When I compiled uml on x86_64, I got this warning: MODPOST vmlinux.o WARNING: vmlinux.o (.__syscall_stub.2): unexpected non-allocatable section. Did you forget to use "ax"/"aw" in a .S file? Note that for example <linux/init.h> contains section definitions for use in .S files. Because modpost checks for missing SHF_ALLOC section flag. So just add it. :) Signed-off-by: WANG Cong <amwang@redhat.com> Cc: Jeff Dike <jdike@addtoit.com> Cc: Sam Ravnborg <sam@ravnborg.org> --- --- a/arch/um/sys-x86_64/stub.S +++ b/arch/um/sys-x86_64/stub.S @@ -1,7 +1,7 @@ #include "as-layout.h" .globl syscall_stub -.section .__syscall_stub, "x" +.section .__syscall_stub, "ax" syscall_stub: syscall /* We don't have 64-bit constants, so this constructs the address --- a/arch/um/sys-i386/stub.S +++ b/arch/um/sys-i386/stub.S @@ -1,7 +1,7 @@ #include "as-layout.h" .globl syscall_stub -.section .__syscall_stub, "x" +.section .__syscall_stub, "ax" .globl batch_syscall_stub batch_syscall_stub: