Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933204Ab1FWRfw (ORCPT ); Thu, 23 Jun 2011 13:35:52 -0400 Received: from mail.windriver.com ([147.11.1.11]:34183 "EHLO mail.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933188Ab1FWRft (ORCPT ); Thu, 23 Jun 2011 13:35:49 -0400 From: Paul Gortmaker To: stable@kernel.org, linux-kernel@vger.kernel.org Cc: stable-review@kernel.org, Guy Martin , James Bottomley , Paul Gortmaker Subject: [34-longterm 063/247] parisc : Remove broken line wrapping handling pdc_iodc_print() Date: Thu, 23 Jun 2011 13:32:11 -0400 Message-Id: <1308850515-15242-4-git-send-email-paul.gortmaker@windriver.com> X-Mailer: git-send-email 1.7.4.4 In-Reply-To: <1308850515-15242-1-git-send-email-paul.gortmaker@windriver.com> References: <1308849690-14530-1-git-send-email-paul.gortmaker@windriver.com> <1308850515-15242-1-git-send-email-paul.gortmaker@windriver.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2887 Lines: 83 From: Guy Martin ------------------- This is a commit scheduled for the next v2.6.34 longterm release. If you see a problem with using this for longterm, please comment. ------------------- commit fbea668498e93bb38ac9226c7af9120a25957375 upstream. Remove the broken line wrapping handling in pdc_iodc_print(). It is broken in 3 ways : - It doesn't keep track of the current screen position, it just assumes that the new buffer will be printed at the begining of the screen. - It doesn't take in account that non printable characters won't increase the current position on the screen. - And last but not least, it triggers a kernel panic if a backspace is the first char in the provided buffer : Backtrace: [<0000000040128ec4>] pdc_console_write+0x44/0x78 [<0000000040128f18>] pdc_console_tty_write+0x20/0x38 [<000000004032f1ac>] n_tty_write+0x2a4/0x550 [<000000004032b158>] tty_write+0x1e0/0x2d8 [<00000000401bb420>] vfs_write+0xb8/0x188 [<00000000401bb630>] sys_write+0x68/0xb8 [<0000000040104eb8>] syscall_exit+0x0/0x14 Most terminals handle the line wrapping just fine. I've confirmed that it works correctly on a C8000 with both vga and serial output. Signed-off-by: Guy Martin Signed-off-by: James Bottomley Signed-off-by: Paul Gortmaker --- arch/parisc/kernel/firmware.c | 13 +------------ 1 files changed, 1 insertions(+), 12 deletions(-) diff --git a/arch/parisc/kernel/firmware.c b/arch/parisc/kernel/firmware.c index df971fa..4896ed0 100644 --- a/arch/parisc/kernel/firmware.c +++ b/arch/parisc/kernel/firmware.c @@ -1126,15 +1126,13 @@ int pdc_iodc_print(const unsigned char *str, unsigned count) unsigned int i; unsigned long flags; - for (i = 0; i < count && i < 79;) { + for (i = 0; i < count;) { switch(str[i]) { case '\n': iodc_dbuf[i+0] = '\r'; iodc_dbuf[i+1] = '\n'; i += 2; goto print; - case '\b': /* BS */ - i--; /* overwrite last */ default: iodc_dbuf[i] = str[i]; i++; @@ -1142,15 +1140,6 @@ int pdc_iodc_print(const unsigned char *str, unsigned count) } } - /* if we're at the end of line, and not already inserting a newline, - * insert one anyway. iodc console doesn't claim to support >79 char - * lines. don't account for this in the return value. - */ - if (i == 79 && iodc_dbuf[i-1] != '\n') { - iodc_dbuf[i+0] = '\r'; - iodc_dbuf[i+1] = '\n'; - } - print: spin_lock_irqsave(&pdc_lock, flags); real32_call(PAGE0->mem_cons.iodc_io, -- 1.7.4.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/