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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 50AD7C48BE5 for ; Mon, 21 Jun 2021 06:50:48 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id D59DF6109E for ; Mon, 21 Jun 2021 06:50:47 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D59DF6109E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ellerman.id.au Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4G7gCW2wHvz3c44 for ; Mon, 21 Jun 2021 16:50:47 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=ellerman.id.au header.i=@ellerman.id.au header.a=rsa-sha256 header.s=201909 header.b=Uyj1eoyZ; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=ozlabs.org (client-ip=2401:3900:2:1::2; helo=ozlabs.org; envelope-from=michael@ozlabs.org; receiver=) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=ellerman.id.au header.i=@ellerman.id.au header.a=rsa-sha256 header.s=201909 header.b=Uyj1eoyZ; dkim-atps=neutral Received: from ozlabs.org (bilbo.ozlabs.org [IPv6:2401:3900:2:1::2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4G7gBQ6CRfz2yXh for ; Mon, 21 Jun 2021 16:49:50 +1000 (AEST) Received: by ozlabs.org (Postfix, from userid 1034) id 4G7gBG1tZKz9sW7; Mon, 21 Jun 2021 16:49:42 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ellerman.id.au; s=201909; t=1624258182; bh=/1SDxNaltuutHLL7NBoTW0wRrrQbKL1s2r0ffiYuMFA=; h=From:To:Subject:Date:From; b=Uyj1eoyZ+yJiW51VtHTeynhIfvFj4oaFVx8ZWd1SOTkg1O67hJmd/aGnEFmAgCU8J MCwczZ/9mn9O6RgaVVvSd9C37BEXmdkOmPlWBev2N9IiZSPHRYxnPLDVfaQj7Vayy2 9NR8bF6no2Io12u7W9fu2naSabBNq1o5wisZv0Bb5BpgSIR1Ve39TRqcf2DUI8JtDD 9AsAzSL84zK5lisQVX53BVmdjMU5OIeHoH8O2PWxmwVCN76NvvKa9ngC0kTCLxCdtd PFZJWskg2Y9Wl/WKM3UAn+3AUDyUAkDFgzu1FHy91kjkncp8GMO3XXDHkVeQX+qVNG yhaRb+9PvhjaQ== From: Michael Ellerman To: linuxppc-dev@lists.ozlabs.org Subject: [PATCH 1/2] powerpc/prom_init: Convert prom_strcpy() into prom_strscpy_pad() Date: Mon, 21 Jun 2021 16:49:37 +1000 Message-Id: <20210621064938.2021419-1-mpe@ellerman.id.au> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" In a subsequent patch we'd like to have something like a strscpy_pad() implementation usable in prom_init.c. Currently we have a strcpy() implementation with only one caller, so convert it into strscpy_pad() and update the caller. Signed-off-by: Michael Ellerman --- arch/powerpc/kernel/prom_init.c | 30 ++++++++++++++++++++++++------ 1 file changed, 24 insertions(+), 6 deletions(-) diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c index 523b31685c4c..c18d55f8b951 100644 --- a/arch/powerpc/kernel/prom_init.c +++ b/arch/powerpc/kernel/prom_init.c @@ -242,13 +242,31 @@ static int __init prom_strcmp(const char *cs, const char *ct) return 0; } -static char __init *prom_strcpy(char *dest, const char *src) +static ssize_t __init prom_strscpy_pad(char *dest, const char *src, size_t n) { - char *tmp = dest; + ssize_t rc; + size_t i; - while ((*dest++ = *src++) != '\0') - /* nothing */; - return tmp; + if (n == 0 || n > INT_MAX) + return -E2BIG; + + // Copy up to n bytes + for (i = 0; i < n && src[i] != '\0'; i++) + dest[i] = src[i]; + + rc = i; + + // If we copied all n then we have run out of space for the nul + if (rc == n) { + // Rewind by one character to ensure nul termination + i--; + rc = -E2BIG; + } + + for (; i < n; i++) + dest[i] = '\0'; + + return rc; } static int __init prom_strncmp(const char *cs, const char *ct, size_t count) @@ -2701,7 +2719,7 @@ 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_strscpy_pad(namep, "phandle", sizeof("phandle")); mem_start = (unsigned long)namep + prom_strlen(namep) + 1; /* Build string array */ -- 2.25.1