diff --git a/seccomp.c b/seccomp.c
index e85666d..e62f99a 100644
--- a/seccomp.c
+++ b/seccomp.c
@@ -162,32 +162,39 @@
 #endif
 
 static void
-decode_fprog(struct tcb *tcp, unsigned short len, unsigned long addr)
+decode_seccomp_fprog(struct tcb *tcp, unsigned short len, unsigned long addr)
 {
-	if (!len || abbrev(tcp)) {
-		tprintf("{len = %u, filter = ", len);
-		printaddr(addr);
-		tprints("}");
-	} else {
-		unsigned int i = 0;
+	struct bpf_filter filter;
+	const unsigned long start_addr = addr;
+	unsigned int i = 0;
 
-		tprints("[");
-		while (i < len && i < BPF_MAXINSNS) {
-			struct bpf_filter filter;
-
-			if (umove(tcp, addr, &filter) < 0)
+	for (; addr >= start_addr && i < len; ++i, addr += sizeof(filter)) {
+		if (i) {
+			tprints(", ");
+			if (i >= BPF_MAXINSNS) {
+				tprints("...");
 				break;
-			if (i)
-				tprints(", ");
-			decode_filter(&filter);
-
-			addr += sizeof(filter);
-			++i;
+			}
 		}
-		if (i < len)
-			tprints("...");
-		tprints("]");
+		if (umove_or_printaddr(tcp, addr, &filter))
+			break;
+		if (!i)
+			tprints("[");
+		decode_filter(&filter);
 	}
+	if (i)
+		tprints("]");
+}
+
+static void
+print_seccomp_fprog(struct tcb *tcp, unsigned short len, unsigned long addr)
+{
+	tprintf("{len=%u, filter=", len);
+	if (abbrev(tcp) || !len)
+		printaddr(addr);
+	else
+		decode_seccomp_fprog(tcp, len, addr);
+	tprints("}");
 }
 
 #include "seccomp_fprog.h"
@@ -198,7 +205,7 @@
 	struct seccomp_fprog fprog;
 
 	if (fetch_seccomp_fprog(tcp, addr, &fprog))
-		decode_fprog(tcp, fprog.len, fprog.filter);
+		print_seccomp_fprog(tcp, fprog.len, fprog.filter);
 }
 
 static void
diff --git a/tests/.gitignore b/tests/.gitignore
index 01b6236..3ed6cee 100644
--- a/tests/.gitignore
+++ b/tests/.gitignore
@@ -128,6 +128,7 @@
 sched_xetparam
 sched_xetscheduler
 scm_rights
+seccomp-filter-v
 seccomp-strict
 select
 sendfile
diff --git a/tests/Makefile.am b/tests/Makefile.am
index 9572015..db33f4d 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -177,6 +177,7 @@
 	sched_xetparam \
 	sched_xetscheduler \
 	scm_rights \
+	seccomp-filter-v \
 	seccomp-strict \
 	select \
 	sendfile \
@@ -375,6 +376,7 @@
 	sched_xetparam.test \
 	sched_xetscheduler.test \
 	scm_rights-fd.test \
+	seccomp-filter-v.test \
 	seccomp-strict.test \
 	select.test \
 	sendfile.test \
diff --git a/tests/prctl-seccomp-filter-v.c b/tests/prctl-seccomp-filter-v.c
index c7fb137..a03f202 100644
--- a/tests/prctl-seccomp-filter-v.c
+++ b/tests/prctl-seccomp-filter-v.c
@@ -91,7 +91,7 @@
 };
 
 static const struct sock_fprog prog = {
-	.len = sizeof(filter) / sizeof(filter[0]),
+	.len = ARRAY_SIZE(filter),
 	.filter = (struct sock_filter *) filter,
 };
 
@@ -102,7 +102,8 @@
 
 	puts("prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)  = 0");
 
-	printf("prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, [");
+	printf("prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, {len=%u, filter=[",
+	       prog.len);
 
 	printf("BPF_STMT(BPF_LD|BPF_W|BPF_ABS, %#x), ",
 	       (unsigned) offsetof(struct seccomp_data, nr));
@@ -116,7 +117,7 @@
 
 	printf("BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL)");
 
-	puts("]) = 0");
+	puts("]}) = 0");
 	puts("+++ exited with 0 +++");
 
 	fflush(stdout);
diff --git a/tests/seccomp-filter-v.c b/tests/seccomp-filter-v.c
new file mode 100644
index 0000000..9a70658
--- /dev/null
+++ b/tests/seccomp-filter-v.c
@@ -0,0 +1,213 @@
+/*
+ * Check verbose decoding of seccomp SECCOMP_SET_MODE_FILTER.
+ *
+ * Copyright (c) 2015-2016 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 "tests.h"
+
+#include <errno.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <sys/syscall.h>
+#include <unistd.h>
+
+#ifdef HAVE_PRCTL
+# include <sys/prctl.h>
+#endif
+#ifdef HAVE_LINUX_SECCOMP_H
+# include <linux/seccomp.h>
+#endif
+#ifdef HAVE_LINUX_FILTER_H
+# include <linux/filter.h>
+#endif
+
+#if defined __NR_seccomp \
+ && defined PR_SET_NO_NEW_PRIVS \
+ && defined SECCOMP_SET_MODE_FILTER \
+ && defined SECCOMP_RET_ERRNO \
+ && defined BPF_JUMP \
+ && defined BPF_STMT
+
+#define SOCK_FILTER_ALLOW_SYSCALL(nr) \
+		BPF_JUMP(BPF_JMP|BPF_K|BPF_JEQ, __NR_ ## nr, 0, 1), \
+		BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW)
+
+#define SOCK_FILTER_DENY_SYSCALL(nr, err) \
+		BPF_JUMP(BPF_JMP|BPF_K|BPF_JEQ, __NR_ ## nr, 0, 1), \
+		BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO|(SECCOMP_RET_DATA & (err)))
+
+#define SOCK_FILTER_KILL_PROCESS \
+		BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL)
+
+#define PRINT_ALLOW_SYSCALL(nr) \
+	tprintf("BPF_JUMP(BPF_JMP|BPF_K|BPF_JEQ, %#x, 0, 0x1), " \
+	       "BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), ", \
+	       __NR_ ## nr)
+
+#define PRINT_DENY_SYSCALL(nr, err) \
+	tprintf("BPF_JUMP(BPF_JMP|BPF_K|BPF_JEQ, %#x, 0, 0x1), " \
+	       "BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO|%#x), ", \
+	       __NR_ ## nr, err)
+
+static const struct sock_filter filter_c[] = {
+	/* load syscall number */
+	BPF_STMT(BPF_LD|BPF_W|BPF_ABS, offsetof(struct seccomp_data, nr)),
+
+	/* allow syscalls */
+	SOCK_FILTER_ALLOW_SYSCALL(close),
+	SOCK_FILTER_ALLOW_SYSCALL(exit),
+	SOCK_FILTER_ALLOW_SYSCALL(exit_group),
+
+	/* deny syscalls */
+	SOCK_FILTER_DENY_SYSCALL(sync, EBUSY),
+	SOCK_FILTER_DENY_SYSCALL(setsid, EPERM),
+
+	/* kill process */
+	SOCK_FILTER_KILL_PROCESS
+};
+
+#ifndef BPF_MAXINSNS
+# define BPF_MAXINSNS 4096
+#endif
+
+int
+main(void)
+{
+	tprintf("%s", "");
+
+	static const char kill_stmt_txt[] =
+		"BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL)";
+	struct sock_filter *const filter =
+		tail_memdup(filter_c, sizeof(filter_c));
+	struct sock_filter *const big_filter =
+		tail_alloc(sizeof(*big_filter) * (BPF_MAXINSNS + 1));
+	struct sock_fprog *const prog = tail_alloc(sizeof(*prog));
+
+	int fds[2];
+	if (pipe(fds))
+		perror_msg_and_fail("pipe");
+	if (prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0))
+		perror_msg_and_skip("PR_SET_NO_NEW_PRIVS");
+
+	prog->filter = filter +  ARRAY_SIZE(filter_c);
+	prog->len = 1;
+	syscall(__NR_seccomp, SECCOMP_SET_MODE_FILTER, 0, prog);
+	tprintf("seccomp(SECCOMP_SET_MODE_FILTER, 0, {len=1, filter=%p})"
+		" = -1 EFAULT (%m)\n", prog->filter);
+
+	prog->filter = filter +  ARRAY_SIZE(filter_c) - 1;
+	prog->len = 3;
+	syscall(__NR_seccomp, SECCOMP_SET_MODE_FILTER, 0, prog);
+	tprintf("seccomp(SECCOMP_SET_MODE_FILTER, 0, {len=%u"
+		", filter=[%s, %p]}) = -1 EFAULT (%m)\n",
+		prog->len, kill_stmt_txt, filter +  ARRAY_SIZE(filter_c));
+
+	prog->len = 0;
+	syscall(__NR_seccomp, SECCOMP_SET_MODE_FILTER, 0, prog);
+	tprintf("seccomp(SECCOMP_SET_MODE_FILTER, 0, {len=0, filter=%p})"
+		" = -1 EINVAL (%m)\n", prog->filter);
+
+	unsigned int i;
+	for (i = 0; i <= BPF_MAXINSNS; ++i) {
+		const struct sock_filter stmt =
+			BPF_STMT(BPF_CLASS(i), i << 16);
+		big_filter[i] = stmt;
+	}
+
+	prog->filter = big_filter;
+	prog->len = BPF_MAXINSNS + 1;
+	tprintf("seccomp(SECCOMP_SET_MODE_FILTER, %s, {len=%u, filter=[",
+		"SECCOMP_FILTER_FLAG_TSYNC|0xfffffffe", prog->len);
+	for (i = 0; i < BPF_MAXINSNS; ++i) {
+		if (i)
+			tprintf(", ");
+		switch(BPF_CLASS(i)) {
+		case BPF_LD:
+			tprintf("BPF_STMT(BPF_LD|BPF_W|BPF_IMM, %#x)", i << 16);
+			break;
+		case BPF_LDX:
+			tprintf("BPF_STMT(BPF_LDX|BPF_W|BPF_IMM, %#x)", i << 16);
+			break;
+		case BPF_ST:
+			tprintf("BPF_STMT(BPF_ST, %#x)", i << 16);
+			break;
+		case BPF_STX:
+			tprintf("BPF_STMT(BPF_STX, %#x)", i << 16);
+			break;
+		case BPF_ALU:
+			tprintf("BPF_STMT(BPF_ALU|BPF_K|BPF_ADD, %#x)", i << 16);
+			break;
+		case BPF_JMP:
+			tprintf("BPF_STMT(BPF_JMP|BPF_K|BPF_JA, %#x)", i << 16);
+			break;
+		case BPF_RET:
+			tprintf("BPF_STMT(BPF_RET|BPF_K, %#x"
+				" /* SECCOMP_RET_??? */)", i << 16);
+			break;
+		case BPF_MISC:
+			tprintf("BPF_STMT(BPF_MISC|BPF_TAX, %#x)", i << 16);
+			break;
+		}
+	}
+	tprintf(", ...]})");
+	syscall(__NR_seccomp, SECCOMP_SET_MODE_FILTER, -1, prog);
+	tprintf(" = -1 EINVAL (%m)\n");
+
+	prog->filter = filter;
+	prog->len = ARRAY_SIZE(filter_c);
+
+	tprintf("seccomp(SECCOMP_SET_MODE_FILTER, 0, {len=%u, filter=[",
+		prog->len);
+
+	tprintf("BPF_STMT(BPF_LD|BPF_W|BPF_ABS, %#x), ",
+	       (unsigned) offsetof(struct seccomp_data, nr));
+
+	PRINT_ALLOW_SYSCALL(close);
+	PRINT_ALLOW_SYSCALL(exit);
+	PRINT_ALLOW_SYSCALL(exit_group);
+
+	PRINT_DENY_SYSCALL(sync, EBUSY),
+	PRINT_DENY_SYSCALL(setsid, EPERM),
+
+	tprintf("%s]}) = 0\n+++ exited with 0 +++\n", kill_stmt_txt);
+
+	if (syscall(__NR_seccomp, SECCOMP_SET_MODE_FILTER, 0, prog))
+		perror_msg_and_skip("SECCOMP_SET_MODE_FILTER");
+
+	if (close(0) || close(1))
+		_exit(77);
+
+	_exit(0);
+}
+
+#else
+
+SKIP_MAIN_UNDEFINED("__NR_seccomp && PR_SET_NO_NEW_PRIVS"
+		    " && SECCOMP_SET_MODE_FILTER && SECCOMP_RET_ERRNO"
+		    " && BPF_JUMP && BPF_STMT")
+
+#endif
diff --git a/tests/seccomp-filter-v.test b/tests/seccomp-filter-v.test
new file mode 100755
index 0000000..f873eb6
--- /dev/null
+++ b/tests/seccomp-filter-v.test
@@ -0,0 +1,6 @@
+#!/bin/sh
+
+# Check verbose decoding of seccomp SECCOMP_SET_MODE_FILTER.
+
+. "${srcdir=.}/init.sh"
+run_strace_match_diff -v -e trace=seccomp