From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by inbox.dpdk.org (Postfix) with ESMTP id 9B288A00C2; Wed, 22 Apr 2020 20:16:44 +0200 (CEST) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id BFCE31D58E; Wed, 22 Apr 2020 20:16:42 +0200 (CEST) Received: from mail-qk1-f193.google.com (mail-qk1-f193.google.com [209.85.222.193]) by dpdk.org (Postfix) with ESMTP id 33C0C1D58C for ; Wed, 22 Apr 2020 20:16:42 +0200 (CEST) Received: by mail-qk1-f193.google.com with SMTP id b62so3442939qkf.6 for ; Wed, 22 Apr 2020 11:16:42 -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=I86adsQf6YOuHk4/hcl0IQ0VyaAPCTKy1hpvvuMvToA=; b=kEQbdwRbxa5/7bJKbRIdBspuT3Lc6bFii+ekue2VJ+MNl8l6iWl0w20jp9KumfoLV9 gqSZ091najgAJqOs1b8HkyJPQn6g0m+4fwFrWqb9oKkrJl5hSvXgAAsMsF4a4TIt5MD2 TimqbgVtgnWo1LBX20/pMxVv/a4cM5+pe93ZWVjzWbXldgmWmaucX0RK3TBOaOuA33tm K5hsMEeP+fuxMD2VHejQztyMTH7RIfxa8TQU7+DK/fUefPFHXkqtVuxFnJSvYDCryQYK Y/rJDjyxKfCbOSSb4lDqT1JM7h8O4WxXiTz1nHGb7Fycibu7bzx2apWXs73G/FDmejiR mH+w== 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=I86adsQf6YOuHk4/hcl0IQ0VyaAPCTKy1hpvvuMvToA=; b=hECihx4iSwCT3ErcHlsMpNDCBSf7IMXJd7ig1KrBWyKP6mMzYINshZ92xnMGajWVb/ zwreTLnSBoVhuo8jGtAk/y3yF4ygopUHHOVKEyhNfNrMvN0SgSK9Dm2xcs6kRdxTCKqZ 0RtwX/3jN9nI2b+hUyNmddJWv6bMVoIp8NgX3GjErFLEfNSWXFZShj2gTA872qCQSV8z LOs+LySWYk8DNs+A1v5L7hoI/KiwSwrIJLHj1PS0pDfTr+PlNURJS+m+aZHjV6RkurVj US/+iFyxO1tfyUWfqe7iu3tFP+GU8GAcVBO72QEqX1PXreC0RvIXk6sL0I880Zmnn4GV Og2w== X-Gm-Message-State: AGi0PubPTUMlxCR1s0/dfnAaP0Y3bVj6L0PBqzwnl9+x6EiSVK1FXOHV Fc8qT6kZl/cUFQSpTdeEHT21RXVahuA= X-Google-Smtp-Source: APiQypIY/lsYH9jkplAgo63dsv2FusR2ApzoSWwTm3r+WrnEFIwF2IWQPt9IeqRI9ywlYYxRIrzKQg== X-Received: by 2002:a37:6415:: with SMTP id y21mr18669645qkb.258.1587579401043; Wed, 22 Apr 2020 11:16:41 -0700 (PDT) Received: from localhost.localdomain ([168.121.99.161]) by smtp.gmail.com with ESMTPSA id d26sm4360227qkk.69.2020.04.22.11.16.39 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Wed, 22 Apr 2020 11:16:40 -0700 (PDT) From: Dan Gora To: dev@dpdk.org, =?UTF-8?q?Mattias=20R=C3=B6nnblom?= Cc: David Marchand , Jerin Jacob , Dan Gora Date: Wed, 22 Apr 2020 15:15:24 -0300 Message-Id: <20200422181524.18679-3-dg@adax.com> X-Mailer: git-send-email 2.24.1.425.g7034cd094b In-Reply-To: <20200422181524.18679-1-dg@adax.com> References: <20200421195446.1730-1-dg@adax.com> <20200422181524.18679-1-dg@adax.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Subject: [dpdk-dev] [PATCH v3 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 | 36 +++++++++++++++++++++++++----- lib/librte_eal/meson.build | 3 --- 2 files changed, 30 insertions(+), 9 deletions(-) diff --git a/lib/librte_eal/common/rte_random.c b/lib/librte_eal/common/rte_random.c index 2c84c8527..f8036aa20 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 +177,41 @@ 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 == NULL) + return -1; + + dlerror(); + sym = dlsym(handle, "getentropy"); + if (dlerror() != NULL) { + /* Cannot resolve getentropy */ + dlclose(handle); + 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 -- 2.24.1.425.g7034cd094b