The patch titled
random: simplify add_ptr logic
has been added to the -mm tree. Its filename is
random-simplify-add_ptr-logic.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 add_ptr logic
From: Matt Mackall <mpm@xxxxxxxxxxx>
The add_ptr variable wasn't used in a sensible way, use only i instead.
i got reused later for a different purpose, use j instead.
While we're here, put tap0 first in the tap list and add a comment.
Signed-off-by: Matt Mackall <mpm@xxxxxxxxxxx>
Cc: Theodore Ts'o <tytso@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/char/random.c | 21 ++++++++++-----------
1 file changed, 10 insertions(+), 11 deletions(-)
diff -puN drivers/char/random.c~random-simplify-add_ptr-logic drivers/char/random.c
--- a/drivers/char/random.c~random-simplify-add_ptr-logic
+++ a/drivers/char/random.c
@@ -454,7 +454,7 @@ static void __add_entropy_words(struct e
static __u32 const twist_table[8] = {
0x00000000, 0x3b6e20c8, 0x76dc4190, 0x4db26158,
0xedb88320, 0xd6d6a3e8, 0x9b64c2b0, 0xa00ae278 };
- unsigned long i, add_ptr, tap1, tap2, tap3, tap4, tap5;
+ unsigned long i, j, tap1, tap2, tap3, tap4, tap5;
int input_rotate;
int wordmask = r->poolinfo->poolwords - 1;
__u32 w;
@@ -469,19 +469,21 @@ static void __add_entropy_words(struct e
spin_lock_irqsave(&r->lock, flags);
input_rotate = r->input_rotate;
- add_ptr = r->add_ptr;
+ i = r->add_ptr;
while (nwords--) {
w = rol32(*in++, input_rotate & 31);
- i = add_ptr = (add_ptr - 1) & wordmask;
+ i = (i - 1) & wordmask;
/* XOR in the various taps */
+ w ^= r->pool[i];
w ^= r->pool[(i + tap1) & wordmask];
w ^= r->pool[(i + tap2) & wordmask];
w ^= r->pool[(i + tap3) & wordmask];
w ^= r->pool[(i + tap4) & wordmask];
w ^= r->pool[(i + tap5) & wordmask];
- w ^= r->pool[i];
+
+ /* Mix the result back in with a twist */
r->pool[i] = (w >> 3) ^ twist_table[w & 7];
/*
@@ -494,14 +496,11 @@ static void __add_entropy_words(struct e
}
r->input_rotate = input_rotate;
- r->add_ptr = add_ptr;
+ r->add_ptr = i;
- if (out) {
- for (i = 0; i < 16; i++) {
- out[i] = r->pool[add_ptr];
- add_ptr = (add_ptr - 1) & wordmask;
- }
- }
+ if (out)
+ for (j = 0; j < 16; j++)
+ out[j] = r->pool[(i - j) & wordmask];
spin_unlock_irqrestore(&r->lock, flags);
}
_
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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