Index: sys/conf/options.mips
===================================================================
--- sys/conf/options.mips
+++ sys/conf/options.mips
@@ -47,6 +47,8 @@
 CPU_XBURST	opt_global.h
 CPU_MALTA	opt_global.h
 
+MIPS_ALLOW_PAGE_ALIASING	opt_global.h
+
 # which MACHINE_ARCH architecture
 MIPS
 MIPSHF
Index: sys/kern/vfs_bio.c
===================================================================
--- sys/kern/vfs_bio.c
+++ sys/kern/vfs_bio.c
@@ -4933,7 +4933,7 @@
  * Once the MIPS pmap/cache code grows to support this function on
  * earlier chips, it should be flipped back off.
  */
-#ifdef	__mips__
+#if defined(__mips__) || !defined(MIPS_ALLOW_PAGE_ALIASING)
 static int buf_pager_relbuf = 1;
 #else
 static int buf_pager_relbuf = 0;
Index: sys/mips/conf/std.MALTA
===================================================================
--- sys/mips/conf/std.MALTA
+++ sys/mips/conf/std.MALTA
@@ -28,6 +28,7 @@
 options 	_KPOSIX_PRIORITY_SCHEDULING #Posix P1003_1B real-time extensions
 options 	CAPABILITY_MODE		# Capsicum capability mode
 options 	CAPABILITIES		# Capsicum capabilities
+options 	MIPS_ALLOW_PAGE_ALIASING #Support features requing page aliasing
 
 options 	TMPFS			#Efficient memory filesystem
 
Index: sys/mips/include/vmparam.h
===================================================================
--- sys/mips/include/vmparam.h
+++ sys/mips/include/vmparam.h
@@ -97,9 +97,11 @@
  * and some QED CPUs perform some virtual address checks before the
  * offset is calculated.
  */
-#define	USRSTACK		(VM_MAXUSER_ADDRESS - PAGE_SIZE)
+#define	SHAREDPAGE		(VM_MAXUSER_ADDRESS - PAGE_SIZE)
+#define	USRSTACK		SHAREDPAGE
 #ifdef __mips_n64
-#define	FREEBSD32_USRSTACK	(((vm_offset_t)0x80000000) - PAGE_SIZE)
+#define	FREEBSD32_SHAREDPAGE	(((vm_offset_t)0x80000000) - PAGE_SIZE)
+#define	FREEBSD32_USRSTACK	FREEBSD32_SHAREDPAGE
 #endif
 
 /*
Index: sys/mips/mips/elf_machdep.c
===================================================================
--- sys/mips/mips/elf_machdep.c
+++ sys/mips/mips/elf_machdep.c
@@ -77,14 +77,24 @@
 	.sv_setregs	= exec_setregs,
 	.sv_fixlimit	= NULL,
 	.sv_maxssiz	= NULL,
-	.sv_flags	= SV_ABI_FREEBSD | SV_LP64,
+	.sv_flags	= SV_ABI_FREEBSD | SV_LP64 |
+#ifdef MIPS_ALLOW_PAGE_ALIASING
+			    SV_SHP,
+#else
+			    0,
+#endif
 	.sv_set_syscall_retval = cpu_set_syscall_retval,
 	.sv_fetch_syscall_args = cpu_fetch_syscall_args,
 	.sv_syscallnames = syscallnames,
+#ifdef MIPS_ALLOW_PAGE_ALIASING
+	.sv_shared_page_base = SHAREDPAGE,
+	.sv_shared_page_len = PAGE_SIZE,
+#endif
 	.sv_schedtail	= NULL,
 	.sv_thread_detach = NULL,
 	.sv_trap	= NULL,
 };
+INIT_SYSENTVEC(elf64_sysvec, &elf64_freebsd_sysvec);
 
 static Elf64_Brandinfo freebsd_brand_info = {
 	.brand		= ELFOSABI_FREEBSD,
@@ -133,14 +143,24 @@
 	.sv_setregs	= exec_setregs,
 	.sv_fixlimit	= NULL,
 	.sv_maxssiz	= NULL,
-	.sv_flags	= SV_ABI_FREEBSD | SV_ILP32,
+	.sv_flags	= SV_ABI_FREEBSD | SV_ILP32 |
+#ifdef MIPS_ALLOW_PAGE_ALIASING
+			    SV_SHP,
+#else
+			    0,
+#endif
 	.sv_set_syscall_retval = cpu_set_syscall_retval,
 	.sv_fetch_syscall_args = cpu_fetch_syscall_args,
 	.sv_syscallnames = syscallnames,
+#ifdef MIPS_ALLOW_PAGE_ALIASING
+	.sv_shared_page_base = SHAREDPAGE,
+	.sv_shared_page_len = PAGE_SIZE,
+#endif
 	.sv_schedtail	= NULL,
 	.sv_thread_detach = NULL,
 	.sv_trap	= NULL,
 };
+INIT_SYSENTVEC(elf32_sysvec, &elf32_freebsd_sysvec);
 
 static Elf32_Brandinfo freebsd_brand_info = {
 	.brand		= ELFOSABI_FREEBSD,
Index: sys/mips/mips/freebsd32_machdep.c
===================================================================
--- sys/mips/mips/freebsd32_machdep.c
+++ sys/mips/mips/freebsd32_machdep.c
@@ -101,10 +101,19 @@
 	.sv_setregs	= freebsd32_exec_setregs,
 	.sv_fixlimit	= NULL,
 	.sv_maxssiz	= NULL,
-	.sv_flags	= SV_ABI_FREEBSD | SV_ILP32,
+	.sv_flags	= SV_ABI_FREEBSD | SV_ILP32 |
+#ifdef MIPS_ALLOW_PAGE_ALIASING
+			  SV_SHP,
+#else
+			  0,
+#endif
 	.sv_set_syscall_retval = cpu_set_syscall_retval,
 	.sv_fetch_syscall_args = cpu_fetch_syscall_args,
 	.sv_syscallnames = freebsd32_syscallnames,
+#ifdef MIPS_ALLOW_PAGE_ALIASING
+	.sv_shared_page_base = FREEBSD32_SHAREDPAGE,
+	.sv_shared_page_len = PAGE_SIZE,
+#endif
 	.sv_schedtail	= NULL,
 	.sv_thread_detach = NULL,
 	.sv_trap	= NULL,
Index: sys/mips/mips/pm_machdep.c
===================================================================
--- sys/mips/mips/pm_machdep.c
+++ sys/mips/mips/pm_machdep.c
@@ -176,10 +176,15 @@
 	regs->pc = (register_t)(intptr_t)catcher;
 	regs->t9 = (register_t)(intptr_t)catcher;
 	regs->sp = (register_t)(intptr_t)sfp;
-	/*
-	 * Signal trampoline code is at base of user stack.
-	 */
-	regs->ra = (register_t)(intptr_t)PS_STRINGS - *(p->p_sysent->sv_szsigcode);
+	if (p->p_sysent->sv_sigcode_base != 0) {
+		/* Signal trampoline code is in the shared page */
+		regs->ra = p->p_sysent->sv_sigcode_base;
+	} else {
+		/* Signal trampoline code is at base of user stack. */
+		/* XXX: GC this code path once shared page is stable */
+		regs->ra = (register_t)(intptr_t)PS_STRINGS -
+		    *(p->p_sysent->sv_szsigcode);
+	}
 	PROC_LOCK(p);
 	mtx_lock(&psp->ps_mtx);
 }