From: Dmitry V. Levin <ldv@altlinux.org>
Date: Sun, 15 Nov 2015 02:22:44 +0000 (+0000)
Subject: Implement userfaultfd syscall decoding
X-Git-Tag: v4.11~142
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=a6ebdb149edadac7ddb793448778bd8643003d27;p=strace

Implement userfaultfd syscall decoding

* userfaultfd.c: New file.
* Makefile.am (strace_SOURCES): Add it.
* xlat/uffd_flags.in: New file.
* linux/dummy.h (userfaultfd): Remove.
* tests/userfaultfd.c: New file.
* tests/userfaultfd.test: New test.
* tests/Makefile.am (check_PROGRAMS): Add userfaultfd.
(TESTS): Add userfaultfd.test.
* tests/.gitignore: Add userfaultfd.
---

diff --git a/Makefile.am b/Makefile.am
index 8070ba3e..82cd7ca8 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -154,6 +154,7 @@ strace_SOURCES =	\
 	umask.c		\
 	umount.c	\
 	uname.c		\
+	userfaultfd.c	\
 	util.c		\
 	utime.c		\
 	utimes.c	\
diff --git a/linux/dummy.h b/linux/dummy.h
index 3a333ac3..6c8d1452 100644
--- a/linux/dummy.h
+++ b/linux/dummy.h
@@ -42,7 +42,6 @@
 #define	sys_name_to_handle_at	printargs
 #define	sys_open_by_handle_at	printargs
 #define	sys_sysfs		printargs
-#define	sys_userfaultfd		printargs
 #define	sys_vm86		printargs
 #define	sys_vm86old		printargs
 
diff --git a/tests/.gitignore b/tests/.gitignore
index 62574686..c886eb92 100644
--- a/tests/.gitignore
+++ b/tests/.gitignore
@@ -65,6 +65,7 @@ uio
 umovestr
 umovestr2
 unix-pair-send-recv
+userfaultfd
 utime
 utimensat
 wait
diff --git a/tests/Makefile.am b/tests/Makefile.am
index c52f2760..e0e352f4 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -78,6 +78,7 @@ check_PROGRAMS = \
 	umovestr \
 	umovestr2 \
 	unix-pair-send-recv \
+	userfaultfd \
 	utime \
 	utimensat \
 	wait \
@@ -170,6 +171,7 @@ TESTS = \
 	uid16.test \
 	uid32.test \
 	uio.test \
+	userfaultfd.test \
 	utime.test \
 	utimensat.test \
 	wait.test \
diff --git a/tests/userfaultfd.c b/tests/userfaultfd.c
new file mode 100644
index 00000000..2dcf31cb
--- /dev/null
+++ b/tests/userfaultfd.c
@@ -0,0 +1,26 @@
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/syscall.h>
+
+int
+main(void)
+{
+#if defined __NR_userfaultfd && defined O_CLOEXEC
+	if (syscall(__NR_userfaultfd, 1 | O_NONBLOCK | O_CLOEXEC) != -1)
+		return 77;
+	printf("userfaultfd(O_NONBLOCK|O_CLOEXEC|0x1) = -1 %s\n",
+	       errno == ENOSYS ?
+			"ENOSYS (Function not implemented)" :
+			"EINVAL (Invalid argument)");
+	puts("+++ exited with 0 +++");
+	return 0;
+#else
+        return 77;
+#endif
+}
diff --git a/tests/userfaultfd.test b/tests/userfaultfd.test
new file mode 100755
index 00000000..b9c83682
--- /dev/null
+++ b/tests/userfaultfd.test
@@ -0,0 +1,13 @@
+#!/bin/sh
+
+# Check userfaultfd syscall decoding.
+
+. "${srcdir=.}/init.sh"
+
+run_prog > /dev/null
+OUT="$LOG.out"
+run_strace -a38 -euserfaultfd $args > "$OUT"
+match_diff "$OUT" "$LOG"
+rm -f "$OUT"
+
+exit 0
diff --git a/userfaultfd.c b/userfaultfd.c
new file mode 100644
index 00000000..7f8e3e46
--- /dev/null
+++ b/userfaultfd.c
@@ -0,0 +1,11 @@
+#include "defs.h"
+#include <fcntl.h>
+
+#include "xlat/uffd_flags.h"
+
+SYS_FUNC(userfaultfd)
+{
+	printflags(uffd_flags, tcp->u_arg[0], "UFFD_???");
+
+	return RVAL_DECODED | RVAL_FD;
+}
diff --git a/xlat/uffd_flags.in b/xlat/uffd_flags.in
new file mode 100644
index 00000000..fb0338bc
--- /dev/null
+++ b/xlat/uffd_flags.in
@@ -0,0 +1,2 @@
+O_NONBLOCK
+O_CLOEXEC