The patch titled random: simplify add_ptr logic has been added to the -mm tree. Its filename is random-simplify-add_ptr-logic.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** 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 - To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html