diff options
Diffstat (limited to 'include/linux/syscalls.h')
| -rw-r--r-- | include/linux/syscalls.h | 42 |
1 files changed, 35 insertions, 7 deletions
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index b961184f597a..70fcda1a9049 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -81,6 +81,17 @@ union bpf_attr; #include <linux/key.h> #include <trace/syscall.h> +#ifdef CONFIG_ARCH_HAS_SYSCALL_WRAPPER +/* + * It may be useful for an architecture to override the definitions of the + * SYSCALL_DEFINE0() and __SYSCALL_DEFINEx() macros, in particular to use a + * different calling convention for syscalls. To allow for that, the prototypes + * for the 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 */ + /* * __MAP - apply a macro to syscall arguments * __MAP(n, m, t1, a1, t2, a2, ..., tn, an) will expand to @@ -91,7 +102,7 @@ union bpf_attr; * for SYSCALL_DEFINE<n>/COMPAT_SYSCALL_DEFINE<n> */ #define __MAP0(m,...) -#define __MAP1(m,t,a) m(t,a) +#define __MAP1(m,t,a,...) m(t,a) #define __MAP2(m,t,a,...) m(t,a), __MAP1(m,__VA_ARGS__) #define __MAP3(m,t,a,...) m(t,a), __MAP2(m,__VA_ARGS__) #define __MAP4(m,t,a,...) m(t,a), __MAP3(m,__VA_ARGS__) @@ -189,11 +200,13 @@ static inline int is_syscall_trace_event(struct trace_event_call *tp_event) } #endif +#ifndef SYSCALL_DEFINE0 #define SYSCALL_DEFINE0(sname) \ SYSCALL_METADATA(_##sname, 0); \ asmlinkage long sys_##sname(void); \ ALLOW_ERROR_INJECTION(sys_##sname, ERRNO); \ asmlinkage long sys_##sname(void) +#endif /* SYSCALL_DEFINE0 */ #define SYSCALL_DEFINE1(name, ...) SYSCALL_DEFINEx(1, _##name, __VA_ARGS__) #define SYSCALL_DEFINE2(name, ...) SYSCALL_DEFINEx(2, _##name, __VA_ARGS__) @@ -209,20 +222,28 @@ static inline int is_syscall_trace_event(struct trace_event_call *tp_event) __SYSCALL_DEFINEx(x, sname, __VA_ARGS__) #define __PROTECT(...) asmlinkage_protect(__VA_ARGS__) + +/* + * The asmlinkage stub is aliased to a function named __se_sys_*() which + * sign-extends 32-bit ints to longs whenever needed. The actual work is + * done within __do_sys_*(). + */ +#ifndef __SYSCALL_DEFINEx #define __SYSCALL_DEFINEx(x, name, ...) \ asmlinkage long sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)) \ - __attribute__((alias(__stringify(SyS##name)))); \ + __attribute__((alias(__stringify(__se_sys##name)))); \ ALLOW_ERROR_INJECTION(sys##name, ERRNO); \ - static inline long SYSC##name(__MAP(x,__SC_DECL,__VA_ARGS__)); \ - asmlinkage long SyS##name(__MAP(x,__SC_LONG,__VA_ARGS__)); \ - asmlinkage long SyS##name(__MAP(x,__SC_LONG,__VA_ARGS__)) \ + static inline long __do_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__));\ + asmlinkage long __se_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)); \ + asmlinkage long __se_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)) \ { \ - long ret = SYSC##name(__MAP(x,__SC_CAST,__VA_ARGS__)); \ + long ret = __do_sys##name(__MAP(x,__SC_CAST,__VA_ARGS__));\ __MAP(x,__SC_TEST,__VA_ARGS__); \ __PROTECT(x, ret,__MAP(x,__SC_ARGS,__VA_ARGS__)); \ return ret; \ } \ - static inline long SYSC##name(__MAP(x,__SC_DECL,__VA_ARGS__)) + static inline long __do_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)) +#endif /* __SYSCALL_DEFINEx */ /* * Called before coming back to user-mode. Returning to user-mode with an @@ -252,7 +273,12 @@ static inline void addr_limit_user_check(void) * 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 sys_io_setup(unsigned nr_reqs, aio_context_t __user *ctx); asmlinkage long sys_io_destroy(aio_context_t ctx); asmlinkage long sys_io_submit(aio_context_t, long, @@ -1076,6 +1102,8 @@ asmlinkage long sys_old_mmap(struct mmap_arg_struct __user *arg); */ asmlinkage long sys_ni_syscall(void); +#endif /* CONFIG_ARCH_HAS_SYSCALL_WRAPPER */ + /* * Kernel code should not call syscalls (i.e., sys_xyzyyz()) directly. |