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[209.132.180.67]) by mx.google.com with ESMTP id 142-v6si11054667pga.694.2018.05.30.14.29.21; Wed, 30 May 2018 14:29:21 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@pobox.com header.s=sasl header.b=I1zImX7T; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=linaro.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932621AbeE3V3S (ORCPT + 30 others); Wed, 30 May 2018 17:29:18 -0400 Received: from pb-smtp2.pobox.com ([64.147.108.71]:54855 "EHLO pb-smtp2.pobox.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932402AbeE3V2V (ORCPT ); Wed, 30 May 2018 17:28:21 -0400 Received: from pb-smtp2.pobox.com (unknown [127.0.0.1]) by pb-smtp2.pobox.com (Postfix) with ESMTP id 52693F3518; Wed, 30 May 2018 17:28:19 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=pobox.com; h=from:to:cc :subject:date:message-id:in-reply-to:references:mime-version :content-type:content-transfer-encoding; s=sasl; bh=7/XAO+Hax1n3 TNG7LB0OA6bInwI=; b=I1zImX7TG2rRI0XpQJigBSsto7eWCUmEVR+4dHvKbUZb 184OVhcuKUePjttZ358WB0RxKM770ikXDVXxHV3UhGkzEdIm7bCH9lpa1+v8hL/I y1CVRSs9gzfCty+yFB33b3Ybo5AthsqYn3/RK5+A9oa/mgWnZf9783ob5oasUgM= Received: from pb-smtp2.nyi.icgroup.com (unknown [127.0.0.1]) by pb-smtp2.pobox.com (Postfix) with ESMTP id 47DFFF3516; Wed, 30 May 2018 17:28:19 -0400 (EDT) Received: from yoda.home (unknown [70.82.104.228]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by pb-smtp2.pobox.com (Postfix) with ESMTPSA id BC293F3510; Wed, 30 May 2018 17:28:18 -0400 (EDT) Received: from xanadu.home (xanadu.home [192.168.2.2]) by yoda.home (Postfix) with ESMTP id 0BEE62DA06A7; Wed, 30 May 2018 17:28:18 -0400 (EDT) From: Nicolas Pitre To: Greg Kroah-Hartman Cc: Dave Mielke , Samuel Thibault , linux-kernel@vger.kernel.org Subject: [PATCH 3/5] vt: introduce unicode mode for /dev/vcs Date: Wed, 30 May 2018 17:27:43 -0400 Message-Id: <20180530212745.10997-4-nicolas.pitre@linaro.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180530212745.10997-1-nicolas.pitre@linaro.org> References: <20180530212745.10997-1-nicolas.pitre@linaro.org> MIME-Version: 1.0 X-Pobox-Relay-ID: 5EF23544-6450-11E8-B718-67830C78B957-78420484!pb-smtp2.pobox.com Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Now that the core vt code knows how to preserve unicode values for each displayed character, it is then possible to let user space access it via /dev/vcs*. Unicode characters are presented as 32 bit values in native endianity via the /dev/vcsu* devices, mimicking the simple /dev/vcs* devices. Unicode with attributes (similarly to /dev/vcsa*) is not supported at the moment. Data is available only as long as the console is in UTF-8 mode. ENODATA is returned otherwise. This was tested with the latest development version (to become version 5.7) of BRLTTY. Amongst other things, this allows ⠋⠕⠗ ⠞⠓⠊⠎ ⠃⠗⠁⠊⠇⠇⠑⠀⠞⠑⠭⠞⠀to appear directly on braille displays regardless of the console font being used. Signed-off-by: Nicolas Pitre Tested-by: Dave Mielke --- drivers/tty/vt/vc_screen.c | 89 ++++++++++++++++++++++++++++++++------ drivers/tty/vt/vt.c | 61 ++++++++++++++++++++++++++ include/linux/selection.h | 5 +++ 3 files changed, 141 insertions(+), 14 deletions(-) -- 2.17.0 diff --git a/drivers/tty/vt/vc_screen.c b/drivers/tty/vt/vc_screen.c index e4a66e1fd0..9c44252e52 100644 --- a/drivers/tty/vt/vc_screen.c +++ b/drivers/tty/vt/vc_screen.c @@ -10,6 +10,12 @@ * Attribute/character pair is in native endianity. * [minor: N+128] * + * /dev/vcsuN: similar to /dev/vcsaN but using 4-byte unicode values + * instead of 1-byte screen glyph values. + * [minor: N+64] + * + * /dev/vcsuaN: same idea as /dev/vcsaN for unicode (not yet implemented). + * * This replaces screendump and part of selection, so that the system * administrator can control access using file system permissions. * @@ -51,6 +57,26 @@ #define CON_BUF_SIZE (CONFIG_BASE_SMALL ? 256 : PAGE_SIZE) +/* + * Our minor space: + * + * 0 ... 63 glyph mode without attributes + * 64 ... 127 unicode mode without attributes + * 128 ... 191 glyph mode with attributes + * 192 ... 255 unused (reserved for unicode with attributes) + * + * This relies on MAX_NR_CONSOLES being <= 63, meaning 63 actual consoles + * with minors 0, 64, 128 and 192 being proxies for the foreground console. + */ +#if MAX_NR_CONSOLES > 63 +#warning "/dev/vcs* devices may not accommodate more than 63 consoles" +#endif + +#define console(inode) (iminor(inode) & 63) +#define use_unicode(inode) (iminor(inode) & 64) +#define use_attributes(inode) (iminor(inode) & 128) + + struct vcs_poll_data { struct notifier_block notifier; unsigned int cons_num; @@ -102,7 +128,7 @@ vcs_poll_data_get(struct file *file) poll = kzalloc(sizeof(*poll), GFP_KERNEL); if (!poll) return NULL; - poll->cons_num = iminor(file_inode(file)) & 127; + poll->cons_num = console(file_inode(file)); init_waitqueue_head(&poll->waitq); poll->notifier.notifier_call = vcs_notifier; if (register_vt_notifier(&poll->notifier) != 0) { @@ -140,7 +166,7 @@ vcs_poll_data_get(struct file *file) static struct vc_data* vcs_vc(struct inode *inode, int *viewed) { - unsigned int currcons = iminor(inode) & 127; + unsigned int currcons = console(inode); WARN_CONSOLE_UNLOCKED(); @@ -164,7 +190,6 @@ static int vcs_size(struct inode *inode) { int size; - int minor = iminor(inode); struct vc_data *vc; WARN_CONSOLE_UNLOCKED(); @@ -175,8 +200,12 @@ vcs_size(struct inode *inode) size = vc->vc_rows * vc->vc_cols; - if (minor & 128) + if (use_attributes(inode)) { + if (use_unicode(inode)) + return -EOPNOTSUPP; size = 2*size + HEADER_SIZE; + } else if (use_unicode(inode)) + size *= 4; return size; } @@ -197,12 +226,10 @@ static ssize_t vcs_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) { struct inode *inode = file_inode(file); - unsigned int currcons = iminor(inode); struct vc_data *vc; struct vcs_poll_data *poll; - long pos; - long attr, read; - int col, maxcol, viewed; + long pos, read; + int attr, uni_mode, row, col, maxcol, viewed; unsigned short *org = NULL; ssize_t ret; char *con_buf; @@ -218,7 +245,8 @@ vcs_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) */ console_lock(); - attr = (currcons & 128); + uni_mode = use_unicode(inode); + attr = use_attributes(inode); ret = -ENXIO; vc = vcs_vc(inode, &viewed); if (!vc) @@ -227,6 +255,10 @@ vcs_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) ret = -EINVAL; if (pos < 0) goto unlock_out; + /* we enforce 32-bit alignment for pos and count in unicode mode */ + if (uni_mode && (pos | count) & 3) + goto unlock_out; + poll = file->private_data; if (count && poll) poll->seen_last_update = true; @@ -266,7 +298,27 @@ vcs_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) con_buf_start = con_buf0 = con_buf; orig_count = this_round; maxcol = vc->vc_cols; - if (!attr) { + if (uni_mode) { + unsigned int nr; + + ret = vc_uniscr_check(vc); + if (ret) + break; + p /= 4; + row = p / vc->vc_cols; + col = p % maxcol; + nr = maxcol - col; + do { + if (nr > this_round/4) + nr = this_round/4; + vc_uniscr_copy_line(vc, con_buf0, row, col, nr); + con_buf0 += nr * 4; + this_round -= nr * 4; + row++; + col = 0; + nr = maxcol; + } while (this_round); + } else if (!attr) { org = screen_pos(vc, p, viewed); col = p % maxcol; p += maxcol - col; @@ -375,7 +427,6 @@ static ssize_t vcs_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { struct inode *inode = file_inode(file); - unsigned int currcons = iminor(inode); struct vc_data *vc; long pos; long attr, size, written; @@ -396,7 +447,7 @@ vcs_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) */ console_lock(); - attr = (currcons & 128); + attr = use_attributes(inode); ret = -ENXIO; vc = vcs_vc(inode, &viewed); if (!vc) @@ -593,9 +644,15 @@ vcs_fasync(int fd, struct file *file, int on) static int vcs_open(struct inode *inode, struct file *filp) { - unsigned int currcons = iminor(inode) & 127; + unsigned int currcons = console(inode); + bool attr = use_attributes(inode); + bool uni_mode = use_unicode(inode); int ret = 0; - + + /* we currently don't support attributes in unicode mode */ + if (attr && uni_mode) + return -EOPNOTSUPP; + console_lock(); if(currcons && !vc_cons_allocated(currcons-1)) ret = -ENXIO; @@ -628,6 +685,8 @@ void vcs_make_sysfs(int index) { device_create(vc_class, NULL, MKDEV(VCS_MAJOR, index + 1), NULL, "vcs%u", index + 1); + device_create(vc_class, NULL, MKDEV(VCS_MAJOR, index + 65), NULL, + "vcsu%u", index + 1); device_create(vc_class, NULL, MKDEV(VCS_MAJOR, index + 129), NULL, "vcsa%u", index + 1); } @@ -635,6 +694,7 @@ void vcs_make_sysfs(int index) void vcs_remove_sysfs(int index) { device_destroy(vc_class, MKDEV(VCS_MAJOR, index + 1)); + device_destroy(vc_class, MKDEV(VCS_MAJOR, index + 65)); device_destroy(vc_class, MKDEV(VCS_MAJOR, index + 129)); } @@ -647,6 +707,7 @@ int __init vcs_init(void) vc_class = class_create(THIS_MODULE, "vc"); device_create(vc_class, NULL, MKDEV(VCS_MAJOR, 0), NULL, "vcs"); + device_create(vc_class, NULL, MKDEV(VCS_MAJOR, 64), NULL, "vcsu"); device_create(vc_class, NULL, MKDEV(VCS_MAJOR, 128), NULL, "vcsa"); for (i = 0; i < MIN_NR_CONSOLES; i++) vcs_make_sysfs(i); diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c index 3a801a60f4..2cba6089ca 100644 --- a/drivers/tty/vt/vt.c +++ b/drivers/tty/vt/vt.c @@ -483,6 +483,67 @@ static void vc_uniscr_copy_area(struct uni_screen *dst, } } +/* + * Called from vcs_read() to make sure unicode screen retrieval is possible. + * This will initialize the unicode screen buffer if not already done. + * This returns 0 if OK, or a negative error code otherwise. + * In particular, -ENODATA is returned if the console is not in UTF-8 mode. + */ +int vc_uniscr_check(struct vc_data *vc) +{ + struct uni_screen *uniscr; + unsigned short *p; + int x, y, mask; + + if (__is_defined(NO_VC_UNI_SCREEN)) + return -EOPNOTSUPP; + + WARN_CONSOLE_UNLOCKED(); + + if (!vc->vc_utf) + return -ENODATA; + + if (vc->vc_uni_screen) + return 0; + + uniscr = vc_uniscr_alloc(vc->vc_cols, vc->vc_rows); + if (!uniscr) + return -ENOMEM; + + /* + * Let's populate it initially with (imperfect) reverse translation. + * This is the next best thing we can do short of having it enabled + * from the start even when no users rely on this functionality. True + * unicode content will be available after a complete screen refresh. + */ + p = (unsigned short *)vc->vc_origin; + mask = vc->vc_hi_font_mask | 0xff; + for (y = 0; y < vc->vc_rows; y++) { + char32_t *line = uniscr->lines[y]; + for (x = 0; x < vc->vc_cols; x++) { + u16 glyph = scr_readw(p++) & mask; + line[x] = inverse_translate(vc, glyph, true); + } + } + + vc->vc_uni_screen = uniscr; + return 0; +} + +/* + * Called from vcs_read() to get the unicode data from the screen. + * This must be preceded by a successful call to vc_uniscr_check() once + * the console lock has been taken. + */ +void vc_uniscr_copy_line(struct vc_data *vc, void *dest, + unsigned int row, unsigned int col, unsigned int nr) +{ + struct uni_screen *uniscr = get_vc_uniscr(vc); + + BUG_ON(!uniscr); + memcpy(dest, &uniscr->lines[row][col], nr * sizeof(char32_t)); +} + static void con_scroll(struct vc_data *vc, unsigned int t, unsigned int b, enum con_scroll dir, unsigned int nr) diff --git a/include/linux/selection.h b/include/linux/selection.h index 5b278ce99d..2b34df9f1e 100644 --- a/include/linux/selection.h +++ b/include/linux/selection.h @@ -42,4 +42,9 @@ extern u16 vcs_scr_readw(struct vc_data *vc, const u16 *org); extern void vcs_scr_writew(struct vc_data *vc, u16 val, u16 *org); extern void vcs_scr_updated(struct vc_data *vc); +extern int vc_uniscr_check(struct vc_data *vc); +extern void vc_uniscr_copy_line(struct vc_data *vc, void *dest, + unsigned int row, unsigned int col, + unsigned int nr); + #endif