From patchwork Mon May 16 22:56:27 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jim Cromie X-Patchwork-Id: 12851586 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 57B08C433F5 for ; Mon, 16 May 2022 22:57:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1350003AbiEPW5h (ORCPT ); Mon, 16 May 2022 18:57:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50384 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1349913AbiEPW50 (ORCPT ); Mon, 16 May 2022 18:57:26 -0400 Received: from mail-il1-x12b.google.com (mail-il1-x12b.google.com [IPv6:2607:f8b0:4864:20::12b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CEBFB45ADD; Mon, 16 May 2022 15:57:18 -0700 (PDT) Received: by mail-il1-x12b.google.com with SMTP id f9so1821295ils.7; Mon, 16 May 2022 15:57:18 -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=4+OOX1OvjkZsN3TSD9RgwwVgcTBaI2m+uT5AbHUS6m0=; b=Fo7YXOf/0vFpkLY8Uk/yY0nT5SmPi5y3dHrHluxiH+jPSSKgG/p1Gz5zK7Vu5n6UxZ adpJHsxKhBbt1AKuP/901DivHo+vHYALOYRgk1qIRa516KCkldDX94eJ7bs7maLShCvL yXLtI4UQzjqwM/jdu7hPJ/Fa8PKfjUkEUkZVEHTUCxZs7L2OQhpyIvljd/WT3ti+Vcb5 jIyuq0xWDkawREPHWBdqqDjrcGo4i4IDSorHGgRDzfopEesYDc1Y563hH+6Si+9YntGB GOGkbE2mJ32gkdmtkIWrgfkvMltVXBVQh4IvArvSY61UnBULbKT1PiPUYwzrahZpFEuZ 6aXA== 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=4+OOX1OvjkZsN3TSD9RgwwVgcTBaI2m+uT5AbHUS6m0=; b=j5AWnH/TY7EFcMjZ5t0orXtrkFGEWqqQoqaCXI24bKuRFAgX0/K2E695mTHt5AYbIm OBbFW2f83H9TKV1T9Gp15oVp9GbAaaPw7nF1MoXPg1FZVmC/uN1IvWP4oD7U68BWv2VR AWKSXJiwa0PnSlnbnhqsYbox+FlkmZp0DwU19/OEcruQZ16Efwp76sjMMWDq9ltgawCi iX5Cl0v3f6j/VbrYk2e3bE8oUn5kNVRJrG5gYhcS0Nu6gihulg0/slY7u9L3AMFAdeXX WJK+k2Al6uw/XFWTbCr9vDI1CUPwRogEneFm2xnzFVwF1oNR5cfHQQNsDIILyoerV18F hCsQ== X-Gm-Message-State: AOAM533hNT9GavVtHCM4JQBAcgtzGFZHjgVLXudQNSk3qQLrj34S6Gez fqVY0j4I8ufHzBNIej8t0fo= X-Google-Smtp-Source: ABdhPJxiH2HWdFdauTnvGpj4Rme8nnchoUQHFiTC7tx6lbGdrSpdRV5tZOHEmwpDAUNac856y9edUg== X-Received: by 2002:a05:6e02:1c4a:b0:2d1:183e:4ce0 with SMTP id d10-20020a056e021c4a00b002d1183e4ce0mr4908778ilg.150.1652741837929; Mon, 16 May 2022 15:57:17 -0700 (PDT) Received: from frodo.hsd1.co.comcast.net ([2601:284:8204:2010::dd9f]) by smtp.googlemail.com with ESMTPSA id k26-20020a02661a000000b0032b74686763sm3133949jac.76.2022.05.16.15.57.16 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 16 May 2022 15:57:17 -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 14/27] dyndbg: add test_dynamic_debug module Date: Mon, 16 May 2022 16:56:27 -0600 Message-Id: <20220516225640.3102269-15-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 Demonstrate dyndbg's "class FOO" and bitmap-to-classes support. This support is meant to plug into drm.debug system, and largely replace the use of drm_debug_enabled(category) with JUMP_LABELs. Recap: #> echo class DRM_UT_CORE +p > /proc/dynamic_debug/control This is made "safe" because dyndbg skips it for any modules which don't know that class (havent called dynamic_debug_register_classes). Other modules may use the same .class_id for a separate classified debug scheme. Use the API: - DYNAMIC_DEBUG_CLASSES(_var, classes), to declare static _var by name - dynamic_debug_register_classes(_var) - dynamic_debug_unregister_classes(_var) Use these 3 times; with base = 0,8,16 respectively, to demonstrate the segmenting of the module's .class_id range [0..30] For each of those 3 class-name-sets, add 2 sysfs-node-bitmaps, one each for p-syslog, and T-tracefs, the latter will work once dyndbg gets that patchset. #> modprobe test_dynamic_debug dyndbg=+pfm #> cat /sys/module/test_dynamic_debug/parameters/do_prints #> echo class FOO +pf > /proc/dynamic_debug/control #> echo class Foo +pfm > /proc/dynamic_debug/control #> cat /sys/module/test_dynamic_debug/parameters/do_prints RFC: This use case exposes a weak point in the api; the 2nd query command given in the dyndbg option will not work like the 1st: #> modprobe test_dynamic_debug dyndbg='+pfm; class FOO +pfm' This is because the option is processed early in module-load, well before the registration can attach the class-map to the module's ddebug_table entry. Signed-off-by: Jim Cromie --- MAINTAINERS | 1 + lib/Kconfig.debug | 11 +++ lib/Makefile | 1 + lib/test_dynamic_debug.c | 172 +++++++++++++++++++++++++++++++++++++++ 4 files changed, 185 insertions(+) create mode 100644 lib/test_dynamic_debug.c diff --git a/MAINTAINERS b/MAINTAINERS index e8c52d0192a6..bf615853be47 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -6918,6 +6918,7 @@ M: Jason Baron S: Maintained F: include/linux/dynamic_debug.h F: lib/dynamic_debug.c +F: lib/test_dynamic_debug.c DYNAMIC INTERRUPT MODERATION M: Tal Gilboa diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 075cd25363ac..c88d691d3df1 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -2601,6 +2601,17 @@ config TEST_STATIC_KEYS If unsure, say N. +config TEST_DYNAMIC_DEBUG + tristate "Test DYNAMIC_DEBUG" + depends on m + depends on DYNAMIC_DEBUG + help + This module registers a tracer callback to count enabled + pr_debugs in a 'do_debugging' function, then alters their + enablements, calls the function, and compares counts. + + If unsure, say N. + config TEST_KMOD tristate "kmod stress tester" depends on m diff --git a/lib/Makefile b/lib/Makefile index 6b9ffc1bd1ee..e5727fbbfc7d 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -82,6 +82,7 @@ obj-$(CONFIG_TEST_SORT) += test_sort.o obj-$(CONFIG_TEST_USER_COPY) += test_user_copy.o obj-$(CONFIG_TEST_STATIC_KEYS) += test_static_keys.o obj-$(CONFIG_TEST_STATIC_KEYS) += test_static_key_base.o +obj-$(CONFIG_TEST_DYNAMIC_DEBUG) += test_dynamic_debug.o obj-$(CONFIG_TEST_PRINTF) += test_printf.o obj-$(CONFIG_TEST_SCANF) += test_scanf.o obj-$(CONFIG_TEST_BITMAP) += test_bitmap.o diff --git a/lib/test_dynamic_debug.c b/lib/test_dynamic_debug.c new file mode 100644 index 000000000000..65c37ba6c0da --- /dev/null +++ b/lib/test_dynamic_debug.c @@ -0,0 +1,172 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Kernel module for testing dynamic_debug + * + * Authors: + * Jim Cromie + */ + +#define pr_fmt(fmt) "test_dd: " fmt + +#include + +static void do_prints(void); /* device under test */ + +/* run tests by reading or writing sysfs node */ + +int param_set_do_prints(const char *instr, const struct kernel_param *kp) +{ + do_prints(); + return 0; +} +EXPORT_SYMBOL(param_set_do_prints); + +int param_get_do_prints(char *buffer, const struct kernel_param *kp) +{ + do_prints(); + return scnprintf(buffer, PAGE_SIZE, "did do_prints\n"); +} +EXPORT_SYMBOL(param_get_do_prints); + +const struct kernel_param_ops param_ops_do_prints = { + .set = param_set_do_prints, + .get = param_get_do_prints, +}; +EXPORT_SYMBOL(param_ops_do_prints); + +module_param_cb(do_prints, ¶m_ops_do_prints, NULL, 0600); + +/* + * Declare 3 groups of classes, with different .class_id[] ranges, + * each with 2 sysfs-node bitmaps controlling p,T flags respectively + * for those named classes. This example is rather more involved than + * anyone will likely use. + + * The T-bitmap sysfs-node functionality will need a few patches which + * add trace-events to dyndbg. + + * Rules: + * - enum symbols must match/correlate with class-name strings + * - base must equal enum's 1st value + */ + +enum cat1 { FOO, BAR, BUZZ }; +DYNAMIC_DEBUG_CLASSES(ddt_classes1, 0, + "FOO", "BAR", "BUZZ"); + +unsigned long bits_1p, bits_1t; +EXPORT_SYMBOL(bits_1p); +EXPORT_SYMBOL(bits_1t); + +static struct ddebug_classes_bitmap_param p1_bitmap = { + .bits = &bits_1p, + .flags = "p", + .map = &ddt_classes1 +}; +module_param_cb(c1_syslog_bits, ¶m_ops_dyndbg_classes, &p1_bitmap, 0600); + +static struct ddebug_classes_bitmap_param t1_bitmap = { + .bits = &bits_1t, + .flags = "T", + .map = &ddt_classes1 +}; +module_param_cb(c1_trace_bits, ¶m_ops_dyndbg_classes, &t1_bitmap, 0600); + + +enum cat2 { Foo = 8, Bar, Buzz }; +DYNAMIC_DEBUG_CLASSES(ddt_classes2, 8, + "Foo", "Bar", "Buzz"); + +unsigned long bits_2p, bits_2t; +EXPORT_SYMBOL(bits_2p); +EXPORT_SYMBOL(bits_2t); + +static struct ddebug_classes_bitmap_param p2_bitmap = { + .bits = &bits_2p, + .flags = "p", + .map = &ddt_classes2 +}; +module_param_cb(c2_syslog_bits, ¶m_ops_dyndbg_classes, &p2_bitmap, 0600); + +static struct ddebug_classes_bitmap_param t2_bitmap = { + .bits = &bits_2t, + .flags = "T", + .map = &ddt_classes2 +}; +module_param_cb(c2_trace_bits, ¶m_ops_dyndbg_classes, &t2_bitmap, 0600); + + +enum cat3 { bing = 16, bong, boom }; +DYNAMIC_DEBUG_CLASSES(ddt_classes3, 16, + "bing", "bong", "boom"); + +unsigned long bits_3p, bits_3t; +EXPORT_SYMBOL(bits_3p); +EXPORT_SYMBOL(bits_3t); + +static struct ddebug_classes_bitmap_param p3_bitmap = { + .bits = &bits_3p, + .flags = "p", + .map = &ddt_classes3 +}; +module_param_cb(c3_syslog_bits, ¶m_ops_dyndbg_classes, &p3_bitmap, 0600); + +static struct ddebug_classes_bitmap_param t3_bitmap = { + .bits = &bits_3t, + .flags = "T", + .map = &ddt_classes3 +}; +module_param_cb(c3_trace_bits, ¶m_ops_dyndbg_classes, &t3_bitmap, 0600); + +static void do_prints(void) +{ + /* raw integer classes */ + __pr_debug_cls(0, "class 0"); + __pr_debug_cls(1, "class 1"); + __pr_debug_cls(2, "class 2"); + + /* enum ints */ + __pr_debug_cls(FOO, "class FOO"); + __pr_debug_cls(BAR, "class BAR"); + __pr_debug_cls(BUZZ, "class BUZZ"); + + __pr_debug_cls(Foo, "class Foo"); + __pr_debug_cls(Bar, "class Bar"); + __pr_debug_cls(Buzz, "class Buzz"); + + __pr_debug_cls(bing, "class bing"); + __pr_debug_cls(bong, "class bong"); + __pr_debug_cls(boom, "class boom"); +} + +static int __init test_dynamic_debug_init(void) +{ + pr_debug("module-init\n"); + /* + * these are too late to enable class FOO at module load time: + * #> modprobe test_dynamic_debug dyndbg='class FOO +p' + */ + dynamic_debug_register_classes(&ddt_classes1); + dynamic_debug_register_classes(&ddt_classes2); + dynamic_debug_register_classes(&ddt_classes3); + + do_prints(); + + pr_debug("module-init done\n"); + return 0; +} + +static void __exit test_dynamic_debug_exit(void) +{ + dynamic_debug_unregister_classes(&ddt_classes1); + dynamic_debug_unregister_classes(&ddt_classes2); + dynamic_debug_unregister_classes(&ddt_classes3); + + pr_debug("module-exit\n"); +} + +module_init(test_dynamic_debug_init); +module_exit(test_dynamic_debug_exit); + +MODULE_AUTHOR("Jim Cromie "); +MODULE_LICENSE("GPL");