From patchwork Thu Aug 22 23:50:52 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Christopherson X-Patchwork-Id: 11110247 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 01DB913A4 for ; Thu, 22 Aug 2019 23:50:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DE29B23401 for ; Thu, 22 Aug 2019 23:50:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727421AbfHVXuy (ORCPT ); Thu, 22 Aug 2019 19:50:54 -0400 Received: from mga02.intel.com ([134.134.136.20]:61185 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726970AbfHVXuy (ORCPT ); Thu, 22 Aug 2019 19:50:54 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga003.jf.intel.com ([10.7.209.27]) by orsmga101.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 22 Aug 2019 16:50:54 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,419,1559545200"; d="scan'208";a="181553109" Received: from sjchrist-coffee.jf.intel.com ([10.54.74.41]) by orsmga003.jf.intel.com with ESMTP; 22 Aug 2019 16:50:53 -0700 From: Sean Christopherson To: Paolo Bonzini , =?utf-8?b?UmFkaW0gS3LEjW3DocWZ?= Cc: kvm@vger.kernel.org, Nadav Amit Subject: [kvm-unit-tests PATCH] x86: Fix breakage of fw_cfg for 32-bit unit tests Date: Thu, 22 Aug 2019 16:50:52 -0700 Message-Id: <20190822235052.3703-1-sean.j.christopherson@intel.com> X-Mailer: git-send-email 2.22.0 MIME-Version: 1.0 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Ensure the fw_cfg overrides are parsed prior consuming any of said overrides. fwcfg_get_u() treats zero as a valid overide value, which is slightly problematic since the overrides are in the .bss and thus initialized to zero. Add a limit check when indexing fw_override so that future code doesn't spontaneously explode. Cc: Nadav Amit Fixes: 03b1e4570f967 ("x86: Support environments without test-devices") Signed-off-by: Sean Christopherson Reviewed-by: Nadav Amit --- lib/x86/fwcfg.c | 10 ++++++++-- lib/x86/fwcfg.h | 2 -- x86/cstart64.S | 2 -- 3 files changed, 8 insertions(+), 6 deletions(-) diff --git a/lib/x86/fwcfg.c b/lib/x86/fwcfg.c index d8d797f..06ef62c 100644 --- a/lib/x86/fwcfg.c +++ b/lib/x86/fwcfg.c @@ -5,10 +5,11 @@ static struct spinlock lock; static long fw_override[FW_CFG_MAX_ENTRY]; +static bool fw_override_done; bool no_test_device; -void read_cfg_override(void) +static void read_cfg_override(void) { const char *str; int i; @@ -26,6 +27,8 @@ void read_cfg_override(void) if ((str = getenv("TEST_DEVICE"))) no_test_device = !atol(str); + + fw_override_done = true; } static uint64_t fwcfg_get_u(uint16_t index, int bytes) @@ -34,7 +37,10 @@ static uint64_t fwcfg_get_u(uint16_t index, int bytes) uint8_t b; int i; - if (fw_override[index] >= 0) + if (!fw_override_done) + read_cfg_override(); + + if (index < FW_CFG_MAX_ENTRY && fw_override[index] >= 0) return fw_override[index]; spin_lock(&lock); diff --git a/lib/x86/fwcfg.h b/lib/x86/fwcfg.h index 88dc7a7..2f17461 100644 --- a/lib/x86/fwcfg.h +++ b/lib/x86/fwcfg.h @@ -36,8 +36,6 @@ extern bool no_test_device; -void read_cfg_override(void); - static inline bool test_device_enabled(void) { return !no_test_device; diff --git a/x86/cstart64.S b/x86/cstart64.S index 23c1bd4..d4e4652 100644 --- a/x86/cstart64.S +++ b/x86/cstart64.S @@ -254,8 +254,6 @@ start64: mov %rax, __args(%rip) call __setup_args - /* Read the configuration before running smp_init */ - call read_cfg_override call smp_init call enable_x2apic