From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from list by lists.gnu.org with archive (Exim 4.90_1) id 1uJuZa-0002ST-RX for mharc-qemu-rust@gnu.org; Tue, 27 May 2025 09:42:30 -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 1uJuZZ-0002SE-CW for qemu-rust@nongnu.org; Tue, 27 May 2025 09:42:29 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1uJuZV-0003aW-8z for qemu-rust@nongnu.org; Tue, 27 May 2025 09:42:27 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1748353343; 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=CumUhn7aR01x5Sy9sVxBT484Uq17U2NwR2iWgSwKD1s=; b=MYVzh8tNFliCed8KmYKIwTCOEKfdrxmxEf3plv3A94fLzcCAjGaZZQELrBYCoA1X8dDiCJ 2xizj90qQ1scVkyMq9dmDDntjSgIWNZwDVtxKuX0Sc6nKDXHDpfxi1HoR9pZsDUeMTrSi2 RdCo2Tc09v9umLabIbm57u6EvGklli4= Received: from mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-42-j9DZ2DrgMGG3rspjKISiqQ-1; Tue, 27 May 2025 09:42:21 -0400 X-MC-Unique: j9DZ2DrgMGG3rspjKISiqQ-1 X-Mimecast-MFC-AGG-ID: j9DZ2DrgMGG3rspjKISiqQ_1748353341 Received: from mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.15]) (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-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id D51DB18003FC; Tue, 27 May 2025 13:42:20 +0000 (UTC) Received: from blackfin.pond.sub.org (unknown [10.45.242.2]) by mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 71C631956095; Tue, 27 May 2025 13:42:20 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 95FE921E66C3; Tue, 27 May 2025 15:42:17 +0200 (CEST) From: Markus Armbruster To: Paolo Bonzini Cc: qemu-devel@nongnu.org, qemu-rust@nongnu.org Subject: Re: [PATCH 05/12] util/error: allow non-NUL-terminated err->src In-Reply-To: <20250526142455.1061519-5-pbonzini@redhat.com> (Paolo Bonzini's message of "Mon, 26 May 2025 16:24:48 +0200") References: <20250526142254.1061009-1-pbonzini@redhat.com> <20250526142455.1061519-5-pbonzini@redhat.com> Date: Tue, 27 May 2025 15:42:17 +0200 Message-ID: <87sekqmapy.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 10.30.177.15 Received-SPF: pass client-ip=170.10.133.124; envelope-from=armbru@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -49 X-Spam_score: -5.0 X-Spam_bar: ----- X-Spam_report: (-5.0 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-2.907, 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=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham 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: Tue, 27 May 2025 13:42:29 -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. Can you elaborate on the portability problem? I figure ... > Signed-off-by: Paolo Bonzini > --- > include/qapi/error-internal.h | 1 + > util/error.c | 8 +++++++- > 2 files changed, 8 insertions(+), 1 deletion(-) > > diff --git a/include/qapi/error-internal.h b/include/qapi/error-internal.h > index d5c3904adec..6178ce4a63d 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; > + ssize_t src_len; > int line; > GString *hint; > }; > diff --git a/util/error.c b/util/error.c > index e5bcb7c0225..6c1033eaba5 100644 > --- a/util/error.c > +++ b/util/error.c > @@ -24,8 +24,13 @@ Error *error_warn; > static void error_handle(Error **errp, Error *err) > { > if (errp == &error_abort) { > + const char *src = err->src; > + if (err->src_len >= 0) { > + /* No need to free it, the program will abort very soon... */ > + src = g_strndup(err->src, err->src_len); > + } > fprintf(stderr, "Unexpected error in %s() at %s:%d:\n", > - err->func, err->src, err->line); > + err->func, src, err->line); ... you're avoiding the simpler fprintf(stderr, "Unexpected error in %s() at %.*s:%d:\n", err->func, err->src_len, err->src, err->line); because of it. (@src_len needs to be int then, and its default value below INT_MAX) > error_report("%s", error_get_pretty(err)); > if (err->hint) { > error_printf("%s", err->hint->str); > @@ -67,6 +72,7 @@ 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;