From 3110c594afb8839ba81b528f316b6d6dce757e99 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ludovic=20Court=C3=A8s?= <ludo@gnu.org>
Date: Tue, 22 May 2018 17:34:47 +0200
Subject: [PATCH 1/3] gnu: parted: Use weak (non-blocking) randomness for FAT
 serial numbers.

Partly fixes <https://bugs.gnu.org/31268>.

* gnu/packages/patches/parted-non-blocking-random.patch: New file.
* gnu/packages/disk.scm (parted)[source]: Use it.
* gnu/local.mk (dist_patch_DATA): Add it.
---
 gnu/local.mk                                  |  1 +
 gnu/packages/disk.scm                         |  3 +-
 .../patches/parted-non-blocking-random.patch  | 39 +++++++++++++++++++
 3 files changed, 42 insertions(+), 1 deletion(-)
 create mode 100644 gnu/packages/patches/parted-non-blocking-random.patch

diff --git a/gnu/local.mk b/gnu/local.mk
index 20975306b..4222050b5 100644
--- a/gnu/local.mk
+++ b/gnu/local.mk
@@ -975,6 +975,7 @@ dist_patch_DATA =						\
   %D%/packages/patches/p7zip-CVE-2017-17969.patch		\
   %D%/packages/patches/p7zip-remove-unused-code.patch		\
   %D%/packages/patches/password-store-gnupg-compat.patch	\
+  %D%/packages/patches/parted-non-blocking-random.patch		\
   %D%/packages/patches/patchelf-page-size.patch			\
   %D%/packages/patches/patchelf-rework-for-arm.patch		\
   %D%/packages/patches/patchutils-xfail-gendiff-tests.patch	\
diff --git a/gnu/packages/disk.scm b/gnu/packages/disk.scm
index d7bf72683..476b26acb 100644
--- a/gnu/packages/disk.scm
+++ b/gnu/packages/disk.scm
@@ -65,7 +65,8 @@
                                   version ".tar.xz"))
               (sha256
                (base32
-                "1r3qpg3bhz37mgvp9chsaa3k0csby3vayfvz8ggsqz194af5i2w5"))))
+                "1r3qpg3bhz37mgvp9chsaa3k0csby3vayfvz8ggsqz194af5i2w5"))
+              (patches (search-patches "parted-non-blocking-random.patch"))))
     (build-system gnu-build-system)
     (arguments
      `(#:phases
diff --git a/gnu/packages/patches/parted-non-blocking-random.patch b/gnu/packages/patches/parted-non-blocking-random.patch
new file mode 100644
index 000000000..e30d9f413
--- /dev/null
+++ b/gnu/packages/patches/parted-non-blocking-random.patch
@@ -0,0 +1,39 @@
+Explicitly use a non-blocking random primitive.  This is used primarily
+to compute FAT "serial numbers" in libparted/fs/r/fat/fat.c:fat_create,
+for which GRND_NONBLOCK is probably good enough.
+
+Assume the running kernel does support 'getrandom', which is the case on
+GuixSD.  See <https://bugs.gnu.org/31268>.
+
+--- a/libparted/labels/misc.h
++++ b/libparted/labels/misc.h
+@@ -17,7 +17,8 @@
+     along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+ 
+ #include <inttypes.h>
+-#include <uuid/uuid.h>
++#include <sys/random.h>
++#include <errno.h>
+ 
+ /* hack: use the ext2 uuid library to generate a reasonably random (hopefully
+  * with /dev/random) number.  Unfortunately, we can only use 4 bytes of it.
+@@ -28,11 +29,17 @@ static inline uint32_t
+ generate_random_uint32 (void)
+ {
+        union {
+-               uuid_t uuid;
++               char uuid[4];
+                uint32_t i;
+        } uu32;
++       ssize_t ret;
+ 
+-       uuid_generate (uu32.uuid);
++       do
++         ret = getrandom (uu32.uuid, sizeof uu32, GRND_NONBLOCK);
++       while (ret == EAGAIN);
++
++       if (ret < sizeof uu32)
++         abort ();
+ 
+        return uu32.i > 0 ? uu32.i : 0xffffffff;
+ }
-- 
2.17.0