From patchwork Mon May 16 22:56:19 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jim Cromie X-Patchwork-Id: 573508 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 25166C433F5 for ; Mon, 16 May 2022 22:57:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345542AbiEPW5n (ORCPT ); Mon, 16 May 2022 18:57:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50158 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1349904AbiEPW5V (ORCPT ); Mon, 16 May 2022 18:57:21 -0400 Received: from mail-il1-x129.google.com (mail-il1-x129.google.com [IPv6:2607:f8b0:4864:20::129]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 19A2342EE8; Mon, 16 May 2022 15:57:08 -0700 (PDT) Received: by mail-il1-x129.google.com with SMTP id b11so7613047ilr.4; Mon, 16 May 2022 15:57:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=FCcwbojewkLsQYvkUKvi9ZnuSdibkB/9h3rl9AlklQ0=; b=BeGrZc1yYBGXRQAvCajroJY45Q74LlURa0Ayje5jv28R3leJsPJbbYx/29IHtflt0j snhm4cXg8IF3NJ9cpM7XtI9fLxm4NYgdEPjk4txQ8yQVjk2+O7jljjqETHuZUwtJDsm5 xWAXYRuk38aNOHxOcKllwLmeH+zvd7FACklgZhNSsZ79osTKBjvhiXgVclwoZqc2bpjE yelTlxzX/Ql/41MYJXeVU+/+QDchf/5JfDBfBDt4HwmxBYj1dPE0ut/Ixz0jldDIZRKo 1zhjm7O4XnQNVRj1apdu3bYwT5J19T4lgLOKFIY25c2+q1MCCblGLIfqkzd5MTcbODwR soNw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=FCcwbojewkLsQYvkUKvi9ZnuSdibkB/9h3rl9AlklQ0=; b=jK6QbjJ/j/nMeW5SVFXvgBaP8+7vzP42QNawoPIfvLusojRIUmOdyOk5ouCndmOgMw smxrVJQdsy7rOMycFbwFeAXSdUrl8LeZN0oj8FeqdOyTeAiPzMHb+uARdsoe7cPWlvjU Jo8mq5H5YZCb32d7t1NoG5siruWQ6Q9qxtbtAXrIwOOFr8P+TfqvBZ4VJyi+4WaRYhUe F/GWHcwSOD8qoJQKswRQ/TwJsdG7fhaFOVkt5c9ysEXmlRBbS4yfeZ7lDA690pytJpEN SfXvv34KQgBiy98y6K+W7Glhd6/gLCsoNjxe6DZ0iR7DejO4GGnerhnvJi2RoLxkRxkR 8hZw== X-Gm-Message-State: AOAM5326V66hazUGCWqgUb0QAAP8gpKNkMPOA+Xu95n/AS83bd6rvvSm ltvrMOWstS6RK8htfHLk+ns= X-Google-Smtp-Source: ABdhPJxVb768sz14W3aG69KflgqJ0KKyFVj6N0LZ3gnkCyX1Snc1VgNcUxaQiUqGSGOvtt6QMgsJEA== X-Received: by 2002:a05:6e02:1187:b0:2cd:9df5:bfd2 with SMTP id y7-20020a056e02118700b002cd9df5bfd2mr11169744ili.121.1652741827704; Mon, 16 May 2022 15:57:07 -0700 (PDT) Received: from frodo.hsd1.co.comcast.net ([2601:284:8204:2010::dd9f]) by smtp.googlemail.com with ESMTPSA id k26-20020a02661a000000b0032b74686763sm3133949jac.76.2022.05.16.15.57.06 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 16 May 2022 15:57:07 -0700 (PDT) From: Jim Cromie To: jbaron@akamai.com, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, amd-gfx@lists.freedesktop.org, intel-gvt-dev@lists.freedesktop.org, intel-gfx@lists.freedesktop.org Cc: gregkh@linuxfoundation.org, daniel.vetter@ffwll.ch, seanpaul@chromium.org, robdclark@gmail.com, rostedt@goodmis.org, mathieu.desnoyers@efficios.com, quic_saipraka@quicinc.com, will@kernel.org, catalin.marinas@arm.com, quic_psodagud@quicinc.com, maz@kernel.org, arnd@arndb.de, linux-arm-kernel@lists.infradead.org, linux-arm-msm@vger.kernel.org, mingo@redhat.com, jim.cromie@gmail.com Subject: [PATCH v2 06/27] dyndbg: add dynamic_debug_(un)register_classes Date: Mon, 16 May 2022 16:56:19 -0600 Message-Id: <20220516225640.3102269-7-jim.cromie@gmail.com> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20220516225640.3102269-1-jim.cromie@gmail.com> References: <20220516225640.3102269-1-jim.cromie@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org Add dynamic_debug_register_classes() to API, allowing user modules (builtin and loadable) to register class_names for the .class_id's they are using. Knowing classes is 1st step to validating with them. Add dynamic_debug_unregister_classes() also. Add struct ddebug_known_classes_map: maps known class_name strings to .class_id[0..N], where N<31. .base allows sharing of that range. A wrapper macro: DYNAMIC_DEBUG_CLASSES(_var, _modmatch, _base, classes) defines and initializes that struct var, _maybe_unused is added so the decl doesn't draw warnings when dyndbg is not enabled; a small list of classnames is tolerable wasted space. _var: user passes this into dynamic_debug_register_classes(var). _base: usually 0, it allows splitting 31 classes into subranges, so that multiple sysfs-nodes can share the module's class-id space. classes: list of strings with classnames, mapped to class-id=idx(+_base) mod_name: KBUILD_MODNAME, available for builtins, loadables mod: ref to loadable module. allows ==, distinguishing loadables. When modules register known classnames, they opt-in to permit dyndbg to allow "class " queries to manipulate their class'd pr_debugs (if any), default class_id pr_debugs are still controllable as before. dynamic_debug_register_classes(&map) finds the module's ddebug_table record, and attaches the map to it. This makes it available to ddebug_change(), which will use it to validate class'd commands. Sharing class-names across multiple modules is how those modules coordinate; all drm* and drivers would respond to: #> echo class DRM_UT_CORE +p > /proc/dynamic_debug/control Therefore no class-name uniqueness check is useful. TODO: Eventually we need a list of registered classes, not just the zero-or-one implemented here. This will support multiple sysfs-nodes, one each for print-to-syslog, print-to-tracefs, or subranges using _base. Signed-off-by: Jim Cromie --- . fix register_classes() for !CONFIG_MODULES . add maybe-unused to var decl in DYNAMIC_DEBUG_CLASSES . kdoc for DYNAMIC_DEBUG_CLASSES . add dynamic_debug_unregister_classes --- include/linux/dynamic_debug.h | 36 ++++++++++++++++++++++++ lib/dynamic_debug.c | 53 +++++++++++++++++++++++++++++++++++ 2 files changed, 89 insertions(+) diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h index 39550fefcf0f..328722ba2d8e 100644 --- a/include/linux/dynamic_debug.h +++ b/include/linux/dynamic_debug.h @@ -56,6 +56,34 @@ struct _ddebug { #endif } __attribute__((aligned(8))); +struct ddebug_known_classes_map { + struct list_head link; + struct module *mod; + const char *mod_name; /* needed for builtins */ + const int base; /* index of 1st .class_id, allows split/shared space */ + const int length; + const char *classes[]; /* index maps .class_id */ +}; + +#define NUM_TYPE_ARGS(eltype, ...) \ + (sizeof((eltype[]) {__VA_ARGS__}) / sizeof(eltype)) +/** + * DYNAMIC_DEBUG_CLASSES - declare classnames known by a module + * @_var: passed to dynamic_debug_register_classes(_var) + * @_base: offset of 1st class-name. splits .class_id space + * @classes: class-names known/used by of .class_ids[_base.._base+length] + * + * @classes specifies names for the classids used by a module; dyndbg + * accepts "class " commands if is known and registered. + */ +#define DYNAMIC_DEBUG_CLASSES(_var, _base, ...) \ + static __maybe_unused struct ddebug_known_classes_map _var = { \ + .mod = THIS_MODULE, \ + .mod_name = KBUILD_MODNAME, \ + .base = _base, \ + .length = NUM_TYPE_ARGS(char*, __VA_ARGS__), \ + .classes = { __VA_ARGS__ } \ + } #if defined(CONFIG_DYNAMIC_DEBUG_CORE) @@ -206,6 +234,9 @@ void __dynamic_ibdev_dbg(struct _ddebug *descriptor, KERN_DEBUG, prefix_str, prefix_type, \ rowsize, groupsize, buf, len, ascii) +int dynamic_debug_register_classes(struct ddebug_known_classes_map *map); +void dynamic_debug_unregister_classes(struct ddebug_known_classes_map *map); + #else /* !CONFIG_DYNAMIC_DEBUG_CORE */ #include @@ -247,6 +278,11 @@ static inline int ddebug_dyndbg_module_param_cb(char *param, char *val, } while (0) +static inline int dynamic_debug_register_classes(const struct ddebug_known_classes_map *map) +{ return 0; } +static inline void dynamic_debug_unregister_classes(struct ddebug_known_classes_map *map) +{} + #endif /* !CONFIG_DYNAMIC_DEBUG_CORE */ #endif diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c index cdc0b03b1148..8f600c13048a 100644 --- a/lib/dynamic_debug.c +++ b/lib/dynamic_debug.c @@ -45,6 +45,8 @@ extern struct _ddebug __stop___dyndbg[]; struct ddebug_table { struct list_head link; const char *mod_name; + /* a module can have multiple class-sets eventually, but not yet */ + struct ddebug_known_classes_map const *map; unsigned int num_ddebugs; struct _ddebug *ddebugs; }; @@ -916,6 +918,57 @@ static const struct proc_ops proc_fops = { .proc_write = ddebug_proc_write }; +/** + * dynamic_debug_register_classes - register a module's known classes + * @map: &struct ddebug_known_classes_map + * + * modules using non-default pr_debug.class_id's should call this to + * inform dyndbg which classes they use (0..N), and what their + * classnames are. They are then usable in ```echo $cmd >control``` + */ +int dynamic_debug_register_classes(struct ddebug_known_classes_map *map) +{ + struct ddebug_table *dt; + int rc = -ENOENT; + + mutex_lock(&ddebug_lock); +#ifdef CONFIG_MODULES + if (map->mod) { + /* loadable module */ + list_for_each_entry(dt, &ddebug_tables, link) { + if (dt->mod_name == map->mod->name) { + rc = 0; + dt->map = map; + break; + } + } + } +#endif + if (!map->mod) { + /* builtin module */ + list_for_each_entry(dt, &ddebug_tables, link) { + if (!strcmp(dt->mod_name, map->mod_name)) { + rc = 0; + dt->map = map; + break; + } + } + } + mutex_unlock(&ddebug_lock); + if (rc) + pr_warn("register_classes: module %s not found\n", map->mod_name); + else + vpr_info("register_classes: %s\n", map->mod_name); + + return rc; +} +EXPORT_SYMBOL(dynamic_debug_register_classes); + +void dynamic_debug_unregister_classes(struct ddebug_known_classes_map *map) +{ + vpr_info("unregister_classes: %s\n", map->mod_name); +} + /* * Allocate a new ddebug_table for the given module * and add it to the global list.