From patchwork Fri Dec 17 14:41:17 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anders Roxell X-Patchwork-Id: 12684843 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 E9E24C4332F for ; Fri, 17 Dec 2021 14:41:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237474AbhLQOlo (ORCPT ); Fri, 17 Dec 2021 09:41:44 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45364 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237451AbhLQOlf (ORCPT ); Fri, 17 Dec 2021 09:41:35 -0500 Received: from mail-ed1-x52e.google.com (mail-ed1-x52e.google.com [IPv6:2a00:1450:4864:20::52e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 90942C061756 for ; Fri, 17 Dec 2021 06:41:34 -0800 (PST) Received: by mail-ed1-x52e.google.com with SMTP id b7so8651936edd.6 for ; Fri, 17 Dec 2021 06:41:34 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=YtXzvh0C6WiWca/wi/qfYHW/5QpcMjxHI9YNhLAWuJ0=; b=Z5ZRrmxwSJv9i19fPSkPWScIrN4tJBVTD5Er/ou2k9ZfJbuqbPWdF0gB+PYhYh83cs 5TCqk+2oZdFe+S3/0evA0R3hOmhwoDopVdaZBhTEMTAJpL2jXWW3IMZPZAxxTFY6S7u/ cPMwtote0l2lYQVFo5IRKzVDdo08mtzkYJdkQEIO+kF9froty6srsvbSDovwuGCC4ibm iiF6JInTkfPm4f3XwtZ205yhv9/doP5v3OFIwEnmsWZiu8uEWM0HrUJ2/RjcHJ9FG5XH btGf5ySG+s1sdl43Ooa2e2jLF7wFgnCJJTWuJHIJjNUz/lJYsfCtCovNBNwb4NXPdys+ NSWg== 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=YtXzvh0C6WiWca/wi/qfYHW/5QpcMjxHI9YNhLAWuJ0=; b=FJr22JuRnySraByYR7h2WEOP9WMs7Q095XjKfUBPCsCaNquqKcNmSNLadn2DEz7M7/ ZEr5TwpVUyIVClR5UHaIZpQyY0JxGKs41p8gm8pcQDCBNzLEOA+/eaBlu7rcTsGlnJyl nMCVkpC5MbCOd0yaGu1or5xQGNHBoGBTjXEiaC+M5l8qviez6jpdhUpqLVR/cXTfW8cg YfuhX74DP15+Ylg3eJb83I8J+2l4YYzXL9FBN9oall0T4J7GzwZ6FDO4kv/q4yEbsbF9 sGElu5XL1Io7hsZhJqIeINRQtoOgHYv4JOr8qSHXblwKRZPZKtHawKdWGJ3/jAhINtN5 gCWA== X-Gm-Message-State: AOAM532AuK4IhFS4In8R4N0j9fCfSJ6ZSf+K/FyiiB3QHhD2UG/0XP5K jFweDyrZ+HaWNnnKmTk4nRDk5g== X-Google-Smtp-Source: ABdhPJwE5DG1GPBbARyfTn2B2dT+ezPQUD+vIyLEwqxURyDd3r3xXCtCoRncy6rsxZvxSAb+TFQ4oA== X-Received: by 2002:a05:6402:c8:: with SMTP id i8mr3113551edu.183.1639752093143; Fri, 17 Dec 2021 06:41:33 -0800 (PST) Received: from localhost (c-9b28e555.07-21-73746f28.bbcust.telenor.se. [85.229.40.155]) by smtp.gmail.com with ESMTPSA id gn26sm2942234ejc.14.2021.12.17.06.41.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 17 Dec 2021 06:41:32 -0800 (PST) From: Anders Roxell To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, woojung.huh@microchip.com, UNGLinuxDriver@microchip.com, davem@davemloft.net, netdev@vger.kernel.org, linux-usb@vger.kernel.org, clang-built-linux@googlegroups.com, ulli.kroll@googlemail.com, linux@armlinux.org.uk, linux-arm-kernel@lists.infradead.org, amitkarwar@gmail.com, nishants@marvell.com, gbhat@marvell.com, huxinming820@gmail.com, kvalo@codeaurora.org, linux-wireless@vger.kernel.org, rostedt@goodmis.org, mingo@redhat.com, dmitry.torokhov@gmail.com, ndesaulniers@google.com, nathan@kernel.org, linux-input@vger.kernel.org, Stefan Agner , Arnd Bergmann , Russell King , Anders Roxell Subject: [PATCH 4.19 4/6] ARM: 8800/1: use choice for kernel unwinders Date: Fri, 17 Dec 2021 15:41:17 +0100 Message-Id: <20211217144119.2538175-5-anders.roxell@linaro.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20211217144119.2538175-1-anders.roxell@linaro.org> References: <20211217144119.2538175-1-anders.roxell@linaro.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org From: Stefan Agner commit f9b58e8c7d031b0daa5c9a9ee27f5a4028ba53ac upstream. While in theory multiple unwinders could be compiled in, it does not make sense in practise. Use a choice to make the unwinder selection mutually exclusive and mandatory. Already before this commit it has not been possible to deselect FRAME_POINTER. Remove the obsolete comment. Furthermore, to produce a meaningful backtrace with FRAME_POINTER enabled the kernel needs a specific function prologue: mov ip, sp stmfd sp!, {fp, ip, lr, pc} sub fp, ip, #4 To get to the required prologue gcc uses apcs and no-sched-prolog. This compiler options are not available on clang, and clang is not able to generate the required prologue. Make the FRAME_POINTER config symbol depending on !clang. Suggested-by: Arnd Bergmann Signed-off-by: Stefan Agner Reviewed-by: Arnd Bergmann Signed-off-by: Russell King Signed-off-by: Anders Roxell --- arch/arm/Kconfig.debug | 44 +++++++++++++++++++++++++++--------------- lib/Kconfig.debug | 6 +++--- 2 files changed, 31 insertions(+), 19 deletions(-) diff --git a/arch/arm/Kconfig.debug b/arch/arm/Kconfig.debug index bee0ba1d1cfb..01c760929c9e 100644 --- a/arch/arm/Kconfig.debug +++ b/arch/arm/Kconfig.debug @@ -45,30 +45,42 @@ config DEBUG_WX If in doubt, say "Y". -# RMK wants arm kernels compiled with frame pointers or stack unwinding. -# If you know what you are doing and are willing to live without stack -# traces, you can get a slightly smaller kernel by setting this option to -# n, but then RMK will have to kill you ;). -config FRAME_POINTER - bool - depends on !THUMB2_KERNEL - default y if !ARM_UNWIND || FUNCTION_GRAPH_TRACER +choice + prompt "Choose kernel unwinder" + default UNWINDER_ARM if AEABI && !FUNCTION_GRAPH_TRACER + default UNWINDER_FRAME_POINTER if !AEABI || FUNCTION_GRAPH_TRACER + help + This determines which method will be used for unwinding kernel stack + traces for panics, oopses, bugs, warnings, perf, /proc//stack, + livepatch, lockdep, and more. + +config UNWINDER_FRAME_POINTER + bool "Frame pointer unwinder" + depends on !THUMB2_KERNEL && !CC_IS_CLANG + select ARCH_WANT_FRAME_POINTERS + select FRAME_POINTER help - If you say N here, the resulting kernel will be slightly smaller and - faster. However, if neither FRAME_POINTER nor ARM_UNWIND are enabled, - when a problem occurs with the kernel, the information that is - reported is severely limited. + This option enables the frame pointer unwinder for unwinding + kernel stack traces. -config ARM_UNWIND - bool "Enable stack unwinding support (EXPERIMENTAL)" +config UNWINDER_ARM + bool "ARM EABI stack unwinder" depends on AEABI - default y + select ARM_UNWIND help This option enables stack unwinding support in the kernel using the information automatically generated by the compiler. The resulting kernel image is slightly bigger but the performance is not affected. Currently, this feature - only works with EABI compilers. If unsure say Y. + only works with EABI compilers. + +endchoice + +config ARM_UNWIND + bool + +config FRAME_POINTER + bool config OLD_MCOUNT bool diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 6970759f296c..621859a453f8 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1178,7 +1178,7 @@ config LOCKDEP bool depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT select STACKTRACE - select FRAME_POINTER if !MIPS && !PPC && !ARM_UNWIND && !S390 && !MICROBLAZE && !ARC && !X86 + select FRAME_POINTER if !MIPS && !PPC && !ARM && !S390 && !MICROBLAZE && !ARC && !X86 select KALLSYMS select KALLSYMS_ALL @@ -1589,7 +1589,7 @@ config FAULT_INJECTION_STACKTRACE_FILTER depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT depends on !X86_64 select STACKTRACE - select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM_UNWIND && !ARC && !X86 + select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM && !ARC && !X86 help Provide stacktrace filter for fault-injection capabilities @@ -1598,7 +1598,7 @@ config LATENCYTOP depends on DEBUG_KERNEL depends on STACKTRACE_SUPPORT depends on PROC_FS - select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM_UNWIND && !ARC && !X86 + select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM && !ARC && !X86 select KALLSYMS select KALLSYMS_ALL select STACKTRACE