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[23.128.96.18]) by mx.google.com with ESMTP id u18si9980979ejb.504.2021.03.09.13.42.15; Tue, 09 Mar 2021 13:42:53 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@cisco.com header.s=iport header.b=hC3NS+4U; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=QUARANTINE sp=QUARANTINE dis=NONE) header.from=cisco.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231970AbhCIVlU (ORCPT + 99 others); Tue, 9 Mar 2021 16:41:20 -0500 Received: from rcdn-iport-1.cisco.com ([173.37.86.72]:52092 "EHLO rcdn-iport-1.cisco.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232102AbhCIVky (ORCPT ); Tue, 9 Mar 2021 16:40:54 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=cisco.com; i=@cisco.com; l=7313; q=dns/txt; s=iport; t=1615326054; x=1616535654; h=date:from:to:cc:subject:message-id:references: mime-version:content-transfer-encoding:in-reply-to; bh=rW2dGFdz1Viogy9BvbMFOe3/vVZakbjcs4YVqhr4xkM=; b=hC3NS+4UidjxHgpMH8jEkOJbz5YU5RwNCxnFJxPRyV9BdmUb5YNT2yUw gifH1GCXYCbyi/6MtgHVeHETl1ns3oaUg+g1kxTO1crB/8Tiar1Qcymn+ Ic5bDAbSDdXa8bZpfpP2S6krh8ENXFVDbwcWbM04WcfMJWQU47LS2YTHG w=; X-IronPort-AV: E=Sophos;i="5.81,236,1610409600"; d="scan'208";a="861832335" Received: from alln-core-6.cisco.com ([173.36.13.139]) by rcdn-iport-1.cisco.com with ESMTP/TLS/DHE-RSA-SEED-SHA; 09 Mar 2021 21:40:54 +0000 Received: from zorba ([10.24.4.5]) by alln-core-6.cisco.com (8.15.2/8.15.2) with ESMTPS id 129Lepbs004030 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Tue, 9 Mar 2021 21:40:52 GMT Date: Tue, 9 Mar 2021 13:40:51 -0800 From: Daniel Walker To: Christophe Leroy 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 Subject: Re: [PATCH v2 4/7] CMDLINE: powerpc: convert to generic builtin command line Message-ID: <20210309214051.GS109100@zorba> References: <20210309000247.2989531-5-danielwa@cisco.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-Auto-Response-Suppress: DR, OOF, AutoReply X-Outbound-SMTP-Client: 10.24.4.5, [10.24.4.5] X-Outbound-Node: alln-core-6.cisco.com Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Mar 09, 2021 at 08:56:47AM +0100, Christophe Leroy wrote: > > > Le 09/03/2021 ? 01:02, Daniel Walker a ?crit?: > > 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. > > - > > -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. > > 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. > > 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