26	/* CPU capabilities, second part */
+#define	LINUX_AT_HWCAP2		26	/* CPU capabilities */
+#define	LINUX_AT_HWCAP3		29	/* CPU capabilities */
+#define	LINUX_AT_HWCAP4		30	/* CPU capabilities */
 #define	LINUX_AT_EXECFN		31	/* filename of program */
 #define	LINUX_AT_SYSINFO	32	/* vsyscall */
 #define	LINUX_AT_SYSINFO_EHDR	33	/* vdso header */
diff --git a/sys/i386/linux/linux_sysvec.c b/sys/i386/linux/linux_sysvec.c
--- a/sys/i386/linux/linux_sysvec.c
+++ b/sys/i386/linux/linux_sysvec.c
@@ -606,6 +606,8 @@
 	.sv_trap	= NULL,
 	.sv_hwcap	= NULL,
 	.sv_hwcap2	= NULL,
+	.sv_hwcap3	= NULL,
+	.sv_hwcap4	= NULL,
 	.sv_onexec	= linux_on_exec_vmspace,
 	.sv_onexit	= linux_on_exit,
 	.sv_ontdexit	= linux_thread_dtor,
@@ -650,6 +652,8 @@
 	.sv_trap	= NULL,
 	.sv_hwcap	= NULL,
 	.sv_hwcap2	= NULL,
+	.sv_hwcap3	= NULL,
+	.sv_hwcap4	= NULL,
 	.sv_onexec	= linux_on_exec_vmspace,
 	.sv_onexit	= linux_on_exit,
 	.sv_ontdexit	= linux_thread_dtor,
diff --git a/sys/kern/imgact_elf.c b/sys/kern/imgact_elf.c
--- a/sys/kern/imgact_elf.c
+++ b/sys/kern/imgact_elf.c
@@ -1487,6 +1487,10 @@
 		AUXARGS_ENTRY(pos, AT_HWCAP, *imgp->sysent->sv_hwcap);
 	if (imgp->sysent->sv_hwcap2 != NULL)
 		AUXARGS_ENTRY(pos, AT_HWCAP2, *imgp->sysent->sv_hwcap2);
+	if (imgp->sysent->sv_hwcap3 != NULL)
+		AUXARGS_ENTRY(pos, AT_HWCAP3, *imgp->sysent->sv_hwcap3);
+	if (imgp->sysent->sv_hwcap4 != NULL)
+		AUXARGS_ENTRY(pos, AT_HWCAP4, *imgp->sysent->sv_hwcap4);
 	bsdflags = 0;
 	bsdflags |= __elfN(sigfastblock) ? ELF_BSDF_SIGFASTBLK : 0;
 	oc = atomic_load_int(&vm_overcommit);
diff --git a/sys/powerpc/powerpc/elf32_machdep.c b/sys/powerpc/powerpc/elf32_machdep.c
--- a/sys/powerpc/powerpc/elf32_machdep.c
+++ b/sys/powerpc/powerpc/elf32_machdep.c
@@ -134,6 +134,8 @@
 	.sv_trap	= NULL,
 	.sv_hwcap	= &cpu_features,
 	.sv_hwcap2	= &cpu_features2,
+	.sv_hwcap3	= NULL,
+	.sv_hwcap4	= NULL,
 	.sv_onexec_old	= exec_onexec_old,
 	.sv_onexit	= exit_onexit,
 	.sv_regset_begin = SET_BEGIN(__elfN(regset)),
diff --git a/sys/powerpc/powerpc/elf64_machdep.c b/sys/powerpc/powerpc/elf64_machdep.c
--- a/sys/powerpc/powerpc/elf64_machdep.c
+++ b/sys/powerpc/powerpc/elf64_machdep.c
@@ -97,6 +97,8 @@
 	.sv_trap	= NULL,
 	.sv_hwcap	= &cpu_features,
 	.sv_hwcap2	= &cpu_features2,
+	.sv_hwcap3	= NULL,
+	.sv_hwcap4	= NULL,
 	.sv_onexec_old	= exec_onexec_old,
 	.sv_onexit	= exit_onexit,
 	.sv_regset_begin = SET_BEGIN(__elfN(regset)),
@@ -139,6 +141,8 @@
 	.sv_trap	= NULL,
 	.sv_hwcap	= &cpu_features,
 	.sv_hwcap2	= &cpu_features2,
+	.sv_hwcap3	= NULL,
+	.sv_hwcap4	= NULL,
 	.sv_onexec_old	= exec_onexec_old,
 	.sv_onexit	= exit_onexit,
 	.sv_regset_begin = SET_BEGIN(__elfN(regset)),
diff --git a/sys/powerpc/powerpc/elf_common.c b/sys/powerpc/powerpc/elf_common.c
--- a/sys/powerpc/powerpc/elf_common.c
+++ b/sys/powerpc/powerpc/elf_common.c
@@ -93,6 +93,7 @@
 		AUXARGS_ENTRY(pos, AT_OLD_HWCAP, *imgp->sysent->sv_hwcap);
 	if (imgp->sysent->sv_hwcap2 != NULL)
 		AUXARGS_ENTRY(pos, AT_OLD_HWCAP2, *imgp->sysent->sv_hwcap2);
+	if (imgp->sysent->sv_hwcap3 != NULL)
 	AUXARGS_ENTRY(pos, AT_OLD_NULL, 0);
 
 	free(imgp->auxargs, M_TEMP);
diff --git a/sys/sys/elf_common.h b/sys/sys/elf_common.h
--- a/sys/sys/elf_common.h
+++ b/sys/sys/elf_common.h
@@ -1015,8 +1015,10 @@
 #define	AT_USRSTACKBASE	35	/* Top of user stack */
 #define	AT_USRSTACKLIM	36	/* Grow limit of user stack */
 #define	AT_CHERI_STATS	37	/* Reserved */
+#define	AT_HWCAP3	38	/* CPU feature flags 3. */
+#define	AT_HWCAP4	39	/* CPU feature flags 4. */
 
-#define	AT_COUNT	38	/* Count of defined aux entry types. */
+#define	AT_COUNT	40	/* Count of defined aux entry types. */
 
 /*
  * Relocation types.
diff --git a/sys/sys/sysent.h b/sys/sys/sysent.h
--- a/sys/sys/sysent.h
+++ b/sys/sys/sysent.h
@@ -145,6 +145,8 @@
 	int		(*sv_trap)(struct thread *);
 	u_long		*sv_hwcap;	/* Value passed in AT_HWCAP. */
 	u_long		*sv_hwcap2;	/* Value passed in AT_HWCAP2. */
+	u_long		*sv_hwcap3;	/* Value passed in AT_HWCAP3. */
+	u_long		*sv_hwcap4;	/* Value passed in AT_HWCAP4. */
 	const char	*(*sv_machine_arch)(struct proc *);
 	vm_offset_t	sv_fxrng_gen_offset;
 	void		(*sv_onexec_old)(struct thread *td);