Huge cleanup of random(4) code.

* GENERAL
- Update copyright.
- Make kernel options for RANDOM_YARROW and RANDOM_DUMMY. Set
  neither to ON, which means we want Fortuna
- If there is no 'device random' in the kernel, there will be NO
  random(4) device in the kernel, and the KERN_ARND sysctl will
  return nothing. With RANDOM_DUMMY there will be a random(4) that
  always blocks.
- Repair kern.arandom (KERN_ARND sysctl). The old version went
  through arc4random(9) and was a bit weird.
- Adjust arc4random stirring a bit - the existing code looks a little
  suspect.
- Fix the nasty pre- and post-read overloading by providing explictit
  functions to do these tasks.
- Redo read_random(9) so as to duplicate random(4)'s read internals.
  This makes it a first-class citizen rather than a hack.
- Move stuff out of locked regions when it does not need to be
  there.
- Trim RANDOM_DEBUG printfs. Some are excess to requirement, some
  behind boot verbose.
- Use SYSINIT to sequence the startup.
- Fix init/deinit sysctl stuff.
- Make relevant sysctls also tunables.
- Add different harvesting "styles" to allow for different requirements
  (direct, queue, fast).
- Add harvesting of FFS atime events. This needs to be checked for
  weighing down the FS code.
- Add harvesting of slab allocator events. This needs to be checked for
  weighing down the allocator code.
- Fix the random(9) manpage.
- Loadable modules are not present for now. These will be re-engineered
  when the dust settles.
- Use macros for locks.
- Fix comments.

* src/share/man/...
- Update the man pages.

* src/etc/...
- The startup/shutdown work is done in D2924.

* src/UPDATING
- Add UPDATING announcement.

* src/sys/dev/random/build.sh
- Add copyright.
- Add libz for unit tests.

* src/sys/dev/random/dummy.c
- Remove; no longer needed. Functionality incorporated into randomdev.*.

* live_entropy_sources.c live_entropy_sources.h
- Remove; content moved.
- move content to randomdev.[ch] and optimise.

* src/sys/dev/random/random_adaptors.c src/sys/dev/random/random_adaptors.h
- Remove; plugability is no longer used. Compile-time algorithm
  selection is the way to go.

* src/sys/dev/random/random_harvestq.c src/sys/dev/random/random_harvestq.h
- Add early (re)boot-time randomness caching.

* src/sys/dev/random/randomdev_soft.c src/sys/dev/random/randomdev_soft.h
- Remove; no longer needed.

* src/sys/dev/random/uint128.h
- Provide a fake uint128_t; if a real one ever arrived, we can use
  that instead. All that is needed here is N=0, N++, N==0, and some
  localised trickery is used to manufacture a 128-bit 0ULLL.

* src/sys/dev/random/unit_test.c src/sys/dev/random/unit_test.h
- Improve unit tests; previously the testing human needed clairvoyance;
  now the test will do a basic check of compressibility. Clairvoyant
  talent is still a good idea.
- This is still a long way off a proper unit test.

* src/sys/dev/random/fortuna.c src/sys/dev/random/fortuna.h
- Improve messy union to just uint128_t.
- Remove unneeded 'static struct fortuna_start_cache'.
- Tighten up up arithmetic.
- Provide a method to allow eternal junk to be introduced; harden
  it against blatant by compress/hashing.
- Assert that locks are held correctly.
- Fix the nasty pre- and post-read overloading by providing explictit
  functions to do these tasks.
- Turn into self-sufficient module (no longer requires randomdev_soft.[ch])

* src/sys/dev/random/yarrow.c src/sys/dev/random/yarrow.h
- Improve messy union to just uint128_t.
- Remove unneeded 'staic struct start_cache'.
- Tighten up up arithmetic.
- Provide a method to allow eternal junk to be introduced; harden
  it against blatant by compress/hashing.
- Assert that locks are held correctly.
- Fix the nasty pre- and post-read overloading by providing explictit
  functions to do these tasks.
- Turn into self-sufficient module (no longer requires randomdev_soft.[ch])
- Fix some magic numbers elsewhere used as FAST and SLOW.

Differential Revision: https://reviews.freebsd.org/D2025
Reviewed by: vsevolod,delphij,rwatson,trasz,jmg
Approved by: so (delphij)

1 files changed, 12 insertions, 6 deletions

diff --git a/sys/ufs/ffs/ffs_inode.c b/sys/ufs/ffs/ffs_inode.c
index 608f876..1647080 100644
--- a/sys/ufs/ffs/ffs_inode.c
+++ b/sys/ufs/ffs/ffs_inode.c
@@ -36,16 +36,17 @@ __FBSDID("$FreeBSD$");
 
 #include <sys/param.h>
 #include <sys/systm.h>
-#include <sys/mount.h>
-#include <sys/proc.h>
 #include <sys/bio.h>
 #include <sys/buf.h>
-#include <sys/vnode.h>
 #include <sys/malloc.h>
+#include <sys/mount.h>
+#include <sys/proc.h>
+#include <sys/random.h>
 #include <sys/resourcevar.h>
 #include <sys/rwlock.h>
-#include <sys/vmmeter.h>
 #include <sys/stat.h>
+#include <sys/vmmeter.h>
+#include <sys/vnode.h>
 
 #include <vm/vm.h>
 #include <vm/vm_extern.h>
@@ -143,12 +144,17 @@ loop:
 		softdep_update_inodeblock(ip, bp, waitfor);
 	else if (ip->i_effnlink != ip->i_nlink)
 		panic("ffs_update: bad link cnt");
-	if (ip->i_ump->um_fstype == UFS1)
+	if (ip->i_ump->um_fstype == UFS1) {
 		*((struct ufs1_dinode *)bp->b_data +
 		    ino_to_fsbo(fs, ip->i_number)) = *ip->i_din1;
-	else
+		/* XXX: FIX? The entropy here is desirable, but the harvesting may be expensive */
+		random_harvest_queue(&(ip->i_din1), sizeof(ip->i_din1), 1, RANDOM_FS_ATIME);
+	} else {
 		*((struct ufs2_dinode *)bp->b_data +
 		    ino_to_fsbo(fs, ip->i_number)) = *ip->i_din2;
+		/* XXX: FIX? The entropy here is desirable, but the harvesting may be expensive */
+		random_harvest_queue(&(ip->i_din2), sizeof(ip->i_din2), 1, RANDOM_FS_ATIME);
+	}
 	if (waitfor && !DOINGASYNC(vp))
 		error = bwrite(bp);
 	else if (vm_page_count_severe() || buf_dirty_count_severe()) {