From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from list by lists.gnu.org with archive (Exim 4.90_1) id 1uM2hP-0003C0-Sy for mharc-qemu-rust@gnu.org; Mon, 02 Jun 2025 06:47:23 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1uM2hN-0003AJ-A1 for qemu-rust@nongnu.org; Mon, 02 Jun 2025 06:47:22 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1uM2hL-00004x-Ss for qemu-rust@nongnu.org; Mon, 02 Jun 2025 06:47:21 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1748861239; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=ZNOZV4SF2jwGyHGdvtD7zvzaKkwIXZBSN8hM7F2iFiY=; b=EKjSsbmPhHrSoHLvEUrkxOosIRxzethq5Imh7bH2kN3fIxmonUtJATMp9s/5s1Y2NRYyzQ uGkJnX8D3XAIRA4UbreA7fEM70S+fU8juRGH+JMC/AmdxeQ/QnCGcBD0faiUy77m8kmHQA 0qGTPyX4vgrm70NWf2FpEmA6lZuc6Io= Received: from mx-prod-mc-02.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-35-KUW24mnZOqasi0PY5TVNJQ-1; Mon, 02 Jun 2025 06:47:16 -0400 X-MC-Unique: KUW24mnZOqasi0PY5TVNJQ-1 X-Mimecast-MFC-AGG-ID: KUW24mnZOqasi0PY5TVNJQ_1748861235 Received: from mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.40]) (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 mx-prod-mc-02.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 15374195609E; Mon, 2 Jun 2025 10:47:15 +0000 (UTC) Received: from blackfin.pond.sub.org (unknown [10.45.242.38]) by mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 92B6D1955F2C; Mon, 2 Jun 2025 10:47:14 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id F342521E66C3; Mon, 02 Jun 2025 12:47:11 +0200 (CEST) From: Markus Armbruster To: Paolo Bonzini Cc: qemu-devel@nongnu.org, qemu-rust@nongnu.org Subject: Re: [PATCH 04/14] util/error: allow non-NUL-terminated err->src In-Reply-To: <20250530080307.2055502-5-pbonzini@redhat.com> (Paolo Bonzini's message of "Fri, 30 May 2025 10:02:56 +0200") References: <20250530080307.2055502-1-pbonzini@redhat.com> <20250530080307.2055502-5-pbonzini@redhat.com> Date: Mon, 02 Jun 2025 12:47:11 +0200 Message-ID: <87zfeqifo0.fsf@pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 3.0 on 10.30.177.40 Received-SPF: pass client-ip=170.10.129.124; envelope-from=armbru@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -31 X-Spam_score: -3.2 X-Spam_bar: --- X-Spam_report: (-3.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.071, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H5=-1, RCVD_IN_MSPIKE_WL=-0.01, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-rust@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: QEMU Rust-related patches and discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 02 Jun 2025 10:47:22 -0000 Paolo Bonzini writes: > Rust makes the current file available as a statically-allocated string, > but without a NUL terminator. Allow this by storing an optional maximum > length in the Error. > > Note that for portability I am not relying on fprintf's precision > specifier not accessing memory beyond what will be printed. Stale paragraph :) > Signed-off-by: Paolo Bonzini > --- > include/qapi/error-internal.h | 1 + > util/error.c | 5 +++-- > 2 files changed, 4 insertions(+), 2 deletions(-) > > diff --git a/include/qapi/error-internal.h b/include/qapi/error-internal.h > index d5c3904adec..f5eb8ad2379 100644 > --- a/include/qapi/error-internal.h > +++ b/include/qapi/error-internal.h > @@ -19,6 +19,7 @@ struct Error > char *msg; > ErrorClass err_class; > const char *src, *func; > + int src_len; In actual usage, we have two cases: * @src_len is -1 and @src is null-terminated * @src_len is non-negative and @src is an array of at least that many characters, not necessarily null-terminated This is locally unobvious, and therefore deserves a comment. Unterminated char * pretty much always deserve one :) > int line; > GString *hint; > }; > diff --git a/util/error.c b/util/error.c > index e5bcb7c0225..3449ecc0b92 100644 > --- a/util/error.c > +++ b/util/error.c > @@ -24,8 +24,8 @@ Error *error_warn; > static void error_handle(Error **errp, Error *err) > { > if (errp == &error_abort) { > - fprintf(stderr, "Unexpected error in %s() at %s:%d:\n", > - err->func, err->src, err->line); > + fprintf(stderr, "Unexpected error in %s() at %.*s:%d:\n", > + err->func, err->src_len, err->src, err->line); > error_report("%s", error_get_pretty(err)); > if (err->hint) { > error_printf("%s", err->hint->str); > @@ -67,6 +67,7 @@ static void error_setv(Error **errp, > g_free(msg); > } > err->err_class = err_class; > + err->src_len = -1; > err->src = src; > err->line = line; > err->func = func; This part looks fine to me.