1 files changed, 41 insertions, 6 deletions

diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 3cb15ea48aee..a78186d826d7 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -100,11 +100,12 @@ union bpf_attr;
 #define __MAP(n,...) __MAP##n(__VA_ARGS__)
 
 #define __SC_DECL(t, a)	t a
-#define __TYPE_IS_L(t)	(__same_type((t)0, 0L))
-#define __TYPE_IS_UL(t)	(__same_type((t)0, 0UL))
-#define __TYPE_IS_LL(t) (__same_type((t)0, 0LL) || __same_type((t)0, 0ULL))
+#define __TYPE_AS(t, v)	__same_type((__force t)0, v)
+#define __TYPE_IS_L(t)	(__TYPE_AS(t, 0L))
+#define __TYPE_IS_UL(t)	(__TYPE_AS(t, 0UL))
+#define __TYPE_IS_LL(t) (__TYPE_AS(t, 0LL) || __TYPE_AS(t, 0ULL))
 #define __SC_LONG(t, a) __typeof(__builtin_choose_expr(__TYPE_IS_LL(t), 0LL, 0L)) a
-#define __SC_CAST(t, a)	(t) a
+#define __SC_CAST(t, a)	(__force t) a
 #define __SC_ARGS(t, a)	a
 #define __SC_TEST(t, a) (void)BUILD_BUG_ON_ZERO(!__TYPE_IS_LL(t) && sizeof(t) > sizeof(long))
 
@@ -172,8 +173,20 @@ extern struct trace_event_functions exit_syscall_print_funcs;
 	static struct syscall_metadata __used			\
 	  __attribute__((section("__syscalls_metadata")))	\
 	 *__p_syscall_meta_##sname = &__syscall_meta_##sname;
+
+static inline int is_syscall_trace_event(struct trace_event_call *tp_event)
+{
+	return tp_event->class == &event_class_syscall_enter ||
+	       tp_event->class == &event_class_syscall_exit;
+}
+
 #else
 #define SYSCALL_METADATA(sname, nb, ...)
+
+static inline int is_syscall_trace_event(struct trace_event_call *tp_event)
+{
+	return 0;
+}
 #endif
 
 #define SYSCALL_DEFINE0(sname)					\
@@ -187,6 +200,8 @@ extern struct trace_event_functions exit_syscall_print_funcs;
 #define SYSCALL_DEFINE5(name, ...) SYSCALL_DEFINEx(5, _##name, __VA_ARGS__)
 #define SYSCALL_DEFINE6(name, ...) SYSCALL_DEFINEx(6, _##name, __VA_ARGS__)
 
+#define SYSCALL_DEFINE_MAXARGS	6
+
 #define SYSCALL_DEFINEx(x, sname, ...)				\
 	SYSCALL_METADATA(sname, x, __VA_ARGS__)			\
 	__SYSCALL_DEFINEx(x, sname, __VA_ARGS__)
@@ -206,6 +221,26 @@ extern struct trace_event_functions exit_syscall_print_funcs;
 	}								\
 	static inline long SYSC##name(__MAP(x,__SC_DECL,__VA_ARGS__))
 
+/*
+ * Called before coming back to user-mode. Returning to user-mode with an
+ * address limit different than USER_DS can allow to overwrite kernel memory.
+ */
+static inline void addr_limit_user_check(void)
+{
+#ifdef TIF_FSCHECK
+	if (!test_thread_flag(TIF_FSCHECK))
+		return;
+#endif
+
+	if (CHECK_DATA_CORRUPTION(!segment_eq(get_fs(), USER_DS),
+				  "Invalid address limit on user-mode return"))
+		force_sig(SIGKILL, current);
+
+#ifdef TIF_FSCHECK
+	clear_thread_flag(TIF_FSCHECK);
+#endif
+}
+
 asmlinkage long sys32_quotactl(unsigned int cmd, const char __user *special,
 			       qid_t id, void __user *addr);
 asmlinkage long sys_time(time_t __user *tloc);
@@ -578,12 +613,12 @@ asmlinkage long sys_preadv(unsigned long fd, const struct iovec __user *vec,
 			   unsigned long vlen, unsigned long pos_l, unsigned long pos_h);
 asmlinkage long sys_preadv2(unsigned long fd, const struct iovec __user *vec,
 			    unsigned long vlen, unsigned long pos_l, unsigned long pos_h,
-			    int flags);
+			    rwf_t flags);
 asmlinkage long sys_pwritev(unsigned long fd, const struct iovec __user *vec,
 			    unsigned long vlen, unsigned long pos_l, unsigned long pos_h);
 asmlinkage long sys_pwritev2(unsigned long fd, const struct iovec __user *vec,
 			    unsigned long vlen, unsigned long pos_l, unsigned long pos_h,
-			    int flags);
+			    rwf_t flags);
 asmlinkage long sys_getcwd(char __user *buf, unsigned long size);
 asmlinkage long sys_mkdir(const char __user *pathname, umode_t mode);
 asmlinkage long sys_chdir(const char __user *filename);