Merge branch 'compat' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux into features

Pull tip branch with Arnds compat system call wrapper rework.

3 files changed, 166 insertions, 0 deletions

diff --git a/arch/s390/include/asm/ftrace.h b/arch/s390/include/asm/ftrace.h
index 8ea270fdc7fb..5a3c95b11952 100644
--- a/arch/s390/include/asm/ftrace.h
+++ b/arch/s390/include/asm/ftrace.h
@@ -81,5 +81,30 @@ static inline void ftrace_generate_call_insn(struct ftrace_insn *insn,
 #endif
 }
 
+/*
+ * Even though the system call numbers are identical for s390/s390x a
+ * different system call table is used for compat tasks. This may lead
+ * to e.g. incorrect or missing trace event sysfs files.
+ * Therefore simply do not trace compat system calls at all.
+ * See kernel/trace/trace_syscalls.c.
+ */
+#define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS
+static inline bool arch_trace_is_compat_syscall(struct pt_regs *regs)
+{
+	return is_compat_task();
+}
+
+#define ARCH_HAS_SYSCALL_MATCH_SYM_NAME
+static inline bool arch_syscall_match_sym_name(const char *sym,
+					       const char *name)
+{
+	/*
+	 * Skip __s390_ and __s390x_ prefix - due to compat wrappers
+	 * and aliasing some symbols of 64 bit system call functions
+	 * may get the __s390_ prefix instead of the __s390x_ prefix.
+	 */
+	return !strcmp(sym + 7, name) || !strcmp(sym + 8, name);
+}
+
 #endif /* __ASSEMBLY__ */
 #endif /* _ASM_S390_FTRACE_H */
diff --git a/arch/s390/include/asm/syscall_wrapper.h b/arch/s390/include/asm/syscall_wrapper.h
new file mode 100644
index 000000000000..5596c5c625d2
--- /dev/null
+++ b/arch/s390/include/asm/syscall_wrapper.h
@@ -0,0 +1,135 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * syscall_wrapper.h - s390 specific wrappers to syscall definitions
+ *
+ */
+
+#ifndef _ASM_S390_SYSCALL_WRAPPER_H
+#define _ASM_S390_SYSCALL_WRAPPER_H
+
+#ifdef CONFIG_COMPAT
+#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) &&		\
+		     !__TYPE_IS_LL(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;					\
+	if (__TYPE_IS_LL(t))						\
+		return -ENOSYS;						\
+	(t)__ReS;							\
+})
+
+#define __S390_SYS_STUBx(x, name, ...)					\
+	asmlinkage long __s390_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__))\
+	ALLOW_ERROR_INJECTION(__s390_sys##name, ERRNO);			\
+	asmlinkage long __s390_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__))\
+	{								\
+		long ret = __s390x_sys##name(__MAP(x,__SC_COMPAT_CAST,__VA_ARGS__));\
+		__MAP(x,__SC_TEST,__VA_ARGS__);				\
+		return ret;						\
+	}
+
+/*
+ * To keep the naming coherent, re-define SYSCALL_DEFINE0 to create an alias
+ * named __s390x_sys_*()
+ */
+#define COMPAT_SYSCALL_DEFINE0(sname)					\
+	SYSCALL_METADATA(_##sname, 0);					\
+	asmlinkage long __s390_compat_sys_##sname(void);		\
+	ALLOW_ERROR_INJECTION(__s390_compat__sys_##sname, ERRNO);	\
+	asmlinkage long __s390_compat_sys_##sname(void)
+
+#define SYSCALL_DEFINE0(sname)						\
+	SYSCALL_METADATA(_##sname, 0);					\
+	asmlinkage long __s390x_sys_##sname(void);			\
+	ALLOW_ERROR_INJECTION(__s390x_sys_##sname, ERRNO);		\
+	asmlinkage long __s390_sys_##sname(void)			\
+		__attribute__((alias(__stringify(__s390x_sys_##sname)))); \
+	asmlinkage long __s390x_sys_##sname(void)
+
+#define COND_SYSCALL(name)						\
+	cond_syscall(__s390x_sys_##name);				\
+	cond_syscall(__s390_sys_##name)
+
+#define SYS_NI(name)							\
+	SYSCALL_ALIAS(__s390x_sys_##name, sys_ni_posix_timers);		\
+	SYSCALL_ALIAS(__s390_sys_##name, sys_ni_posix_timers)
+
+#define COMPAT_SYSCALL_DEFINEx(x, name, ...)					\
+	__diag_push();								\
+	__diag_ignore(GCC, 8, "-Wattribute-alias",				\
+		      "Type aliasing is used to sanitize syscall arguments");\
+	asmlinkage long __s390_compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__));	\
+	asmlinkage long __s390_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__))	\
+	{									\
+		long ret = __do_compat_sys##name(__MAP(x,__SC_DELOUSE,__VA_ARGS__));\
+		__MAP(x,__SC_TEST,__VA_ARGS__);					\
+		return ret;							\
+	}									\
+	__diag_pop();								\
+	static inline long __do_compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__))
+
+/*
+ * As some compat syscalls may not be implemented, we need to expand
+ * COND_SYSCALL_COMPAT in kernel/sys_ni.c and COMPAT_SYS_NI in
+ * kernel/time/posix-stubs.c to cover this case as well.
+ */
+#define COND_SYSCALL_COMPAT(name)					\
+	cond_syscall(__s390_compat_sys_##name)
+
+#define COMPAT_SYS_NI(name)						\
+	SYSCALL_ALIAS(__s390_compat_sys_##name, sys_ni_posix_timers)
+
+#else /* CONFIG_COMPAT */
+
+#define __S390_SYS_STUBx(x, fullname, name, ...)
+
+#define SYSCALL_DEFINE0(sname)						\
+	SYSCALL_METADATA(_##sname, 0);					\
+	asmlinkage long __s390x_sys_##sname(void);			\
+	ALLOW_ERROR_INJECTION(__s390x_sys_##sname, ERRNO);		\
+	asmlinkage long __s390x_sys_##sname(void)
+
+#define COND_SYSCALL(name)						\
+	cond_syscall(__s390x_sys_##name)
+
+#define SYS_NI(name)							\
+	SYSCALL_ALIAS(__s390x_sys_##name, sys_ni_posix_timers);
+
+#endif /* CONFIG_COMPAT */
+
+#define __SYSCALL_DEFINEx(x, name, ...)						\
+	__diag_push();								\
+	__diag_ignore(GCC, 8, "-Wattribute-alias",				\
+		      "Type aliasing is used to sanitize syscall arguments");\
+	asmlinkage long __s390x_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__))	\
+		__attribute__((alias(__stringify(__se_sys##name))));		\
+	ALLOW_ERROR_INJECTION(__s390x_sys##name, ERRNO);				\
+	static long __se_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__));		\
+	static inline long __do_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__));	\
+	__S390_SYS_STUBx(x, name, __VA_ARGS__)					\
+	asmlinkage long __se_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__))		\
+	{									\
+		long ret = __do_sys##name(__MAP(x,__SC_CAST,__VA_ARGS__));	\
+		__MAP(x,__SC_TEST,__VA_ARGS__);					\
+		return ret;							\
+	}									\
+	__diag_pop();								\
+	static inline long __do_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__))
+
+#endif /* _ASM_X86_SYSCALL_WRAPPER_H */
diff --git a/arch/s390/include/uapi/asm/posix_types.h b/arch/s390/include/uapi/asm/posix_types.h
index 2a3fc638414b..1913613e71b6 100644
--- a/arch/s390/include/uapi/asm/posix_types.h
+++ b/arch/s390/include/uapi/asm/posix_types.h
@@ -20,6 +20,12 @@ typedef long            __kernel_ssize_t;
 typedef unsigned short	__kernel_old_dev_t;
 #define __kernel_old_dev_t __kernel_old_dev_t
 
+#ifdef __KERNEL__
+typedef unsigned short __kernel_old_uid_t;
+typedef unsigned short __kernel_old_gid_t;
+#define __kernel_old_uid_t __kernel_old_uid_t
+#endif
+
 #ifndef __s390x__
 
 typedef unsigned long   __kernel_ino_t;