util: add anon_file.h for all memfd/temp file usage

Move the Weston os_create_anonymous_file code from egl/wayland into util,
add support for Linux memfd and FreeBSD SHM_ANON,
use that code in anv/aubinator instead of explicit memfd calls for portability.

Acked-by: Lionel Landwerlin <[email protected]>
Reviewed-by: Eric Engestrom <[email protected]>

4 files changed, 193 insertions, 0 deletions

diff --git a/src/util/Makefile.sources b/src/util/Makefile.sources
index cbbf5126875..fdb9b6dd135 100644
--- a/src/util/Makefile.sources
+++ b/src/util/Makefile.sources
@@ -1,4 +1,6 @@
 MESA_UTIL_FILES := \
+	anon_file.h \
+	anon_file.c \
 	bigmath.h \
 	bitscan.c \
 	bitscan.h \
diff --git a/src/util/anon_file.c b/src/util/anon_file.c
new file mode 100644
index 00000000000..184b8445bad
--- /dev/null
+++ b/src/util/anon_file.c
@@ -0,0 +1,155 @@
+/*
+ * Copyright © 2012 Collabora, Ltd.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial
+ * portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT.  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+/*
+ * Based on weston shared/os-compatibility.c
+ */
+
+#ifndef WIN32
+#include "anon_file.h"
+
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+
+#ifdef __FreeBSD__
+#include <sys/mman.h>
+#elif defined(HAVE_MEMFD_CREATE)
+#include <sys/syscall.h>
+#include <linux/memfd.h>
+#endif
+
+#if !(defined(__FreeBSD__) || defined(HAVE_MEMFD_CREATE) || defined(HAVE_MKOSTEMP))
+static int
+set_cloexec_or_close(int fd)
+{
+   long flags;
+
+   if (fd == -1)
+      return -1;
+
+   flags = fcntl(fd, F_GETFD);
+   if (flags == -1)
+      goto err;
+
+   if (fcntl(fd, F_SETFD, flags | FD_CLOEXEC) == -1)
+      goto err;
+
+   return fd;
+
+err:
+   close(fd);
+   return -1;
+}
+#endif
+
+#if !(defined(__FreeBSD__) || defined(HAVE_MEMFD_CREATE))
+static int
+create_tmpfile_cloexec(char *tmpname)
+{
+   int fd;
+
+#ifdef HAVE_MKOSTEMP
+   fd = mkostemp(tmpname, O_CLOEXEC);
+#else
+   fd = mkstemp(tmpname);
+#endif
+
+   if (fd < 0) {
+      return fd;
+   }
+
+#ifndef HAVE_MKOSTEMP
+   fd = set_cloexec_or_close(fd);
+#endif
+
+   unlink(tmpname);
+   return fd;
+}
+#endif
+
+/*
+ * Create a new, unique, anonymous file of the given size, and
+ * return the file descriptor for it. The file descriptor is set
+ * CLOEXEC. The file is immediately suitable for mmap()'ing
+ * the given size at offset zero.
+ *
+ * An optional name for debugging can be provided as the second argument.
+ *
+ * The file should not have a permanent backing store like a disk,
+ * but may have if XDG_RUNTIME_DIR is not properly implemented in OS.
+ *
+ * If memfd or SHM_ANON is supported, the filesystem is not touched at all.
+ * Otherwise, the file name is deleted from the file system.
+ *
+ * The file is suitable for buffer sharing between processes by
+ * transmitting the file descriptor over Unix sockets using the
+ * SCM_RIGHTS methods.
+ */
+int
+os_create_anonymous_file(off_t size, char *debug_name)
+{
+   int fd, ret;
+#ifdef __FreeBSD__
+   (void*)debug_name;
+   fd = shm_open(SHM_ANON, O_CREAT | O_RDWR | O_CLOEXEC, 0600);
+#elif defined(HAVE_MEMFD_CREATE)
+   if (!debug_name)
+      debug_name = "mesa-shared";
+   fd = syscall(SYS_memfd_create, debug_name, MFD_CLOEXEC);
+#else
+   const char *path;
+   char *name;
+
+   path = getenv("XDG_RUNTIME_DIR");
+   if (!path) {
+      errno = ENOENT;
+      return -1;
+   }
+
+   if (debug_name)
+      asprintf(&name, "%s/mesa-shared-%s-XXXXXX", path, debug_name);
+   else
+      asprintf(&name, "%s/mesa-shared-XXXXXX", path);
+   if (!name)
+      return -1;
+
+   fd = create_tmpfile_cloexec(name);
+
+   free(name);
+#endif
+
+   if (fd < 0)
+      return -1;
+
+   ret = ftruncate(fd, size);
+   if (ret < 0) {
+      close(fd);
+      return -1;
+   }
+
+   return fd;
+}
+#endif
diff --git a/src/util/anon_file.h b/src/util/anon_file.h
new file mode 100644
index 00000000000..8bec8d5458b
--- /dev/null
+++ b/src/util/anon_file.h
@@ -0,0 +1,34 @@
+/*
+ * Copyright © 2012 Collabora, Ltd.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial
+ * portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT.  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#ifndef _ANON_FILE_H_
+#define _ANON_FILE_H_
+
+#include <sys/types.h>
+#include "util/macros.h"
+
+int os_create_anonymous_file(off_t size, char *debug_name);
+
+#endif
diff --git a/src/util/meson.build b/src/util/meson.build
index 95aff3b442f..cf1616e7bc6 100644
--- a/src/util/meson.build
+++ b/src/util/meson.build
@@ -23,6 +23,8 @@ inc_util = include_directories('.')
 subdir('xmlpool')
 
 files_mesa_util = files(
+  'anon_file.h',
+  'anon_file.c',
   'bigmath.h',
   'bitscan.c',
   'bitscan.h',