From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6F0DAC433EA for ; Wed, 24 Mar 2021 15:33:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5F7BB61992 for ; Wed, 24 Mar 2021 15:33:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236759AbhCXPcs (ORCPT ); Wed, 24 Mar 2021 11:32:48 -0400 Received: from pegase1.c-s.fr ([93.17.236.30]:50422 "EHLO pegase1.c-s.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236763AbhCXPcV (ORCPT ); Wed, 24 Mar 2021 11:32:21 -0400 Received: from localhost (mailhub1-int [192.168.12.234]) by localhost (Postfix) with ESMTP id 4F5C0L2sW7z9v23n; Wed, 24 Mar 2021 16:32:18 +0100 (CET) X-Virus-Scanned: Debian amavisd-new at c-s.fr Received: from pegase1.c-s.fr ([192.168.12.234]) by localhost (pegase1.c-s.fr [192.168.12.234]) (amavisd-new, port 10024) with ESMTP id FoMssj87XpiI; Wed, 24 Mar 2021 16:32:18 +0100 (CET) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase1.c-s.fr (Postfix) with ESMTP id 4F5C0L1pWyz9v23m; Wed, 24 Mar 2021 16:32:18 +0100 (CET) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id C1C068B82B; Wed, 24 Mar 2021 16:32:19 +0100 (CET) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id IYkaSLfBGIjX; Wed, 24 Mar 2021 16:32:19 +0100 (CET) Received: from [192.168.4.90] (unknown [192.168.4.90]) by messagerie.si.c-s.fr (Postfix) with ESMTP id A77598B812; Wed, 24 Mar 2021 16:32:18 +0100 (CET) Subject: Re: [PATCH v2 4/7] CMDLINE: powerpc: convert to generic builtin command line To: Daniel Walker Cc: Will Deacon , Rob Herring , Daniel Gimpelevich , Andrew Morton , x86@kernel.org, linux-mips@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, xe-linux-external@cisco.com, Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras , Ruslan Ruslichenko , Ruslan Bilovol , linux-kernel@vger.kernel.org References: <20210309000247.2989531-5-danielwa@cisco.com> <20210309214051.GS109100@zorba> From: Christophe Leroy Message-ID: <9c5b8e33-026e-c9d6-c267-a5dd4a2b999c@csgroup.eu> Date: Wed, 24 Mar 2021 16:31:35 +0100 User-Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: <20210309214051.GS109100@zorba> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: fr Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Le 09/03/2021 à 22:40, Daniel Walker a écrit : > On Tue, Mar 09, 2021 at 08:56:47AM +0100, Christophe Leroy wrote: >> >> >> Le 09/03/2021 à 01:02, Daniel Walker a écrit : >>> This updates the powerpc code to use the CONFIG_GENERIC_CMDLINE >>> option. >>> >>> Cc: xe-linux-external@cisco.com >>> Signed-off-by: Ruslan Ruslichenko >>> Signed-off-by: Ruslan Bilovol >>> Signed-off-by: Daniel Walker >>> --- >>> arch/powerpc/Kconfig | 37 +-------------------------------- >>> arch/powerpc/kernel/prom.c | 1 + >>> arch/powerpc/kernel/prom_init.c | 35 ++++++++++++++++++------------- >>> 3 files changed, 23 insertions(+), 50 deletions(-) >>> >>> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig >>> index 107bb4319e0e..276b06d5c961 100644 >>> --- a/arch/powerpc/Kconfig >>> +++ b/arch/powerpc/Kconfig >>> @@ -167,6 +167,7 @@ config PPC >>> select EDAC_SUPPORT >>> select GENERIC_ATOMIC64 if PPC32 >>> select GENERIC_CLOCKEVENTS_BROADCAST if SMP >>> + select GENERIC_CMDLINE >>> select GENERIC_CMOS_UPDATE >>> select GENERIC_CPU_AUTOPROBE >>> select GENERIC_CPU_VULNERABILITIES if PPC_BARRIER_NOSPEC >>> @@ -906,42 +907,6 @@ config PPC_DENORMALISATION >>> Add support for handling denormalisation of single precision >>> values. Useful for bare metal only. If unsure say Y here. >>> -config CMDLINE >>> - string "Initial kernel command string" >>> - default "" >>> - help >>> - On some platforms, there is currently no way for the boot loader to >>> - pass arguments to the kernel. For these platforms, you can supply >>> - some command-line options at build time by entering them here. In >>> - most cases you will need to specify the root device here. >>> - >>> -choice >>> - prompt "Kernel command line type" if CMDLINE != "" >>> - default CMDLINE_FROM_BOOTLOADER >>> - >>> -config CMDLINE_FROM_BOOTLOADER >>> - bool "Use bootloader kernel arguments if available" >>> - help >>> - Uses the command-line options passed by the boot loader. If >>> - the boot loader doesn't provide any, the default kernel command >>> - string provided in CMDLINE will be used. I can't see how the above is supported in the generic builtin. Taking into account that it is the default on powerpc, I'm having hardtime with that. >>> - >>> -config CMDLINE_EXTEND >>> - bool "Extend bootloader kernel arguments" >>> - help >>> - The command-line arguments provided by the boot loader will be >>> - appended to the default kernel command string. >>> - >>> -config CMDLINE_FORCE >>> - bool "Always use the default kernel command string" >>> - help >>> - Always use the default kernel command string, even if the boot >>> - loader passes other arguments to the kernel. >>> - This is useful if you cannot or don't want to change the >>> - command-line options your boot loader passes to the kernel. >>> - >>> -endchoice >>> - >>> config EXTRA_TARGETS >>> string "Additional default image types" >>> help >>> diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c >>> index ae3c41730367..96d0a01be1b4 100644 >>> --- a/arch/powerpc/kernel/prom.c >>> +++ b/arch/powerpc/kernel/prom.c >>> @@ -27,6 +27,7 @@ >>> #include >>> #include >>> #include >>> +#include >> >> Why is this needed in prom.c ? > > Must have been a mistake, I don't think it's needed. > > >>> #include >>> #include >>> #include >>> diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c >>> index e9d4eb6144e1..657241534d69 100644 >>> --- a/arch/powerpc/kernel/prom_init.c >>> +++ b/arch/powerpc/kernel/prom_init.c >>> @@ -27,6 +27,7 @@ >>> #include >>> #include >>> #include >>> +#include >>> #include >>> #include >>> #include >>> @@ -242,15 +243,6 @@ static int __init prom_strcmp(const char *cs, const char *ct) >>> return 0; >>> } >>> -static char __init *prom_strcpy(char *dest, const char *src) >>> -{ >>> - char *tmp = dest; >>> - >>> - while ((*dest++ = *src++) != '\0') >>> - /* nothing */; >>> - return tmp; >>> -} >>> - >> >> This game with prom_strcpy() should go a separate preceeding patch. >> >> Also, it looks like checkpatch.pl recommends to use strscpy() instead of strlcpy(). > > strscpy() is very large. I'm not sure it's compatible with this prom_init.c > environment. Ok you are right, lets keep strlcpy() and ignore checkpatch complaints > >>> static int __init prom_strncmp(const char *cs, const char *ct, size_t count) >>> { >>> unsigned char c1, c2; >>> @@ -276,6 +268,20 @@ static size_t __init prom_strlen(const char *s) >>> return sc - s; >>> } >>> +static size_t __init prom_strlcpy(char *dest, const char *src, size_t size) >>> +{ >>> + size_t ret = prom_strlen(src); >>> + >>> + if (size) { >>> + size_t len = (ret >= size) ? size - 1 : ret; >>> + >>> + memcpy(dest, src, len); >>> + dest[len] = '\0'; >>> + } >>> + return ret; >>> +} >>> + >>> + >>> static int __init prom_memcmp(const void *cs, const void *ct, size_t count) >>> { >>> const unsigned char *su1, *su2; >>> @@ -304,6 +310,7 @@ static char __init *prom_strstr(const char *s1, const char *s2) >>> return NULL; >>> } >>> +#ifdef GENERIC_CMDLINE_NEED_STRLCAT >>> static size_t __init prom_strlcat(char *dest, const char *src, size_t count) >>> { >>> size_t dsize = prom_strlen(dest); >>> @@ -323,6 +330,7 @@ static size_t __init prom_strlcat(char *dest, const char *src, size_t count) >>> return res; >>> } >>> +#endif >>> #ifdef CONFIG_PPC_PSERIES >>> static int __init prom_strtobool(const char *s, bool *res) >>> @@ -775,12 +783,11 @@ static void __init early_cmdline_parse(void) >>> prom_cmd_line[0] = 0; >>> p = prom_cmd_line; >>> - if (!IS_ENABLED(CONFIG_CMDLINE_FORCE) && (long)prom.chosen > 0) >>> + if ((long)prom.chosen > 0) >>> l = prom_getprop(prom.chosen, "bootargs", p, COMMAND_LINE_SIZE-1); >>> - if (IS_ENABLED(CONFIG_CMDLINE_EXTEND) || l <= 0 || p[0] == '\0') >>> - prom_strlcat(prom_cmd_line, " " CONFIG_CMDLINE, >>> - sizeof(prom_cmd_line)); >>> + cmdline_add_builtin_custom(prom_cmd_line, (l > 0 ? p : NULL), sizeof(prom_cmd_line), >>> + __prombss, prom_strlcpy, prom_strlcat); >> >> So we are referencing a function that doesn't exist (namely prom_strlcat). >> But it works because cmdline_add_builtin_custom() looks like a function but >> is in fact an obscure macro that doesn't use prom_strlcat() unless >> GENERIC_CMDLINE_NEED_STRLCAT is defined. >> >> IMHO that's awful for readability and code maintenance. > > powerpc is a special case, there's no other users like this. The reason is > because of all the difficulty in this prom_init.c code. A lot of the generic > code has similar kind of changes to work across architectures. Any feedback on the proposed changes I made on the 13th ? I know it is partly buggy but that was more for the principle. I can make clean working patch if it helps. > > >>> prom_printf("command line: %s\n", prom_cmd_line); >>> @@ -2706,7 +2713,7 @@ static void __init flatten_device_tree(void) >>> /* Add "phandle" in there, we'll need it */ >>> namep = make_room(&mem_start, &mem_end, 16, 1); >>> - prom_strcpy(namep, "phandle"); >>> + prom_strlcpy(namep, "phandle", 8); >> >> Should be in a separate patch. > > I can move it, I missed that from the first round. > > Daniel > Christophe