From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ot1-x32e.google.com (mail-ot1-x32e.google.com [IPv6:2607:f8b0:4864:20::32e]) by sourceware.org (Postfix) with ESMTPS id 16F683858D38 for ; Mon, 10 Apr 2023 21:25:07 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 16F683858D38 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=gmail.com Received: by mail-ot1-x32e.google.com with SMTP id f10-20020a9d2c0a000000b006a13f728172so812070otb.3 for ; Mon, 10 Apr 2023 14:25:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; t=1681161906; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=1MEAoL3INrrpN5xM7BXpaBLSBIKmHa1mj7ckkYUHZgo=; b=NeC8CP1W4HGjnUCyicfg9qpoSsakQYkRT2zz4t4I2jBsa/A7pUhlDu8TfnH8zxFFMO CGkTI9ifv2wcdzPFXRTfWgZLQy2ezFlXdBvu+3L2xZEF4gc/lKXICX0cFZeNdozE9t10 DSp5N5sLnXNkd3ZxtfhIvWac36KYe9VN0zKE6g1Ch0mEmFOJpLBdeFGcJ2U1bmdhNcc6 GS5e+Um6teO2FBJYNkwuoOr6BOZrc9NGSNlSksWmQpp6A4C72h+FOcIsEw8ct4bgu7sx EFsZNIrhKce6FtoaEydL93S/nM+S5Gwm937c/3yhPZGUZ/HcVbE+7FhxriOncZdrlvJc Df6A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1681161906; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=1MEAoL3INrrpN5xM7BXpaBLSBIKmHa1mj7ckkYUHZgo=; b=gZPe2BPigEXYKwsH8a1IzdFpaa9BNrxdJ1NtUADvFAulN0ak6hPiNeiFUvG0TY2296 pCJv1Tjrw8wALnnx7UXcKeYb+y4p9MQdoUgiV+NxB7AjljFnQoAGpXrfaCRl8Psl4Y7K um40kkzvbbtCej9ioTFIqP8UyOvVO9r5li5GW0WFS36RCCgLita1jcmuzpHPt4bWOQ+0 uXR9o6tHjrWZXpGpxxsgqKWE/nmXikJtxu9H74JhhLWVdDly7NmWH+LIYw1QxMz9leFd O8BEADPJxJseQSHLsqjIi2d628Cc8rF6gwKuMPQZZ9zzjh4D+ceRgmhgzO53i0ovEkV8 KebA== X-Gm-Message-State: AAQBX9duUu/+FoHiu88R8OEyBOkr+MwVJmyVmdZEO3qcOkhoJ1zWK8Kf IUy/Rf16Pxb/yJYzit/gm6dv/1ZryQtHQATvjp8= X-Google-Smtp-Source: AKy350bvHi8E/F5LuW147CprIjh8GbfrNSM2EajY/4MXRVZ7qnAEJmU39Yf3BNI9Dc9yLaif7vtJiR/2n8/4axo3/+s= X-Received: by 2002:a05:6830:1d55:b0:699:7883:940d with SMTP id p21-20020a0568301d5500b006997883940dmr2280878oth.7.1681161906388; Mon, 10 Apr 2023 14:25:06 -0700 (PDT) MIME-Version: 1.0 References: <20230319151017.531737-1-bugaevc@gmail.com> <20230410192038.6emffvywx6uclxbn@begin> In-Reply-To: <20230410192038.6emffvywx6uclxbn@begin> From: Sergey Bugaev Date: Tue, 11 Apr 2023 00:24:55 +0300 Message-ID: Subject: Re: [RFC PATCH 00/34] The rest of the x86_64-gnu port To: Samuel Thibault Cc: libc-alpha@sourceware.org, bug-hurd@gnu.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Spam-Status: No, score=-2.8 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS,TXREP 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: On Mon, Apr 10, 2023 at 10:20=E2=80=AFPM Samuel Thibault wrote: > > Sergey Bugaev, le dim. 19 mars 2023 18:09:43 +0300, a ecrit: > > As for sigreturn specifically: I'm concerned about the possibility that > > putting the register dump onto the user's stack (or at %rsp - 128, on x= 86_64) > > may clobber the data trampoline.c puts there (unless an altstack is use= d), > > including the very sigcontext. > > I guess we could make sure that the offset of ctx in stackframe is not > hit by data written by sigreturn.c. Right; it would be easiest to reserve enough space for the register dump at the end of 'struct stackframe', i.e. right after the user's stack. Sergey