From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk0-f198.google.com (mail-qk0-f198.google.com [209.85.220.198]) by kanga.kvack.org (Postfix) with ESMTP id 323236B02C3 for ; Wed, 16 Aug 2017 18:47:02 -0400 (EDT) Received: by mail-qk0-f198.google.com with SMTP id f207so15170010qke.3 for ; Wed, 16 Aug 2017 15:47:02 -0700 (PDT) Received: from mail-qk0-f178.google.com (mail-qk0-f178.google.com. [209.85.220.178]) by mx.google.com with ESMTPS id u43si1811998qte.372.2017.08.16.15.47.01 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 16 Aug 2017 15:47:01 -0700 (PDT) Received: by mail-qk0-f178.google.com with SMTP id u139so28256166qka.1 for ; Wed, 16 Aug 2017 15:47:01 -0700 (PDT) From: Laura Abbott Subject: [PATCHv2 2/2] extract early boot entropy from the passed cmdline Date: Wed, 16 Aug 2017 15:46:50 -0700 Message-Id: <20170816224650.1089-3-labbott@redhat.com> In-Reply-To: <20170816224650.1089-1-labbott@redhat.com> References: <20170816224650.1089-1-labbott@redhat.com> Sender: owner-linux-mm@kvack.org List-ID: To: Kees Cook Cc: Daniel Micay , kernel-hardening@lists.openwall.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Andrew Morton , Laura Abbott From: Daniel Micay Existing Android bootloaders usually pass data useful as early entropy on the kernel command-line. It may also be the case on other embedded systems. Sample command-line from a Google Pixel running CopperheadOS: console=ttyHSL0,115200,n8 androidboot.console=ttyHSL0 androidboot.hardware=sailfish user_debug=31 ehci-hcd.park=3 lpm_levels.sleep_disabled=1 cma=32M@0-0xffffffff buildvariant=user veritykeyid=id:dfcb9db0089e5b3b4090a592415c28e1cb4545ab androidboot.bootdevice=624000.ufshc androidboot.verifiedbootstate=yellow androidboot.veritymode=enforcing androidboot.keymaster=1 androidboot.serialno=FA6CE0305299 androidboot.baseband=msm mdss_mdp.panel=1:dsi:0:qcom,mdss_dsi_samsung_ea8064tg_1080p_cmd:1:none:cfg:single_dsi androidboot.slot_suffix=_b fpsimd.fpsimd_settings=0 app_setting.use_app_setting=0 kernelflag=0x00000000 debugflag=0x00000000 androidboot.hardware.revision=PVT radioflag=0x00000000 radioflagex1=0x00000000 radioflagex2=0x00000000 cpumask=0x00000000 androidboot.hardware.ddr=4096MB,Hynix,LPDDR4 androidboot.ddrinfo=00000006 androidboot.ddrsize=4GB androidboot.hardware.color=GRA00 androidboot.hardware.ufs=32GB,Samsung androidboot.msm.hw_ver_id=268824801 androidboot.qf.st=2 androidboot.cid=11111111 androidboot.mid=G-2PW4100 androidboot.bootloader=8996-012001-1704121145 androidboot.oem_unlock_support=1 androidboot.fp_src=1 androidboot.htc.hrdump=detected androidboot.ramdump.opt=mem@2g:2g,mem@4g:2g androidboot.bootreason=reboot androidboot.ramdump_enable=0 ro root=/dev/dm-0 dm="system none ro,0 1 android-verity /dev/sda34" rootwait skip_initramfs init=/init androidboot.wificountrycode=US androidboot.boottime=1BLL:85,1BLE:669,2BLL:0,2BLE:1777,SW:6,KL:8136 Among other things, it contains a value unique to the device (androidboot.serialno=FA6CE0305299), unique to the OS builds for the device variant (veritykeyid=id:dfcb9db0089e5b3b4090a592415c28e1cb4545ab) and timings from the bootloader stages in milliseconds (androidboot.boottime=1BLL:85,1BLE:669,2BLL:0,2BLE:1777,SW:6,KL:8136). Signed-off-by: Daniel Micay [labbott: Line-wrapped command line] Signed-off-by: Laura Abbott --- init/main.c | 1 + 1 file changed, 1 insertion(+) diff --git a/init/main.c b/init/main.c index 21d599eaad06..cb051aec46ef 100644 --- a/init/main.c +++ b/init/main.c @@ -533,6 +533,7 @@ asmlinkage __visible void __init start_kernel(void) */ add_latent_entropy(); boot_init_stack_canary(); + add_device_randomness(command_line, strlen(command_line)); mm_init_cpumask(&init_mm); setup_command_line(command_line); setup_nr_cpu_ids(); -- 2.13.0 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org