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-rw-r--r--include/linux/compat.h51
-rw-r--r--include/linux/syscalls.h42
2 files changed, 74 insertions, 19 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
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.