-Wmissing-prototypes warnings in user-mode linux

[Jani Nikula]

On Tue, 05 Mar 2024, Johannes Berg <johannes at sipsolutions.net> wrote:
> On Tue, 2024-03-05 at 12:34 +0200, Jani Nikula wrote:
>> We're seeing a lot of -Wmissing-prototypes warnings when building
>> user-mode Linux. For example, our CI hits things like [1], and it's just
>> extra noise in the build.
>
> Yeah ...
>
>> I started adding some prototypes, but I lost my way around the arch/
>> subdirectory a bit. I'm not always quite sure what should or could be
>> included where, or whether a new header should be added instead, etc.,
>> so it wasn't going as quickly as I'd hoped.
>> 
>> Do you perhaps already have plans or, better yet, patches to address
>> this? Feels like it should be fairly quick for someone familiar with the
>> arch/um codebase.
>
> I think this series addressed most already?
>
> https://patchwork.ozlabs.org/project/linux-um/list/?series=393619
>
> But I haven't checked myself yet.

Oh, nice, it certainly helps!

But after applying that in my branch, I do still get a bunch of
warnings.

BR,
Jani.



../arch/x86/um/user-offsets.c:17:6: warning: no previous prototype for ‘foo’ [-Wmissing-prototypes]
   17 | void foo(void)
      |      ^~~
In file included from ../arch/um/kernel/asm-offsets.c:1:
../arch/x86/um/shared/sysdep/kernel-offsets.h:9:6: warning: no previous prototype for ‘foo’ [-Wmissing-prototypes]
    9 | void foo(void)
      |      ^~~
../arch/x86/um/os-Linux/registers.c:146:15: warning: no previous prototype for ‘get_thread_reg’ [-Wmissing-prototypes]
  146 | unsigned long get_thread_reg(int reg, jmp_buf *buf)
      |               ^~~~~~~~~~~~~~
../arch/x86/um/vdso/um_vdso.c:16:5: warning: no previous prototype for ‘__vdso_clock_gettime’ [-Wmissing-prototypes]
   16 | int __vdso_clock_gettime(clockid_t clock, struct __kernel_old_timespec *ts)
      |     ^~~~~~~~~~~~~~~~~~~~
../arch/x86/um/vdso/um_vdso.c:30:5: warning: no previous prototype for ‘__vdso_gettimeofday’ [-Wmissing-prototypes]
   30 | int __vdso_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz)
      |     ^~~~~~~~~~~~~~~~~~~
../arch/x86/um/vdso/um_vdso.c:44:21: warning: no previous prototype for ‘__vdso_time’ [-Wmissing-prototypes]
   44 | __kernel_old_time_t __vdso_time(__kernel_old_time_t *t)
      |                     ^~~~~~~~~~~
../arch/x86/um/vdso/um_vdso.c:57:1: warning: no previous prototype for ‘__vdso_getcpu’ [-Wmissing-prototypes]
   57 | __vdso_getcpu(unsigned *cpu, unsigned *node, struct getcpu_cache *unused)
      | ^~~~~~~~~~~~~
../arch/x86/um/ptrace_64.c:111:5: warning: no previous prototype for ‘poke_user’ [-Wmissing-prototypes]
  111 | int poke_user(struct task_struct *child, long addr, long data)
      |     ^~~~~~~~~
../arch/x86/um/ptrace_64.c:171:5: warning: no previous prototype for ‘peek_user’ [-Wmissing-prototypes]
  171 | int peek_user(struct task_struct *child, long addr, long data)
      |     ^~~~~~~~~
../arch/x86/um/signal.c:560:6: warning: no previous prototype for ‘sys_rt_sigreturn’ [-Wmissing-prototypes]
  560 | long sys_rt_sigreturn(void)
      |      ^~~~~~~~~~~~~~~~
../arch/um/os-Linux/skas/process.c:107:6: warning: no previous prototype for ‘wait_stub_done’ [-Wmissing-prototypes]
  107 | void wait_stub_done(int pid)
      |      ^~~~~~~~~~~~~~
../arch/um/os-Linux/skas/process.c:683:6: warning: no previous prototype for ‘__switch_mm’ [-Wmissing-prototypes]
  683 | void __switch_mm(struct mm_id *mm_idp)
      |      ^~~~~~~~~~~
../arch/um/kernel/um_arch.c:408:19: warning: no previous prototype for ‘read_initrd’ [-Wmissing-prototypes]
  408 | int __init __weak read_initrd(void)
      |                   ^~~~~~~~~~~
../arch/um/kernel/um_arch.c:461:7: warning: no previous prototype for ‘text_poke’ [-Wmissing-prototypes]
  461 | void *text_poke(void *addr, const void *opcode, size_t len)
      |       ^~~~~~~~~
../arch/um/kernel/um_arch.c:473:6: warning: no previous prototype for ‘text_poke_sync’ [-Wmissing-prototypes]
  473 | void text_poke_sync(void)
      |      ^~~~~~~~~~~~~~
../arch/um/os-Linux/main.c:187:7: warning: no previous prototype for ‘__wrap_malloc’ [-Wmissing-prototypes]
  187 | void *__wrap_malloc(int size)
      |       ^~~~~~~~~~~~~
../arch/um/os-Linux/main.c:208:7: warning: no previous prototype for ‘__wrap_calloc’ [-Wmissing-prototypes]
  208 | void *__wrap_calloc(int n, int size)
      |       ^~~~~~~~~~~~~
../arch/um/os-Linux/main.c:222:6: warning: no previous prototype for ‘__wrap_free’ [-Wmissing-prototypes]
  222 | void __wrap_free(void *ptr)
      |      ^~~~~~~~~~~
../arch/um/os-Linux/mem.c:28:6: warning: no previous prototype for ‘kasan_map_memory’ [-Wmissing-prototypes]
   28 | void kasan_map_memory(void *start, size_t len)
      |      ^~~~~~~~~~~~~~~~
../arch/um/os-Linux/mem.c:212:13: warning: no previous prototype for ‘check_tmpexec’ [-Wmissing-prototypes]
  212 | void __init check_tmpexec(void)
      |             ^~~~~~~~~~~~~
../arch/x86/um/syscalls_64.c:48:6: warning: no previous prototype for ‘arch_switch_to’ [-Wmissing-prototypes]
   48 | void arch_switch_to(struct task_struct *to)
      |      ^~~~~~~~~~~~~~
../arch/um/os-Linux/start_up.c:301:12: warning: no previous prototype for ‘parse_iomem’ [-Wmissing-prototypes]
  301 | int __init parse_iomem(char *str, int *add)
      |            ^~~~~~~~~~~



-- 
Jani Nikula, Intel