[Mesa-dev] [PATCH v2 3/5] util: add anon_file.h for all memfd/temp file usage

Greg V greg at unrelenting.technology
Thu Jan 18 22:54:44 UTC 2018


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 instead of explicit memfd calls for portability.
---
 src/egl/drivers/dri2/platform_wayland.c | 116 +---------------------
 src/intel/vulkan/anv_allocator.c        |  21 +---
 src/intel/vulkan/anv_gem_stubs.c        |  15 +--
 src/util/Makefile.sources               |   1 +
 src/util/anon_file.h                    | 169 ++++++++++++++++++++++++++++++++
 src/util/meson.build                    |   1 +
 6 files changed, 178 insertions(+), 145 deletions(-)
 create mode 100644 src/util/anon_file.h

diff --git a/src/egl/drivers/dri2/platform_wayland.c b/src/egl/drivers/dri2/platform_wayland.c
index d221728ff2..2e47fe5b15 100644
--- a/src/egl/drivers/dri2/platform_wayland.c
+++ b/src/egl/drivers/dri2/platform_wayland.c
@@ -43,6 +43,7 @@
 #include "egl_dri2_fallbacks.h"
 #include "loader.h"
 #include "util/u_vector.h"
+#include "util/anon_file.h"
 #include "eglglobals.h"
 
 #include <wayland-client.h>
@@ -1477,121 +1478,6 @@ dri2_wl_swrast_get_stride_for_format(int format, int w)
       return 4 * w;
 }
 
-/*
- * Taken from weston shared/os-compatibility.c
- */
-
-#ifndef 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
-
-/*
- * Taken from weston shared/os-compatibility.c
- */
-
-static int
-create_tmpfile_cloexec(char *tmpname)
-{
-   int fd;
-
-#ifdef HAVE_MKOSTEMP
-   fd = mkostemp(tmpname, O_CLOEXEC);
-   if (fd >= 0)
-      unlink(tmpname);
-#else
-   fd = mkstemp(tmpname);
-   if (fd >= 0) {
-      fd = set_cloexec_or_close(fd);
-      unlink(tmpname);
-   }
-#endif
-
-   return fd;
-}
-
-/*
- * Taken from weston shared/os-compatibility.c
- *
- * 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.
- *
- * 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.
- *
- * 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.
- *
- * If the C library implements posix_fallocate(), it is used to
- * guarantee that disk space is available for the file at the
- * given size. If disk space is insufficent, errno is set to ENOSPC.
- * If posix_fallocate() is not supported, program may receive
- * SIGBUS on accessing mmap()'ed file contents instead.
- */
-static int
-os_create_anonymous_file(off_t size)
-{
-   static const char templ[] = "/mesa-shared-XXXXXX";
-   const char *path;
-   char *name;
-   int fd;
-   int ret;
-
-   path = getenv("XDG_RUNTIME_DIR");
-   if (!path) {
-      errno = ENOENT;
-      return -1;
-   }
-
-   name = malloc(strlen(path) + sizeof(templ));
-   if (!name)
-      return -1;
-
-   strcpy(name, path);
-   strcat(name, templ);
-
-   fd = create_tmpfile_cloexec(name);
-
-   free(name);
-
-   if (fd < 0)
-      return -1;
-
-   ret = ftruncate(fd, size);
-   if (ret < 0) {
-      close(fd);
-      return -1;
-   }
-
-   return fd;
-}
-
 
 static EGLBoolean
 dri2_wl_swrast_allocate_buffer(struct dri2_egl_surface *dri2_surf,
diff --git a/src/intel/vulkan/anv_allocator.c b/src/intel/vulkan/anv_allocator.c
index fe14d6cfab..aa669359d7 100644
--- a/src/intel/vulkan/anv_allocator.c
+++ b/src/intel/vulkan/anv_allocator.c
@@ -25,13 +25,13 @@
 #include <unistd.h>
 #include <limits.h>
 #include <assert.h>
-#include <linux/memfd.h>
 #include <sys/mman.h>
 
 #include "anv_private.h"
 
 #include "util/hash_table.h"
 #include "util/simple_mtx.h"
+#include "util/anon_file.h"
 
 #ifdef HAVE_VALGRIND
 #define VG_NOACCESS_READ(__ptr) ({                       \
@@ -109,14 +109,6 @@ struct anv_mmap_cleanup {
 
 #define ANV_MMAP_CLEANUP_INIT ((struct anv_mmap_cleanup){0})
 
-#ifndef HAVE_MEMFD_CREATE
-static inline int
-memfd_create(const char *name, unsigned int flags)
-{
-   return syscall(SYS_memfd_create, name, flags);
-}
-#endif
-
 static inline uint32_t
 ilog2_round_up(uint32_t value)
 {
@@ -252,18 +244,13 @@ anv_block_pool_init(struct anv_block_pool *pool,
    pool->bo_flags = bo_flags;
    anv_bo_init(&pool->bo, 0, 0);
 
-   pool->fd = memfd_create("block pool", MFD_CLOEXEC);
-   if (pool->fd == -1)
-      return vk_error(VK_ERROR_INITIALIZATION_FAILED);
-
    /* Just make it 2GB up-front.  The Linux kernel won't actually back it
     * with pages until we either map and fault on one of them or we use
     * userptr and send a chunk of it off to the GPU.
     */
-   if (ftruncate(pool->fd, BLOCK_POOL_MEMFD_SIZE) == -1) {
-      result = vk_error(VK_ERROR_INITIALIZATION_FAILED);
-      goto fail_fd;
-   }
+   pool->fd = os_create_anonymous_file(BLOCK_POOL_MEMFD_SIZE);
+   if (pool->fd == -1)
+      return vk_error(VK_ERROR_INITIALIZATION_FAILED);
 
    if (!u_vector_init(&pool->mmap_cleanups,
                       round_to_power_of_two(sizeof(struct anv_mmap_cleanup)),
diff --git a/src/intel/vulkan/anv_gem_stubs.c b/src/intel/vulkan/anv_gem_stubs.c
index 26eb5c8a61..d4dd11c506 100644
--- a/src/intel/vulkan/anv_gem_stubs.c
+++ b/src/intel/vulkan/anv_gem_stubs.c
@@ -21,32 +21,21 @@
  * IN THE SOFTWARE.
  */
 
-#include <linux/memfd.h>
 #include <sys/mman.h>
 #include <sys/syscall.h>
 
+#include "util/anon_file.h"
 #include "anv_private.h"
 
-#ifndef HAVE_MEMFD_CREATE
-static inline int
-memfd_create(const char *name, unsigned int flags)
-{
-   return syscall(SYS_memfd_create, name, flags);
-}
-#endif
-
 uint32_t
 anv_gem_create(struct anv_device *device, uint64_t size)
 {
-   int fd = memfd_create("fake bo", MFD_CLOEXEC);
+   int fd = os_create_anonymous_file(size);
    if (fd == -1)
       return 0;
 
    assert(fd != 0);
 
-   if (ftruncate(fd, size) == -1)
-      return 0;
-
    return fd;
 }
 
diff --git a/src/util/Makefile.sources b/src/util/Makefile.sources
index 104ecae8ed..f30a063630 100644
--- a/src/util/Makefile.sources
+++ b/src/util/Makefile.sources
@@ -1,4 +1,5 @@
 MESA_UTIL_FILES := \
+	anon_file.h \
 	bitscan.c \
 	bitscan.h \
 	bitset.h \
diff --git a/src/util/anon_file.h b/src/util/anon_file.h
new file mode 100644
index 0000000000..fa8642dc98
--- /dev/null
+++ b/src/util/anon_file.h
@@ -0,0 +1,169 @@
+/*
+ * Copyright © 2012 Collabora, Ltd.
+ * Copyright © 2018 Greg V
+ *
+ * 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
+ */
+
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+
+#ifdef __FreeBSD__
+#include <sys/mman.h>
+#elif HAVE_LINUX_MEMFD_H
+#define _GNU_SOURCE
+#include <sys/syscall.h>
+#include <linux/memfd.h>
+#endif
+
+#ifndef 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
+
+
+#ifndef __FreeBSD__
+
+static int
+create_tmpfile_cloexec(char *tmpname)
+{
+   int fd;
+
+#ifdef HAVE_LINUX_MEMFD_H
+   fd = syscall(SYS_memfd_create, tmpname, MFD_CLOEXEC);
+#elif HAVE_MKOSTEMP
+   fd = mkostemp(tmpname, O_CLOEXEC);
+   if (fd >= 0)
+      unlink(tmpname);
+#else
+   fd = mkstemp(tmpname);
+   if (fd >= 0) {
+      fd = set_cloexec_or_close(fd);
+      unlink(tmpname);
+   }
+#endif
+
+   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.
+ *
+ * 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.
+ *
+ * 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.
+ *
+ * If the C library implements posix_fallocate(), it is used to
+ * guarantee that disk space is available for the file at the
+ * given size. If disk space is insufficent, errno is set to ENOSPC.
+ * If posix_fallocate() is not supported, program may receive
+ * SIGBUS on accessing mmap()'ed file contents instead.
+ */
+static int
+os_create_anonymous_file(off_t size)
+{
+   int fd, ret;
+#ifdef __FreeBSD__
+   fd = shm_open(SHM_ANON, O_CREAT | O_RDWR, 0600); // shm_open is always CLOEXEC
+#else
+   static const char templ[] = "/mesa-shared-XXXXXX";
+   const char *path;
+   char *name;
+
+   path = getenv("XDG_RUNTIME_DIR");
+   if (!path) {
+      errno = ENOENT;
+      return -1;
+   }
+
+   name = malloc(strlen(path) + sizeof(templ));
+   if (!name)
+      return -1;
+
+   strcpy(name, path);
+   strcat(name, templ);
+
+   fd = create_tmpfile_cloexec(name);
+
+   free(name);
+#endif
+
+   if (fd < 0)
+      return -1;
+
+#if defined(HAVE_POSIX_FALLOCATE) && !defined(__FreeBSD__)
+   do {
+      ret = posix_fallocate(fd, 0, size);
+   } while (ret == EINTR);
+   if (ret != 0) {
+      close(fd);
+      errno = ret;
+      return -1;
+   }
+#else
+   do {
+      ret = ftruncate(fd, size);
+   } while (ret < 0 && errno == EINTR);
+   if (ret < 0) {
+      close(fd);
+      return -1;
+   }
+#endif
+
+   return fd;
+}
diff --git a/src/util/meson.build b/src/util/meson.build
index fa591c92e5..4e9ba14a2c 100644
--- a/src/util/meson.build
+++ b/src/util/meson.build
@@ -23,6 +23,7 @@ inc_util = include_directories('.')
 subdir('xmlpool')
 
 files_mesa_util = files(
+  'anon_file.h',
   'bitscan.c',
   'bitscan.h',
   'bitset.h',
-- 
2.15.1



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