[Minios-devel] [UNIKRAFT PATCH v2 5/6] lib/ukswrand: Clean-up: devfs nodes are independent of MWC algorithm

[Simon Kuenzer <simon.kuenzer@xxxxxxxxx>]

This patch cleans up the devfs integration of ukswrand:
- The config option is properly namespaced.
- mwc_dev.c is actually independent of the random number generator MWC.
  We move this file to dev.c
- Crash the system when registration failed within the constructor.
  This behavior can be changed as soon as we introduce Unikraft init
  functions that can return error codes.

Signed-off-by: Simon Kuenzer <simon.kuenzer@xxxxxxxxx>
---
 lib/ukswrand/Config.uk            |  5 ++---
 lib/ukswrand/Makefile.uk          |  6 ++----
 lib/ukswrand/{mwc_dev.c => dev.c} | 26 ++++++++++++++++++--------
 3 files changed, 22 insertions(+), 15 deletions(-)
 rename lib/ukswrand/{mwc_dev.c => dev.c} (83%)

diff --git a/lib/ukswrand/Config.uk b/lib/ukswrand/Config.uk
index a1a84bc5..40d22c86 100644
--- a/lib/ukswrand/Config.uk
+++ b/lib/ukswrand/Config.uk
@@ -18,9 +18,8 @@ config LIBUKSWRAND_INITIALSEED
        int "Initial random seed"
        default 23
 
-config DEV_RANDOM
-       bool "/dev/random device"
+config LIBUKSWRAND_DEVFS
+       bool "Register random and urandom to devfs"
        select LIBDEVFS
        default n
-
 endif
diff --git a/lib/ukswrand/Makefile.uk b/lib/ukswrand/Makefile.uk
index 25247474..b19094e0 100644
--- a/lib/ukswrand/Makefile.uk
+++ b/lib/ukswrand/Makefile.uk
@@ -3,7 +3,5 @@ $(eval $(call addlib_s,libukswrand,$(CONFIG_LIBUKSWRAND)))
 CINCLUDES-$(CONFIG_LIBUKSWRAND)        += -I$(LIBUKSWRAND_BASE)/include
 CXXINCLUDES-$(CONFIG_LIBUKSWRAND) += -I$(LIBUKSWRAND_BASE)/include
 
-LIBUKSWRAND_SRCS-$(CONFIG_LIBUKSWRAND_MWC) += $(LIBUKSWRAND_BASE)/mwc.c
-ifdef CONFIG_DEV_RANDOM
-LIBUKSWRAND_SRCS-$(CONFIG_LIBUKSWRAND_MWC) += $(LIBUKSWRAND_BASE)/mwc_dev.c
-endif
+LIBUKSWRAND_SRCS-$(CONFIG_LIBUKSWRAND_MWC)   += $(LIBUKSWRAND_BASE)/mwc.c
+LIBUKSWRAND_SRCS-$(CONFIG_LIBUKSWRAND_DEVFS) += $(LIBUKSWRAND_BASE)/dev.c
diff --git a/lib/ukswrand/mwc_dev.c b/lib/ukswrand/dev.c
similarity index 83%
rename from lib/ukswrand/mwc_dev.c
rename to lib/ukswrand/dev.c
index 5a4cb100..c5ce5f87 100644
--- a/lib/ukswrand/mwc_dev.c
+++ b/lib/ukswrand/dev.c
@@ -101,19 +101,29 @@ static struct driver drv_urandom = {
        .name = DEV_URANDOM_NAME
 };
 
-__constructor_prio(102) static void _uk_dev_swrand_ctor(void)
+/*
+ * NOTE: We register the device nodes as application constructor
+ * because at that point of time we can expect that a memory allocator
+ * is available.
+ */
+/*
+ * TODO: Move this registration to an Unikraft init table as soon we have it
+ * available. Application constructors may require random and urandom already
+ * being available when they get called.
+ */
+__constructor_prio(101) static void _uk_dev_swrand_ctor(void)
 {
        struct device *dev;
 
-       uk_pr_info("Add /dev/random and /dev/urandom\n");
+       uk_pr_info("Register random and urandom to devfs\n");
 
-       /* register /dev/urandom */
+       /* register urandom */
        dev = device_create(&drv_urandom, DEV_URANDOM_NAME, D_CHR);
-       if (dev == NULL)
-               uk_pr_info("Failed to register /dev/urandom\n");
+       if (!dev)
+               UK_CRASH("Failed to register urandom to devfs\n");
 
-       /* register /dev/random */
+       /* register random */
        dev = device_create(&drv_random, DEV_RANDOM_NAME, D_CHR);
-       if (dev == NULL)
-               uk_pr_info("Failed to register /dev/random\n");
+       if (!dev)
+               UK_CRASH("Failed to register random to devfs\n");
 }
-- 
2.20.1


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