Re: [RFC PATCH 2/3] add statmnt(2) syscall

[kernel test robot <lkp@intel.com>]

Hi Miklos,

[This is a private test report for your RFC patch.]
kernel test robot noticed the following build errors:

[auto build test ERROR on tip/x86/asm]
[also build test ERROR on linux/master linus/master v6.6-rc1 next-20230913]
[cannot apply to arnd-asm-generic/master]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Miklos-Szeredi/add-unique-mount-ID/20230913-232732
base:   tip/x86/asm
patch link:    https://lore.kernel.org/r/20230913152238.905247-3-mszeredi%40redhat.com
patch subject: [RFC PATCH 2/3] add statmnt(2) syscall
config: um-i386_defconfig (https://download.01.org/0day-ci/archive/20230914/202309140628.cbfucE4v-lkp@intel.com/config)
compiler: gcc-7 (Ubuntu 7.5.0-6ubuntu2) 7.5.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20230914/202309140628.cbfucE4v-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202309140628.cbfucE4v-lkp@intel.com/

All error/warnings (new ones prefixed by >>):

   In file included from fs/namespace.c:11:0:
   include/linux/syscalls.h:412:15: warning: 'struct statmnt' declared inside parameter list will not be visible outside of this definition or declaration
           struct statmnt __user *buf, size_t bufsize,
                  ^~~~~~~
>> fs/namespace.c:4690:18: warning: no previous declaration for 'lookup_mnt_in_ns' [-Wmissing-declarations]
    struct vfsmount *lookup_mnt_in_ns(u64 id, struct mnt_namespace *ns)
                     ^~~~~~~~~~~~~~~~
   fs/namespace.c:4750:10: error: unknown type name 'stmt_str_t'; did you mean 'stmt_func_t'?
             stmt_str_t *str)
             ^~~~~~~~~~
             stmt_func_t
   fs/namespace.c: In function 'do_statmnt':
   fs/namespace.c:4946:2: error: implicit declaration of function 'stmt_string'; did you mean 'stmt_string_seq'? [-Werror=implicit-function-declaration]
     stmt_string(s, STMT_MNT_ROOT, stmt_mnt_root, &sm->mnt_root);
     ^~~~~~~~~~~
     stmt_string_seq
   In file included from fs/namespace.c:11:0:
   fs/namespace.c: At top level:
>> include/linux/syscalls.h:244:18: error: conflicting types for 'sys_statmnt'
     asmlinkage long sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)) \
                     ^
   include/linux/syscalls.h:230:2: note: in expansion of macro '__SYSCALL_DEFINEx'
     __SYSCALL_DEFINEx(x, sname, __VA_ARGS__)
     ^~~~~~~~~~~~~~~~~
   include/linux/syscalls.h:223:36: note: in expansion of macro 'SYSCALL_DEFINEx'
    #define SYSCALL_DEFINE5(name, ...) SYSCALL_DEFINEx(5, _##name, __VA_ARGS__)
                                       ^~~~~~~~~~~~~~~
   fs/namespace.c:4960:1: note: in expansion of macro 'SYSCALL_DEFINE5'
    SYSCALL_DEFINE5(statmnt, u64, mnt_id,
    ^~~~~~~~~~~~~~~
   include/linux/syscalls.h:411:17: note: previous declaration of 'sys_statmnt' was here
    asmlinkage long sys_statmnt(u64 mnt_id, u64 mask,
                    ^~~~~~~~~~~
   fs/namespace.c:4720:12: warning: 'stmt_string_seq' defined but not used [-Wunused-function]
    static int stmt_string_seq(struct stmt_state *s, stmt_func_t func)
               ^~~~~~~~~~~~~~~
   cc1: some warnings being treated as errors


vim +/sys_statmnt +244 include/linux/syscalls.h

1bd21c6c21e848 Dominik Brodowski   2018-04-05  233  
e145242ea0df6b Dominik Brodowski   2018-04-09  234  /*
e145242ea0df6b Dominik Brodowski   2018-04-09  235   * The asmlinkage stub is aliased to a function named __se_sys_*() which
e145242ea0df6b Dominik Brodowski   2018-04-09  236   * sign-extends 32-bit ints to longs whenever needed. The actual work is
e145242ea0df6b Dominik Brodowski   2018-04-09  237   * done within __do_sys_*().
e145242ea0df6b Dominik Brodowski   2018-04-09  238   */
1bd21c6c21e848 Dominik Brodowski   2018-04-05  239  #ifndef __SYSCALL_DEFINEx
bed1ffca022cc8 Frederic Weisbecker 2009-03-13  240  #define __SYSCALL_DEFINEx(x, name, ...)					\
bee20031772af3 Arnd Bergmann       2018-06-19  241  	__diag_push();							\
bee20031772af3 Arnd Bergmann       2018-06-19  242  	__diag_ignore(GCC, 8, "-Wattribute-alias",			\
bee20031772af3 Arnd Bergmann       2018-06-19  243  		      "Type aliasing is used to sanitize syscall arguments");\
83460ec8dcac14 Andi Kleen          2013-11-12 @244  	asmlinkage long sys##name(__MAP(x,__SC_DECL,__VA_ARGS__))	\
e145242ea0df6b Dominik Brodowski   2018-04-09  245  		__attribute__((alias(__stringify(__se_sys##name))));	\
c9a211951c7c79 Howard McLauchlan   2018-03-21  246  	ALLOW_ERROR_INJECTION(sys##name, ERRNO);			\
e145242ea0df6b Dominik Brodowski   2018-04-09  247  	static inline long __do_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__));\
e145242ea0df6b Dominik Brodowski   2018-04-09  248  	asmlinkage long __se_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__));	\
e145242ea0df6b Dominik Brodowski   2018-04-09  249  	asmlinkage long __se_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__))	\
1a94bc34768e46 Heiko Carstens      2009-01-14  250  	{								\
e145242ea0df6b Dominik Brodowski   2018-04-09  251  		long ret = __do_sys##name(__MAP(x,__SC_CAST,__VA_ARGS__));\
07fe6e00f6cca6 Al Viro             2013-01-21  252  		__MAP(x,__SC_TEST,__VA_ARGS__);				\
2cf0966683430b Al Viro             2013-01-21  253  		__PROTECT(x, ret,__MAP(x,__SC_ARGS,__VA_ARGS__));	\
2cf0966683430b Al Viro             2013-01-21  254  		return ret;						\
1a94bc34768e46 Heiko Carstens      2009-01-14  255  	}								\
bee20031772af3 Arnd Bergmann       2018-06-19  256  	__diag_pop();							\
e145242ea0df6b Dominik Brodowski   2018-04-09  257  	static inline long __do_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__))
1bd21c6c21e848 Dominik Brodowski   2018-04-05  258  #endif /* __SYSCALL_DEFINEx */
1a94bc34768e46 Heiko Carstens      2009-01-14  259  

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