From patchwork Tue Aug 4 16:24:01 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrzej Pietrasiewicz X-Patchwork-Id: 11700619 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 9B7AF6C1 for ; Tue, 4 Aug 2020 16:24:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A26F02177B for ; Tue, 4 Aug 2020 16:24:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729664AbgHDQYO (ORCPT ); Tue, 4 Aug 2020 12:24:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46828 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729889AbgHDQYN (ORCPT ); Tue, 4 Aug 2020 12:24:13 -0400 Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [IPv6:2a00:1098:0:82:1000:25:2eeb:e3e3]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0BA27C06174A; Tue, 4 Aug 2020 09:24:11 -0700 (PDT) Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: andrzej.p) with ESMTPSA id EFC502950FC From: Andrzej Pietrasiewicz To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , Jiri Slaby , Dmitry Torokhov , Andrzej Pietrasiewicz , linux-input@vger.kernel.org, kernel@collabora.com Subject: [PATCH 1/2] tty/sysrq: Extend the sysrq_key_table to cover capital letters Date: Tue, 4 Aug 2020 18:24:01 +0200 Message-Id: <20200804162402.2087-2-andrzej.p@collabora.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200804162402.2087-1-andrzej.p@collabora.com> References: <20200804162402.2087-1-andrzej.p@collabora.com> Sender: linux-input-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-input@vger.kernel.org All slots in sysrq_key_table[] are either used, reserved or at least commented with their intended use. This patch adds capital letter versions available, which means adding 26 more entries. For already existing SysRq operations the user presses Alt-SysRq-, and for the newly added ones Alt-Shift-SysRq-. Signed-off-by: Andrzej Pietrasiewicz --- Documentation/admin-guide/sysrq.rst | 2 ++ drivers/tty/sysrq.c | 49 +++++++++++++++++++++++++++-- 2 files changed, 49 insertions(+), 2 deletions(-) diff --git a/Documentation/admin-guide/sysrq.rst b/Documentation/admin-guide/sysrq.rst index e6424d8c5846..67dfa4c29093 100644 --- a/Documentation/admin-guide/sysrq.rst +++ b/Documentation/admin-guide/sysrq.rst @@ -79,6 +79,8 @@ On all echo t > /proc/sysrq-trigger +The :kbd:`` is case sensitive. + What are the 'command' keys? ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ diff --git a/drivers/tty/sysrq.c b/drivers/tty/sysrq.c index 7c95afa905a0..52e344bfe8c0 100644 --- a/drivers/tty/sysrq.c +++ b/drivers/tty/sysrq.c @@ -442,7 +442,7 @@ static const struct sysrq_key_op sysrq_unrt_op = { /* Key Operations table and lock */ static DEFINE_SPINLOCK(sysrq_key_table_lock); -static const struct sysrq_key_op *sysrq_key_table[36] = { +static const struct sysrq_key_op *sysrq_key_table[62] = { &sysrq_loglevel_op, /* 0 */ &sysrq_loglevel_op, /* 1 */ &sysrq_loglevel_op, /* 2 */ @@ -499,6 +499,32 @@ static const struct sysrq_key_op *sysrq_key_table[36] = { /* y: May be registered on sparc64 for global register dump */ NULL, /* y */ &sysrq_ftrace_dump_op, /* z */ + NULL, /* A */ + NULL, /* B */ + NULL, /* C */ + NULL, /* D */ + NULL, /* E */ + NULL, /* F */ + NULL, /* G */ + NULL, /* H */ + NULL, /* I */ + NULL, /* J */ + NULL, /* K */ + NULL, /* L */ + NULL, /* M */ + NULL, /* N */ + NULL, /* O */ + NULL, /* P */ + NULL, /* Q */ + NULL, /* R */ + NULL, /* S */ + NULL, /* T */ + NULL, /* U */ + NULL, /* V */ + NULL, /* W */ + NULL, /* X */ + NULL, /* Y */ + NULL, /* Z */ }; /* key2index calculation, -1 on invalid index */ @@ -510,6 +536,8 @@ static int sysrq_key_table_key2index(int key) retval = key - '0'; else if ((key >= 'a') && (key <= 'z')) retval = key + 10 - 'a'; + else if ((key >= 'A') && (key <= 'Z')) + retval = key + 36 - 'A'; else retval = -1; return retval; @@ -623,6 +651,8 @@ struct sysrq_state { unsigned long key_down[BITS_TO_LONGS(KEY_CNT)]; unsigned int alt; unsigned int alt_use; + unsigned int shift; + unsigned int shift_use; bool active; bool need_reinject; bool reinjecting; @@ -807,10 +837,20 @@ static bool sysrq_handle_keypress(struct sysrq_state *sysrq, } break; + case KEY_LEFTSHIFT: + case KEY_RIGHTSHIFT: + if (!value) + sysrq->shift = KEY_RESERVED; + else if (value != 2) + sysrq->shift = code; + break; + case KEY_SYSRQ: if (value == 1 && sysrq->alt != KEY_RESERVED) { sysrq->active = true; sysrq->alt_use = sysrq->alt; + /* either RESERVED (for released) or actual code */ + sysrq->shift_use = sysrq->shift; /* * If nothing else will be pressed we'll need * to re-inject Alt-SysRq keysroke. @@ -833,8 +873,13 @@ static bool sysrq_handle_keypress(struct sysrq_state *sysrq, default: if (sysrq->active && value && value != 2) { + unsigned char c = sysrq_xlate[code]; + sysrq->need_reinject = false; - __handle_sysrq(sysrq_xlate[code], true); + if (sysrq->shift_use != KEY_RESERVED) + if (c >= 'a' && c <= 'z') + c &= ~(1 << 5); /* to uppercase */ + __handle_sysrq(c, true); } break; } From patchwork Tue Aug 4 16:24:02 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrzej Pietrasiewicz X-Patchwork-Id: 11700623 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 2AC426C1 for ; Tue, 4 Aug 2020 16:24:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3230F2177B for ; Tue, 4 Aug 2020 16:24:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729898AbgHDQYY (ORCPT ); Tue, 4 Aug 2020 12:24:24 -0400 Received: from bhuna.collabora.co.uk ([46.235.227.227]:34188 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729884AbgHDQYL (ORCPT ); Tue, 4 Aug 2020 12:24:11 -0400 Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: andrzej.p) with ESMTPSA id 51D2C2950FD From: Andrzej Pietrasiewicz To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , Jiri Slaby , Dmitry Torokhov , Andrzej Pietrasiewicz , linux-input@vger.kernel.org, kernel@collabora.com Subject: [PATCH 2/2] tty/sysrq: Add configurable handler to execute a compound action Date: Tue, 4 Aug 2020 18:24:02 +0200 Message-Id: <20200804162402.2087-3-andrzej.p@collabora.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200804162402.2087-1-andrzej.p@collabora.com> References: <20200804162402.2087-1-andrzej.p@collabora.com> Sender: linux-input-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-input@vger.kernel.org Userland might want to execute e.g. 'w' (show blocked tasks), followed by 's' (sync), followed by 1000 ms delay and then followed by 'c' (crash) upon a single magic SysRq. Or one might want to execute the famous "Raising Elephants Is So Utterly Boring" action. This patch adds a configurable handler, triggered with 'C', for this exact purpose. The user specifies the composition of the compound action using syntax similar to getopt, where each letter corresponds to an individual action and a colon followed by a number corresponds to a delay of that many milliseconds, e.g.: ws:1000c or r:100eis:1000ub Signed-off-by: Andrzej Pietrasiewicz Reported-by: kernel test robot --- Documentation/admin-guide/sysrq.rst | 9 ++++ drivers/tty/sysrq.c | 81 ++++++++++++++++++++++++++++- include/linux/sysrq.h | 1 + 3 files changed, 90 insertions(+), 1 deletion(-) diff --git a/Documentation/admin-guide/sysrq.rst b/Documentation/admin-guide/sysrq.rst index 67dfa4c29093..80bdd8bf9636 100644 --- a/Documentation/admin-guide/sysrq.rst +++ b/Documentation/admin-guide/sysrq.rst @@ -32,6 +32,7 @@ to 1. Here is the list of possible values in /proc/sys/kernel/sysrq: 64 = 0x40 - enable signalling of processes (term, kill, oom-kill) 128 = 0x80 - allow reboot/poweroff 256 = 0x100 - allow nicing of all RT tasks + 512 = 0x200 - allow compound action You can set the value in the file by the following command:: @@ -148,6 +149,14 @@ Command Function ``z`` Dump the ftrace buffer +``C`` Execute a predefined, compound action. The action is defined with + sysrq.sysrq_compound_action module parameter, whose value contains known + command keys (except ``C`` to prevent recursion). The command keys can + be optionally followed by a colon and a number of milliseconds to wait + after executing the last action. For example: + + sysrq.sysrq_compound_action=r:100eis:1000ub + ``0``-``9`` Sets the console log level, controlling which kernel messages will be printed to your console. (``0``, for example would make it so that only emergency messages like PANICs or OOPSes would diff --git a/drivers/tty/sysrq.c b/drivers/tty/sysrq.c index 52e344bfe8c0..ffcda1316675 100644 --- a/drivers/tty/sysrq.c +++ b/drivers/tty/sysrq.c @@ -19,6 +19,7 @@ #include #include #include +#include #include #include #include @@ -439,6 +440,15 @@ static const struct sysrq_key_op sysrq_unrt_op = { .enable_mask = SYSRQ_ENABLE_RTNICE, }; +static void sysrq_action_compound(int key); + +static struct sysrq_key_op sysrq_action_compound_op = { + .handler = sysrq_action_compound, + .help_msg = "execute-compound-action(C)", + .action_msg = "Execute compound action", + .enable_mask = SYSRQ_ENABLE_COMPOUND, +}; + /* Key Operations table and lock */ static DEFINE_SPINLOCK(sysrq_key_table_lock); @@ -501,7 +511,7 @@ static const struct sysrq_key_op *sysrq_key_table[62] = { &sysrq_ftrace_dump_op, /* z */ NULL, /* A */ NULL, /* B */ - NULL, /* C */ + &sysrq_action_compound_op, /* C */ NULL, /* D */ NULL, /* E */ NULL, /* F */ @@ -634,6 +644,7 @@ EXPORT_SYMBOL(handle_sysrq); #ifdef CONFIG_INPUT static int sysrq_reset_downtime_ms; +static char *sysrq_compound_action; /* Simple translation table for the SysRq keys */ static const unsigned char sysrq_xlate[KEY_CNT] = @@ -787,6 +798,61 @@ static void sysrq_of_get_keyreset_config(void) { } #endif +#define SYSRQ_COMPOUND_ACTION_VALIDATE 0 +#define SYSRQ_COMPOUND_ACTION_RUN 1 + +static int sysrq_process_compound_action(int pass) +{ + const char *action = sysrq_compound_action; + const struct sysrq_key_op *op_p; + int ret, delay; + + while (*action) { + op_p = __sysrq_get_key_op(*action); + if (!op_p) + return -EINVAL; + + /* Don't allow calling ourselves recursively */ + if (op_p == &sysrq_action_compound_op) + return -EINVAL; + + if (pass == SYSRQ_COMPOUND_ACTION_RUN) + __handle_sysrq(*action, false); + + if (*++action == ':') { + ret = sscanf(action++, ":%d", &delay); + if (ret < 1) /* we want at least ":[0-9]" => 1 item */ + return -EINVAL; + + while (*action >= '0' && *action <= '9') + ++action; + if (pass == SYSRQ_COMPOUND_ACTION_RUN) + mdelay(delay); + } + } + + return 0; +} + +static void sysrq_action_compound(int key) +{ + if (!sysrq_compound_action) { + pr_err("Unconfigured compound action for %s", + sysrq_action_compound_op.help_msg); + + return; + } + + if (sysrq_process_compound_action(SYSRQ_COMPOUND_ACTION_VALIDATE)) { + pr_err("Incorrect compound action %s for %s", + sysrq_compound_action, + sysrq_action_compound_op.help_msg); + + return; + } + + sysrq_process_compound_action(SYSRQ_COMPOUND_ACTION_RUN); +} static void sysrq_reinject_alt_sysrq(struct work_struct *work) { @@ -1079,8 +1145,21 @@ module_param_array_named(reset_seq, sysrq_reset_seq, sysrq_reset_seq, module_param_named(sysrq_downtime_ms, sysrq_reset_downtime_ms, int, 0644); +module_param(sysrq_compound_action, charp, 0644); +MODULE_PARM_DESC(sysrq_compound_action, + "Compound sysrq action to be executed on Alt-Shift-SysRq-C\n" + "The compound action definition consists of known SysRq action letters except 'C',\n" + "each letter can be optionally followed by a colon and a number of milliseconds to wait\n" + "after executing the last action.\n" + "Example:\n" + "To unRaw, wait 100ms, tErminate, kIll, Sync, wait 1000ms, Unmount, Boot\n" + "sysrq.sysrq_compound_action=r:100eis:1000ub"); #else +{ +} + +static void sysrq_action_compound(int key) static inline void sysrq_register_handler(void) { } diff --git a/include/linux/sysrq.h b/include/linux/sysrq.h index 3a582ec7a2f1..6df4442f12a9 100644 --- a/include/linux/sysrq.h +++ b/include/linux/sysrq.h @@ -28,6 +28,7 @@ #define SYSRQ_ENABLE_SIGNAL 0x0040 #define SYSRQ_ENABLE_BOOT 0x0080 #define SYSRQ_ENABLE_RTNICE 0x0100 +#define SYSRQ_ENABLE_COMPOUND 0x0200 struct sysrq_key_op { void (* const handler)(int);