Convert parser of seccomp filter program to new mpers infrastructure

* seccomp_fprog.h: New file.
* fetch_seccomp_fprog.c: New file.
* Makefile.am (strace_SOURCES): Add them.
* seccomp.c: Include "seccomp_fprog.h".
(print_seccomp_filter): Use fetch_seccomp_fprog.

Author: ldv-alt

Makefile.am

@@ -59,6 +59,7 @@ strace_SOURCES =	\
 	fallocate.c	\
 	fanotify.c	\
 	fchownat.c	\
+	fetch_seccomp_fprog.c \
 	file.c		\
 	futex.c		\
 	get_robust_list.c \
@@ -123,6 +124,7 @@ strace_SOURCES =	\
 	sched.c		\
 	scsi.c		\
 	seccomp.c	\
+	seccomp_fprog.h \
 	sendfile.c	\
 	sigaltstack.c	\
 	signal.c	\

fetch_seccomp_fprog.c

@@ -0,0 +1,24 @@
+#include "defs.h"
+
+#include DEF_MPERS_TYPE(seccomp_fprog_t)
+
+#include "seccomp_fprog.h"
+typedef struct seccomp_fprog seccomp_fprog_t;
+
+#include MPERS_DEFS
+
+MPERS_PRINTER_DECL(bool, fetch_seccomp_fprog)(struct tcb *tcp, const long addr, void *p)
+{
+	struct seccomp_fprog *pfp = p;
+	seccomp_fprog_t mfp;
+
+	if (sizeof(*pfp) == sizeof(mfp))
+		return !umove_or_printaddr(tcp, addr, pfp);
+
+	if (umove_or_printaddr(tcp, addr, &mfp))
+		return false;
+
+	pfp->len = mfp.len;
+	pfp->filter = mfp.filter;
+	return true;
+}

seccomp.c

@@ -190,30 +190,15 @@ decode_fprog(struct tcb *tcp, unsigned short len, unsigned long addr)
 	}
 }
 
+#include "seccomp_fprog.h"
+
 void
 print_seccomp_filter(struct tcb *tcp, unsigned long addr)
 {
-#if SUPPORTED_PERSONALITIES > 1 && SIZEOF_LONG > 4
-	if (current_wordsize == 4) {
-		struct {
-			unsigned short len;
-			uint32_t filter;
-		} fprog;
-
-		if (!umove_or_printaddr(tcp, addr, &fprog))
-			decode_fprog(tcp, fprog.len, fprog.filter);
-	} else {
-#endif
-		struct {
-			unsigned short len;
-			unsigned long filter;
-		} fprog;
-
-		if (!umove_or_printaddr(tcp, addr, &fprog))
-			decode_fprog(tcp, fprog.len, fprog.filter);
-#if SUPPORTED_PERSONALITIES > 1 && SIZEOF_LONG > 4
-	}
-#endif
+	struct seccomp_fprog fprog;
+
+	if (fetch_seccomp_fprog(tcp, addr, &fprog))
+		decode_fprog(tcp, fprog.len, fprog.filter);
 }
 
 static void

seccomp_fprog.h

@@ -0,0 +1,4 @@
+struct seccomp_fprog {
+	unsigned short len;
+	unsigned long filter;
+};