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[2620:137:e000::1:20]) by mx.google.com with ESMTP id q4-20020aa7d444000000b005223b462b62si1550483edr.639.2023.07.27.15.33.43; Thu, 27 Jul 2023 15:34:26 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@google.com header.s=20221208 header.b=D8uvkEu4; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232217AbjG0W06 (ORCPT + 99 others); Thu, 27 Jul 2023 18:26:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44512 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231161AbjG0W0y (ORCPT ); Thu, 27 Jul 2023 18:26:54 -0400 Received: from mail-oa1-x49.google.com (mail-oa1-x49.google.com [IPv6:2001:4860:4864:20::49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 331A0F0 for ; Thu, 27 Jul 2023 15:26:53 -0700 (PDT) Received: by mail-oa1-x49.google.com with SMTP id 586e51a60fabf-1bb91fb58f2so2681977fac.2 for ; Thu, 27 Jul 2023 15:26:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1690496812; x=1691101612; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=Y8k3rjyBf0fojb2EPgR8sOqghPhE9G594McR+LDMAVU=; b=D8uvkEu4/smEbpJTeMq90Bq5KeP1e5xIGLkQWzLEkXeN8AQU0NkbUy0zuQd+TUDBSx k3+CzER9oXoVsUCZvuh9ZIN4VObo+hEN4Z+y+rd2eVuE4GcNw/Ge5AGR5mdVOQA76bwG RNF1S8VERGMdefiESkMUi5anwpf8ky6b04huvSD7HuzDBWA7L1zc9uqa9vXivFgWWNuz Iho8dePREXhDWuWuG/4dhsZjV+1VOiSIAAkrXITi6ge7gaLlbxA3VbqTOo3LaknExZlo ubzzY+BjDM4VT64nFYkLUAMdC3XqpY8qwN3NTMwuL/P/ctD0iXxag6tLvhN2RzQTBur3 Dk+Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1690496812; x=1691101612; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=Y8k3rjyBf0fojb2EPgR8sOqghPhE9G594McR+LDMAVU=; b=ewucLlnjTv1uwSdV9YZXHHbDIOo1OOEMvsHmuy2O3uMlX8M2JoteU7Qj/2lEE2TsE1 dRUe8CSYKoNTfa+WvpNdOZN3E0Q0+WMJVXfh5+iTsMcnFgsc4aUf3P1xiG6n86lU2kmE 1sBHCoBhQjdXyl6EQIz4oSV0i2x12xE3tj1nUTbluwjfp0qEmcwirETMt/yo8HZyrSVT ggijOnNheflkB0KOWaP7HHXZmx3o+sImAxkjtqpWYaPOsuyRAcXEL9VEDeh6gn6IfIg6 sjKbUbMiQukXogAzZJLbnn/T7wvHFJW7Z7CHYxUkfVEtpaYM1oql5ZjZDWth+/IaOiHY XPCw== X-Gm-Message-State: ABy/qLZl9hBoEw8DP/BvkNpqzYQNH97ktoTEIHgNH5lGPLO+YEK7F/cT ewKQOR0E+e2oGX1wTS9wMjvPBUYvAt1ewFLrPQ== X-Received: from jstitt-linux1.c.googlers.com ([fda3:e722:ac3:cc00:2b:ff92:c0a8:23b5]) (user=justinstitt job=sendgmr) by 2002:a05:6870:5b0d:b0:1bb:785d:7436 with SMTP id ds13-20020a0568705b0d00b001bb785d7436mr961489oab.10.1690496812558; Thu, 27 Jul 2023 15:26:52 -0700 (PDT) Date: Thu, 27 Jul 2023 22:26:41 +0000 Mime-Version: 1.0 X-B4-Tracking: v=1; b=H4sIACDvwmQC/6tWKk4tykwtVrJSqFYqSi3LLM7MzwNyDHUUlJIzE vPSU3UzU4B8JSMDI2MDcyNz3eL80rwUIJmsm1aco2uSlmxqamaZYm5umKoE1FNQlJqWWQE2Lzq 2thYAMKv4Nl8AAAA= X-Developer-Key: i=justinstitt@google.com; a=ed25519; pk=tC3hNkJQTpNX/gLKxTNQKDmiQl6QjBNCGKJINqAdJsE= X-Developer-Signature: v=1; a=ed25519-sha256; t=1690496811; l=2165; i=justinstitt@google.com; s=20230717; h=from:subject:message-id; bh=xEnu5xQr3cyZZvwQfMubiCiEuFBVC3Uk0Y9589JdUxw=; b=hmOqBlRYlYKaC3Yr5Zy8g3r9+9++L/pbK5ub/HORCIbyUCI0NGjnrADamWXFeaNB3CVKyg4I+ L5n1tag1LikDFx+k0EHDanF323xxdNABjjW0T5SEFnG7vM0e2joX6sH X-Mailer: b4 0.12.3 Message-ID: <20230727-sound-soc-fsl-v1-1-4fc0ed7e0366@google.com> Subject: [PATCH] ASoC: fsl_micfil: refactor deprecated strncpy From: Justin Stitt To: Shengjiu Wang , Xiubo Li , Fabio Estevam , Nicolin Chen , Liam Girdwood , Mark Brown , Jaroslav Kysela , Takashi Iwai Cc: alsa-devel@alsa-project.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, Kees Cook , Justin Stitt X-Spam-Status: No, score=-9.6 required=5.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE, SPF_HELO_NONE,SPF_PASS,T_SCC_BODY_TEXT_LINE,USER_IN_DEF_DKIM_WL autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: 1772614861762872588 X-GMAIL-MSGID: 1772614861762872588 `strncpy` is deprecated for use on NUL-terminated destination strings [1]. A suitable replacement is `strscpy` [2] due to the fact that it guarantees NUL-termination on its destination buffer argument which is _not_ always the case for `strncpy`! In this case, though, there was great care taken to ensure that the destination buffer would be NUL-terminated through the use of `len - 1` ensuring that the previously zero-initialized buffer would not overwrite the last NUL byte. This means that there's no bug here. However, `strscpy` will add a mandatory NUL byte to the destination buffer as promised by the following `strscpy` implementation [3]: | /* Hit buffer length without finding a NUL; force NUL-termination. */ | if (res) | dest[res-1] = '\0'; This means we can lose the `- 1` which clears up whats happening here. All the while, we get one step closer to eliminating the ambiguous `strncpy` api in favor of its less ambiguous replacement like `strscpy`, `strscpy_pad`, `strtomem` and `strtomem_pad` amongst others. [1]: www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [2]: manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [3]: https://elixir.bootlin.com/linux/v6.3/source/lib/string.c#L183 Link: https://github.com/KSPP/linux/issues/90 Signed-off-by: Justin Stitt --- sound/soc/fsl/fsl_micfil.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- base-commit: 57012c57536f8814dec92e74197ee96c3498d24e change-id: 20230727-sound-soc-fsl-4fc5569d771e Best regards, -- Justin Stitt diff --git a/sound/soc/fsl/fsl_micfil.c b/sound/soc/fsl/fsl_micfil.c index 3f08082a55be..fe28b27e50d0 100644 --- a/sound/soc/fsl/fsl_micfil.c +++ b/sound/soc/fsl/fsl_micfil.c @@ -1044,7 +1044,7 @@ static int fsl_micfil_probe(struct platform_device *pdev) return -ENOMEM; micfil->pdev = pdev; - strncpy(micfil->name, np->name, sizeof(micfil->name) - 1); + strscpy(micfil->name, np->name, sizeof(micfil->name)); micfil->soc = of_device_get_match_data(&pdev->dev);