Bugfix: allow no-exec (NX) stack

x86_32/sha256_xmm.asm

@@ -250,3 +250,10 @@ LAB_RET:
 	pop	edi
 	pop	esi
 	retn	4
+
+%ifidn __OUTPUT_FORMAT__,elf
+section .note.GNU-stack noalloc noexec nowrite progbits
+%endif
+%ifidn __OUTPUT_FORMAT__,elf32
+section .note.GNU-stack noalloc noexec nowrite progbits
+%endif

x86_64/sha256_sse4_amd64.asm

@@ -256,3 +256,10 @@ LAB_LOOP:
 LAB_RET:
 	pop	rbx
 	ret
+
+%ifidn __OUTPUT_FORMAT__,elf
+section .note.GNU-stack noalloc noexec nowrite progbits
+%endif
+%ifidn __OUTPUT_FORMAT__,elf64
+section .note.GNU-stack noalloc noexec nowrite progbits
+%endif

x86_64/sha256_xmm_amd64.asm

@@ -320,3 +320,10 @@ sha256_sse2_64_new:
 LAB_RET:
     pop       rbx
     ret
+
+%ifidn __OUTPUT_FORMAT__,elf
+section .note.GNU-stack noalloc noexec nowrite progbits
+%endif
+%ifidn __OUTPUT_FORMAT__,elf64
+section .note.GNU-stack noalloc noexec nowrite progbits
+%endif