The patch titled
random: simplify and rename credit_entropy_store
has been added to the -mm tree. Its filename is
random-simplify-and-rename-credit_entropy_store.patch
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*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: random: simplify and rename credit_entropy_store
From: Matt Mackall <mpm@xxxxxxxxxxx>
- emphasize bits in the name
- make zero bits lock-free
- simplify logic
Signed-off-by: Matt Mackall <mpm@xxxxxxxxxxx>
Cc: Theodore Ts'o <tytso@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/char/random.c | 32 +++++++++++++++-----------------
1 file changed, 15 insertions(+), 17 deletions(-)
diff -puN drivers/char/random.c~random-simplify-and-rename-credit_entropy_store drivers/char/random.c
--- a/drivers/char/random.c~random-simplify-and-rename-credit_entropy_store
+++ a/drivers/char/random.c
@@ -441,7 +441,7 @@ static struct entropy_store nonblocking_
/*
* This function adds bytes into the entropy "pool". It does not
* update the entropy estimate. The caller should call
- * credit_entropy_store if this is appropriate.
+ * credit_entropy_bits if this is appropriate.
*
* The pool is stirred with a primitive polynomial of the appropriate
* degree, and then twisted. We twist by three bits at a time because
@@ -515,24 +515,22 @@ static void mix_pool_bytes(struct entrop
/*
* Credit (or debit) the entropy store with n bits of entropy
*/
-static void credit_entropy_store(struct entropy_store *r, int nbits)
+static void credit_entropy_bits(struct entropy_store *r, int nbits)
{
unsigned long flags;
+ if (!nbits)
+ return;
+
spin_lock_irqsave(&r->lock, flags);
- if (r->entropy_count + nbits < 0) {
- DEBUG_ENT("negative entropy/overflow (%d+%d)\n",
- r->entropy_count, nbits);
+ DEBUG_ENT("added %d entropy credits to %s\n", nbits, r->name);
+ r->entropy_count += nbits;
+ if (r->entropy_count < 0) {
+ DEBUG_ENT("negative entropy/overflow\n");
r->entropy_count = 0;
- } else if (r->entropy_count + nbits > r->poolinfo->POOLBITS) {
+ } else if (r->entropy_count > r->poolinfo->POOLBITS)
r->entropy_count = r->poolinfo->POOLBITS;
- } else {
- r->entropy_count += nbits;
- if (nbits)
- DEBUG_ENT("added %d entropy credits to %s\n",
- nbits, r->name);
- }
/* should we wake readers? */
if (r == &input_pool && r->entropy_count >= random_read_wakeup_thresh)
@@ -619,8 +617,8 @@ static void add_timer_randomness(struct
* Round down by 1 bit on general principles,
* and limit entropy entimate to 12 bits.
*/
- credit_entropy_store(&input_pool,
- min_t(int, fls(delta>>1), 11));
+ credit_entropy_bits(&input_pool,
+ min_t(int, fls(delta>>1), 11));
}
out:
preempt_enable();
@@ -703,7 +701,7 @@ static void xfer_secondary_pool(struct e
bytes = extract_entropy(r->pull, tmp, bytes,
random_read_wakeup_thresh / 8, rsvd);
mix_pool_bytes(r, tmp, bytes);
- credit_entropy_store(r, bytes*8);
+ credit_entropy_bits(r, bytes*8);
}
}
@@ -1074,7 +1072,7 @@ static long random_ioctl(struct file *f,
return -EPERM;
if (get_user(ent_count, p))
return -EFAULT;
- credit_entropy_store(&input_pool, ent_count);
+ credit_entropy_bits(&input_pool, ent_count);
return 0;
case RNDADDENTROPY:
if (!capable(CAP_SYS_ADMIN))
@@ -1089,7 +1087,7 @@ static long random_ioctl(struct file *f,
size);
if (retval < 0)
return retval;
- credit_entropy_store(&input_pool, ent_count);
+ credit_entropy_bits(&input_pool, ent_count);
return 0;
case RNDZAPENTCNT:
case RNDCLEARPOOL:
_
Patches currently in -mm which might be from mpm@xxxxxxxxxxx are
git-x86.patch
maps4-add-proportional-set-size-accounting-in-smaps.patch
maps4-rework-task_size-macros.patch
maps4-rework-task_size-macros-mips-fix.patch
maps4-move-is_swap_pte.patch
maps4-introduce-a-generic-page-walker.patch
maps4-use-pagewalker-in-clear_refs-and-smaps.patch
maps4-simplify-interdependence-of-maps-and-smaps.patch
maps4-move-clear_refs-code-to-task_mmuc.patch
maps4-regroup-task_mmu-by-interface.patch
maps4-add-proc-pid-pagemap-interface.patch
maps4-add-proc-pid-pagemap-interface-fix.patch
maps4-add-proc-kpagecount-interface.patch
maps4-add-proc-kpagecount-interface-fix.patch
maps4-add-proc-kpageflags-interface.patch
maps4-add-proc-kpageflags-interface-fix.patch
maps4-add-proc-kpageflags-interface-fix-2.patch
maps4-add-proc-kpageflags-interface-fix-2-fix.patch
maps4-make-page-monitoring-proc-file-optional.patch
maps4-make-page-monitoring-proc-file-optional-fix.patch
remove-unused-code-from-mm-tiny-shmemc.patch
drivers-char-randomcwrite_pool-cond_resched-needed.patch
random-clean-up-checkpatch-complaints.patch
random-consolidate-wakeup-logic.patch
random-use-unlocked_ioctl.patch
random-reuse-rand_initialize.patch
random-improve-variable-naming-clear-extract-buffer.patch
random-make-backtracking-attacks-harder.patch
random-remove-cacheline-alignment-for-locks.patch
random-eliminate-redundant-new_rotate-variable.patch
random-remove-some-prefetch-logic.patch
random-simplify-add_ptr-logic.patch
random-make-mixing-interface-byte-oriented.patch
random-simplify-and-rename-credit_entropy_store.patch
-
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