Index: sys/kern/kern_exec.c
===================================================================
--- sys/kern/kern_exec.c
+++ sys/kern/kern_exec.c
@@ -361,7 +361,6 @@
 	struct ucred *oldcred;
 	struct uidinfo *euip = NULL;
 	register_t *stack_base;
-	int error, i;
 	struct image_params image_params, *imgp;
 	struct vattr attr;
 	int (*img_first)(struct image_params *);
@@ -380,6 +379,8 @@
 #ifdef HWPMC_HOOKS
 	struct pmckern_procexec pe;
 #endif
+	int error, i, orig_osrel;
+	uint32_t orig_fctl0;
 	static const char fexecv_proc_title[] = "(fexecv)";
 
 	imgp = &image_params;
@@ -405,6 +406,8 @@
 	imgp->attr = &attr;
 	imgp->args = args;
 	oldcred = p->p_ucred;
+	orig_osrel = imgp->proc->p_osrel;
+	orig_fctl0 = imgp->proc->p_fctl0;
 
 #ifdef MAC
 	error = mac_execve_enter(imgp, mac_p);
@@ -868,6 +871,11 @@
 	SDT_PROBE1(proc, , , exec__success, args->fname);
 
 exec_fail_dealloc:
+	if (error != 0) {
+		p->p_osrel = orig_osrel;
+		p->p_fctl0 = orig_fctl0;
+	}
+
 	if (imgp->firstpage != NULL)
 		exec_unmap_first_page(imgp);
 
Index: sys/sys/elf_common.h
===================================================================
--- sys/sys/elf_common.h
+++ sys/sys/elf_common.h
@@ -784,6 +784,7 @@
 /* NT_FREEBSD_FEATURE_CTL desc[0] bits */
 #define	NT_FREEBSD_FCTL_ASLR_DISABLE	0x00000001
 #define	NT_FREEBSD_FCTL_PROTMAX_DISABLE	0x00000002
+#define	NT_FREEBSD_FCTL_STKGAP_DISABLE	0x00000004
 
 /* Values for n_type.  Used in core files. */
 #define	NT_PRSTATUS	1	/* Process status. */
Index: sys/vm/vm_map.c
===================================================================
--- sys/vm/vm_map.c
+++ sys/vm/vm_map.c
@@ -69,6 +69,7 @@
 
 #include <sys/param.h>
 #include <sys/systm.h>
+#include <sys/elf.h>
 #include <sys/kernel.h>
 #include <sys/ktr.h>
 #include <sys/lock.h>
@@ -4137,7 +4138,8 @@
 	    addrbos + max_ssize > vm_map_max(map) ||
 	    addrbos + max_ssize <= addrbos)
 		return (KERN_INVALID_ADDRESS);
-	sgp = (curproc->p_flag2 & P2_STKGAP_DISABLE) != 0 ? 0 :
+	sgp = ((curproc->p_flag2 & P2_STKGAP_DISABLE) != 0 ||
+	    (curproc->p_fctl0 & NT_FREEBSD_FCTL_STKGAP_DISABLE) != 0) ? 0 :
 	    (vm_size_t)stack_guard_page * PAGE_SIZE;
 	if (sgp >= max_ssize)
 		return (KERN_INVALID_ARGUMENT);
@@ -4274,7 +4276,8 @@
 	} else {
 		return (KERN_FAILURE);
 	}
-	guard = (curproc->p_flag2 & P2_STKGAP_DISABLE) != 0 ? 0 :
+	guard = ((curproc->p_flag2 & P2_STKGAP_DISABLE) != 0 ||
+	    (curproc->p_fctl0 & NT_FREEBSD_FCTL_STKGAP_DISABLE) != 0) ? 0 :
 	    gap_entry->next_read;
 	max_grow = gap_entry->end - gap_entry->start;
 	if (guard > max_grow)
Index: tools/tools/controlelf/controlelf.c
===================================================================
--- tools/tools/controlelf/controlelf.c
+++ tools/tools/controlelf/controlelf.c
@@ -63,7 +63,9 @@
 
 static struct ControlFeatures featurelist[] = {
 	{ "aslr",	NT_FREEBSD_FCTL_ASLR_DISABLE,	"Disable ASLR" },
-	{ "protmax",	NT_FREEBSD_FCTL_PROTMAX_DISABLE,"Disable implicit PROT_MAX" },
+	{ "protmax",	NT_FREEBSD_FCTL_PROTMAX_DISABLE,
+	    "Disable implicit PROT_MAX" },
+	{ "stackgap",	NT_FREEBSD_FCTL_STKGAP_DISABLE, "Disable stack gap" },
 };
 
 static struct option long_opts[] = {