linux/arch/s390/include/asm/syscall_wrapper.h
Arnd Bergmann efb150df1d s390: syscall_wrapper: avoid clang warning
Building system calls with clang results in a warning
about an alias from a global function to a static one:

../fs/namei.c:3847:1: warning: unused function '__se_sys_mkdirat' [-Wunused-function]
SYSCALL_DEFINE3(mkdirat, int, dfd, const char __user *, pathname, umode_t, mode)
^
../include/linux/syscalls.h:219:36: note: expanded from macro 'SYSCALL_DEFINE3'
 #define SYSCALL_DEFINE3(name, ...) SYSCALL_DEFINEx(3, _##name, __VA_ARGS__)
                                   ^
../include/linux/syscalls.h:228:2: note: expanded from macro 'SYSCALL_DEFINEx'
        __SYSCALL_DEFINEx(x, sname, __VA_ARGS__)
        ^
../arch/s390/include/asm/syscall_wrapper.h:126:18: note: expanded from macro '__SYSCALL_DEFINEx'
        asmlinkage long __se_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__))          \
                        ^
<scratch space>:31:1: note: expanded from here
__se_sys_mkdirat
^

The only reference to the static __se_sys_mkdirat() here is the alias, but
this only gets evaluated later. Making this function global as well avoids
the warning.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-11 13:36:51 +02:00

136 lines
4.7 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* syscall_wrapper.h - s390 specific wrappers to syscall definitions
*
*/
#ifndef _ASM_S390_SYSCALL_WRAPPER_H
#define _ASM_S390_SYSCALL_WRAPPER_H
#ifdef CONFIG_COMPAT
#define __SC_COMPAT_TYPE(t, a) \
__typeof(__builtin_choose_expr(sizeof(t) > 4, 0L, (t)0)) a
#define __SC_COMPAT_CAST(t, a) \
({ \
long __ReS = a; \
\
BUILD_BUG_ON((sizeof(t) > 4) && !__TYPE_IS_L(t) && \
!__TYPE_IS_UL(t) && !__TYPE_IS_PTR(t) && \
!__TYPE_IS_LL(t)); \
if (__TYPE_IS_L(t)) \
__ReS = (s32)a; \
if (__TYPE_IS_UL(t)) \
__ReS = (u32)a; \
if (__TYPE_IS_PTR(t)) \
__ReS = a & 0x7fffffff; \
if (__TYPE_IS_LL(t)) \
return -ENOSYS; \
(t)__ReS; \
})
#define __S390_SYS_STUBx(x, name, ...) \
asmlinkage long __s390_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__))\
ALLOW_ERROR_INJECTION(__s390_sys##name, ERRNO); \
asmlinkage long __s390_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__))\
{ \
long ret = __s390x_sys##name(__MAP(x,__SC_COMPAT_CAST,__VA_ARGS__));\
__MAP(x,__SC_TEST,__VA_ARGS__); \
return ret; \
}
/*
* To keep the naming coherent, re-define SYSCALL_DEFINE0 to create an alias
* named __s390x_sys_*()
*/
#define COMPAT_SYSCALL_DEFINE0(sname) \
SYSCALL_METADATA(_##sname, 0); \
asmlinkage long __s390_compat_sys_##sname(void); \
ALLOW_ERROR_INJECTION(__s390_compat__sys_##sname, ERRNO); \
asmlinkage long __s390_compat_sys_##sname(void)
#define SYSCALL_DEFINE0(sname) \
SYSCALL_METADATA(_##sname, 0); \
asmlinkage long __s390x_sys_##sname(void); \
ALLOW_ERROR_INJECTION(__s390x_sys_##sname, ERRNO); \
asmlinkage long __s390_sys_##sname(void) \
__attribute__((alias(__stringify(__s390x_sys_##sname)))); \
asmlinkage long __s390x_sys_##sname(void)
#define COND_SYSCALL(name) \
cond_syscall(__s390x_sys_##name); \
cond_syscall(__s390_sys_##name)
#define SYS_NI(name) \
SYSCALL_ALIAS(__s390x_sys_##name, sys_ni_posix_timers); \
SYSCALL_ALIAS(__s390_sys_##name, sys_ni_posix_timers)
#define COMPAT_SYSCALL_DEFINEx(x, name, ...) \
__diag_push(); \
__diag_ignore(GCC, 8, "-Wattribute-alias", \
"Type aliasing is used to sanitize syscall arguments");\
asmlinkage long __s390_compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)); \
asmlinkage long __s390_compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)) \
__attribute__((alias(__stringify(__se_compat_sys##name)))); \
ALLOW_ERROR_INJECTION(compat_sys##name, ERRNO); \
static inline long __do_compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__));\
asmlinkage long __se_compat_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)); \
asmlinkage long __se_compat_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)) \
{ \
long ret = __do_compat_sys##name(__MAP(x,__SC_DELOUSE,__VA_ARGS__));\
__MAP(x,__SC_TEST,__VA_ARGS__); \
return ret; \
} \
__diag_pop(); \
static inline long __do_compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__))
/*
* As some compat syscalls may not be implemented, we need to expand
* COND_SYSCALL_COMPAT in kernel/sys_ni.c and COMPAT_SYS_NI in
* kernel/time/posix-stubs.c to cover this case as well.
*/
#define COND_SYSCALL_COMPAT(name) \
cond_syscall(__s390_compat_sys_##name)
#define COMPAT_SYS_NI(name) \
SYSCALL_ALIAS(__s390_compat_sys_##name, sys_ni_posix_timers)
#else /* CONFIG_COMPAT */
#define __S390_SYS_STUBx(x, fullname, name, ...)
#define SYSCALL_DEFINE0(sname) \
SYSCALL_METADATA(_##sname, 0); \
asmlinkage long __s390x_sys_##sname(void); \
ALLOW_ERROR_INJECTION(__s390x_sys_##sname, ERRNO); \
asmlinkage long __s390x_sys_##sname(void)
#define COND_SYSCALL(name) \
cond_syscall(__s390x_sys_##name)
#define SYS_NI(name) \
SYSCALL_ALIAS(__s390x_sys_##name, sys_ni_posix_timers);
#endif /* CONFIG_COMPAT */
#define __SYSCALL_DEFINEx(x, name, ...) \
__diag_push(); \
__diag_ignore(GCC, 8, "-Wattribute-alias", \
"Type aliasing is used to sanitize syscall arguments");\
asmlinkage long __s390x_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)) \
__attribute__((alias(__stringify(__se_sys##name)))); \
ALLOW_ERROR_INJECTION(__s390x_sys##name, ERRNO); \
long __se_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)); \
static inline long __do_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)); \
__S390_SYS_STUBx(x, name, __VA_ARGS__) \
asmlinkage long __se_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)) \
{ \
long ret = __do_sys##name(__MAP(x,__SC_CAST,__VA_ARGS__)); \
__MAP(x,__SC_TEST,__VA_ARGS__); \
return ret; \
} \
__diag_pop(); \
static inline long __do_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__))
#endif /* _ASM_X86_SYSCALL_WRAPPER_H */