From patchwork Tue Apr 21 19:54:45 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Gora X-Patchwork-Id: 69041 X-Patchwork-Delegate: david.marchand@redhat.com Return-Path: X-Original-To: patchwork@inbox.dpdk.org Delivered-To: patchwork@inbox.dpdk.org Received: from dpdk.org (dpdk.org [92.243.14.124]) by inbox.dpdk.org (Postfix) with ESMTP id 9AF8CA05A0; Tue, 21 Apr 2020 21:56:03 +0200 (CEST) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 7160C1D440; Tue, 21 Apr 2020 21:56:03 +0200 (CEST) Received: from mail-qk1-f195.google.com (mail-qk1-f195.google.com [209.85.222.195]) by dpdk.org (Postfix) with ESMTP id 8157B1D42B for ; Tue, 21 Apr 2020 21:56:02 +0200 (CEST) Received: by mail-qk1-f195.google.com with SMTP id c63so27042qke.2 for ; Tue, 21 Apr 2020 12:56:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=KL+B0oxJJedSmraeocVbwGlHlliCXNGiszzEiebUHyI=; b=easdE+lF9pM31vTU8GI2S1gaZEAyCjGlRKLb40uTvFFtYPkbP5+E7WqcwYBZwkBX9m es8eiu2yz+jqlQl6jhaM8oLNIPhQj9LZ6tng0JXdRADdynS6T1Sw69AMcOP7xqrbcQ9o qjQ4emb2MA0A3WZ5NAFE384u4trla4uP0T87joHxn5nJLTY/Fdh0nekNn4Lbldpd/+yg xkKBkgUBL7a6cVLWf5kRlor3jFwOrwrhS0eTB+p2eiF5SQzxz1gDJgtJ7WHCSg+E7ZEF VUo7e5dp9mpNqXkTpdDxg/f2FiWGc1m/MwjOWqMqY0YVnbrboGpFL2TjCEjNKsuJcN3u 4dRA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:from:to:cc:subject:date:message-id :in-reply-to:references:mime-version:content-transfer-encoding; bh=KL+B0oxJJedSmraeocVbwGlHlliCXNGiszzEiebUHyI=; b=ujKDjNHdYztWBlDdPqRUpG0cE2R0UEeB3te/+DWo2MBqkGcesCgSQ2F8F5lMoDuJpz Fw9+eMuT/0dJ2w2d+aCfbQJQZV4aILUtFFS05tZ+cxugiP+dj7Euf9NMPpzWjc8WD7NI tSamejOweWdaWe4U+ENMt20fbvplOfCbpBze2c8viJz5HfUd32di/ynS3wWXJJKiSk6V IUOZkGr7X6PJLRuPua9HRMIfl7t80pVtrVg7mWurkoL1FySRidcZx+76Izgq0QOuriGa ldEnPk65fKwvT6bELwcpLT4OxjpZ2BKx6RhitJyA2eIpeEO0ngAOD4XjuqhUu2L/wXUz Ys7w== X-Gm-Message-State: AGi0PuYl+9JMkpOnNEdoi6rv9GJbxzP925O6tau/IU7iOTKgWlIkcDp0 Q68Ev1yPJGcvUSxEtoSdQLFBSvW07HA= X-Google-Smtp-Source: APiQypJkHwmWKi3bAVlIxc5La3Ihe27h6ObX6LDJDsSetr8pdqGXL0lq+VD6gxonMNnFM9HiUHwJrA== X-Received: by 2002:a37:64d2:: with SMTP id y201mr23964986qkb.370.1587498961676; Tue, 21 Apr 2020 12:56:01 -0700 (PDT) Received: from localhost.localdomain ([168.121.99.161]) by smtp.gmail.com with ESMTPSA id o94sm2423378qtd.34.2020.04.21.12.55.59 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Tue, 21 Apr 2020 12:56:01 -0700 (PDT) From: Dan Gora To: dev@dpdk.org, =?utf-8?q?Mattias_R=C3=B6nnblom?= Cc: David Marchand , Jerin Jacob , Dan Gora Date: Tue, 21 Apr 2020 16:54:45 -0300 Message-Id: <20200421195446.1730-3-dg@adax.com> X-Mailer: git-send-email 2.24.1.425.g7034cd094b In-Reply-To: <20200421195446.1730-1-dg@adax.com> References: <20200421195446.1730-1-dg@adax.com> MIME-Version: 1.0 Subject: [dpdk-dev] [PATCH 2/2] eal: resolve getentropy at run time for random seed X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" The getentropy() function was introduced into glibc v2.25 and so is not available on all supported platforms. Previously, if DPDK was compiled (using meson) on a system which has getentropy(), it would introduce a dependency on glibc v2.25 which would prevent that binary from running on a system with an older glibc. Similarly if DPDK was compiled on a system which did not have getentropy(), getentropy() could not be used even if the execution system supported it. Introduce a new static function, __rte_getentropy() which will try to resolve the getentropy() function dynamically using dlopen()/dlsym(), returning failure if the getentropy() function cannot be resolved or if it fails. This also allows getentropy() to be used as the random seed source when the traditional Makefile build for DPDK is used. Signed-off-by: Dan Gora --- lib/librte_eal/common/rte_random.c | 33 ++++++++++++++++++++++++------ lib/librte_eal/meson.build | 3 --- 2 files changed, 27 insertions(+), 9 deletions(-) diff --git a/lib/librte_eal/common/rte_random.c b/lib/librte_eal/common/rte_random.c index df02f1307..f8203f4c7 100644 --- a/lib/librte_eal/common/rte_random.c +++ b/lib/librte_eal/common/rte_random.c @@ -7,6 +7,7 @@ #endif #include #include +#include #include #include @@ -176,18 +177,38 @@ rte_rand_max(uint64_t upper_bound) return res; } +/* Try to use the getentropy() function from glibc >= 2.25 */ +static int +__rte_getentropy(uint64_t *ge_seed) +{ + void *handle = NULL; + void **sym; + int (*getentropy_p)(void *__buffer, size_t __length); + int gc_rc; + + handle = dlopen("libc.so.6", RTLD_LAZY); + if (!handle) + return -1; + + sym = dlsym(handle, "getentropy"); + if (!sym || !*sym) + /* Cannot resolve getentropy */ + return -1; + + getentropy_p = (int (*)(void *, size_t)) sym; + gc_rc = (*getentropy_p)((void *)ge_seed, sizeof(*ge_seed)); + dlclose(handle); + return gc_rc; +} + static uint64_t __rte_random_initial_seed(void) { -#ifdef RTE_LIBEAL_USE_GETENTROPY - int ge_rc; uint64_t ge_seed; - ge_rc = getentropy(&ge_seed, sizeof(ge_seed)); - - if (ge_rc == 0) + if (__rte_getentropy(&ge_seed) == 0) return ge_seed; -#endif + #if defined(RTE_ARCH_X86) /* first fallback: rdseed instruction, if available */ if (rte_cpu_get_flag_enabled(RTE_CPUFLAG_RDSEED)) { diff --git a/lib/librte_eal/meson.build b/lib/librte_eal/meson.build index 0267c3b9d..748359b8c 100644 --- a/lib/librte_eal/meson.build +++ b/lib/librte_eal/meson.build @@ -15,9 +15,6 @@ deps += 'kvargs' if dpdk_conf.has('RTE_USE_LIBBSD') ext_deps += libbsd endif -if cc.has_function('getentropy', prefix : '#include ') - cflags += '-DRTE_LIBEAL_USE_GETENTROPY' -endif if cc.has_header('getopt.h') cflags += ['-DHAVE_GETOPT_H', '-DHAVE_GETOPT', '-DHAVE_GETOPT_LONG'] endif