From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id C387AC87FC6 for ; Mon, 21 Jul 2025 06:01:17 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1udjZj-0008L6-Ou; Mon, 21 Jul 2025 02:00:41 -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 1udjZ4-0008Cl-G9 for qemu-devel@nongnu.org; Mon, 21 Jul 2025 01:59:55 -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 1udjZ2-00067s-Rv for qemu-devel@nongnu.org; Mon, 21 Jul 2025 01:59:54 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1753077592; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=5KWT+/o3dTqGxj2GxT8gQwaUixPakGt6yMy2ciNkG3w=; b=hvHFMNZZWq1TVipq4SUE3YDx4GaERhrPVFq9RUQSnsGrat1RgHlaS9xB+BgrQzGdO3CkeL G0cTvYpz6XrGA5a5RkymkvddjSoCSPhC9C4YYUSlQ4/cVePpmxLBZuqs9tsZeHPIUupdG8 rEtKUQd9rLdNUrHGjC7q9+Ii7aXbvOc= Received: from mx-prod-mc-08.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-677-JWcRK7uvNIm9-G3zb9D82A-1; Mon, 21 Jul 2025 01:59:50 -0400 X-MC-Unique: JWcRK7uvNIm9-G3zb9D82A-1 X-Mimecast-MFC-AGG-ID: JWcRK7uvNIm9-G3zb9D82A_1753077589 Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.17]) (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-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 1D9931800C30; Mon, 21 Jul 2025 05:59:49 +0000 (UTC) Received: from localhost.localdomain (unknown [10.72.112.190]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 33E59195608D; Mon, 21 Jul 2025 05:59:46 +0000 (UTC) From: Jason Wang To: qemu-devel@nongnu.org Cc: Peter Maydell , Jason Wang Subject: [PULL 05/12] hw/net/npcm_gmac.c: Correct test for when to reallocate packet buffer Date: Mon, 21 Jul 2025 13:59:20 +0800 Message-ID: <20250721055927.75951-6-jasowang@redhat.com> In-Reply-To: <20250721055927.75951-1-jasowang@redhat.com> References: <20250721055927.75951-1-jasowang@redhat.com> MIME-Version: 1.0 Content-type: text/plain Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 Received-SPF: pass client-ip=170.10.129.124; envelope-from=jasowang@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=-0.088, 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_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org From: Peter Maydell In gmac_try_send_next_packet() we have code that does "if this block of data won't fit in the buffer, reallocate it". However, the condition it uses is if ((prev_buf_size + tx_buf_len) > sizeof(buf)) where buf is a uint8_t *. This means that sizeof(buf) is always 8 bytes, and the condition will almost always be true, so we will reallocate the buffer more often than we need to. Correct the condition to test against tx_buffer_size, which is where we track how big the allocated buffer is. Signed-off-by: Peter Maydell Signed-off-by: Jason Wang --- hw/net/npcm_gmac.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/hw/net/npcm_gmac.c b/hw/net/npcm_gmac.c index a0050a7725..0c17ae9b2a 100644 --- a/hw/net/npcm_gmac.c +++ b/hw/net/npcm_gmac.c @@ -569,7 +569,7 @@ static void gmac_try_send_next_packet(NPCMGMACState *gmac) tx_buf_len = TX_DESC_TDES1_BFFR1_SZ_MASK(tx_desc.tdes1); buf = &tx_send_buffer[prev_buf_size]; - if ((prev_buf_size + tx_buf_len) > sizeof(buf)) { + if ((prev_buf_size + tx_buf_len) > tx_buffer_size) { tx_buffer_size = prev_buf_size + tx_buf_len; tx_send_buffer = g_realloc(tx_send_buffer, tx_buffer_size); buf = &tx_send_buffer[prev_buf_size]; @@ -591,7 +591,7 @@ static void gmac_try_send_next_packet(NPCMGMACState *gmac) tx_buf_len = TX_DESC_TDES1_BFFR2_SZ_MASK(tx_desc.tdes1); buf = &tx_send_buffer[prev_buf_size]; - if ((prev_buf_size + tx_buf_len) > sizeof(buf)) { + if ((prev_buf_size + tx_buf_len) > tx_buffer_size) { tx_buffer_size = prev_buf_size + tx_buf_len; tx_send_buffer = g_realloc(tx_send_buffer, tx_buffer_size); buf = &tx_send_buffer[prev_buf_size]; -- 2.42.0