From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by sourceware.org (Postfix) with ESMTPS id 1068F3858CD1 for ; Fri, 8 Dec 2023 17:36:38 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 1068F3858CD1 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=redhat.com ARC-Filter: OpenARC Filter v1.0.0 sourceware.org 1068F3858CD1 Authentication-Results: server2.sourceware.org; arc=none smtp.remote-ip=170.10.133.124 ARC-Seal: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1702056999; cv=none; b=JPqu0FxooE/dzK+U008ENVxWOdLlZvNOrLuNyQwbgn07LUpjKZRzrMFyBx+/Mu+MmSR2gOQ1W3IdmERAen20IhVJBjPfe9CvGzVwhPXrMye43h08bCXpPry7tpKXiyJUmDpY5i57b0EmuJxSiMWKzHjX2zwAA59AWin3zhutZkM= ARC-Message-Signature: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1702056999; c=relaxed/simple; bh=fWwaouoTzrrQWwj0fv0Hq98iag4g4kOt6Xs5WMdexN0=; 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Fri, 08 Dec 2023 12:36:33 -0500 X-MC-Unique: -KjcB6H_OSKjdPLnPZXGrQ-1 Received: from smtp.corp.redhat.com (int-mx10.intmail.prod.int.rdu2.redhat.com [10.11.54.10]) (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 mimecast-mx02.redhat.com (Postfix) with ESMTPS id 414E01C172B1; Fri, 8 Dec 2023 17:36:33 +0000 (UTC) Received: from oldenburg.str.redhat.com (unknown [10.39.192.131]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 3A745492BE6; Fri, 8 Dec 2023 17:36:32 +0000 (UTC) From: Florian Weimer To: Adhemerval Zanella Cc: libc-alpha@sourceware.org, Noah Goldstein , Zack Weinberg Subject: Re: [PATCH] stdlib: Reinstate stable mergesort implementation on qsort References: <20231206202228.1842209-1-adhemerval.zanella@linaro.org> Date: Fri, 08 Dec 2023 18:36:30 +0100 In-Reply-To: <20231206202228.1842209-1-adhemerval.zanella@linaro.org> (Adhemerval Zanella's message of "Wed, 6 Dec 2023 17:22:28 -0300") Message-ID: <8734wcegv5.fsf@oldenburg.str.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.3 (gnu/linux) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.10 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Spam-Status: No, score=-4.9 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE,RCVD_IN_MSPIKE_H3,RCVD_IN_MSPIKE_WL,SPF_HELO_NONE,SPF_NONE,TXREP,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: * Adhemerval Zanella: > +static void > +indirect_msort_with_tmp (const struct msort_param *p, void *b, size_t n, > +=09=09=09 size_t s) > +{ > + /* Indirect sorting. */ > + char *ip =3D (char *) b; > + void **tp =3D (void **) (p->t + n * sizeof (void *)); > + void **t =3D tp; > + void *tmp_storage =3D (void *) (tp + n); > +=09memcpy (tmp_storage, ip, s); > __qsort_r (void *const pbase, size_t total_elems, size_t size, > =09 __compar_d_fn_t cmp, void *arg) > { > if (total_elems <=3D 1) > return; > =20 > + char tmp[QSORT_STACK_SIZE]; > + size_t total_size =3D total_elems * size; > + char *buf; I don't see how the total_size computation makes sure that the tmp_storage place actually exists when =E2=80=A6 > + if (total_size < sizeof buf) > + buf =3D tmp; > + else > + { > + int save =3D errno; > + buf =3D malloc (total_size); > + __set_errno (save); > + if (buf =3D=3D NULL) > +=09{ > +=09 /* Fallback to heapsort in case of memory failure. */ > +=09 heapsort_r (pbase, total_elems - 1, size, cmp, arg); > +=09 return; > +=09} > + } > =20 > + if (size > INDIRECT_SORT_SIZE_THRES) > { > + const struct msort_param msort_param =3D > +=09{ > +=09 .s =3D sizeof (void *), > +=09 .cmp =3D cmp, > +=09 .arg =3D arg, > +=09 .var =3D SWAP_VOID_ARG, > +=09 .t =3D buf, > +=09}; > + indirect_msort_with_tmp (&msort_param, pbase, total_elems, size); it is passed to indirect_msort_with_tmp here. Thanks, Florian