From nobody Sun Nov 24 00:01:38 2024 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1728329022565535.0474750400505; Mon, 7 Oct 2024 12:23:42 -0700 (PDT) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1sxtEE-0004Ah-9P; Mon, 07 Oct 2024 15:17:10 -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 1sxtE8-000463-5j; Mon, 07 Oct 2024 15:17:04 -0400 Received: from isrv.corpit.ru ([86.62.121.231]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1sxtE6-00043B-6f; Mon, 07 Oct 2024 15:17:03 -0400 Received: from tsrv.corpit.ru (tsrv.tls.msk.ru [192.168.177.2]) by isrv.corpit.ru (Postfix) with ESMTP id 0E5749623F; Mon, 7 Oct 2024 22:16:48 +0300 (MSK) Received: from tls.msk.ru (mjt.wg.tls.msk.ru [192.168.177.130]) by tsrv.corpit.ru (Postfix) with SMTP id D136814F720; Mon, 7 Oct 2024 22:16:54 +0300 (MSK) Received: (nullmailer pid 2592709 invoked by uid 1000); Mon, 07 Oct 2024 19:16:54 -0000 From: Michael Tokarev To: qemu-devel@nongnu.org Cc: qemu-stable@nongnu.org, Tiago Pasqualini , =?UTF-8?q?Daniel=20P=20=2E=20Berrang=C3=A9?= , Michael Tokarev Subject: [Stable-9.1.1 03/32] crypto: run qcrypto_pbkdf2_count_iters in a new thread Date: Mon, 7 Oct 2024 22:16:20 +0300 Message-Id: <20241007191654.2592616-3-mjt@tls.msk.ru> X-Mailer: git-send-email 2.39.5 In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=86.62.121.231; envelope-from=mjt@tls.msk.ru; helo=isrv.corpit.ru X-Spam_score_int: -68 X-Spam_score: -6.9 X-Spam_bar: ------ X-Spam_report: (-6.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_HI=-5, 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-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+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZM-MESSAGEID: 1728329023924116600 From: Tiago Pasqualini CPU time accounting in the kernel has been demonstrated to have a sawtooth pattern[1][2]. This can cause the getrusage system call to not be as accurate as we are expecting, which can cause this calculation to stall. The kernel discussions shows that this inaccuracy happens when CPU time gets big enough, so this patch changes qcrypto_pbkdf2_count_iters to run in a fresh thread to avoid this inaccuracy. It also adds a sanity check to fail the process if CPU time is not accounted. [1] https://lore.kernel.org/lkml/159231011694.16989.16351419333851309713.ti= p-bot2@tip-bot2/ [2] https://lore.kernel.org/lkml/20221226031010.4079885-1-maxing.lan@byteda= nce.com/t/#m1c7f2fdc0ea742776a70fd1aa2a2e414c437f534 Resolves: #2398 Signed-off-by: Tiago Pasqualini Signed-off-by: Daniel P. Berrang=C3=A9 (cherry picked from commit c72cab5ad9f849bbcfcf4be7952b8b8946cc626e) Signed-off-by: Michael Tokarev diff --git a/crypto/pbkdf.c b/crypto/pbkdf.c index 8d198c152c..d1c06ef3ed 100644 --- a/crypto/pbkdf.c +++ b/crypto/pbkdf.c @@ -19,6 +19,7 @@ */ =20 #include "qemu/osdep.h" +#include "qemu/thread.h" #include "qapi/error.h" #include "crypto/pbkdf.h" #ifndef _WIN32 @@ -85,12 +86,28 @@ static int qcrypto_pbkdf2_get_thread_cpu(unsigned long = long *val_ms, #endif } =20 -uint64_t qcrypto_pbkdf2_count_iters(QCryptoHashAlgorithm hash, - const uint8_t *key, size_t nkey, - const uint8_t *salt, size_t nsalt, - size_t nout, - Error **errp) +typedef struct CountItersData { + QCryptoHashAlgorithm hash; + const uint8_t *key; + size_t nkey; + const uint8_t *salt; + size_t nsalt; + size_t nout; + uint64_t iterations; + Error **errp; +} CountItersData; + +static void *threaded_qcrypto_pbkdf2_count_iters(void *data) { + CountItersData *iters_data =3D (CountItersData *) data; + QCryptoHashAlgorithm hash =3D iters_data->hash; + const uint8_t *key =3D iters_data->key; + size_t nkey =3D iters_data->nkey; + const uint8_t *salt =3D iters_data->salt; + size_t nsalt =3D iters_data->nsalt; + size_t nout =3D iters_data->nout; + Error **errp =3D iters_data->errp; + uint64_t ret =3D -1; g_autofree uint8_t *out =3D g_new(uint8_t, nout); uint64_t iterations =3D (1 << 15); @@ -114,7 +131,10 @@ uint64_t qcrypto_pbkdf2_count_iters(QCryptoHashAlgorit= hm hash, =20 delta_ms =3D end_ms - start_ms; =20 - if (delta_ms > 500) { + if (delta_ms =3D=3D 0) { /* sanity check */ + error_setg(errp, "Unable to get accurate CPU usage"); + goto cleanup; + } else if (delta_ms > 500) { break; } else if (delta_ms < 100) { iterations =3D iterations * 10; @@ -129,5 +149,24 @@ uint64_t qcrypto_pbkdf2_count_iters(QCryptoHashAlgorit= hm hash, =20 cleanup: memset(out, 0, nout); - return ret; + iters_data->iterations =3D ret; + return NULL; +} + +uint64_t qcrypto_pbkdf2_count_iters(QCryptoHashAlgorithm hash, + const uint8_t *key, size_t nkey, + const uint8_t *salt, size_t nsalt, + size_t nout, + Error **errp) +{ + CountItersData data =3D { + hash, key, nkey, salt, nsalt, nout, 0, errp + }; + QemuThread thread; + + qemu_thread_create(&thread, "pbkdf2", threaded_qcrypto_pbkdf2_count_it= ers, + &data, QEMU_THREAD_JOINABLE); + qemu_thread_join(&thread); + + return data.iterations; } --=20 2.39.5