diff options
Diffstat (limited to 'include/linux/compat.h')
| -rw-r--r-- | include/linux/compat.h | 51 |
1 files changed, 39 insertions, 12 deletions
diff --git a/include/linux/compat.h b/include/linux/compat.h index f188eab10570..081281ad5772 100644 --- a/include/linux/compat.h +++ b/include/linux/compat.h @@ -24,6 +24,17 @@ #include <asm/siginfo.h> #include <asm/signal.h> +#ifdef CONFIG_ARCH_HAS_SYSCALL_WRAPPER +/* + * It may be useful for an architecture to override the definitions of the + * COMPAT_SYSCALL_DEFINE0 and COMPAT_SYSCALL_DEFINEx() macros, in particular + * to use a different calling convention for syscalls. To allow for that, + + the prototypes for the compat_sys_*() functions below will *not* be included + * if CONFIG_ARCH_HAS_SYSCALL_WRAPPER is enabled. + */ +#include <asm/syscall_wrapper.h> +#endif /* CONFIG_ARCH_HAS_SYSCALL_WRAPPER */ + #ifndef COMPAT_USE_64BIT_TIME #define COMPAT_USE_64BIT_TIME 0 #endif @@ -32,10 +43,12 @@ #define __SC_DELOUSE(t,v) ((__force t)(unsigned long)(v)) #endif +#ifndef COMPAT_SYSCALL_DEFINE0 #define COMPAT_SYSCALL_DEFINE0(name) \ asmlinkage long compat_sys_##name(void); \ ALLOW_ERROR_INJECTION(compat_sys_##name, ERRNO); \ asmlinkage long compat_sys_##name(void) +#endif /* COMPAT_SYSCALL_DEFINE0 */ #define COMPAT_SYSCALL_DEFINE1(name, ...) \ COMPAT_SYSCALL_DEFINEx(1, _##name, __VA_ARGS__) @@ -50,18 +63,25 @@ #define COMPAT_SYSCALL_DEFINE6(name, ...) \ COMPAT_SYSCALL_DEFINEx(6, _##name, __VA_ARGS__) -#define COMPAT_SYSCALL_DEFINEx(x, name, ...) \ - asmlinkage long compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__));\ - asmlinkage long compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__))\ - __attribute__((alias(__stringify(compat_SyS##name)))); \ - ALLOW_ERROR_INJECTION(compat_sys##name, ERRNO); \ - static inline long C_SYSC##name(__MAP(x,__SC_DECL,__VA_ARGS__));\ - asmlinkage long compat_SyS##name(__MAP(x,__SC_LONG,__VA_ARGS__));\ - asmlinkage long compat_SyS##name(__MAP(x,__SC_LONG,__VA_ARGS__))\ - { \ - return C_SYSC##name(__MAP(x,__SC_DELOUSE,__VA_ARGS__)); \ - } \ - static inline long C_SYSC##name(__MAP(x,__SC_DECL,__VA_ARGS__)) +/* + * The asmlinkage stub is aliased to a function named __se_compat_sys_*() which + * sign-extends 32-bit ints to longs whenever needed. The actual work is + * done within __do_compat_sys_*(). + */ +#ifndef COMPAT_SYSCALL_DEFINEx +#define COMPAT_SYSCALL_DEFINEx(x, name, ...) \ + asmlinkage long compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)); \ + asmlinkage long 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__)) \ + { \ + return __do_compat_sys##name(__MAP(x,__SC_DELOUSE,__VA_ARGS__));\ + } \ + static inline long __do_compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)) +#endif /* COMPAT_SYSCALL_DEFINEx */ #ifndef compat_user_stack_pointer #define compat_user_stack_pointer() current_user_stack_pointer() @@ -519,7 +539,12 @@ int __compat_save_altstack(compat_stack_t __user *, unsigned long); * Please note that these prototypes here are only provided for information * purposes, for static analysis, and for linking from the syscall table. * These functions should not be called elsewhere from kernel code. + * + * As the syscall calling convention may be different from the default + * for architectures overriding the syscall calling convention, do not + * include the prototypes if CONFIG_ARCH_HAS_SYSCALL_WRAPPER is enabled. */ +#ifndef CONFIG_ARCH_HAS_SYSCALL_WRAPPER asmlinkage long compat_sys_io_setup(unsigned nr_reqs, u32 __user *ctx32p); asmlinkage long compat_sys_io_submit(compat_aio_context_t ctx_id, int nr, u32 __user *iocb); @@ -957,6 +982,8 @@ asmlinkage long compat_sys_stime(compat_time_t __user *tptr); /* obsolete: net/socket.c */ asmlinkage long compat_sys_socketcall(int call, u32 __user *args); +#endif /* CONFIG_ARCH_HAS_SYSCALL_WRAPPER */ + /* * For most but not all architectures, "am I in a compat syscall?" and |