Implement mlock2 syscall decoding

* mem.c: Include "xlat/mlock_flags.h".
(SYS_FUNC(mlock2)): New function.
* xlat/mlock_flags.in: New file.
* xlat/mlockall_flags.in: Add MCL_ONFAULT, add default values.
* linux/dummy.h (mlock2): Remove.
* tests/mlock2.c: New file.
* tests/mlock2.test: New test.
* tests/Makefile.am (check_PROGRAMS): Add mlock2.
(TESTS): Add mlock2.test.
* tests/.gitignore Add mlock2.

linux/dummy.h

@@ -37,7 +37,6 @@
 #define	sys_kcmp		printargs
 #define	sys_kexec_file_load	printargs
 #define	sys_lookup_dcookie	printargs
-#define	sys_mlock2		printargs
 #define	sys_name_to_handle_at	printargs
 #define	sys_open_by_handle_at	printargs
 #define	sys_sysfs		printargs

mem.c

@@ -247,6 +247,17 @@ SYS_FUNC(msync)
 	return RVAL_DECODED;
 }
 
+#include "xlat/mlock_flags.h"
+
+SYS_FUNC(mlock2)
+{
+	printaddr(tcp->u_arg[0]);
+	tprintf(", %lu, ", tcp->u_arg[1]);
+	printflags(mlock_flags, tcp->u_arg[2], "MLOCK_???");
+
+	return RVAL_DECODED;
+}
+
 SYS_FUNC(mincore)
 {
 	if (entering(tcp)) {

tests/.gitignore

@@ -20,6 +20,7 @@ ipc_sem
 ipc_shm
 membarrier
 memfd_create
+mlock2
 mmap
 mmap64
 mmsg

tests/Makefile.am

@@ -33,6 +33,7 @@ check_PROGRAMS = \
 	ipc_shm \
 	membarrier \
 	memfd_create \
+	mlock2 \
 	mmap \
 	mmap64 \
 	mmsg \
@@ -148,6 +149,7 @@ TESTS = \
 	sysinfo.test \
 	membarrier.test \
 	memfd_create.test \
+	mlock2.test \
 	mmap.test \
 	mmap64.test \
 	mmsg.test \

tests/mlock2.c

@@ -0,0 +1,25 @@
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include <errno.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/syscall.h>
+
+int
+main(void)
+{
+#ifdef __NR_mlock2
+	if (syscall(__NR_mlock2, 0xdeadbeef, 0xdefaced, 0xffff) != -1)
+		return 77;
+	printf("mlock2(0xdeadbeef, 233811181, MLOCK_ONFAULT|0xfffe) = -1 %s\n",
+	       errno == ENOSYS ?
+			"ENOSYS (Function not implemented)" :
+			"EINVAL (Invalid argument)");
+	puts("+++ exited with 0 +++");
+	return 0;
+#else
+        return 77;
+#endif
+}

tests/mlock2.test

@@ -0,0 +1,13 @@
+#!/bin/sh
+
+# Check mlock2 syscall decoding.
+
+. "${srcdir=.}/init.sh"
+
+run_prog > /dev/null
+OUT="$LOG.out"
+run_strace -e mlock2 $args > "$OUT"
+match_diff "$OUT" "$LOG"
+rm -f "$OUT"
+
+exit 0

xlat/mlock_flags.in

@@ -0,0 +1 @@
+MLOCK_ONFAULT	1

xlat/mlockall_flags.in

@@ -1,2 +1,3 @@
-MCL_CURRENT
-MCL_FUTURE
+MCL_CURRENT	1
+MCL_FUTURE	2
+MCL_ONFAULT	4