Index: sys/kern/imgact_elf.c
===================================================================
--- sys/kern/imgact_elf.c
+++ sys/kern/imgact_elf.c
@@ -1248,6 +1248,7 @@
 	map = &vmspace->vm_map;
 
 	imgp->proc->p_sysent = sv;
+	imgp->proc->p_elf_brand_info = brand_info;
 
 	maxv = vm_map_max(map) - lim_max(td, RLIMIT_STACK);
 	if (et_dyn_addr == ET_DYN_ADDR_RAND) {
Index: sys/kern/kern_thread.c
===================================================================
--- sys/kern/kern_thread.c
+++ sys/kern/kern_thread.c
@@ -100,7 +100,7 @@
     "struct proc KBI p_filemon");
 _Static_assert(offsetof(struct proc, p_comm) == 0x3d0,
     "struct proc KBI p_comm");
-_Static_assert(offsetof(struct proc, p_emuldata) == 0x4b0,
+_Static_assert(offsetof(struct proc, p_emuldata) == 0x4b8,
     "struct proc KBI p_emuldata");
 #endif
 #ifdef __i386__
@@ -120,7 +120,7 @@
     "struct proc KBI p_filemon");
 _Static_assert(offsetof(struct proc, p_comm) == 0x27c,
     "struct proc KBI p_comm");
-_Static_assert(offsetof(struct proc, p_emuldata) == 0x308,
+_Static_assert(offsetof(struct proc, p_emuldata) == 0x30c,
     "struct proc KBI p_emuldata");
 #endif
 
Index: sys/sys/imgact_elf.h
===================================================================
--- sys/sys/imgact_elf.h
+++ sys/sys/imgact_elf.h
@@ -89,6 +89,7 @@
 	Elf_Brandnote *brand_note;
 	boolean_t	(*header_supported)(struct image_params *,
 	    int32_t *, uint32_t *);
+		/* High 8 bits of flags is private to the ABI */
 #define	BI_CAN_EXEC_DYN		0x0001
 #define	BI_BRAND_NOTE		0x0002	/* May have note.ABI-tag section. */
 #define	BI_BRAND_NOTE_MANDATORY	0x0004	/* Must have note.ABI-tag section. */
Index: sys/sys/proc.h
===================================================================
--- sys/sys/proc.h
+++ sys/sys/proc.h
@@ -702,6 +702,8 @@
 					       our subtree. */
 	uint16_t	p_elf_machine;	/* (x) ELF machine type */
 	uint64_t	p_elf_flags;	/* (x) ELF flags */
+	void		*p_elf_brand_info; /* (x) Elf_brandinfo, NULL for
+						  non Elf binaries */
 /* End area that is copied on creation. */
 #define	p_endcopy	p_xexit