From mboxrd@z Thu Jan 1 00:00:00 1970 From: akpm@linux-foundation.org Subject: [withdrawn] kfifo-make-kfifo_in-atomic.patch removed from -mm tree Date: Fri, 08 Jan 2010 13:05:09 -0800 Message-ID: <201001082105.o08L597o014012@imap1.linux-foundation.org> Reply-To: linux-kernel@vger.kernel.org Return-path: Received: from smtp1.linux-foundation.org ([140.211.169.13]:58384 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753652Ab0AHVGU (ORCPT ); Fri, 8 Jan 2010 16:06:20 -0500 Sender: mm-commits-owner@vger.kernel.org List-Id: mm-commits@vger.kernel.org To: andi@firstfloor.org, ak@linux.intel.com, awalls@radix.net, dhillonv10@gmail.com, dmitry.torokhov@gmail.com, rdreier@cisco.com, stefani@seibold.net, mm-commits@vger.kernel.org The patch titled kfifo: make kfifo_in atomic has been removed from the -mm tree. Its filename was kfifo-make-kfifo_in-atomic.patch This patch was dropped because it was withdrawn The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: kfifo: make kfifo_in atomic From: Andi Kleen Right now kfifo_in allows copying in less than the input amount. This is unfortunately not a good idea on any record oriented users: if the size of the kfifo is not a multiple of the record (and that can easily happen due to the power-of-two requirement) then when the FIFO fills up partial records could be put in. Such a condition would be fatal for any record consumer who would get permanently desynchronized. In fact I doubt unless the input is a totally boundary less data stream I doubt anything could handle this. Change kfifo_in() to always put in everything or nothing. The return value is now always 0 or the full length. Signed-off-by: Andi Kleen Cc: Stefani Seibold Cc: Roland Dreier Cc: Dmitry Torokhov Cc: Andy Walls Cc: Vikram Dhillon Signed-off-by: Andrew Morton --- kernel/kfifo.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff -puN kernel/kfifo.c~kfifo-make-kfifo_in-atomic kernel/kfifo.c --- a/kernel/kfifo.c~kfifo-make-kfifo_in-atomic +++ a/kernel/kfifo.c @@ -228,9 +228,8 @@ EXPORT_SYMBOL(__kfifo_in_n); * @from: the data to be added. * @len: the length of the data to be added. * - * This function copies at most @len bytes from the @from buffer into - * the FIFO depending on the free space, and returns the number of - * bytes copied. + * This function copies @len bytes from the @from buffer into + * the FIFO and returns 0 if there is not enough space. * * Note that with only one concurrent reader and one concurrent * writer, you don't need extra locking to use these functions. @@ -238,8 +237,8 @@ EXPORT_SYMBOL(__kfifo_in_n); unsigned int kfifo_in(struct kfifo *fifo, const void *from, unsigned int len) { - len = min(kfifo_avail(fifo), len); - + if (kfifo_avail(fifo) < len) + return 0; __kfifo_in_data(fifo, from, len, 0); __kfifo_add_in(fifo, len); return len; _ Patches currently in -mm which might be from andi@firstfloor.org are kernel-signalc-fix-kernel-information-leak-with-print-fatal-signals=1.patch proc-revert-procfs-provide-stack-information-for-threads.patch kfifo-use-void-pointers-for-user-buffers.patch kfifo-make-kfifo_in-atomic.patch kfifo-sanitize-_user-error-handling.patch kfifo-add-kfifo_out_peek.patch kfifo-add-kfifo_initialized.patch kfifo-document-everywhere-that-size-has-to-be-power-of-two.patch hardware-latency-detector-remove-default-m.patch kbuild-move-fno-dwarf2-cfi-asm-to-powerpc-only.patch mm-introduce-dump_page-and-print-symbolic-flag-names.patch coredump-unify-dump_seek-implementations-for-each-binfmt_c.patch coredump-move-dump_write-and-dump_seek-into-a-header-file.patch elf-coredump-replace-elf_core_extra_-macros-by-functions.patch elf-coredump-make-offset-calculation-process-and-writing-process-explicit.patch elf-coredump-add-extended-numbering-support.patch tracehooks-kill-some-pt_ptraced-checks.patch tracehooks-check-pt_ptraced-before-reporting-the-single-step.patch ptrace_signal-check-pt_ptraced-before-reporting-a-signal.patch export-__ptrace_detach-and-do_notify_parent_cldstop.patch reorder-the-code-in-kernel-ptracec.patch implement-utrace-ptrace.patch utrace-core.patch