From patchwork Wed Dec 21 16:37:38 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Manuel_Sch=C3=B6lling?= X-Patchwork-Id: 9483255 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id B953F6027D for ; Wed, 21 Dec 2016 16:39:26 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id AAF5228306 for ; Wed, 21 Dec 2016 16:39:26 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 9F43F28458; Wed, 21 Dec 2016 16:39:26 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,FREEMAIL_FROM, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E712528410 for ; Wed, 21 Dec 2016 16:39:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934931AbcLUQiX (ORCPT ); Wed, 21 Dec 2016 11:38:23 -0500 Received: from mout.gmx.net ([212.227.15.15]:62395 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934685AbcLUQiV (ORCPT ); Wed, 21 Dec 2016 11:38:21 -0500 Received: from schoellingm.dzne.de ([37.201.241.239]) by mail.gmx.com (mrgmx003 [212.227.17.190]) with ESMTPSA (Nemesis) id 0Mfn40-1byvE91bNs-00NAse; Wed, 21 Dec 2016 17:38:13 +0100 From: =?UTF-8?q?Manuel=20Sch=C3=B6lling?= To: plagnioj@jcrosoft.com, tomi.valkeinen@ti.com Cc: manuel.schoelling@gmx.de, jslaby@suse.cz, gregkh@linuxfoundation.org, andrey_utkin@fastmail.com, kilobyte@angband.pl, linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH RESEND v7 3/3] console: Add persistent scrollback buffers for all VGA consoles Date: Wed, 21 Dec 2016 17:37:38 +0100 Message-Id: <1482338258-21388-4-git-send-email-manuel.schoelling@gmx.de> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1482338258-21388-1-git-send-email-manuel.schoelling@gmx.de> References: <1480848836-11330-1-git-send-email-manuel.schoelling@gmx.de> <1482338258-21388-1-git-send-email-manuel.schoelling@gmx.de> MIME-Version: 1.0 X-Provags-ID: V03:K0:EKF7js5/ovzY5L3eQlocBwx9NssfFwF9o4HPU+hoJ/L5CsSmLGk aEIdU/4dWjC702Knek0Khlz84uHnojfUhYSfiy+xqYzGV40Mjv5fTY1OlqM2fDujM6OKlIF yPD+WcclPNMFGiMkgJjh52qeqUOXxNAfNoErCtnxpRAJ4iNfiNBWXYjS4JMLVXKJ1ter6q/ HJJ8yEUfZr3//TPDl5Tgg== X-UI-Out-Filterresults: notjunk:1; V01:K0:EM5I1p3wKWU=:ggdOBgQuEp0AW0OLFYxXHl EKfAk5uMGFBN1rAwJomN029mleMxvHoYFWuFv0ZW3dYvoYk5zsqAejdz7MNt3UajIybbCsfMv g++uxc5NbNmDLkigcMKYv/bBsNlylS6KO0XCUNvtDabiWqdOmGwAZjYs8Joo51aVZrWlaBJ+e /QxHVM4I8GYFSK8hrSWf47H/C+NgfTf9DpUJRduOYAFPth2P0DKhucvV/BH1de/2AUcOfWQrU s1xTxLv8u6+L7tMHQcgJqnaTebKDej2ijm5+39Dtg+F2rZUWyM9lQYc/0/+mTavBQBHD5w1hR 50MpdRBHrG/k4jV484N6gtZnkzyRfek2oID8Oqr/k7A2wYky+kdbRF/5hNLvihMARQvXpCLOf m4trfdF9bLAVRbd3UFiOTEJcSOCgqd+Hy3Ye5+kZuCJTql894pIDmwLKVCSgxI6mesocHmGOJ bFZL4+VAvDYCZq1cwCHO1UPeWAqJ9SuQypHQazIk1xDqaYmVM09P5N39FFgp5rKLg1QsgZ3X5 UUK0/C1N2xAUfB13vvnDIWojDX5tLwI6aVGjNX/KTNdwNc4RrvdEMTD+HFmlFDD2UMX4fqAIZ EjEqi2c97R+TXxMyqivwGNcQSNe+JVvIATsHdcGRaKBWeN+bf7tyDKbItJUomID3IZF79d/3S DC9JAmDF4bjouKfRvFP4jsOK0P6DRu7QlazCUBldfhO8Xypo9hBcC3e8QGyTBWdB11OBWYBEu 7WyO+Tf0TyLq6tp0H2wXnjDswKOpmUDUoJyKDvc8kKRbbHyDcrx07JixHh5H37L3gIZNNliPR tktrbO5 Sender: linux-fbdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Add a scrollback buffers for each VGA console. The benefit is that the scrollback history is not flushed when switching between consoles but is persistent. The buffers are allocated on demand when a new console is opened. This breaks tools like clear_console that rely on flushing the scrollback history by switching back and forth between consoles which is why this feature is disabled by default. Use the escape sequence \e[3J instead for flushing the buffer. Signed-off-by: Manuel Schölling Reviewed-by: Andrey Utkin Tested-by: Andrey Utkin Tested-by: Adam Borowski --- drivers/video/console/Kconfig | 25 +++++++- drivers/video/console/vgacon.c | 142 ++++++++++++++++++++++++++--------------- 2 files changed, 111 insertions(+), 56 deletions(-) diff --git a/drivers/video/console/Kconfig b/drivers/video/console/Kconfig index 38da6e2..c5742d2 100644 --- a/drivers/video/console/Kconfig +++ b/drivers/video/console/Kconfig @@ -43,9 +43,28 @@ config VGACON_SOFT_SCROLLBACK_SIZE range 1 1024 default "64" help - Enter the amount of System RAM to allocate for the scrollback - buffer. Each 64KB will give you approximately 16 80x25 - screenfuls of scrollback buffer + Enter the amount of System RAM to allocate for scrollback + buffers of VGA consoles. Each 64KB will give you approximately + 16 80x25 screenfuls of scrollback buffer. + +config VGACON_SOFT_SCROLLBACK_PERSISTENT + bool "Persistent Scrollback History for each console" + depends on VGACON_SOFT_SCROLLBACK + default n + help + Say Y here if the scrollback history should persist when switching + between consoles. Otherwise, the scrollback history will be flushed + each time the console is switched. + + This feature might break your tool of choice to flush the scrollback + buffer, e.g. clear(1) will work fine but Debian's clear_console(1) + will be broken, which might cause security issues. + You can use the escape sequence \e[3J instead if this feature is + activated. + + Note that a buffer of VGACON_SOFT_SCROLLBACK_SIZE is taken for each + created tty device. + So if you use a RAM-constrained system, say N here. config MDA_CONSOLE depends on !M68K && !PARISC && ISA diff --git a/drivers/video/console/vgacon.c b/drivers/video/console/vgacon.c index 9a7c2bb..ca23d22 100644 --- a/drivers/video/console/vgacon.c +++ b/drivers/video/console/vgacon.c @@ -162,7 +162,7 @@ static inline void vga_set_mem_top(struct vc_data *c) #ifdef CONFIG_VGACON_SOFT_SCROLLBACK /* software scrollback */ -static struct vgacon_scrollback_info { +struct vgacon_scrollback_info { void *data; int tail; int size; @@ -171,74 +171,110 @@ static struct vgacon_scrollback_info { int cur; int save; int restore; -} vgacon_scrollback; +}; + +static struct vgacon_scrollback_info *vgacon_scrollback_cur; +#ifdef CONFIG_VGACON_SOFT_SCROLLBACK_PERSISTENT +static struct vgacon_scrollback_info vgacon_scrollbacks[MAX_NR_CONSOLES]; +#else +static struct vgacon_scrollback_info vgacon_scrollbacks[1]; +#endif -static void vgacon_scrollback_reset(size_t reset_size) +static void vgacon_scrollback_reset(int vc_num, size_t reset_size) { - if (vgacon_scrollback.data && reset_size > 0) - memset(vgacon_scrollback.data, 0, reset_size); + struct vgacon_scrollback_info *scrollback = &vgacon_scrollbacks[vc_num]; + + if (scrollback->data && reset_size > 0) + memset(scrollback->data, 0, reset_size); - vgacon_scrollback.cnt = 0; - vgacon_scrollback.tail = 0; - vgacon_scrollback.cur = 0; + scrollback->cnt = 0; + scrollback->tail = 0; + scrollback->cur = 0; } -static void vgacon_scrollback_init(int pitch) +static void vgacon_scrollback_init(int vc_num) { - int rows = CONFIG_VGACON_SOFT_SCROLLBACK_SIZE * 1024/pitch; - - if (vgacon_scrollback.data) { - vgacon_scrollback.cnt = 0; - vgacon_scrollback.tail = 0; - vgacon_scrollback.cur = 0; - vgacon_scrollback.rows = rows - 1; - vgacon_scrollback.size = rows * pitch; + int pitch = vga_video_num_columns * 2; + size_t size = CONFIG_VGACON_SOFT_SCROLLBACK_SIZE * 1024; + int rows = size / pitch; + void *data; + + data = kmalloc_array(CONFIG_VGACON_SOFT_SCROLLBACK_SIZE, 1024, + GFP_NOWAIT); + + vgacon_scrollbacks[vc_num].data = data; + vgacon_scrollback_cur = &vgacon_scrollbacks[vc_num]; + + vgacon_scrollback_cur->rows = rows - 1; + vgacon_scrollback_cur->size = rows * pitch; + + vgacon_scrollback_reset(vc_num, size); +} + +static void vgacon_scrollback_switch(int vc_num) +{ +#ifndef CONFIG_VGACON_SOFT_SCROLLBACK_PERSISTENT + vc_num = 0; +#endif + + if (!vgacon_scrollbacks[vc_num].data) { + vgacon_scrollback_init(vc_num); + } else { +#ifdef CONFIG_VGACON_SOFT_SCROLLBACK_PERSISTENT + vgacon_scrollback_cur = &vgacon_scrollbacks[vc_num]; +#else + size_t size = CONFIG_VGACON_SOFT_SCROLLBACK_SIZE * 1024; + + vgacon_scrollback_reset(vc_num, size); +#endif } } static void vgacon_scrollback_startup(void) { - vgacon_scrollback.data = kcalloc(CONFIG_VGACON_SOFT_SCROLLBACK_SIZE, - 1024, GFP_NOWAIT); - vgacon_scrollback_init(vga_video_num_columns * 2); + vgacon_scrollback_cur = &vgacon_scrollbacks[0]; + vgacon_scrollback_init(0); } static void vgacon_scrollback_update(struct vc_data *c, int t, int count) { void *p; - if (!vgacon_scrollback.size || c->vc_num != fg_console) + if (!vgacon_scrollback_cur->data || !vgacon_scrollback_cur->size || + c->vc_num != fg_console) return; p = (void *) (c->vc_origin + t * c->vc_size_row); while (count--) { - scr_memcpyw(vgacon_scrollback.data + vgacon_scrollback.tail, + scr_memcpyw(vgacon_scrollback_cur->data + + vgacon_scrollback_cur->tail, p, c->vc_size_row); - vgacon_scrollback.cnt++; + + vgacon_scrollback_cur->cnt++; p += c->vc_size_row; - vgacon_scrollback.tail += c->vc_size_row; + vgacon_scrollback_cur->tail += c->vc_size_row; - if (vgacon_scrollback.tail >= vgacon_scrollback.size) - vgacon_scrollback.tail = 0; + if (vgacon_scrollback_cur->tail >= vgacon_scrollback_cur->size) + vgacon_scrollback_cur->tail = 0; - if (vgacon_scrollback.cnt > vgacon_scrollback.rows) - vgacon_scrollback.cnt = vgacon_scrollback.rows; + if (vgacon_scrollback_cur->cnt > vgacon_scrollback_cur->rows) + vgacon_scrollback_cur->cnt = vgacon_scrollback_cur->rows; - vgacon_scrollback.cur = vgacon_scrollback.cnt; + vgacon_scrollback_cur->cur = vgacon_scrollback_cur->cnt; } } static void vgacon_restore_screen(struct vc_data *c) { - vgacon_scrollback.save = 0; + vgacon_scrollback_cur->save = 0; - if (!vga_is_gfx && !vgacon_scrollback.restore) { + if (!vga_is_gfx && !vgacon_scrollback_cur->restore) { scr_memcpyw((u16 *) c->vc_origin, (u16 *) c->vc_screenbuf, c->vc_screenbuf_size > vga_vram_size ? vga_vram_size : c->vc_screenbuf_size); - vgacon_scrollback.restore = 1; - vgacon_scrollback.cur = vgacon_scrollback.cnt; + vgacon_scrollback_cur->restore = 1; + vgacon_scrollback_cur->cur = vgacon_scrollback_cur->cnt; } } @@ -252,41 +288,41 @@ static void vgacon_scrolldelta(struct vc_data *c, int lines) return; } - if (!vgacon_scrollback.data) + if (!vgacon_scrollback_cur->data) return; - if (!vgacon_scrollback.save) { + if (!vgacon_scrollback_cur->save) { vgacon_cursor(c, CM_ERASE); vgacon_save_screen(c); - vgacon_scrollback.save = 1; + vgacon_scrollback_cur->save = 1; } - vgacon_scrollback.restore = 0; - start = vgacon_scrollback.cur + lines; + vgacon_scrollback_cur->restore = 0; + start = vgacon_scrollback_cur->cur + lines; end = start + abs(lines); if (start < 0) start = 0; - if (start > vgacon_scrollback.cnt) - start = vgacon_scrollback.cnt; + if (start > vgacon_scrollback_cur->cnt) + start = vgacon_scrollback_cur->cnt; if (end < 0) end = 0; - if (end > vgacon_scrollback.cnt) - end = vgacon_scrollback.cnt; + if (end > vgacon_scrollback_cur->cnt) + end = vgacon_scrollback_cur->cnt; - vgacon_scrollback.cur = start; + vgacon_scrollback_cur->cur = start; count = end - start; - soff = vgacon_scrollback.tail - ((vgacon_scrollback.cnt - end) * - c->vc_size_row); + soff = vgacon_scrollback_cur->tail - + ((vgacon_scrollback_cur->cnt - end) * c->vc_size_row); soff -= count * c->vc_size_row; if (soff < 0) - soff += vgacon_scrollback.size; + soff += vgacon_scrollback_cur->size; - count = vgacon_scrollback.cnt - start; + count = vgacon_scrollback_cur->cnt - start; if (count > c->vc_rows) count = c->vc_rows; @@ -300,13 +336,13 @@ static void vgacon_scrolldelta(struct vc_data *c, int lines) count *= c->vc_size_row; /* how much memory to end of buffer left? */ - copysize = min(count, vgacon_scrollback.size - soff); - scr_memcpyw(d, vgacon_scrollback.data + soff, copysize); + copysize = min(count, vgacon_scrollback_cur->size - soff); + scr_memcpyw(d, vgacon_scrollback_cur->data + soff, copysize); d += copysize; count -= copysize; if (count) { - scr_memcpyw(d, vgacon_scrollback.data, count); + scr_memcpyw(d, vgacon_scrollback_cur->data, count); d += count; } @@ -320,13 +356,13 @@ static void vgacon_flush_scrollback(struct vc_data *c) { size_t size = CONFIG_VGACON_SOFT_SCROLLBACK_SIZE * 1024; - if (c->vc_num == fg_console) - vgacon_scrollback_reset(size); + vgacon_scrollback_reset(c->vc_num, size); } #else #define vgacon_scrollback_startup(...) do { } while (0) #define vgacon_scrollback_init(...) do { } while (0) #define vgacon_scrollback_update(...) do { } while (0) +#define vgacon_scrollback_switch(...) do { } while (0) static void vgacon_restore_screen(struct vc_data *c) { @@ -805,7 +841,7 @@ static int vgacon_switch(struct vc_data *c) vgacon_doresize(c, c->vc_cols, c->vc_rows); } - vgacon_scrollback_init(c->vc_size_row); + vgacon_scrollback_switch(c->vc_num); return 0; /* Redrawing not needed */ }