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From: marcandre.lureau@redhat.com
To: qemu-devel@nongnu.org
Cc: haifeng.lin@huawei.com, mst@redhat.com, thibaut.collet@6wind.com,
	jasowang@redhat.com, pbonzini@redhat.com,
	"Marc-André Lureau" <marcandre.lureau@redhat.com>
Subject: [Qemu-devel] [PATCH v8 07/27] util: add fallback for qemu_memfd_alloc()
Date: Fri,  9 Oct 2015 17:17:21 +0200	[thread overview]
Message-ID: <1444403861-3240-8-git-send-email-marcandre.lureau@redhat.com> (raw)
In-Reply-To: <1444403861-3240-1-git-send-email-marcandre.lureau@redhat.com>

From: Marc-André Lureau <marcandre.lureau@redhat.com>

Add an open/unlink/mmap fallback for system that do not support
memfd (only available since 3.17, ~1y ago).

This patch may require additional SELinux policies to work for enforced
systems, but should fail gracefully in this case.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
---
 util/memfd.c | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/util/memfd.c b/util/memfd.c
index c119483..4b23765 100644
--- a/util/memfd.c
+++ b/util/memfd.c
@@ -97,8 +97,24 @@ void *qemu_memfd_alloc(const char *name, size_t size, unsigned int seals,
             return NULL;
         }
     } else {
-        perror("memfd");
-        return NULL;
+        const char *tmpdir = g_get_tmp_dir();
+        gchar *fname;
+
+        fname = g_strdup_printf("%s/memfd-XXXXXX", tmpdir);
+        mfd = mkstemp(fname);
+        unlink(fname);
+        g_free(fname);
+
+        if (mfd == -1) {
+            perror("mkstemp");
+            return NULL;
+        }
+
+        if (ftruncate(mfd, size) == -1) {
+            perror("ftruncate");
+            close(mfd);
+            return NULL;
+        }
     }
 
     ptr = mmap(0, size, PROT_READ | PROT_WRITE, MAP_SHARED, mfd, 0);
-- 
2.4.3

  parent reply	other threads:[~2015-10-09 15:18 UTC|newest]

Thread overview: 39+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-10-09 15:17 [Qemu-devel] [PATCH v8 00/27] vhost-user: add migration support marcandre.lureau
2015-10-09 15:17 ` [Qemu-devel] [PATCH v8 01/27] exec: factor out duplicate mmap code marcandre.lureau
2015-10-09 15:17 ` [Qemu-devel] [PATCH v8 02/27] configure: probe for memfd marcandre.lureau
2015-10-09 15:17 ` [Qemu-devel] [PATCH v8 03/27] linux-headers: add unistd.h marcandre.lureau
2015-10-09 15:17 ` [Qemu-devel] [PATCH v8 04/27] build-sys: split util-obj- on multi-lines marcandre.lureau
2015-10-09 15:17 ` [Qemu-devel] [PATCH v8 05/27] util: add linux-only memfd fallback marcandre.lureau
2015-10-09 15:17 ` [Qemu-devel] [PATCH v8 06/27] util: add memfd helpers marcandre.lureau
2015-10-09 15:17 ` marcandre.lureau [this message]
2015-10-09 15:17 ` [Qemu-devel] [PATCH v8 08/27] vhost: document log resizing marcandre.lureau
2015-10-09 15:17 ` [Qemu-devel] [PATCH v8 09/27] vhost: add vhost_set_log_base op marcandre.lureau
2015-10-09 15:17 ` [Qemu-devel] [PATCH v8 10/27] vhost-user: add vhost_user_requires_shm_log() marcandre.lureau
2015-10-09 15:17 ` [Qemu-devel] [PATCH v8 11/27] vhost: alloc shareable log marcandre.lureau
2015-10-09 15:17 ` [Qemu-devel] [PATCH v8 12/27] vhost-user: send log shm fd along with log_base marcandre.lureau
2015-10-09 15:17 ` [Qemu-devel] [PATCH v8 13/27] vhost-user: add a migration blocker marcandre.lureau
2015-10-09 15:17 ` [Qemu-devel] [PATCH v8 14/27] vhost: use a function for each call marcandre.lureau
2015-10-09 15:17 ` [Qemu-devel] [PATCH v8 15/27] vhost-user: document migration log marcandre.lureau
2015-10-09 15:17 ` [Qemu-devel] [PATCH v8 16/27] net: add trace_vhost_user_event marcandre.lureau
2015-10-09 15:17 ` [Qemu-devel] [PATCH v8 17/27] vhost user: add support of live migration marcandre.lureau
2015-10-09 15:17 ` [Qemu-devel] [PATCH v8 18/27] vhost user: add rarp sending after live migration for legacy guest marcandre.lureau
2015-10-09 15:17 ` [Qemu-devel] [PATCH v8 19/27] vhost-user: use an enum helper for features mask marcandre.lureau
2015-10-09 15:17 ` [Qemu-devel] [PATCH v8 20/27] vhost: add migration block if memfd failed marcandre.lureau
2015-10-09 15:17 ` [Qemu-devel] [PATCH v8 21/27] vhost-user-test: move wait_for_fds() out marcandre.lureau
2015-10-09 15:17 ` [Qemu-devel] [PATCH v8 22/27] vhost-user-test: remove useless static check marcandre.lureau
2015-10-09 15:17 ` [Qemu-devel] [PATCH v8 23/27] vhost-user-test: wrap server in TestServer struct marcandre.lureau
2015-10-09 15:17 ` [Qemu-devel] [PATCH v8 24/27] vhost-user-test: learn to tweak various qemu arguments marcandre.lureau
2015-10-09 15:17 ` [Qemu-devel] [PATCH v8 25/27] vhost-user-test: add live-migration test marcandre.lureau
2015-10-09 15:17 ` [Qemu-devel] [PATCH v8 26/27] vhost-user-test: check ownership during migration marcandre.lureau
2015-10-09 15:17 ` [Qemu-devel] [PATCH v8 27/27] seccomp: add memfd_create to whitelist marcandre.lureau
2015-10-09 15:21   ` Eduardo Otubo
2015-10-12 15:56 ` [Qemu-devel] [PATCH v8 00/27] vhost-user: add migration support Thibaut Collet
2015-10-13 12:19   ` Thibaut Collet
2015-10-18  8:21     ` Michael S. Tsirkin
2015-10-19 13:22       ` Thibaut Collet
2015-10-19 15:39         ` Michael S. Tsirkin
2015-10-19 16:42           ` Thibaut Collet
2015-10-19 21:12             ` Michael S. Tsirkin
2015-10-20  6:30               ` Thibaut Collet
2015-10-20 10:21                 ` Michael S. Tsirkin
2015-10-20 11:47                   ` Thibaut Collet

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