Fix decoding of statfs family syscalls

Fix decoders of fstatfs, fstatfs64, statfs, and statfs64 syscalls
by rewriting them using mpers infrastructure.

* fetch_struct_statfs.c: New file.
* fstatfs.c: Likewise.
* fstatfs64.c: Likewise.
* print_statfs.c: Likewise.
* statfs.h: Likewise.
* statfs64.c: Likewise.
* statfs.c: Remove everything except SYS_FUNC(statfs).
* configure.ac: Remove the check for struct statfs64 in <sys/vfs.h>.
Add checks for struct statfs and struct statfs64 in <asm/statfs.h>.
Add checks for f_frsize and f_flags members of these structures.
* defs.h (struct strace_statfs): New forward declaration.
(print_struct_statfs, print_struct_statfs64): New prototypes.
* Makefile.am (libstrace_a_SOURCES): Add fstatfs.c, fstatfs64.c,
statfs.c, and statfs64.c.
(strace_SOURCES): Add fetch_struct_statfs.c, print_statfs.c,
and statfs.h.
* NEWS: Mention this fix.
* tests/fstatfs.c: New file.
* tests/fstatfs64.c: Likewise.
* tests/statfs64.c: Likewise.
* tests/xstatfs.c: Likewise.
* tests/xstatfs64.c: Likewise.
* tests/xstatfsx.c: Likewise.
* tests/fstatfs.test: New test.
* tests/fstatfs64.test: Likewise.
* tests/statfs64.test: Likewise.
* tests/statfs.c: Rewrite using xstatfs.c.
* tests/statfs.test: Update.
* tests/.gitignore: Add fstatfs, fstatfs64, and statfs64.
* tests/Makefile.am (check_PROGRAMS): Likewise.
(DECODER_TESTS): Add  fstatfs.test, fstatfs64.test, and statfs64.test.
(EXTRA_DIST): Add xstatfs.c, xstatfs64.c, and xstatfsx.c.
diff --git a/fetch_struct_statfs.c b/fetch_struct_statfs.c
new file mode 100644
index 0000000..7c8b088
--- /dev/null
+++ b/fetch_struct_statfs.c
@@ -0,0 +1,126 @@
+/*
+ * Copyright (c) 2014-2016 Dmitry V. Levin <ldv@altlinux.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "defs.h"
+
+#include DEF_MPERS_TYPE(struct_statfs)
+#include DEF_MPERS_TYPE(struct_statfs64)
+
+#include <linux/types.h>
+#include <asm/statfs.h>
+typedef struct statfs struct_statfs;
+typedef struct statfs64 struct_statfs64;
+
+#include MPERS_DEFS
+
+#include "statfs.h"
+
+#define ASSIGN_NUMBER(dst, src)				\
+	if (sizeof(src) == sizeof(int))			\
+		dst = (unsigned int) (src);		\
+	else if (sizeof(src) == sizeof(long))		\
+		dst = (unsigned long) (src);		\
+	else						\
+		dst = (unsigned long long) (src)
+
+MPERS_PRINTER_DECL(bool, fetch_struct_statfs)(struct tcb *tcp, const long addr, struct strace_statfs *p)
+{
+	struct_statfs b;
+
+	if (umove_or_printaddr(tcp, addr, &b))
+		return false;
+
+	ASSIGN_NUMBER(p->f_type, b.f_type);
+	ASSIGN_NUMBER(p->f_bsize, b.f_bsize);
+	ASSIGN_NUMBER(p->f_blocks, b.f_blocks);
+	ASSIGN_NUMBER(p->f_bfree, b.f_bfree);
+	ASSIGN_NUMBER(p->f_bavail, b.f_bavail);
+	ASSIGN_NUMBER(p->f_files, b.f_files);
+	ASSIGN_NUMBER(p->f_ffree, b.f_ffree);
+#if defined HAVE_STRUCT_STATFS_F_FSID_VAL
+	ASSIGN_NUMBER(p->f_fsid[0], b.f_fsid.val[0]);
+	ASSIGN_NUMBER(p->f_fsid[1], b.f_fsid.val[1]);
+#elif defined HAVE_STRUCT_STATFS_F_FSID___VAL
+	ASSIGN_NUMBER(p->f_fsid[0], b.f_fsid.__val[0]);
+	ASSIGN_NUMBER(p->f_fsid[1], b.f_fsid.__val[1]);
+#endif
+	ASSIGN_NUMBER(p->f_namelen, b.f_namelen);
+#ifdef HAVE_STRUCT_STATFS_F_FRSIZE
+	ASSIGN_NUMBER(p->f_frsize, b.f_frsize);
+#endif
+#ifdef HAVE_STRUCT_STATFS_F_FLAGS
+	ASSIGN_NUMBER(p->f_flags, b.f_flags);
+#endif
+
+	return true;
+}
+
+#if defined ARM || (defined AARCH64 && defined IN_MPERS)
+/* See arch/arm/kernel/sys_oabi-compat.c for details. */
+# define COMPAT_STATFS64_PADDED_SIZE (sizeof(struct_statfs64) + 4)
+#endif
+
+MPERS_PRINTER_DECL(bool, fetch_struct_statfs64)(struct tcb *tcp, const long addr, const unsigned long size, struct strace_statfs *p)
+{
+	struct_statfs64 b;
+
+        if (sizeof(b) != size
+#ifdef COMPAT_STATFS64_PADDED_SIZE
+	    && sizeof(b) != COMPAT_STATFS64_PADDED_SIZE
+#endif
+	   ) {
+		printaddr(addr);
+		return false;
+	}
+
+	if (umove_or_printaddr(tcp, addr, &b))
+		return false;
+
+	ASSIGN_NUMBER(p->f_type, b.f_type);
+	ASSIGN_NUMBER(p->f_bsize, b.f_bsize);
+	ASSIGN_NUMBER(p->f_blocks, b.f_blocks);
+	ASSIGN_NUMBER(p->f_bfree, b.f_bfree);
+	ASSIGN_NUMBER(p->f_bavail, b.f_bavail);
+	ASSIGN_NUMBER(p->f_files, b.f_files);
+	ASSIGN_NUMBER(p->f_ffree, b.f_ffree);
+#if defined HAVE_STRUCT_STATFS64_F_FSID_VAL
+	ASSIGN_NUMBER(p->f_fsid[0], b.f_fsid.val[0]);
+	ASSIGN_NUMBER(p->f_fsid[1], b.f_fsid.val[1]);
+#elif defined HAVE_STRUCT_STATFS64_F_FSID___VAL
+	ASSIGN_NUMBER(p->f_fsid[0], b.f_fsid.__val[0]);
+	ASSIGN_NUMBER(p->f_fsid[1], b.f_fsid.__val[1]);
+#endif
+	ASSIGN_NUMBER(p->f_namelen, b.f_namelen);
+#ifdef HAVE_STRUCT_STATFS64_F_FRSIZE
+	ASSIGN_NUMBER(p->f_frsize, b.f_frsize);
+#endif
+#ifdef HAVE_STRUCT_STATFS64_F_FLAGS
+	ASSIGN_NUMBER(p->f_flags, b.f_flags);
+#endif
+
+	return true;
+}