From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BBE1BC433EF for ; Wed, 26 Jan 2022 22:52:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231830AbiAZWwF (ORCPT ); Wed, 26 Jan 2022 17:52:05 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34854 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232046AbiAZWwE (ORCPT ); Wed, 26 Jan 2022 17:52:04 -0500 Received: from mail-il1-x12d.google.com (mail-il1-x12d.google.com [IPv6:2607:f8b0:4864:20::12d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3AFA4C061748; Wed, 26 Jan 2022 14:52:04 -0800 (PST) Received: by mail-il1-x12d.google.com with SMTP id e8so955900ilm.13; Wed, 26 Jan 2022 14:52:04 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=SbX/CA9rx3VdoijI1jnik093tt/YSMZq2p12OY56GJE=; b=FDvaV/SVpssUS1kX5dDZFCvk8MRpwyvPx0Z+IIgr78SYs83UY/9cNwv7wxVU1y71zf YFn/8hqfrl1wpKm+qrMwLTtYLgFwIHRyIQvqaO8hmWCF3/DT0nR2VJbNPIhsV+2792di Ndq/uKMuB8daKf19+dT1VHwKgYjzr9DN4aHQKfqjtxDYXvNa4EFjA5GxA22vTDUcn4JF 6jMRF8eZyCPe0ilfZBvCGqBHNsU8fABVwF6U63Hq6deKhB72TpkZyGtaZvdCyfVw8icq cbAnBwyH1JDD81+4HRRQ5b+NL34bUnHL/pxfxb1FCI+VZh3/OMe0W+NyRVlJWZqseDyF +ZYQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=SbX/CA9rx3VdoijI1jnik093tt/YSMZq2p12OY56GJE=; b=MzHU2+FiqXoXktfOO9hrCVfkAEoFrTQCtLWWd3YAj3o9u2ZgPekMZSlvlqQi2J9C8t Y4khvDno/bslm94o6kMw8XqmQTxDLDE4HpRTa49oRlMp6nLKxJP9tdTA3X4CDIw4nCe3 FZf7Xqc+IJePYU2mPPxski9+X1VnwpF8aO94zkXPy93qDQz4pOthW7Ucx4BHtKP4Ji3r O8ZsOV/3AO+NiK0MNUAv4mU5+18wUaYwQxzjEW9bfIaDm4ZFCGZ5HHF345nQaWF+MFOt llWbIyY90wy66nYOB7JwFUdXXXcuitarwWxh7EyPA6dyjk135JF2MaR9FzX+VQW0khYX X/fg== X-Gm-Message-State: AOAM531ynjfs7XUBHx07MvqJyVa7b8DgE4PEmQ+sxJhwYtOH7mE3hLQY FCYbgmcf527StMvN5AFRf4dKZjBoe2fJz/XewUs= X-Google-Smtp-Source: ABdhPJz7GBY/JMkN6SYLj8sxtQBg5EJtrS4PlUVpZ/JYCUtK5E7iqpZDgUjlCM2KZJxqGEF7BOK/ADklNvpBSQT7mZ4= X-Received: by 2002:a05:6e02:158a:: with SMTP id m10mr925657ilu.59.1643237523612; Wed, 26 Jan 2022 14:52:03 -0800 (PST) MIME-Version: 1.0 References: <20220119135450.564115-1-Jason@zx2c4.com> In-Reply-To: <20220119135450.564115-1-Jason@zx2c4.com> From: John Stultz Date: Wed, 26 Jan 2022 14:51:52 -0800 Message-ID: Subject: Re: [PATCH] lib/crypto: blake2s: avoid indirect calls to compression function for Clang CFI To: "Jason A. Donenfeld" Cc: Miles Chen , Ard Biesheuvel , Linux ARM , Linux Crypto Mailing List , Linux Kernel Mailing List , linux-mediatek@lists.infradead.org, Nick Desaulniers , Sami Tolvanen , YongQin Liu Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org On Fri, Jan 21, 2022 at 11:17 AM Jason A. Donenfeld wrote: > > blake2s_compress_generic is weakly aliased to blake2s_generic. The > current harness for function selection uses a function pointer, which is > ordinarily inlined and resolved at compile time. But when Clang's CFI is > enabled, CFI still triggers when making an indirect call via a weak > symbol. This seems like a bug in Clang's CFI, as though it's bucketing > weak symbols and strong symbols differently. It also only seems to > trigger when "full LTO" mode is used, rather than "thin LTO". > > [ 0.000000][ T0] Kernel panic - not syncing: CFI failure (target: blake2s_compress_generic+0x0/0x1444) > [ 0.000000][ T0] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.16.0-mainline-06981-g076c855b846e #1 > [ 0.000000][ T0] Hardware name: MT6873 (DT) > [ 0.000000][ T0] Call trace: > [ 0.000000][ T0] dump_backtrace+0xfc/0x1dc > [ 0.000000][ T0] dump_stack_lvl+0xa8/0x11c > [ 0.000000][ T0] panic+0x194/0x464 > [ 0.000000][ T0] __cfi_check_fail+0x54/0x58 > [ 0.000000][ T0] __cfi_slowpath_diag+0x354/0x4b0 > [ 0.000000][ T0] blake2s_update+0x14c/0x178 > [ 0.000000][ T0] _extract_entropy+0xf4/0x29c > [ 0.000000][ T0] crng_initialize_primary+0x24/0x94 > [ 0.000000][ T0] rand_initialize+0x2c/0x6c > [ 0.000000][ T0] start_kernel+0x2f8/0x65c > [ 0.000000][ T0] __primary_switched+0xc4/0x7be4 > [ 0.000000][ T0] Rebooting in 5 seconds.. YongQin also reported hitting this issue(also, only in the LTO=full case) on the db845c dev board. Sami pointed me to this patch and I just wanted to confirm it gets things booting again. Reported-by: YongQin Liu Tested-by: John Stultz Thanks so much for the quick analysis and fix! -john From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 886D4C433EF for ; Wed, 26 Jan 2022 22:52:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:Cc:To:Subject:Message-ID:Date:From: In-Reply-To:References:MIME-Version:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=8NhVH3y+RO2HfoDzjXZPi+LugqF04Pa45CsIIXSc1PM=; b=XlXGz6GCWsvX3c yuPIRg5Am2pWV8SEsYepczcqsM3Flx9ao+Wpr2QdPAsnSnVo9faJQeeBv43q59SHzJSz4mCUWhZbw dOo/046BvWkGWKze7DCOoZ0BSIfH5RMshOewcPwG84jJuB+5L0O/mtLgXAnIFKwRwTrNKKk+vigF8 BzWvtqrrSijbUBTjO2Z+vmB6r2o8EHjXENCwyoexrFLAITHtpd8hakJBtu4FHGtLguXTrdxTdp3xi FqnZS0kul6gNSlH6VDKbnzd/4rdpV7u95iQYuSxRPTXDW+h1/doLudvjYBTyNr8YYg4TO8FkuF6Ul 6vLd6/agV/6X32nt4SvA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nCr9J-00Di5C-NA; Wed, 26 Jan 2022 22:52:21 +0000 Received: from mail-il1-x12c.google.com ([2607:f8b0:4864:20::12c]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nCr97-00Di2P-0c; Wed, 26 Jan 2022 22:52:10 +0000 Received: by mail-il1-x12c.google.com with SMTP id z4so998940ilz.4; Wed, 26 Jan 2022 14:52:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=SbX/CA9rx3VdoijI1jnik093tt/YSMZq2p12OY56GJE=; b=FDvaV/SVpssUS1kX5dDZFCvk8MRpwyvPx0Z+IIgr78SYs83UY/9cNwv7wxVU1y71zf YFn/8hqfrl1wpKm+qrMwLTtYLgFwIHRyIQvqaO8hmWCF3/DT0nR2VJbNPIhsV+2792di Ndq/uKMuB8daKf19+dT1VHwKgYjzr9DN4aHQKfqjtxDYXvNa4EFjA5GxA22vTDUcn4JF 6jMRF8eZyCPe0ilfZBvCGqBHNsU8fABVwF6U63Hq6deKhB72TpkZyGtaZvdCyfVw8icq cbAnBwyH1JDD81+4HRRQ5b+NL34bUnHL/pxfxb1FCI+VZh3/OMe0W+NyRVlJWZqseDyF +ZYQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=SbX/CA9rx3VdoijI1jnik093tt/YSMZq2p12OY56GJE=; b=2Hcp08FQ4HGRDyJya2Q29492JArLlTn6JC0SP5Fe/5Psl6lkCvZrzjcuk+FMoANkdP I1Nb6FprJisia515iwSktl/w/P8b7S/nAyrKc3nA29bZRinWAzwsz1MzoDX8oY4q99zt kWp20Ik5JB+9f2w9h/i5MRCSeF4mZ7GKmSODKUlStMgS1kj4KtGD1G91h3oL2IlhT1ax cQlaEZj817X1vjX3kuYLzdu3IhVziUg+xd75LO8v0OYA69TAAm+vjTHe2hjs4gg2icbl LlxCOi2Zb05W01DICuFGvUZYDUbnJiCK78RqUGhvs0aEioFjIbMFYH4L1cCACLSnbfWr sxQg== X-Gm-Message-State: AOAM5331oZQJwRaIEeO3epGI904wpXMMyHlPKbhHrtrm2EWOcamm9GiU YYmwFk+Lq0Gz0Kjdlu7JMhDMh7ckdBowQ6QDx2g= X-Google-Smtp-Source: ABdhPJz7GBY/JMkN6SYLj8sxtQBg5EJtrS4PlUVpZ/JYCUtK5E7iqpZDgUjlCM2KZJxqGEF7BOK/ADklNvpBSQT7mZ4= X-Received: by 2002:a05:6e02:158a:: with SMTP id m10mr925657ilu.59.1643237523612; Wed, 26 Jan 2022 14:52:03 -0800 (PST) MIME-Version: 1.0 References: <20220119135450.564115-1-Jason@zx2c4.com> In-Reply-To: <20220119135450.564115-1-Jason@zx2c4.com> From: John Stultz Date: Wed, 26 Jan 2022 14:51:52 -0800 Message-ID: Subject: Re: [PATCH] lib/crypto: blake2s: avoid indirect calls to compression function for Clang CFI To: "Jason A. Donenfeld" Cc: Miles Chen , Ard Biesheuvel , Linux ARM , Linux Crypto Mailing List , Linux Kernel Mailing List , linux-mediatek@lists.infradead.org, Nick Desaulniers , Sami Tolvanen , YongQin Liu X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220126_145209_084503_A40F8387 X-CRM114-Status: GOOD ( 12.70 ) X-BeenThere: linux-mediatek@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "Linux-mediatek" Errors-To: linux-mediatek-bounces+linux-mediatek=archiver.kernel.org@lists.infradead.org On Fri, Jan 21, 2022 at 11:17 AM Jason A. Donenfeld wrote: > > blake2s_compress_generic is weakly aliased to blake2s_generic. The > current harness for function selection uses a function pointer, which is > ordinarily inlined and resolved at compile time. But when Clang's CFI is > enabled, CFI still triggers when making an indirect call via a weak > symbol. This seems like a bug in Clang's CFI, as though it's bucketing > weak symbols and strong symbols differently. It also only seems to > trigger when "full LTO" mode is used, rather than "thin LTO". > > [ 0.000000][ T0] Kernel panic - not syncing: CFI failure (target: blake2s_compress_generic+0x0/0x1444) > [ 0.000000][ T0] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.16.0-mainline-06981-g076c855b846e #1 > [ 0.000000][ T0] Hardware name: MT6873 (DT) > [ 0.000000][ T0] Call trace: > [ 0.000000][ T0] dump_backtrace+0xfc/0x1dc > [ 0.000000][ T0] dump_stack_lvl+0xa8/0x11c > [ 0.000000][ T0] panic+0x194/0x464 > [ 0.000000][ T0] __cfi_check_fail+0x54/0x58 > [ 0.000000][ T0] __cfi_slowpath_diag+0x354/0x4b0 > [ 0.000000][ T0] blake2s_update+0x14c/0x178 > [ 0.000000][ T0] _extract_entropy+0xf4/0x29c > [ 0.000000][ T0] crng_initialize_primary+0x24/0x94 > [ 0.000000][ T0] rand_initialize+0x2c/0x6c > [ 0.000000][ T0] start_kernel+0x2f8/0x65c > [ 0.000000][ T0] __primary_switched+0xc4/0x7be4 > [ 0.000000][ T0] Rebooting in 5 seconds.. YongQin also reported hitting this issue(also, only in the LTO=full case) on the db845c dev board. Sami pointed me to this patch and I just wanted to confirm it gets things booting again. Reported-by: YongQin Liu Tested-by: John Stultz Thanks so much for the quick analysis and fix! -john _______________________________________________ Linux-mediatek mailing list Linux-mediatek@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-mediatek From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id DE2E3C433F5 for ; Wed, 26 Jan 2022 22:53:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:Cc:To:Subject:Message-ID:Date:From: In-Reply-To:References:MIME-Version:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=00wi97z+n20EkkyuN+FcETRoouihZS2IJcao6utjD0M=; b=GjvmjXehwHQdRN hsubmeURvUNpn9OVjWKLbpyJQRbgFHYyNu0KbjVra0/1fKTGRljFSML1bi3xJoaxePXjhCRa+df2l 64cYu1jcPKEIKa2qwgZdnYLGzAeWWpZ6gnNGgyGu6Jh08MHbxXBFF5EiKhAknt4f5vRAaGAgXPwLx 5kofT62jEc891b9FQ/Apd9SanfKn6+sSAKhGBqlEmSUw/DPNj65ja/uN68KXq0aAfpmFdxlxgNevC U4ddmlLloJY8yZwgDvYwPtAtuiNMJ2ozZlP0isZPJt6PGnAsC8AQ9/3yCqa19I3CVmq3pyhRccusF emYA1MRFa3hs1l5UOohA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nCr9A-00Di3b-3D; Wed, 26 Jan 2022 22:52:12 +0000 Received: from mail-il1-x12c.google.com ([2607:f8b0:4864:20::12c]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nCr97-00Di2P-0c; Wed, 26 Jan 2022 22:52:10 +0000 Received: by mail-il1-x12c.google.com with SMTP id z4so998940ilz.4; Wed, 26 Jan 2022 14:52:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=SbX/CA9rx3VdoijI1jnik093tt/YSMZq2p12OY56GJE=; b=FDvaV/SVpssUS1kX5dDZFCvk8MRpwyvPx0Z+IIgr78SYs83UY/9cNwv7wxVU1y71zf YFn/8hqfrl1wpKm+qrMwLTtYLgFwIHRyIQvqaO8hmWCF3/DT0nR2VJbNPIhsV+2792di Ndq/uKMuB8daKf19+dT1VHwKgYjzr9DN4aHQKfqjtxDYXvNa4EFjA5GxA22vTDUcn4JF 6jMRF8eZyCPe0ilfZBvCGqBHNsU8fABVwF6U63Hq6deKhB72TpkZyGtaZvdCyfVw8icq cbAnBwyH1JDD81+4HRRQ5b+NL34bUnHL/pxfxb1FCI+VZh3/OMe0W+NyRVlJWZqseDyF +ZYQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=SbX/CA9rx3VdoijI1jnik093tt/YSMZq2p12OY56GJE=; b=2Hcp08FQ4HGRDyJya2Q29492JArLlTn6JC0SP5Fe/5Psl6lkCvZrzjcuk+FMoANkdP I1Nb6FprJisia515iwSktl/w/P8b7S/nAyrKc3nA29bZRinWAzwsz1MzoDX8oY4q99zt kWp20Ik5JB+9f2w9h/i5MRCSeF4mZ7GKmSODKUlStMgS1kj4KtGD1G91h3oL2IlhT1ax cQlaEZj817X1vjX3kuYLzdu3IhVziUg+xd75LO8v0OYA69TAAm+vjTHe2hjs4gg2icbl LlxCOi2Zb05W01DICuFGvUZYDUbnJiCK78RqUGhvs0aEioFjIbMFYH4L1cCACLSnbfWr sxQg== X-Gm-Message-State: AOAM5331oZQJwRaIEeO3epGI904wpXMMyHlPKbhHrtrm2EWOcamm9GiU YYmwFk+Lq0Gz0Kjdlu7JMhDMh7ckdBowQ6QDx2g= X-Google-Smtp-Source: ABdhPJz7GBY/JMkN6SYLj8sxtQBg5EJtrS4PlUVpZ/JYCUtK5E7iqpZDgUjlCM2KZJxqGEF7BOK/ADklNvpBSQT7mZ4= X-Received: by 2002:a05:6e02:158a:: with SMTP id m10mr925657ilu.59.1643237523612; Wed, 26 Jan 2022 14:52:03 -0800 (PST) MIME-Version: 1.0 References: <20220119135450.564115-1-Jason@zx2c4.com> In-Reply-To: <20220119135450.564115-1-Jason@zx2c4.com> From: John Stultz Date: Wed, 26 Jan 2022 14:51:52 -0800 Message-ID: Subject: Re: [PATCH] lib/crypto: blake2s: avoid indirect calls to compression function for Clang CFI To: "Jason A. Donenfeld" Cc: Miles Chen , Ard Biesheuvel , Linux ARM , Linux Crypto Mailing List , Linux Kernel Mailing List , linux-mediatek@lists.infradead.org, Nick Desaulniers , Sami Tolvanen , YongQin Liu X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220126_145209_084503_A40F8387 X-CRM114-Status: GOOD ( 12.70 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, Jan 21, 2022 at 11:17 AM Jason A. Donenfeld wrote: > > blake2s_compress_generic is weakly aliased to blake2s_generic. The > current harness for function selection uses a function pointer, which is > ordinarily inlined and resolved at compile time. But when Clang's CFI is > enabled, CFI still triggers when making an indirect call via a weak > symbol. This seems like a bug in Clang's CFI, as though it's bucketing > weak symbols and strong symbols differently. It also only seems to > trigger when "full LTO" mode is used, rather than "thin LTO". > > [ 0.000000][ T0] Kernel panic - not syncing: CFI failure (target: blake2s_compress_generic+0x0/0x1444) > [ 0.000000][ T0] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.16.0-mainline-06981-g076c855b846e #1 > [ 0.000000][ T0] Hardware name: MT6873 (DT) > [ 0.000000][ T0] Call trace: > [ 0.000000][ T0] dump_backtrace+0xfc/0x1dc > [ 0.000000][ T0] dump_stack_lvl+0xa8/0x11c > [ 0.000000][ T0] panic+0x194/0x464 > [ 0.000000][ T0] __cfi_check_fail+0x54/0x58 > [ 0.000000][ T0] __cfi_slowpath_diag+0x354/0x4b0 > [ 0.000000][ T0] blake2s_update+0x14c/0x178 > [ 0.000000][ T0] _extract_entropy+0xf4/0x29c > [ 0.000000][ T0] crng_initialize_primary+0x24/0x94 > [ 0.000000][ T0] rand_initialize+0x2c/0x6c > [ 0.000000][ T0] start_kernel+0x2f8/0x65c > [ 0.000000][ T0] __primary_switched+0xc4/0x7be4 > [ 0.000000][ T0] Rebooting in 5 seconds.. YongQin also reported hitting this issue(also, only in the LTO=full case) on the db845c dev board. Sami pointed me to this patch and I just wanted to confirm it gets things booting again. Reported-by: YongQin Liu Tested-by: John Stultz Thanks so much for the quick analysis and fix! -john _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel