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Mon, 31 Aug 2026 19:47:25 +0800 (CST) Received: from kwepemo200009.china.huawei.com (unknown [7.202.195.26]) by mail.maildlp.com (Postfix) with ESMTPS id DED7840563; Mon, 31 Aug 2026 19:58:39 +0800 (CST) Received: from [10.174.186.187] (10.174.186.187) by kwepemo200009.china.huawei.com (7.202.195.26) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.45; Mon, 31 Aug 2026 19:58:39 +0800 Message-ID: Date: Mon, 31 Aug 2026 19:58:35 +0800 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH V2] kho: Convert error handling to immediate return pattern To: Mike Rapoport CC: Alexander Graf , Pasha Tatashin , Pratyush Yadav , , , , References: <00c96a62-f783-497c-a7ac-1de495e4af06@huawei.com> <20260824024448.550552-1-longwei27@huawei.com> <178817571946.3691424.3757525664520719609.b4-review@b4> From: "longwei (I)" In-Reply-To: <178817571946.3691424.3757525664520719609.b4-review@b4> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.174.186.187] X-ClientProxiedBy: kwepems200001.china.huawei.com (7.221.188.67) To kwepemo200009.china.huawei.com (7.202.195.26) X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 71E0A20008 X-Stat-Signature: 8qoe75j5ewdqkiuszr1trwghs5fd46ck X-Rspam-User: X-HE-Tag: 1788177525-343604 X-HE-Meta: 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 Ccew0k9f gCJgvduLWA9fLdaFlnMi+xwIy2WKc+s+IYUK/EzZdsLa8XDsKQB9nENGrqJ1LnEG4Aku80/dvHQXgaUXIsaqrB1OABxoaWHLecGFyTLCKfjIRxXCnGJjrwgk3juh6nm/BXO6w41EyuRe3+FqjB7/sDIxFk/Dm5m4GXY/WdHUi00Jutb59sZHrk5FXQ1vPfZOXhfxTPVFuEO5mPQB+dc56dRvvcVtlrijZkbzup5rdGZX7hAlQo4nFOa4OhKpNH9ulsfCc/E0lTFbq15fxBi0T+g6JaLcprv2tMKGQSShGY4Zv4nw9VjRin6h6wotqb536Blir Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Hi Mike Rapoport=EF=BC=8C Thanks for the review. To be honest, I haven't observed any actual failures in this path in our = production environment. This change was identified during our internal team code review=E2=80=94t= he err |=3D func() pattern looked concerning to us at first glance, so we= attempted to clean it up. However, I agree with your assessment: the caller doesn't care about the = exact error value, libfdt uses its own error codes, and this is a cold pa= th where failures are unlikely. The change is indeed unnecessary churn wi= thout a concrete bug to fix. I'll drop this patch. Please ignore this submission. Thanks, Long Wei =E5=9C=A8 2026/8/31 19:28, Mike Rapoport =E5=86=99=E9=81=93: > Hi, >=20 >=20 >> Replace the chained error accumulation (err |=3D func()) with immediat= e >> per-step error checking and early return in kho_out_fdt_setup(). >> >> Two problems with the current approach: >> 1. It continues executing FDT operations even after a failure, which >> is pointless and potentially unsafe on an invalid FDT context. >=20 > Did you actually see failures here or was it an LLM suggesting that the= y > may happen? >=20 >> 2. Bitwise OR of multiple negative error codes produces a result that >> may not represent any actual error, making debugging misleading. >> >> Early return fails fast and preserves the original error code for >> accurate diagnosis. >=20 > The caller does not care about the exact error value, so the diagnosis > statement is moot at best. > Moreover, libfdt does not return Linux error values. >=20