From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932977Ab1DYUxr (ORCPT ); Mon, 25 Apr 2011 16:53:47 -0400 Received: from 1wt.eu ([62.212.114.60]:34788 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932796Ab1DYUxo (ORCPT ); Mon, 25 Apr 2011 16:53:44 -0400 Message-Id: <20110425200234.122397165@pcw.home.local> User-Agent: quilt/0.48-1 Date: Mon, 25 Apr 2011 22:02:58 +0200 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@kernel.org, stable-review@kernel.org Cc: Guy Martin , James Bottomley , Greg Kroah-Hartman Subject: [PATCH 026/173] parisc : Remove broken line wrapping handling pdc_iodc_print() In-Reply-To: <46075c3a3ef08be6d70339617d6afc98@local> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.27.59-stable review patch. If anyone has any objections, please let us know. ------------------ From: Guy Martin 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: Greg Kroah-Hartman --- arch/parisc/kernel/firmware.c | 13 +------------ 1 file changed, 1 insertion(+), 12 deletions(-) --- a/arch/parisc/kernel/firmware.c +++ b/arch/parisc/kernel/firmware.c @@ -1126,15 +1126,13 @@ int pdc_iodc_print(const unsigned char * 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 * } } - /* 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,