[PATCH 3/5] all: s390: move wrapper infrastructure to generic headers

[Yury Norov]

This patch moves required code to generic files to let other arches use
it if needed. Here also, additional code is introduced, as s390 uses asm
syscall tables, while in general case, wrappers may be used in C code.

__SC_COMPAT_CAST for s390 is too specific due to 31-bit pointer length, so it's
moved to arch/s390/include/asm/compat.h. Generic declaration assumes that long,
unsigned long and pointer types are all 32-bit length.

linux/syscalls_structs.h header is introduced, because from now (see next patch)
structure types listed there are needed for both normal and compat mode.

cond_syscall_wrapped now defined two symbols: sys_foo() and compat_sys_foo(), if
compat wrappers are enabled.

Here __SC_WRAP() macro is introduced as well. s390 doesn't need it as it uses
asm-generated syscall table. But architectures that generate that tables with
C code (ARM64/ILP32) should redefine it as '#define __SC_WRAP(name) compat_##name'.

Signed-off-by: Yury Norov <ynorov@xxxxxxxxxxxxxxxxxx>
---
 arch/s390/include/asm/compat.h    | 17 +++++++++--
 arch/s390/kernel/compat_wrapper.c | 51 ---------------------------------
 include/linux/compat.h            | 53 ++++++++++++++++++++++++++++++++++
 include/linux/syscalls.h          | 57 +------------------------------------
 include/linux/syscalls_structs.h  | 60 +++++++++++++++++++++++++++++++++++++++
 include/uapi/asm-generic/unistd.h |  4 +++
 6 files changed, 133 insertions(+), 109 deletions(-)
 create mode 100644 include/linux/syscalls_structs.h

diff --git a/arch/s390/include/asm/compat.h b/arch/s390/include/asm/compat.h
index 352f7bd..f412723 100644
--- a/arch/s390/include/asm/compat.h
+++ b/arch/s390/include/asm/compat.h
@@ -7,13 +7,26 @@
 #include <linux/sched.h>
 #include <linux/thread_info.h>
 
-#define __TYPE_IS_PTR(t) (!__builtin_types_compatible_p(typeof(0?(t)0:0ULL), u64))
-
 #define __SC_DELOUSE(t,v) ({ \
 	BUILD_BUG_ON(sizeof(t) > 4 && !__TYPE_IS_PTR(t)); \
 	(t)(__TYPE_IS_PTR(t) ? ((v) & 0x7fffffff) : (v)); \
 })
 
+#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));		\
+	if (__TYPE_IS_L(t))						\
+		__ReS = (s32)a;						\
+	if (__TYPE_IS_UL(t))						\
+		__ReS = (u32)a;						\
+	if (__TYPE_IS_PTR(t))						\
+		__ReS = a & 0x7fffffff;					\
+	(t)__ReS;							\
+})
+
 #define PSW32_MASK_PER		0x40000000UL
 #define PSW32_MASK_DAT		0x04000000UL
 #define PSW32_MASK_IO		0x02000000UL
diff --git a/arch/s390/kernel/compat_wrapper.c b/arch/s390/kernel/compat_wrapper.c
index ae2cda5..1614e15 100644
--- a/arch/s390/kernel/compat_wrapper.c
+++ b/arch/s390/kernel/compat_wrapper.c
@@ -8,57 +8,6 @@
 #include <linux/compat.h>
 #include "entry.h"
 
-#define COMPAT_SYSCALL_WRAP1(name, ...) \
-	COMPAT_SYSCALL_WRAPx(1, _##name, __VA_ARGS__)
-#define COMPAT_SYSCALL_WRAP2(name, ...) \
-	COMPAT_SYSCALL_WRAPx(2, _##name, __VA_ARGS__)
-#define COMPAT_SYSCALL_WRAP3(name, ...) \
-	COMPAT_SYSCALL_WRAPx(3, _##name, __VA_ARGS__)
-#define COMPAT_SYSCALL_WRAP4(name, ...) \
-	COMPAT_SYSCALL_WRAPx(4, _##name, __VA_ARGS__)
-#define COMPAT_SYSCALL_WRAP5(name, ...) \
-	COMPAT_SYSCALL_WRAPx(5, _##name, __VA_ARGS__)
-#define COMPAT_SYSCALL_WRAP6(name, ...) \
-	COMPAT_SYSCALL_WRAPx(6, _##name, __VA_ARGS__)
-
-#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));		\
-	if (__TYPE_IS_L(t))						\
-		__ReS = (s32)a;						\
-	if (__TYPE_IS_UL(t))						\
-		__ReS = (u32)a;						\
-	if (__TYPE_IS_PTR(t))						\
-		__ReS = a & 0x7fffffff;					\
-	(t)__ReS;							\
-})
-
-/*
- * The COMPAT_SYSCALL_WRAP macro generates system call wrappers to be used by
- * compat tasks. These wrappers will only be used for system calls where only
- * the system call arguments need sign or zero extension or zeroing of the upper
- * 33 bits of pointers.
- * Note: since the wrapper function will afterwards call a system call which
- * again performs zero and sign extension for all system call arguments with
- * a size of less than eight bytes, these compat wrappers only touch those
- * system call arguments with a size of eight bytes ((unsigned) long and
- * pointers). Zero and sign extension for e.g. int parameters will be done by
- * the regular system call wrappers.
- */
-#define COMPAT_SYSCALL_WRAPx(x, name, ...)					\
-asmlinkage long sys##name(__MAP(x,__SC_DECL,__VA_ARGS__));			\
-asmlinkage long notrace compat_sys##name(__MAP(x,__SC_COMPAT_TYPE,__VA_ARGS__));\
-asmlinkage long notrace compat_sys##name(__MAP(x,__SC_COMPAT_TYPE,__VA_ARGS__))	\
-{										\
-	return sys##name(__MAP(x,__SC_COMPAT_CAST,__VA_ARGS__));		\
-}
-
 COMPAT_SYSCALL_WRAP2(creat, const char __user *, pathname, umode_t, mode);
 COMPAT_SYSCALL_WRAP2(link, const char __user *, oldname, const char __user *, newname);
 COMPAT_SYSCALL_WRAP1(unlink, const char __user *, pathname);
diff --git a/include/linux/compat.h b/include/linux/compat.h
index a76c917..f14347e 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -28,6 +28,10 @@
 #define __SC_DELOUSE(t,v) ((t)(unsigned long)(v))
 #endif
 
+#ifndef __TYPE_IS_PTR
+#define __TYPE_IS_PTR(t) (!__builtin_types_compatible_p(typeof(0?(t)0:0ULL), u64))
+#endif
+
 #define COMPAT_SYSCALL_DEFINE0(name) \
 	asmlinkage long compat_sys_##name(void)
 
@@ -718,4 +722,53 @@ asmlinkage long compat_sys_fanotify_mark(int, unsigned int, __u32, __u32,
 #define is_compat_task() (0)
 
 #endif /* CONFIG_COMPAT */
+
+#ifdef CONFIG_COMPAT_WRAPPER
+
+#define COMPAT_SYSCALL_WRAP1(name, ...) COMPAT_SYSCALL_WRAPx(1, _##name, __VA_ARGS__)
+#define COMPAT_SYSCALL_WRAP2(name, ...) COMPAT_SYSCALL_WRAPx(2, _##name, __VA_ARGS__)
+#define COMPAT_SYSCALL_WRAP3(name, ...) COMPAT_SYSCALL_WRAPx(3, _##name, __VA_ARGS__)
+#define COMPAT_SYSCALL_WRAP4(name, ...) COMPAT_SYSCALL_WRAPx(4, _##name, __VA_ARGS__)
+#define COMPAT_SYSCALL_WRAP5(name, ...) COMPAT_SYSCALL_WRAPx(5, _##name, __VA_ARGS__)
+#define COMPAT_SYSCALL_WRAP6(name, ...) COMPAT_SYSCALL_WRAPx(6, _##name, __VA_ARGS__)
+
+#ifndef __SC_COMPAT_TYPE
+#define __SC_COMPAT_TYPE(t, a) \
+	__typeof(__builtin_choose_expr(sizeof(t) > 4, 0L, (t)0)) a
+#endif
+
+#ifndef __SC_COMPAT_CAST
+#define __SC_COMPAT_CAST(t, a) ({					\
+	BUILD_BUG_ON((sizeof(t) > 4) && !__TYPE_IS_L(t) &&		\
+		     !__TYPE_IS_UL(t) && !__TYPE_IS_PTR(t));		\
+	((t) ((t)(-1) < 0 ? (s64)(s32)(a) : (u64)(u32)(a)));		\
+})
+#endif
+
+#ifndef COMPAT_SYSCALL_WRAPx
+/*
+ * The COMPAT_SYSCALL_WRAP macro generates system call wrappers to be used by
+ * compat tasks. These wrappers will only be used for system calls where only
+ * the system call arguments need sign or zero extension or zeroing of the upper
+ * parts of arguments passed in register.
+ * Note: since the wrapper function will afterwards call a system call which
+ * again performs zero and sign extension for all system call arguments with
+ * a size of less than eight bytes, these compat wrappers only touch those
+ * system call arguments with a size of eight bytes ((unsigned) long and
+ * pointers). Zero and sign extension for e.g. int parameters will be done by
+ * the regular system call wrappers.
+ */
+#define COMPAT_SYSCALL_WRAPx(x, name, ...)						\
+asmlinkage long 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))));			\
+asmlinkage long notrace compat_SyS##name(__MAP(x,__SC_COMPAT_TYPE,__VA_ARGS__));	\
+asmlinkage long notrace compat_SyS##name(__MAP(x,__SC_COMPAT_TYPE,__VA_ARGS__))		\
+{											\
+	return sys##name(__MAP(x,__SC_COMPAT_CAST,__VA_ARGS__));			\
+}
+#endif
+
+#endif /* CONFIG_COMPAT_WRAPPER */
+
 #endif /* _LINUX_COMPAT_H */
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 185815c..2875b13 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -11,62 +11,7 @@
 #ifndef _LINUX_SYSCALLS_H
 #define _LINUX_SYSCALLS_H
 
-struct epoll_event;
-struct iattr;
-struct inode;
-struct iocb;
-struct io_event;
-struct iovec;
-struct itimerspec;
-struct itimerval;
-struct kexec_segment;
-struct linux_dirent;
-struct linux_dirent64;
-struct list_head;
-struct mmap_arg_struct;
-struct msgbuf;
-struct user_msghdr;
-struct mmsghdr;
-struct msqid_ds;
-struct new_utsname;
-struct nfsctl_arg;
-struct __old_kernel_stat;
-struct oldold_utsname;
-struct old_utsname;
-struct pollfd;
-struct rlimit;
-struct rlimit64;
-struct rusage;
-struct sched_param;
-struct sched_attr;
-struct sel_arg_struct;
-struct semaphore;
-struct sembuf;
-struct shmid_ds;
-struct sockaddr;
-struct stat;
-struct stat64;
-struct statfs;
-struct statfs64;
-struct __sysctl_args;
-struct sysinfo;
-struct timespec;
-struct timeval;
-struct timex;
-struct timezone;
-struct tms;
-struct utimbuf;
-struct mq_attr;
-struct compat_stat;
-struct compat_timeval;
-struct robust_list_head;
-struct getcpu_cache;
-struct old_linux_dirent;
-struct perf_event_attr;
-struct file_handle;
-struct sigaltstack;
-union bpf_attr;
-
+#include <linux/syscalls_structs.h>
 #include <linux/types.h>
 #include <linux/aio_abi.h>
 #include <linux/capability.h>
diff --git a/include/linux/syscalls_structs.h b/include/linux/syscalls_structs.h
new file mode 100644
index 0000000..a920cbc
--- /dev/null
+++ b/include/linux/syscalls_structs.h
@@ -0,0 +1,60 @@
+#ifndef _LINUX_SYSCALL_STRUCTS_H
+#define _LINUX_SYSCALL_STRUCTS_H
+
+struct epoll_event;
+struct iattr;
+struct inode;
+struct iocb;
+struct io_event;
+struct iovec;
+struct itimerspec;
+struct itimerval;
+struct kexec_segment;
+struct linux_dirent;
+struct linux_dirent64;
+struct list_head;
+struct mmap_arg_struct;
+struct msgbuf;
+struct user_msghdr;
+struct mmsghdr;
+struct msqid_ds;
+struct new_utsname;
+struct nfsctl_arg;
+struct __old_kernel_stat;
+struct oldold_utsname;
+struct old_utsname;
+struct pollfd;
+struct rlimit;
+struct rlimit64;
+struct rusage;
+struct sched_param;
+struct sched_attr;
+struct sel_arg_struct;
+struct semaphore;
+struct sembuf;
+struct shmid_ds;
+struct sockaddr;
+struct stat;
+struct stat64;
+struct statfs;
+struct statfs64;
+struct __sysctl_args;
+struct sysinfo;
+struct timespec;
+struct timeval;
+struct timex;
+struct timezone;
+struct tms;
+struct utimbuf;
+struct mq_attr;
+struct compat_stat;
+struct compat_timeval;
+struct robust_list_head;
+struct getcpu_cache;
+struct old_linux_dirent;
+struct perf_event_attr;
+struct file_handle;
+struct sigaltstack;
+union bpf_attr;
+
+#endif /* _LINUX_SYSCALL_STRUCTS_H */
diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h
index 2622b33..f10a316 100644
--- a/include/uapi/asm-generic/unistd.h
+++ b/include/uapi/asm-generic/unistd.h
@@ -29,6 +29,10 @@
 #define __SC_COMP_3264(_nr, _32, _64, _comp) __SC_3264(_nr, _32, _64)
 #endif
 
+#ifndef __SC_WRAP
+#define __SC_WRAP __SYSCALL
+#endif
+
 #define __NR_io_setup 0
 __SC_COMP(__NR_io_setup, sys_io_setup, compat_sys_io_setup)
 #define __NR_io_destroy 1
-- 
2.5.0