diff --git a/contrib/gcc/config/rs6000/freebsd.h b/contrib/gcc/config/rs6000/freebsd.h
index 34c93b8..fe8e0b6 100644
--- a/contrib/gcc/config/rs6000/freebsd.h
+++ b/contrib/gcc/config/rs6000/freebsd.h
@@ -242,3 +242,5 @@
 #define PROFILE_HOOK(LABEL) \
   do { if (TARGET_64BIT) output_profile_hook (LABEL); } while (0)
 
+#undef NEED_INDICATE_EXEC_STACK
+#define NEED_INDICATE_EXEC_STACK 1
diff --git a/lib/csu/powerpc/crti.S b/lib/csu/powerpc/crti.S
index 544bfa9..da83d1d 100644
--- a/lib/csu/powerpc/crti.S
+++ b/lib/csu/powerpc/crti.S
@@ -47,3 +47,5 @@ _fini:
 	stw 31,12(1)
 	stw 0,20(1)
 	mr 31,1
+
+	.section .note.GNU-stack,"",%progbits
diff --git a/lib/csu/powerpc/crtn.S b/lib/csu/powerpc/crtn.S
index d3baa70..7430118 100644
--- a/lib/csu/powerpc/crtn.S
+++ b/lib/csu/powerpc/crtn.S
@@ -42,3 +42,5 @@ __FBSDID("$FreeBSD$");
 	lwz 31,-4(11)
 	mr 1,11
 	blr
+
+	.section .note.GNU-stack,"",%progbits
diff --git a/lib/csu/powerpc64/crti.S b/lib/csu/powerpc64/crti.S
index edca7ba..16a22c2 100644
--- a/lib/csu/powerpc64/crti.S
+++ b/lib/csu/powerpc64/crti.S
@@ -59,3 +59,5 @@ _fini:
 	stdu 1,-48(1)
 	mflr 0
 	std 0,64(1)
+
+	.section .note.GNU-stack,"",%progbits
diff --git a/lib/csu/powerpc64/crtn.S b/lib/csu/powerpc64/crtn.S
index c62f913..39f21ae 100644
--- a/lib/csu/powerpc64/crtn.S
+++ b/lib/csu/powerpc64/crtn.S
@@ -38,3 +38,5 @@ __FBSDID("$FreeBSD$");
 	ld 0,16(%r1)
 	mtlr 0
 	blr
+
+	.section .note.GNU-stack,"",%progbits
diff --git a/lib/libc/powerpc/gen/_ctx_start.S b/lib/libc/powerpc/gen/_ctx_start.S
index a269e86..2d3cfcf 100644
--- a/lib/libc/powerpc/gen/_ctx_start.S
+++ b/lib/libc/powerpc/gen/_ctx_start.S
@@ -41,3 +41,5 @@
 	 * above branch.
 	 */
 	bl	PIC_PLT(CNAME(abort))	/* abort */
+
+	.section .note.GNU-stack,"",%progbits
diff --git a/lib/libc/powerpc/gen/_setjmp.S b/lib/libc/powerpc/gen/_setjmp.S
index 6d6e5e0..9b9f86e 100644
--- a/lib/libc/powerpc/gen/_setjmp.S
+++ b/lib/libc/powerpc/gen/_setjmp.S
@@ -69,3 +69,5 @@ ENTRY(_longjmp)
 	bnelr
 	li	%r3,1
 	blr
+
+	.section .note.GNU-stack,"",%progbits
diff --git a/lib/libc/powerpc/gen/fabs.S b/lib/libc/powerpc/gen/fabs.S
index 79475ca..7891012 100644
--- a/lib/libc/powerpc/gen/fabs.S
+++ b/lib/libc/powerpc/gen/fabs.S
@@ -33,3 +33,5 @@ __FBSDID("$FreeBSD$");
 ENTRY(fabs)
 	fabs	%f1,%f1
 	blr
+
+	.section .note.GNU-stack,"",%progbits
diff --git a/lib/libc/powerpc/gen/setjmp.S b/lib/libc/powerpc/gen/setjmp.S
index a796120..6aaf81c 100644
--- a/lib/libc/powerpc/gen/setjmp.S
+++ b/lib/libc/powerpc/gen/setjmp.S
@@ -89,3 +89,4 @@ ENTRY(__longjmp)
 	li	%r3,1
 	blr
 
+	.section .note.GNU-stack,"",%progbits
diff --git a/lib/libc/powerpc/gen/sigsetjmp.S b/lib/libc/powerpc/gen/sigsetjmp.S
index 3d5d1e5..5a6fd21 100644
--- a/lib/libc/powerpc/gen/sigsetjmp.S
+++ b/lib/libc/powerpc/gen/sigsetjmp.S
@@ -95,3 +95,5 @@ ENTRY(siglongjmp)
 	bnelr
 	li	%r3,1
 	blr
+
+	.section .note.GNU-stack,"",%progbits
diff --git a/lib/libc/powerpc/sys/brk.S b/lib/libc/powerpc/sys/brk.S
index 9223db3..018eec9 100644
--- a/lib/libc/powerpc/sys/brk.S
+++ b/lib/libc/powerpc/sys/brk.S
@@ -71,3 +71,5 @@ ENTRY(brk)
 
 1:
 	b	PIC_PLT(HIDENAME(cerror))
+
+	.section .note.GNU-stack,"",%progbits
diff --git a/lib/libc/powerpc/sys/cerror.S b/lib/libc/powerpc/sys/cerror.S
index 91a3006..7667cb8 100644
--- a/lib/libc/powerpc/sys/cerror.S
+++ b/lib/libc/powerpc/sys/cerror.S
@@ -54,4 +54,4 @@ HIDENAME(cerror):
 	li	%r4,-1
 	blr				/* return to callers caller */
 
-
+	.section .note.GNU-stack,"",%progbits
diff --git a/lib/libc/powerpc/sys/exect.S b/lib/libc/powerpc/sys/exect.S
index d5f9c20..3c39b3c 100644
--- a/lib/libc/powerpc/sys/exect.S
+++ b/lib/libc/powerpc/sys/exect.S
@@ -37,3 +37,5 @@ ENTRY(exect)
 	blr
 1:
 	b	PIC_PLT(HIDENAME(cerror))
+
+	.section .note.GNU-stack,"",%progbits
diff --git a/lib/libc/powerpc/sys/pipe.S b/lib/libc/powerpc/sys/pipe.S
index 3ca2358..3f6d9a4 100644
--- a/lib/libc/powerpc/sys/pipe.S
+++ b/lib/libc/powerpc/sys/pipe.S
@@ -41,3 +41,5 @@ ENTRY(pipe)
 	blr			/* and return 0 */
 1:
 	b	PIC_PLT(HIDENAME(cerror))
+
+	.section .note.GNU-stack,"",%progbits
diff --git a/lib/libc/powerpc/sys/ptrace.S b/lib/libc/powerpc/sys/ptrace.S
index f47fc67..0bc25c9 100644
--- a/lib/libc/powerpc/sys/ptrace.S
+++ b/lib/libc/powerpc/sys/ptrace.S
@@ -56,3 +56,5 @@ ENTRY(ptrace)
 	blr
 1:
 	b	PIC_PLT(HIDENAME(cerror))
+
+	.section .note.GNU-stack,"",%progbits
diff --git a/lib/libc/powerpc/sys/sbrk.S b/lib/libc/powerpc/sys/sbrk.S
index 47fc0fe..a5e4020 100644
--- a/lib/libc/powerpc/sys/sbrk.S
+++ b/lib/libc/powerpc/sys/sbrk.S
@@ -68,3 +68,5 @@ ENTRY(sbrk)
 	blr
 2:
 	b	PIC_PLT(HIDENAME(cerror))
+
+	.section .note.GNU-stack,"",%progbits
diff --git a/lib/libc/powerpc/sys/setlogin.S b/lib/libc/powerpc/sys/setlogin.S
index c65e639..e0d6d3c 100644
--- a/lib/libc/powerpc/sys/setlogin.S
+++ b/lib/libc/powerpc/sys/setlogin.S
@@ -47,3 +47,5 @@ SYSCALL(setlogin)
 	stw	%r5,CNAME(_logname_valid)@l(%r4)
 #endif
 	blr
+
+	.section .note.GNU-stack,"",%progbits
diff --git a/lib/libc/powerpc64/gen/_ctx_start.S b/lib/libc/powerpc64/gen/_ctx_start.S
index 4dabd13..6e373c8 100644
--- a/lib/libc/powerpc64/gen/_ctx_start.S
+++ b/lib/libc/powerpc64/gen/_ctx_start.S
@@ -45,3 +45,5 @@
 	 */
 	nop
 	bl	PIC_PLT(CNAME(abort))	/* abort */
+
+	.section .note.GNU-stack,"",%progbits
diff --git a/lib/libc/powerpc64/gen/_setjmp.S b/lib/libc/powerpc64/gen/_setjmp.S
index e7ea5f7..a5c247d 100644
--- a/lib/libc/powerpc64/gen/_setjmp.S
+++ b/lib/libc/powerpc64/gen/_setjmp.S
@@ -114,3 +114,5 @@ ENTRY(_longjmp)
 	bnelr
 	li	%r3,1
 	blr
+
+	.section .note.GNU-stack,"",%progbits
diff --git a/lib/libc/powerpc64/gen/fabs.S b/lib/libc/powerpc64/gen/fabs.S
index 79475ca..7891012 100644
--- a/lib/libc/powerpc64/gen/fabs.S
+++ b/lib/libc/powerpc64/gen/fabs.S
@@ -33,3 +33,5 @@ __FBSDID("$FreeBSD$");
 ENTRY(fabs)
 	fabs	%f1,%f1
 	blr
+
+	.section .note.GNU-stack,"",%progbits
diff --git a/lib/libc/powerpc64/gen/setjmp.S b/lib/libc/powerpc64/gen/setjmp.S
index fff8aee..0f33ab2 100644
--- a/lib/libc/powerpc64/gen/setjmp.S
+++ b/lib/libc/powerpc64/gen/setjmp.S
@@ -137,3 +137,4 @@ ENTRY(__longjmp)
 	li	%r3,1
 	blr
 
+	.section .note.GNU-stack,"",%progbits
diff --git a/lib/libc/powerpc64/gen/sigsetjmp.S b/lib/libc/powerpc64/gen/sigsetjmp.S
index 9a26a8f..7b50f9f 100644
--- a/lib/libc/powerpc64/gen/sigsetjmp.S
+++ b/lib/libc/powerpc64/gen/sigsetjmp.S
@@ -142,3 +142,5 @@ ENTRY(siglongjmp)
 	bnelr
 	li	%r3,1
 	blr
+
+	.section .note.GNU-stack,"",%progbits
diff --git a/lib/libc/powerpc64/sys/brk.S b/lib/libc/powerpc64/sys/brk.S
index 59b891c..1e71663 100644
--- a/lib/libc/powerpc64/sys/brk.S
+++ b/lib/libc/powerpc64/sys/brk.S
@@ -69,3 +69,5 @@ ENTRY(brk)
 	ld	%r0,16(%r1)
 	mtlr	%r0
 	blr
+
+	.section .note.GNU-stack,"",%progbits
diff --git a/lib/libc/powerpc64/sys/cerror.S b/lib/libc/powerpc64/sys/cerror.S
index 9afb0f4..db7a10f 100644
--- a/lib/libc/powerpc64/sys/cerror.S
+++ b/lib/libc/powerpc64/sys/cerror.S
@@ -57,4 +57,4 @@ ENTRY(HIDENAME(cerror))
 	li	%r4,-1
 	blr
 
-
+	.section .note.GNU-stack,"",%progbits
diff --git a/lib/libc/powerpc64/sys/exect.S b/lib/libc/powerpc64/sys/exect.S
index eecbd11..b752fb8 100644
--- a/lib/libc/powerpc64/sys/exect.S
+++ b/lib/libc/powerpc64/sys/exect.S
@@ -45,3 +45,5 @@ ENTRY(exect)
 	ld	%r0,16(%r1)
 	mtlr	%r0
 	blr
+
+	.section .note.GNU-stack,"",%progbits
diff --git a/lib/libc/powerpc64/sys/pipe.S b/lib/libc/powerpc64/sys/pipe.S
index fe115b0..0a92df5 100644
--- a/lib/libc/powerpc64/sys/pipe.S
+++ b/lib/libc/powerpc64/sys/pipe.S
@@ -49,3 +49,5 @@ ENTRY(pipe)
 	ld	%r0,16(%r1)
 	mtlr	%r0
 	blr
+
+	.section .note.GNU-stack,"",%progbits
diff --git a/lib/libc/powerpc64/sys/ptrace.S b/lib/libc/powerpc64/sys/ptrace.S
index 3ec4915..bda17e8 100644
--- a/lib/libc/powerpc64/sys/ptrace.S
+++ b/lib/libc/powerpc64/sys/ptrace.S
@@ -63,3 +63,5 @@ ENTRY(ptrace)
 	ld	%r0,16(%r1)
 	mtlr	%r0
 	blr
+
+	.section .note.GNU-stack,"",%progbits
diff --git a/lib/libc/powerpc64/sys/sbrk.S b/lib/libc/powerpc64/sys/sbrk.S
index a7a9c77..c767049 100644
--- a/lib/libc/powerpc64/sys/sbrk.S
+++ b/lib/libc/powerpc64/sys/sbrk.S
@@ -64,3 +64,5 @@ ENTRY(sbrk)
 	ld	%r0,16(%r1)
 	mtlr	%r0
 	blr
+
+	.section .note.GNU-stack,"",%progbits
diff --git a/lib/libc/powerpc64/sys/setlogin.S b/lib/libc/powerpc64/sys/setlogin.S
index 19e3212..6183407 100644
--- a/lib/libc/powerpc64/sys/setlogin.S
+++ b/lib/libc/powerpc64/sys/setlogin.S
@@ -37,3 +37,5 @@ SYSCALL(setlogin)
 	li	%r5,0
 	stw	%r5,CNAME(_logname_valid)@toc@l(%r4)
 	blr
+
+	.section .note.GNU-stack,"",%progbits
diff --git a/lib/libcompiler_rt/Makefile b/lib/libcompiler_rt/Makefile
index a43672a..dcfcf74 100644
--- a/lib/libcompiler_rt/Makefile
+++ b/lib/libcompiler_rt/Makefile
@@ -156,7 +156,8 @@ SYMLINKS+=libcompiler_rt_p.a ${LIBDIR}/libgcc_p.a
 . endif
 .endif
 
-.if ${MACHINE_CPUARCH} == "amd64" || ${MACHINE_CPUARCH} == "i386"
+.if ${MACHINE_CPUARCH} == "amd64" || ${MACHINE_CPUARCH} == "i386" || \
+    ${MACHINE_CPUARCH} == "powerpc"
 AFLAGS+=--noexecstack
 ACFLAGS+=-Wa,--noexecstack
 .endif
diff --git a/libexec/rtld-elf/powerpc/rtld_start.S b/libexec/rtld-elf/powerpc/rtld_start.S
index 00692d2..28ec19b 100644
--- a/libexec/rtld-elf/powerpc/rtld_start.S
+++ b/libexec/rtld-elf/powerpc/rtld_start.S
@@ -197,4 +197,4 @@ _ENTRY(_rtld_powerpc_pltcall)
         mtctr   %r11
         bctr				# (*jmptab[index])()
 
-
+	.section .note.GNU-stack,"",%progbits
diff --git a/libexec/rtld-elf/powerpc64/rtld_start.S b/libexec/rtld-elf/powerpc64/rtld_start.S
index 3c962c2..0694de1 100644
--- a/libexec/rtld-elf/powerpc64/rtld_start.S
+++ b/libexec/rtld-elf/powerpc64/rtld_start.S
@@ -159,3 +159,4 @@ _ENTRY(_rtld_bind_start)
 
 	bctr				# jump to target
 
+	.section .note.GNU-stack,"",%progbits
diff --git a/sys/kern/imgact_elf.c b/sys/kern/imgact_elf.c
index 38029b0..9ce984e 100644
--- a/sys/kern/imgact_elf.c
+++ b/sys/kern/imgact_elf.c
@@ -115,7 +115,12 @@ static int elf_legacy_coredump = 0;
 SYSCTL_INT(_debug, OID_AUTO, __elfN(legacy_coredump), CTLFLAG_RW, 
     &elf_legacy_coredump, 0, "");
 
-static int __elfN(nxstack) = 0;
+static int __elfN(nxstack) =
+#ifdef __amd64__ /* both 64 and 32 bit */
+	1;
+#else
+	0;
+#endif
 SYSCTL_INT(__CONCAT(_kern_elf, __ELF_WORD_SIZE), OID_AUTO,
     nxstack, CTLFLAG_RW, &__elfN(nxstack), 0,
     __XSTRING(__CONCAT(ELF, __ELF_WORD_SIZE)) ": enable non-executable stack");
diff --git a/sys/powerpc/include/vmparam.h b/sys/powerpc/include/vmparam.h
index b92ce70..96ba194 100644
--- a/sys/powerpc/include/vmparam.h
+++ b/sys/powerpc/include/vmparam.h
@@ -35,7 +35,7 @@
 #ifndef _MACHINE_VMPARAM_H_
 #define	_MACHINE_VMPARAM_H_
 
-#define	USRSTACK	VM_MAXUSER_ADDRESS
+#define	USRSTACK	SHAREDPAGE
 
 #ifndef	MAXTSIZ
 #define	MAXTSIZ		(64*1024*1024)		/* max text size */
@@ -64,10 +64,12 @@
 #ifdef __powerpc64__
 #define	VM_MIN_ADDRESS		(0x0000000000000000UL)
 #define	VM_MAXUSER_ADDRESS	(0x7ffffffffffff000UL)
+#define	SHAREDPAGE		(VM_MAXUSER_ADDRESS - PAGE_SIZE)
 #define	VM_MAX_ADDRESS		(0xffffffffffffffffUL)
 #else
 #define	VM_MIN_ADDRESS		((vm_offset_t)0)
 #define	VM_MAXUSER_ADDRESS	((vm_offset_t)0x7ffff000)
+#define	SHAREDPAGE		(VM_MAXUSER_ADDRESS - PAGE_SIZE)
 #define	VM_MAX_ADDRESS		VM_MAXUSER_ADDRESS
 #endif
 #else /* LOCORE */
@@ -77,8 +79,8 @@
 #endif
 #endif /* LOCORE */
 
-#define	FREEBSD32_USRSTACK	0x7ffff000
-
+#define	FREEBSD32_SHAREDPAGE	0x7ffff000
+#define	FREEBSD32_USRSTACK	(FREEBSD32_SHAREDPAGE - PAGE_SIZE)
 
 #ifdef AIM
 #define	KERNBASE		0x00100000UL	/* start of kernel virtual */
diff --git a/sys/powerpc/powerpc/elf32_machdep.c b/sys/powerpc/powerpc/elf32_machdep.c
index 1761215..e35bd19 100644
--- a/sys/powerpc/powerpc/elf32_machdep.c
+++ b/sys/powerpc/powerpc/elf32_machdep.c
@@ -101,10 +101,13 @@ struct sysentvec elf32_freebsd_sysvec = {
 #endif
 	.sv_fixlimit	= NULL,
 	.sv_maxssiz	= NULL,
-	.sv_flags	= SV_ABI_FREEBSD | SV_ILP32,
+	.sv_flags	= SV_ABI_FREEBSD | SV_ILP32 | SV_SHP,
 	.sv_set_syscall_retval = cpu_set_syscall_retval,
 	.sv_fetch_syscall_args = cpu_fetch_syscall_args,
+	.sv_shared_page_base = FREEBSD32_SHAREDPAGE,
+	.sv_shared_page_len = PAGE_SIZE,
 };
+INIT_SYSENTVEC(elf32_sysvec, &elf32_freebsd_sysvec);
 
 static Elf32_Brandinfo freebsd_brand_info = {
 	.brand		= ELFOSABI_FREEBSD,
diff --git a/sys/powerpc/powerpc/elf64_machdep.c b/sys/powerpc/powerpc/elf64_machdep.c
index 1b51920..af5b12d 100644
--- a/sys/powerpc/powerpc/elf64_machdep.c
+++ b/sys/powerpc/powerpc/elf64_machdep.c
@@ -76,11 +76,14 @@ struct sysentvec elf64_freebsd_sysvec = {
 	.sv_setregs	= exec_setregs,
 	.sv_fixlimit	= NULL,
 	.sv_maxssiz	= NULL,
-	.sv_flags	= SV_ABI_FREEBSD | SV_LP64,
+	.sv_flags	= SV_ABI_FREEBSD | SV_LP64 | SV_SHP,
 	.sv_set_syscall_retval = cpu_set_syscall_retval,
 	.sv_fetch_syscall_args = cpu_fetch_syscall_args,
 	.sv_syscallnames = syscallnames,
+	.sv_shared_page_base = SHAREDPAGE,
+	.sv_shared_page_len = PAGE_SIZE,
 };
+INIT_SYSENTVEC(elf64_sysvec, &elf64_freebsd_sysvec);
 
 static Elf64_Brandinfo freebsd_brand_info = {
 	.brand		= ELFOSABI_FREEBSD,
@@ -114,7 +117,6 @@ SYSINIT(oelf64, SI_SUB_EXEC, SI_ORDER_ANY,
 	(sysinit_cfunc_t) elf64_insert_brand_entry,
 	&freebsd_brand_oinfo);
 
-
 void
 elf64_dump_thread(struct thread *td __unused, void *dst __unused,
     size_t *off __unused)
diff --git a/sys/powerpc/powerpc/exec_machdep.c b/sys/powerpc/powerpc/exec_machdep.c
index efcd805..9d38d70 100644
--- a/sys/powerpc/powerpc/exec_machdep.c
+++ b/sys/powerpc/powerpc/exec_machdep.c
@@ -290,8 +290,7 @@ sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
 	mtx_unlock(&psp->ps_mtx);
 	PROC_UNLOCK(p);
 
-	tf->srr0 = (register_t)(p->p_sysent->sv_psstrings -
-	    *(p->p_sysent->sv_szsigcode));
+	tf->srr0 = (register_t)p->p_sysent->sv_sigcode_base;
 
 	/*
 	 * copy the frame out to userland.