Building kernel/sys_ni.c with W=1 omits tons of -Wmissing-prototypes warnings. $ make W=1 kernel/sys_ni.o [ snip ] CC kernel/sys_ni.o In file included from kernel/sys_ni.c:10: ./arch/x86/include/asm/syscall_wrapper.h:83:14: warning: no previous prototype for '__x64_sys_io_setup' [-Wmissing-prototypes] 83 | __weak long __##abi##_##name(const struct pt_regs *__unused) \ | ^~ ./arch/x86/include/asm/syscall_wrapper.h:100:2: note: in expansion of macro '__COND_SYSCALL' 100 | __COND_SYSCALL(x64, sys_##name) | ^~~~~~~~~~~~~~ ./arch/x86/include/asm/syscall_wrapper.h:256:2: note: in expansion of macro '__X64_COND_SYSCALL' 256 | __X64_COND_SYSCALL(name) \ | ^~~~~~~~~~~~~~~~~~ kernel/sys_ni.c:39:1: note: in expansion of macro 'COND_SYSCALL' 39 | COND_SYSCALL(io_setup); | ^~~~~~~~~~~~ ./arch/x86/include/asm/syscall_wrapper.h:83:14: warning: no previous prototype for '__ia32_sys_io_setup' [-Wmissing-prototypes] 83 | __weak long __##abi##_##name(const struct pt_regs *__unused) \ | ^~ ./arch/x86/include/asm/syscall_wrapper.h:120:2: note: in expansion of macro '__COND_SYSCALL' 120 | __COND_SYSCALL(ia32, sys_##name) | ^~~~~~~~~~~~~~ ./arch/x86/include/asm/syscall_wrapper.h:257:2: note: in expansion of macro '__IA32_COND_SYSCALL' 257 | __IA32_COND_SYSCALL(name) | ^~~~~~~~~~~~~~~~~~~ kernel/sys_ni.c:39:1: note: in expansion of macro 'COND_SYSCALL' 39 | COND_SYSCALL(io_setup); | ^~~~~~~~~~~~ ... __SYS_STUB0() and __SYS_STUBx() defined a few lines above have forward declarations. Let's do likewise for __COND_SYSCALL() to fix the warnings. Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx> --- arch/x86/include/asm/syscall_wrapper.h | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/x86/include/asm/syscall_wrapper.h b/arch/x86/include/asm/syscall_wrapper.h index a84333adeef2..80c08c7d5e72 100644 --- a/arch/x86/include/asm/syscall_wrapper.h +++ b/arch/x86/include/asm/syscall_wrapper.h @@ -80,6 +80,7 @@ extern long __ia32_sys_ni_syscall(const struct pt_regs *regs); } #define __COND_SYSCALL(abi, name) \ + __weak long __##abi##_##name(const struct pt_regs *__unused); \ __weak long __##abi##_##name(const struct pt_regs *__unused) \ { \ return sys_ni_syscall(); \ -- 2.27.0