From nobody Tue Sep 9 12:36:05 2025 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 767DFC64EC4 for ; Tue, 21 Feb 2023 20:41:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230180AbjBUUlw (ORCPT ); Tue, 21 Feb 2023 15:41:52 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50468 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229776AbjBUUlu (ORCPT ); Tue, 21 Feb 2023 15:41:50 -0500 Received: from mail-il1-x135.google.com (mail-il1-x135.google.com [IPv6:2607:f8b0:4864:20::135]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 332612D142 for ; Tue, 21 Feb 2023 12:41:49 -0800 (PST) Received: by mail-il1-x135.google.com with SMTP id c4so2428262ilr.13 for ; Tue, 21 Feb 2023 12:41:49 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=landley-net.20210112.gappssmtp.com; s=20210112; h=content-transfer-encoding:in-reply-to:cc:references:to:from :content-language:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=ysPH6WPpk5eU7Ka5J53d3h1W3zWHMXnSdV9y5Xs+C1E=; b=Nn9ZobLLbydXkfGjLJB+NFQlDhB969riVbUYWeDqDKElp4mXynQXXexrDy0ffT6YK4 LoGUUYX6NNlTl09hrodIvLY7GmBIcceWjNAegEsFvcRev8u078caDhxO38Fv/L+i8x2/ JxMK4Ejurbuu4JhDBKiHZwSf4SKsIORadTEsSRqgcjnMpdGc6Q/Jjy7qM6nM/Ysw9EuK qOOffUrokZsXg1SCsJ2XJoEfb3S1VJMvYvU5Nc60od4WmEBrUaleGdLosuUbv8ubAj4o yViwXi1+ssBG1sK8rmQ7/bbhoULipaDOkKvjSi4bVuiwjkgjVMNqJN6SmEmclDiUuHCq AV6A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:in-reply-to:cc:references:to:from :content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=ysPH6WPpk5eU7Ka5J53d3h1W3zWHMXnSdV9y5Xs+C1E=; b=qBbqqF2BHKV6/ecYtK6/eHR/mZGQ5nhZpwl5UtlgqmMiXbiGypd/82OO4/yGLEUYyJ c6pt6Vxbs9Am2m6Nwan9gUtL0kebuKcuS9S564s754pgGnAxk+eb+XNG4Y6g0vsGUTMg +snQUidjLcZ4scKSRBBt5zfFQagN39ufCaXtwf1cR3abJZUaClyGTO6aTEKOIMY8lEqZ Zss2MZP6pxFEZnAesQrRPLHV4UPwFWei3CtZpB5kO8EysSOJ2msuMrBD8J834OS5ANDt vaPAITgdUb/k1uOq3yv2EJMI1/9miDN6jzXRGtdbHd46nLIF1wBkDMqxf95mlYipOFnP lpXg== X-Gm-Message-State: AO0yUKV1aL5zL0+dNNRLrxru+EkbnjAY6b0zrAi24nYXRHoRTC43z2It JMmK4ST3RmVOXmTIP9FK/kw+x8t8K8ZpgxCK5M8= X-Google-Smtp-Source: AK7set+m/ErfaYzUwjNelWdQ0lF2N37seZTfz5TRGJJBUqu3bDINdvRcHS7vIN3ei6Z6Q0u7jbbHlA== X-Received: by 2002:a05:6e02:20e7:b0:316:d9fa:f4fe with SMTP id q7-20020a056e0220e700b00316d9faf4femr3001680ilv.24.1677012108470; Tue, 21 Feb 2023 12:41:48 -0800 (PST) Received: from [172.16.32.78] ([198.232.126.202]) by smtp.gmail.com with ESMTPSA id d14-20020a02a48e000000b00375783003fcsm6303jam.136.2023.02.21.12.41.47 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 21 Feb 2023 12:41:48 -0800 (PST) Message-ID: <63c2936e-6bc7-67e3-eaf3-0123333381f8@landley.net> Date: Tue, 21 Feb 2023 14:55:10 -0600 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.5.0 Subject: [PATCH 1/5] try generic compiler name "cc" before falling back to "gcc". Content-Language: en-US From: Rob Landley To: "linux-kernel@vger.kernel.org" References: Cc: Masahiro Yamada , Nathan Chancellor , Nick Desaulniers , Nicolas Schier , Tom Rix , linux-kbuild@vger.kernel.org, llvm@lists.linux.dev In-Reply-To: Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Distros like debian install the generic "cc" name for both gcc and clang, and the plumbing already does CC_VERSION_TEXT to include Makefile.clang. Previously: https://lkml.iu.edu/hypermail/linux/kernel/2202.0/01505.html Signed-off-by: Rob Landley --- Makefile | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/Makefile b/Makefile index 3f6628780eb2..0ac57ae3b45f 100644 --- a/Makefile +++ b/Makefile @@ -456,7 +456,7 @@ endif HOSTCC =3D $(LLVM_PREFIX)clang$(LLVM_SUFFIX) HOSTCXX =3D $(LLVM_PREFIX)clang++$(LLVM_SUFFIX) else -HOSTCC =3D gcc +HOSTCC :=3D $(shell cc --version >/dev/null 2>&1 && echo cc || echo gcc) HOSTCXX =3D g++ endif HOSTRUSTC =3D rustc @@ -503,7 +503,8 @@ OBJDUMP =3D $(LLVM_PREFIX)llvm-objdump$(LLVM_SUFFIX) READELF =3D $(LLVM_PREFIX)llvm-readelf$(LLVM_SUFFIX) STRIP =3D $(LLVM_PREFIX)llvm-strip$(LLVM_SUFFIX) else -CC =3D $(CROSS_COMPILE)gcc +CC :=3D $(CROSS_COMPILE)$(shell $(CROSS_COMPILE)cc --version \ + >/dev/null 2>&1 && echo cc || echo gcc) LD =3D $(CROSS_COMPILE)ld AR =3D $(CROSS_COMPILE)ar NM =3D $(CROSS_COMPILE)nm From nobody Tue Sep 9 12:36:05 2025 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 7C0DCC636D7 for ; Tue, 21 Feb 2023 20:43:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229624AbjBUUnG (ORCPT ); Tue, 21 Feb 2023 15:43:06 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51210 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229441AbjBUUnE (ORCPT ); Tue, 21 Feb 2023 15:43:04 -0500 Received: from mail-il1-x12e.google.com (mail-il1-x12e.google.com [IPv6:2607:f8b0:4864:20::12e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 34982902C for ; Tue, 21 Feb 2023 12:43:01 -0800 (PST) Received: by mail-il1-x12e.google.com with SMTP id e9so2442922ile.8 for ; Tue, 21 Feb 2023 12:43:01 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=landley-net.20210112.gappssmtp.com; s=20210112; h=content-transfer-encoding:in-reply-to:cc:references:to:from :content-language:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=vm75klYCEzEbHDHndrCCa53U4DXnX5iMoTt+cEU3S0k=; b=2NS3OR2pHewL7snzecmtNkKql2ldQjPzSlRQ492qlYpP3HVihZQxhtknTitHhGpSPp Vg52n9qaS1s1VyIPF0N2gMGATTKkUf23t6apX4QaDB+hHfuu2dEomMXJ9mNJaOEc/lFD f6JAunLj3KSPRrUt9bzYImyTqJjpRfuZtGWQasHgrTRYamZukniq7Klfm0PpgdBt9r3M vI2usPLjKsuGahkHtKG0aRwx26YHOfQ3j3reWufaWNN2MGRJVbgOlcZjt9CCRsEeFEsv 53B6Pw/hW53Gk/SQegxqTDYON/vjCatV7lIlWDkRYWqCc6dvtTWtcWLA70hQBEMDzr5k TiiQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:in-reply-to:cc:references:to:from :content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=vm75klYCEzEbHDHndrCCa53U4DXnX5iMoTt+cEU3S0k=; b=jCDHuxLU/srplZeL0Bd1uVKE1IHJgi4SorSnlFBTSlCjrRugp4Mu4AdsXntobOHvNT 7Knd1mRkICKSjSvGz7QmjDSqxV9IWiB1ws/hvc4qQDkFaqyS/jbkuCqvN8Krh1KZELJ3 PDeva0ABalhPFQ8ZxJPXhQHfkB4Vnbmb3ZXuk9mkE6lAxGUqb8xd9Oil7LW0nVlodJly MDxlq4OmXka+rT1AQJwkHSQoFQ0Xhh4VnUXtmz8L7CoQB9BNsTq55uDqDNWZInsjb2DD 8JV2o4L26FozVE4rTB4k/Loz4hztXf1gojK73j2o5OgmB8RVrlMmvpb8cKRjijULSo+w WqVQ== X-Gm-Message-State: AO0yUKXv1cB3PhcIn5s5Po9ckz/pSINI8xvFT8C/UEaMlYt0w++yfM7t Pt+j3sxMcw1HstCCoXpTcfZ2Dy7WeGlnULBQTv0= X-Google-Smtp-Source: AK7set+BqKb0dyITxhq41Bf+MYdoMIx/gS0nyjZyZhhRsbJhI5wpuapmkXX+TqHUjrCcT/ayrzxnsw== X-Received: by 2002:a05:6e02:8aa:b0:315:9a7e:fb03 with SMTP id a10-20020a056e0208aa00b003159a7efb03mr3718684ilt.29.1677012180442; Tue, 21 Feb 2023 12:43:00 -0800 (PST) Received: from [172.16.32.78] ([198.232.126.202]) by smtp.gmail.com with ESMTPSA id s11-20020a02ad0b000000b003c5144d10b1sm35125jan.83.2023.02.21.12.42.59 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 21 Feb 2023 12:43:00 -0800 (PST) Message-ID: Date: Tue, 21 Feb 2023 14:56:22 -0600 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.5.0 Subject: [PATCH 2/5] X86-64 should not uniquely require a third ELF package to build. Content-Language: en-US From: Rob Landley To: "linux-kernel@vger.kernel.org" References: Cc: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" In-Reply-To: Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" x86-64 is the only architecture that can't compile without an extra ELF library installed on the host. (The kernel already has multiple ELF parse implementations built-in, so requiring another one is questionable at best.) You can switch it back on in menuconfig if you want to, this just stops it being mandatory. See https://lkml.iu.edu/hypermail/linux/kernel/2110.3/00402.html and https://lkml.iu.edu/hypermail/linux/kernel/2110.3/00278.html Signed-off-by: Rob Landley --- arch/x86/Kconfig | 1 - 1 file changed, 1 deletion(-) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 3604074a878b..b63510d79baf 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -243,7 +243,6 @@ config X86 select HAVE_NOINSTR_HACK if HAVE_OBJTOOL select HAVE_NMI select HAVE_NOINSTR_VALIDATION if HAVE_OBJTOOL - select HAVE_OBJTOOL if X86_64 select HAVE_OPTPROBES select HAVE_PCSPKR_PLATFORM select HAVE_PERF_EVENTS From nobody Tue Sep 9 12:36:05 2025 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 14B19C61DA3 for ; Tue, 21 Feb 2023 20:44:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229618AbjBUUoe (ORCPT ); Tue, 21 Feb 2023 15:44:34 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52456 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229441AbjBUUoc (ORCPT ); Tue, 21 Feb 2023 15:44:32 -0500 Received: from mail-io1-xd2c.google.com (mail-io1-xd2c.google.com [IPv6:2607:f8b0:4864:20::d2c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6F1D8DBD2 for ; Tue, 21 Feb 2023 12:44:31 -0800 (PST) Received: by mail-io1-xd2c.google.com with SMTP id 76so2645978iou.9 for ; Tue, 21 Feb 2023 12:44:31 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=landley-net.20210112.gappssmtp.com; s=20210112; h=content-transfer-encoding:in-reply-to:cc:references:to:from :content-language:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=49jaS/AoSPvQMwYGklpLYAUlZviDdzb1WWfRNr+yMgk=; b=TiW6dYtn3K777+JOBrVQT5giuhxe9NEzMr9OlXgXryxTH/e+GodtHhRXpHs6cGuj13 GYNwFVOvFc3XYD0mhC6djWiz4FP2IrJ+ff7pv1EYoo+gvcJIu98SEZRrEPc0I380Z4uu h0f5XpW9dmpOsKofkV20IHDPewuoH9HrykCrvEopHGdJj2xBjIw2YF7r7dsj9X8KaMYZ Bz9e31IwZ1NXgcmICMvoDC8iSf78f5m87hSvXUtaHw5MPndaWCBlx3pB1XhgL3KioyAr g2wbIyDDzBBaZT8QM39vDNL0ikAZLnP6aJqT3EeXtiZTRTpN13UccN7FoYb0eKIT8F34 F/Sw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:in-reply-to:cc:references:to:from :content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=49jaS/AoSPvQMwYGklpLYAUlZviDdzb1WWfRNr+yMgk=; b=HmmUK0mnYp4iZz7H5U5n6kbpiboMiWCjKq8cPq/+mZJjNa2d7fuJDTS5UNVfe/TnQ5 8ITj0BWbgO3DWL+5SqhQXxHZSaO3tT3zXjWJ9jjGoQRQa1XVeIew+jqjtAbFdcIOwcI8 11rDnRI526BqQz3SIYV9P0ang/ABYsqX7ksA7FV3EzxtSlNy21dzSYYEapx4WyUmCKOK Vy5XF7FecHpnrWl4LxPlX2sZs7FTQfcMjpuRjraSd5r5stXRmB+Sa6OwODdjvI5+EbHK PUtypRrtNGpFIYgtmy+dJCc+WBXusBN6X/7HcrsT9HF/H3o6hzK1gokW3g349mUa3Vts Dtwg== X-Gm-Message-State: AO0yUKVO4uvHsDSXLRZqHeNrCIbNDEeIcFp+ssDwB6HJ23SNKk7nu6vI Vr98IKng5+yoaFqYXWZCG2HVEKMZ61PwZzZJSnU= X-Google-Smtp-Source: AK7set9W25tIgR49lWpRHuKJM7verQSDd5z12u/1YC2H1N1xsBFfZkTqFM1FKHmfAivHbyiMhrIycA== X-Received: by 2002:a5e:da41:0:b0:73a:6d8e:9e34 with SMTP id o1-20020a5eda41000000b0073a6d8e9e34mr4221940iop.1.1677012270750; Tue, 21 Feb 2023 12:44:30 -0800 (PST) Received: from [172.16.32.78] ([198.232.126.202]) by smtp.gmail.com with ESMTPSA id y3-20020a6bc403000000b007407e365832sm728702ioa.23.2023.02.21.12.44.30 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 21 Feb 2023 12:44:30 -0800 (PST) Message-ID: <749b6e7c-244e-fdfb-b95c-1803678b8bdc@landley.net> Date: Tue, 21 Feb 2023 14:57:52 -0600 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.5.0 Subject: [PATCH 3/5] Wire up CONFIG_DEVTMPFS_MOUNT to initramfs. Content-Language: en-US From: Rob Landley To: "linux-kernel@vger.kernel.org" References: Cc: Andrew Morton , "Steven Rostedt (Google)" , "Jason A. Donenfeld" , Masami Hiramatsu , Peter Zijlstra , Mark Rutland , Mark-PK Tsai , Alexey Dobriyan , Li Zhe In-Reply-To: Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" The kernel has had CONFIG_DEVTMPFS_MOUNT for years, but it only applied to fallback ROOT=3D not initramfs/initmpfs. As long as the config option exist= s, it might as well work. I use this for board bringup: populating a chdir and calling cpio as a normal user often leaves /dev empty (because mknod requires root access), meaning no /dev/console for init/main.c to open, meaning init runs without stdin/stdout/stderr and has to mount devtmpfs and redirect the filehandles blind with no error output if something goes wrong. Signed-off-by: Rob Landley Previously: https://lkml.org/lkml/2017/9/13/651 --- init/main.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/init/main.c b/init/main.c index e1c3911d7c70..eca7ba2c2764 100644 --- a/init/main.c +++ b/init/main.c @@ -1636,7 +1636,6 @@ static noinline void __init kernel_init_freeable(void) kunit_run_all_tests(); =20 wait_for_initramfs(); - console_on_rootfs(); =20 /* * check if there is an early userspace init. If yes, let it do all @@ -1645,7 +1644,11 @@ static noinline void __init kernel_init_freeable(voi= d) if (init_eaccess(ramdisk_execute_command) !=3D 0) { ramdisk_execute_command =3D NULL; prepare_namespace(); + } else if (IS_ENABLED(CONFIG_DEVTMPFS_MOUNT)) { + init_mkdir("/dev", 0755); + devtmpfs_mount(); } + console_on_rootfs(); =20 /* * Ok, we have completed the initial bootup, and From nobody Tue Sep 9 12:36:05 2025 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 7C688C61DA3 for ; Tue, 21 Feb 2023 20:47:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229698AbjBUUr3 (ORCPT ); Tue, 21 Feb 2023 15:47:29 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54186 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229441AbjBUUr1 (ORCPT ); Tue, 21 Feb 2023 15:47:27 -0500 Received: from mail-il1-x133.google.com (mail-il1-x133.google.com [IPv6:2607:f8b0:4864:20::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A9D3B2E811 for ; Tue, 21 Feb 2023 12:47:25 -0800 (PST) Received: by mail-il1-x133.google.com with SMTP id z3so2421283ilm.0 for ; Tue, 21 Feb 2023 12:47:25 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=landley-net.20210112.gappssmtp.com; s=20210112; h=content-transfer-encoding:in-reply-to:cc:references:to:from :content-language:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=uf0g4olu2xig7H0ri3aToWO9GEhRK/5oEG6kOHqHj/Y=; b=XS/ubnS5zKQD08kJ3z/EGfFnkrgBt3IZR2H9lnj9GPbDHPh6lTtJdiYfA1Az3ZTP+V v7ONqnuVzN/thsi3+pkart7m0Ez+/nQq5A+oZUM6iYBD6shkHjhvnW4rshe2tjHw5Wnh F9bgbJBNMoykBwSC+6EkYfmcl37cl1gPs/IUMX4Xf/w4pp3hNQGDFkYE027d6RVwZAbq 8KK6qJ6fbQD7BY0tHfBHvaRDg44bVVkaxoN/pBI7c5HD0rBP5PI/AX///ldjzieQC3N8 PJTyc/U+GNJnqZlBtQ9ei8Y/CKcaj4+lPljsPv8rRpCT0iGq+wXNZRfesG+kfVgJdtMW MkDg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:in-reply-to:cc:references:to:from :content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=uf0g4olu2xig7H0ri3aToWO9GEhRK/5oEG6kOHqHj/Y=; b=HgVoYykam95EJfs1KgmIsvManigJuvpDu40EIDoc1ye6Ac2sodysDV0Jhp/uCL6btz YYt8xL8RMUmrFff67N/OCTqowy8SanIXUGJjGxg9F1YqkvlplYFWGud/3qw3otCSoi9x BFu8NZkLjJQD/zXYg04Tau9GvsNKjlVWoGJVxz0SfE9jT1LJR4SD/RPkraXIThvwyKSr i8AUANWsn4cvW3JycZNF9nLUSMzM0mtmYUt6sC7AidvMFqNu37Y8L9FoEJhc9e3QgD8x wwh5WRGBOLD4FEaNiS+KSz2/SUeo2qjgEySdfsysr96GTSWV59kf4cqvm8xG9nkOyMTi kYtA== X-Gm-Message-State: AO0yUKUjEUIdxRB9ltrPr8CnglQH2oMNmaFdPZXV1wAslIq6hvjt7u3d 2agUY7kViIKSndVuXvN59k2sW6gP3HdIorzN X-Google-Smtp-Source: AK7set+f2Yq0/yqaozjtP9CV0xJv1LSmfCK6bOBNaNs2oi77h3COo91kiFDKMFqLuVTcR7lMm8WEbQ== X-Received: by 2002:a05:6e02:1c21:b0:315:48df:ecde with SMTP id m1-20020a056e021c2100b0031548dfecdemr3289324ilh.8.1677012444799; Tue, 21 Feb 2023 12:47:24 -0800 (PST) Received: from [172.16.32.78] ([198.232.126.202]) by smtp.gmail.com with ESMTPSA id f13-20020a056e0204cd00b00315d1153ffcsm1488477ils.65.2023.02.21.12.47.24 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 21 Feb 2023 12:47:24 -0800 (PST) Message-ID: <9b8ce4db-9e1b-32b6-f749-94e4decc032e@landley.net> Date: Tue, 21 Feb 2023 15:00:46 -0600 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.5.0 Subject: [PATCH 4/5] Replace timeconst.bc with mktimeconst.c Content-Language: en-US From: Rob Landley To: "linux-kernel@vger.kernel.org" References: Cc: Masahiro Yamada , Nicolas Schier In-Reply-To: Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Update of my decade-old patch replacing timeconst.pl with mktimeconst.c, still removing the only user of "bc" from the build. All that's changed since the 2015 version at: https://github.com/landley/aboriginal/blob/master/sources/patches/linux-nop= erl-timeconst.patch Is one extra iteration of the loop for nanoseconds and different makefile plumbing calling it. In theory this could calculate the values at runtime in a small _init function and eliminate the header or even allow HZ to change at runtime. See https://lkml.iu.edu/hypermail/linux/kernel/2211.0/02589.html Signed-off-by: Rob Landley --- Kbuild | 7 ++- kernel/time/mktimeconst.c | 111 ++++++++++++++++++++++++++++++++++++ kernel/time/timeconst.bc | 117 -------------------------------------- 3 files changed, 116 insertions(+), 119 deletions(-) create mode 100644 kernel/time/mktimeconst.c delete mode 100644 kernel/time/timeconst.bc diff --git a/Kbuild b/Kbuild index 464b34a08f51..8c12f6ef58c6 100644 --- a/Kbuild +++ b/Kbuild @@ -18,9 +18,12 @@ $(bounds-file): kernel/bounds.s FORCE =20 timeconst-file :=3D include/generated/timeconst.h =20 -filechk_gentimeconst =3D echo $(CONFIG_HZ) | bc -q $< +hostprogs +=3D mktimeconst +mktimeconst-objs =3D kernel/time/mktimeconst.o =20 -$(timeconst-file): kernel/time/timeconst.bc FORCE +filechk_gentimeconst =3D $(obj)/mktimeconst $(CONFIG_HZ) - + +$(timeconst-file): $(obj)/mktimeconst FORCE $(call filechk,gentimeconst) =20 # Generate asm-offsets.h diff --git a/kernel/time/mktimeconst.c b/kernel/time/mktimeconst.c new file mode 100644 index 000000000000..c4c0df289472 --- /dev/null +++ b/kernel/time/mktimeconst.c @@ -0,0 +1,113 @@ +// SPDX-License-Identifier: 0BSD +// Copyright 2010-2023 Rob Landley + +#include +#include +#include +#include + +int main(int argc, char *argv[]) +{ + uint64_t hz, periods[] =3D {1000, 1000000, 1000000000}; + char *names[] =3D {"MSEC", "USEC", "NSEC"}; + FILE *file; + int i, j; + + if (argc !=3D 3 || (hz =3D atol(argv[1])) < 1 + || !(file =3D !strcmp(argv[2], "-") ? stdout : fopen(argv[2], "w"))) { + fprintf(stderr, "Usage: mktimeconst HZ FILENAME\n\n"); + fprintf(stderr, "Generate a header file with constants to convert betwee= n\n"); + fprintf(stderr, "decimal HZ timer ticks and milisecond or microsecond de= lays,\n"); + fprintf(stderr, "using reciprocal multiplication to avoid 64 bit divisio= n.\n"); + exit(1); + } + + fprintf(file, + "/* Conversion constants for HZ =3D=3D %"PRIu64" */\n\n" + "/* Automatically generated by kernel/time/mktimeconst.c */\n" + "/* This could be generated in __init code but isn't */\n" + + "#ifndef __KERNEL_TIMECONST_H\n" + "#define __KERNEL_TIMECONST_H\n\n" + "#include \n" + "#include \n\n" + "#if HZ !=3D %"PRIu64"\n" + "#error \"include/generated/timeconst.h has the wrong HZ value!\"\n" + "#endif\n\n", hz, hz); + + /* Repeat for MSEC, USEC, and NSEC */ + + for (i =3D 0; i < 3; i++) { + uint64_t gcd, period; + + /* Find greatest common denominator using Euclid's algorithm. */ + + gcd =3D hz; + period =3D periods[i]; + while (period) { + uint64_t temp =3D gcd % period; + + gcd =3D period; + period =3D temp; + } + + /* Output both directions (HZ_TO_PERIOD and PERIOD_TO_HZ) */ + + for (j =3D 0; j < 2; j++) { + char name[16]; + uint64_t from =3D j ? periods[i] : hz; + uint64_t to =3D j ? hz : periods[i]; + uint64_t mul32 =3D 0, adj32 =3D 0, shift =3D 0; + + sprintf(name, j ? "%s_TO_HZ" : "HZ_TO_%s", names[i]); + + /* Figure out what shift value gives 32 significant + * bits of MUL32 data. (Worst case to=3D1 from=3D1000000 + * uses 52 bits, to<=3D (1UL<<31)) + break; + shift++; + } + + /* ADJ32 is just (((FROM/GCD)-1)< 32) { + uint64_t upper, lower; + + upper =3D (adj32 - 1) << (shift - 32); + lower =3D (upper % adj32) << 32; + adj32 =3D ((upper/adj32) << 32) + (lower/adj32); + } else + adj32 =3D ((adj32 - 1) << shift) / adj32; + + /* Emit the constants into the header file. */ + + fprintf(file, "#define %s_MUL32\tU64_C(0x%"PRIx64")\n", + name, mul32); + fprintf(file, "#define %s_ADJ32\tU64_C(0x%"PRIx64")\n", + name, adj32); + fprintf(file, "#define %s_SHR32\t%"PRIu64"\n", + name, shift); + fprintf(file, "#define %s_NUM\t\tU64_C(%"PRIu64")\n", + name, to/gcd); + fprintf(file, "#define %s_DEN\t\tU64_C(%"PRIu64")\n\n", + name, from/gcd); + } + } + fprintf(file, "#endif /* __KERNEL_TIMECONST_H */\n"); + + /* Notice if the disk fills up. */ + + fflush(file); +} diff --git a/kernel/time/timeconst.bc b/kernel/time/timeconst.bc deleted file mode 100644 index 7ed0e0fb5831..000000000000 --- a/kernel/time/timeconst.bc +++ /dev/null @@ -1,117 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ - -scale=3D0 - -define gcd(a,b) { - auto t; - while (b) { - t =3D b; - b =3D a % b; - a =3D t; - } - return a; -} - -/* Division by reciprocal multiplication. */ -define fmul(b,n,d) { - return (2^b*n+d-1)/d; -} - -/* Adjustment factor when a ceiling value is used. Use as: - (imul * n) + (fmulxx * n + fadjxx) >> xx) */ -define fadj(b,n,d) { - auto v; - d =3D d/gcd(n,d); - v =3D 2^b*(d-1)/d; - return v; -} - -/* Compute the appropriate mul/adj values as well as a shift count, - which brings the mul value into the range 2^b-1 <=3D x < 2^b. Such - a shift value will be correct in the signed integer range and off - by at most one in the upper half of the unsigned range. */ -define fmuls(b,n,d) { - auto s, m; - for (s =3D 0; 1; s++) { - m =3D fmul(s,n,d); - if (m >=3D 2^(b-1)) - return s; - } - return 0; -} - -define timeconst(hz) { - print "/* Automatically generated by kernel/time/timeconst.bc */\n" - print "/* Time conversion constants for HZ =3D=3D ", hz, " */\n" - print "\n" - - print "#ifndef KERNEL_TIMECONST_H\n" - print "#define KERNEL_TIMECONST_H\n\n" - - print "#include \n" - print "#include \n\n" - - print "#if HZ !=3D ", hz, "\n" - print "#error \qinclude/generated/timeconst.h has the wrong HZ value!\q\n" - print "#endif\n\n" - - if (hz < 2) { - print "#error Totally bogus HZ value!\n" - } else { - s=3Dfmuls(32,1000,hz) - obase=3D16 - print "#define HZ_TO_MSEC_MUL32\tU64_C(0x", fmul(s,1000,hz), ")\n" - print "#define HZ_TO_MSEC_ADJ32\tU64_C(0x", fadj(s,1000,hz), ")\n" - obase=3D10 - print "#define HZ_TO_MSEC_SHR32\t", s, "\n" - - s=3Dfmuls(32,hz,1000) - obase=3D16 - print "#define MSEC_TO_HZ_MUL32\tU64_C(0x", fmul(s,hz,1000), ")\n" - print "#define MSEC_TO_HZ_ADJ32\tU64_C(0x", fadj(s,hz,1000), ")\n" - obase=3D10 - print "#define MSEC_TO_HZ_SHR32\t", s, "\n" - - obase=3D10 - cd=3Dgcd(hz,1000) - print "#define HZ_TO_MSEC_NUM\t\t", 1000/cd, "\n" - print "#define HZ_TO_MSEC_DEN\t\t", hz/cd, "\n" - print "#define MSEC_TO_HZ_NUM\t\t", hz/cd, "\n" - print "#define MSEC_TO_HZ_DEN\t\t", 1000/cd, "\n" - print "\n" - - s=3Dfmuls(32,1000000,hz) - obase=3D16 - print "#define HZ_TO_USEC_MUL32\tU64_C(0x", fmul(s,1000000,hz), ")\n" - print "#define HZ_TO_USEC_ADJ32\tU64_C(0x", fadj(s,1000000,hz), ")\n" - obase=3D10 - print "#define HZ_TO_USEC_SHR32\t", s, "\n" - - s=3Dfmuls(32,hz,1000000) - obase=3D16 - print "#define USEC_TO_HZ_MUL32\tU64_C(0x", fmul(s,hz,1000000), ")\n" - print "#define USEC_TO_HZ_ADJ32\tU64_C(0x", fadj(s,hz,1000000), ")\n" - obase=3D10 - print "#define USEC_TO_HZ_SHR32\t", s, "\n" - - obase=3D10 - cd=3Dgcd(hz,1000000) - print "#define HZ_TO_USEC_NUM\t\t", 1000000/cd, "\n" - print "#define HZ_TO_USEC_DEN\t\t", hz/cd, "\n" - print "#define USEC_TO_HZ_NUM\t\t", hz/cd, "\n" - print "#define USEC_TO_HZ_DEN\t\t", 1000000/cd, "\n" - - cd=3Dgcd(hz,1000000000) - print "#define HZ_TO_NSEC_NUM\t\t", 1000000000/cd, "\n" - print "#define HZ_TO_NSEC_DEN\t\t", hz/cd, "\n" - print "#define NSEC_TO_HZ_NUM\t\t", hz/cd, "\n" - print "#define NSEC_TO_HZ_DEN\t\t", 1000000000/cd, "\n" - print "\n" - - print "#endif /* KERNEL_TIMECONST_H */\n" - } - halt -} - -hz =3D read(); -timeconst(hz) From nobody Tue Sep 9 12:36:05 2025 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 32FE2C636D7 for ; Tue, 21 Feb 2023 20:50:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229841AbjBUUu5 (ORCPT ); Tue, 21 Feb 2023 15:50:57 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56818 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229606AbjBUUuz (ORCPT ); Tue, 21 Feb 2023 15:50:55 -0500 Received: from mail-io1-xd29.google.com (mail-io1-xd29.google.com [IPv6:2607:f8b0:4864:20::d29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 540DD2916A for ; Tue, 21 Feb 2023 12:50:54 -0800 (PST) Received: by mail-io1-xd29.google.com with SMTP id d11so2275113iow.0 for ; Tue, 21 Feb 2023 12:50:54 -0800 (PST) DKIM-Signature: v=1; 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Tue, 21 Feb 2023 12:50:53 -0800 (PST) Received: from [172.16.32.78] ([198.232.126.202]) by smtp.gmail.com with ESMTPSA id t17-20020a6b0911000000b00745a82f892bsm188888ioi.15.2023.02.21.12.50.53 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 21 Feb 2023 12:50:53 -0800 (PST) Message-ID: <8244c75f-445e-b15b-9dbf-266e7ca666e2@landley.net> Date: Tue, 21 Feb 2023 15:04:15 -0600 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.5.0 Subject: [PATCH 5/5] fix rootfstype=tmpfs Content-Language: en-US From: Rob Landley To: "linux-kernel@vger.kernel.org" References: Cc: Andrew Morton , Wolfram Sang In-Reply-To: Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Wire up rootfstype=3Dtmpfs to force rootfs to be tmpfs even when you specif= y root=3D Initramfs automatically uses tmpfs (if available) when you DON'T specify a root=3D fallback root to mount over initramfs, but some people can't NOT do that for some reason (old bootloaders), so let rootfstype=3Dtmpfs override = it. My original code tried to do this 10 years ago but got the test wrong, and nobody's corrected it since, so here you go... Signed-off-by: Rob Landley See https://lkml.iu.edu/hypermail/linux/kernel/2207.3/06939.html Reviewed-by: Stefan Berger Tested-by: Stefan Berger --- init/do_mounts.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/init/do_mounts.c b/init/do_mounts.c index 811e94daf0a8..01d80fb828fd 100644 --- a/init/do_mounts.c +++ b/init/do_mounts.c @@ -665,7 +665,7 @@ struct file_system_type rootfs_fs_type =3D { =20 void __init init_rootfs(void) { - if (IS_ENABLED(CONFIG_TMPFS) && !saved_root_name[0] && - (!root_fs_names || strstr(root_fs_names, "tmpfs"))) + if (IS_ENABLED(CONFIG_TMPFS) && (!root_fs_names ? !saved_root_name[0] : + !!strstr(root_fs_names, "tmpfs"))) is_tmpfs =3D true; }