From: Dmitry V. Levin <ldv@altlinux.org>
Date: Wed, 19 Jul 2017 00:33:56 +0000 (+0000)
Subject: userfaultfd: decode struct uffdio_api.features as flags
X-Git-Tag: v4.19~248
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=6644e1f4e1180ea7abc1001aa3527e965a80d3d5;p=strace

userfaultfd: decode struct uffdio_api.features as flags

* xlat/uffd_api_features.in: New file.
* userfaultfd.c: Include "xlat/uffd_api_features.h".
(uffdio_ioctl): Print struct uffdio_api.features using
PRINT_FIELD_FLAGS64 and uffd_api_features.
* NEWS: Mention this.
* tests/ioctl_uffdio.c: Include "xlat.h" and "xlat/uffd_api_features.h".
(main): Update expected output.
---

diff --git a/NEWS b/NEWS
index 6d621e74..305e419f 100644
--- a/NEWS
+++ b/NEWS
@@ -9,6 +9,7 @@ Noteworthy changes in release ?.?? (????-??-??)
     IPV6_ADD_MEMBERSHIP, IPV6_DROP_MEMBERSHIP, IPV6_JOIN_ANYCAST,
     IPV6_LEAVE_ANYCAST, MCAST_JOIN_GROUP, and MCAST_LEAVE_GROUP options
     of setsockopt syscall.
+  * Enhanced decoding of UFFDIO_API ioctl command.
   * Implemented decoding of linux socket filter programs specified
     for SO_ATTACH_FILTER and SO_ATTACH_REUSEPORT_CBPF socket options.
   * Implemented decoding of inet_diag_req_v2, inet_diag_req_compat,
diff --git a/tests/ioctl_uffdio.c b/tests/ioctl_uffdio.c
index 24c642a7..973de39f 100644
--- a/tests/ioctl_uffdio.c
+++ b/tests/ioctl_uffdio.c
@@ -44,6 +44,9 @@
 # include <linux/ioctl.h>
 # include <linux/userfaultfd.h>
 
+#include "xlat.h"
+#include "xlat/uffd_api_features.h"
+
 int
 main(void)
 {
@@ -71,9 +74,11 @@ main(void)
 	api_struct->features = 0;
 	rc = ioctl(fd, UFFDIO_API, api_struct);
 	printf("ioctl(%d, UFFDIO_API, {api=0xaa, features=0", fd);
-	if (api_struct->features)
-		printf(" => features=%#" PRIx64,
-		       (uint64_t) api_struct->features);
+	if (api_struct->features) {
+		printf(" => features=");
+		printflags(uffd_api_features, api_struct->features,
+			   "UFFD_FEATURE_???");
+	}
 	printf(", ioctls=1<<_UFFDIO_REGISTER|"
 	       "1<<_UFFDIO_UNREGISTER|1<<_UFFDIO_API");
 	api_struct->ioctls &= ~(1ull<<_UFFDIO_REGISTER|
diff --git a/userfaultfd.c b/userfaultfd.c
index 07a305b5..7d09a109 100644
--- a/userfaultfd.c
+++ b/userfaultfd.c
@@ -43,6 +43,7 @@ SYS_FUNC(userfaultfd)
 # include <linux/ioctl.h>
 # include <linux/userfaultfd.h>
 
+# include "xlat/uffd_api_features.h"
 # include "xlat/uffd_api_flags.h"
 # include "xlat/uffd_copy_flags.h"
 # include "xlat/uffd_register_ioctl_flags.h"
@@ -75,11 +76,10 @@ uffdio_ioctl(struct tcb *const tcp, const unsigned int code,
 			tprints(", ");
 			if (umove_or_printaddr(tcp, arg, &ua))
 				return RVAL_DECODED | 1;
-			/* Features is intended to contain some flags, but
-			 * there aren't any defined yet.
-			 */
 			PRINT_FIELD_X("{", ua, api);
-			PRINT_FIELD_X(", ", ua, features);
+			PRINT_FIELD_FLAGS64(", ", ua, features,
+					    uffd_api_features,
+					    "UFFD_FEATURE_???");
 			entering_features = malloc(sizeof(*entering_features));
 			if (entering_features) {
 				*entering_features = ua.features;
@@ -90,7 +90,9 @@ uffdio_ioctl(struct tcb *const tcp, const unsigned int code,
 				entering_features = get_tcb_priv_data(tcp);
 				if (!entering_features
 				    || *entering_features != ua.features) {
-					PRINT_FIELD_X(" => ", ua, features);
+					PRINT_FIELD_FLAGS64(" => ", ua, features,
+							    uffd_api_features,
+							    "UFFD_FEATURE_???");
 				}
 				PRINT_FIELD_FLAGS64(", ", ua, ioctls,
 						    uffd_api_flags,
diff --git a/xlat/uffd_api_features.in b/xlat/uffd_api_features.in
new file mode 100644
index 00000000..8b1ea974
--- /dev/null
+++ b/xlat/uffd_api_features.in
@@ -0,0 +1,9 @@
+#val_type uint64_t
+UFFD_FEATURE_PAGEFAULT_FLAG_WP
+UFFD_FEATURE_EVENT_FORK
+UFFD_FEATURE_EVENT_REMAP
+UFFD_FEATURE_EVENT_REMOVE
+UFFD_FEATURE_MISSING_HUGETLBFS
+UFFD_FEATURE_MISSING_SHMEM
+UFFD_FEATURE_EVENT_UNMAP
+UFFD_FEATURE_EVENT_EXIT