syscall: unify common syscall defines

Unify all the common syscall defines in syscalls-common.h and scrub all
the duplicated code from relevant ports.  This should also make converting
existing ports to INLINE_SYSCALL() much easier as they don't have to get
lost in all the unrelated noise, as well as creating new ports.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>

1 files changed, 81 insertions, 0 deletions

diff --git a/libc/sysdeps/linux/common/bits/syscalls-common.h b/libc/sysdeps/linux/common/bits/syscalls-common.h
new file mode 100644
index 000000000..81c82c801
--- /dev/null
+++ b/libc/sysdeps/linux/common/bits/syscalls-common.h
@@ -0,0 +1,81 @@
+/*
+ * Common syscall type defines
+ *
+ * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
+ */
+
+#ifndef _SYSCALLS_COMMON_H
+#define _SYSCALLS_COMMON_H	1
+
+#ifndef _SYSCALL_H
+# error "Never use <bits/syscalls-common.h> directly; include <sys/syscall.h> instead."
+#endif
+
+#ifndef SYS_ify
+# define SYS_ify(syscall_name) (__NR_##syscall_name)
+#endif
+
+#ifndef __ASSEMBLER__
+
+#include <errno.h>
+
+#ifndef INTERNAL_SYSCALL_DECL
+# define INTERNAL_SYSCALL_DECL(err)         do { } while (0)
+#endif
+#ifndef INTERNAL_SYSCALL_ERROR_P
+# define INTERNAL_SYSCALL_ERROR_P(val, err) ((unsigned long)val >= (unsigned long)(-4095))
+#endif
+#ifndef INTERNAL_SYSCALL_ERRNO
+# define INTERNAL_SYSCALL_ERRNO(val, err)   (-(val))
+#endif
+
+/* Define a macro which expands into the inline wrapper code for a system call */
+#ifndef INLINE_SYSCALL
+# define INLINE_SYSCALL(name, nr, args...)				\
+({									\
+	INTERNAL_SYSCALL_DECL(err);					\
+	long res = INTERNAL_SYSCALL(name, err, nr, args);		\
+	if (unlikely(INTERNAL_SYSCALL_ERROR_P(res, err))) {		\
+		__set_errno(INTERNAL_SYSCALL_ERRNO(res, err));		\
+		res = -1L;						\
+	}								\
+	res;								\
+})
+#endif
+
+#ifndef _syscall0
+
+#define C_DECL_ARGS_0()			void
+#define C_DECL_ARGS_1(t, v)		t v
+#define C_DECL_ARGS_2(t, v, args...)	t v, C_DECL_ARGS_1(args)
+#define C_DECL_ARGS_3(t, v, args...)	t v, C_DECL_ARGS_2(args)
+#define C_DECL_ARGS_4(t, v, args...)	t v, C_DECL_ARGS_3(args)
+#define C_DECL_ARGS_5(t, v, args...)	t v, C_DECL_ARGS_4(args)
+#define C_DECL_ARGS_6(t, v, args...)	t v, C_DECL_ARGS_5(args)
+
+#define C_ARGS_0()
+#define C_ARGS_1(t, v)			v
+#define C_ARGS_2(t, v, args...)		v, C_ARGS_1(args)
+#define C_ARGS_3(t, v, args...)		v, C_ARGS_2(args)
+#define C_ARGS_4(t, v, args...)		v, C_ARGS_3(args)
+#define C_ARGS_5(t, v, args...)		v, C_ARGS_4(args)
+#define C_ARGS_6(t, v, args...)		v, C_ARGS_5(args)
+
+#define SYSCALL_FUNC(nargs, type, name, args...)			\
+type name(C_DECL_ARGS_##nargs(args)) {					\
+	return (type)INLINE_SYSCALL(name, nargs, C_ARGS_##nargs(args));	\
+}
+
+#define _syscall0(args...)		SYSCALL_FUNC(0, args)
+#define _syscall1(args...)		SYSCALL_FUNC(1, args)
+#define _syscall2(args...)		SYSCALL_FUNC(2, args)
+#define _syscall3(args...)		SYSCALL_FUNC(3, args)
+#define _syscall4(args...)		SYSCALL_FUNC(4, args)
+#define _syscall5(args...)		SYSCALL_FUNC(5, args)
+#define _syscall6(args...)		SYSCALL_FUNC(6, args)
+
+#endif /* _syscall0 */
+
+#endif /* __ASSEMBLER__ */
+
+#endif