From: Bryan O'Donoghue Subject: [RESEND PATCH 2/6] crypto: caam: Fix endless loop when RNG is already initialized Date: Wed, 24 Jan 2018 14:50:31 +0000 Message-ID: <1516805435-15034-3-git-send-email-pure.logic@nexus-software.ie> References: <1516805435-15034-1-git-send-email-pure.logic@nexus-software.ie> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Cc: fabio.estevam@nxp.com, peng.fan@nxp.com, herbert@gondor.apana.org.au, davem@davemloft.net, lukas.auer@aisec.fraunhofer.de, rui.silva@linaro.org, ryan.harkin@linaro.org, Bryan O'Donoghue To: horia.geanta@nxp.com, aymen.sghaier@nxp.com, linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org Return-path: Received: from mail-wm0-f65.google.com ([74.125.82.65]:43387 "EHLO mail-wm0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934072AbeAXOup (ORCPT ); Wed, 24 Jan 2018 09:50:45 -0500 Received: by mail-wm0-f65.google.com with SMTP id g1so8951375wmg.2 for ; Wed, 24 Jan 2018 06:50:45 -0800 (PST) In-Reply-To: <1516805435-15034-1-git-send-email-pure.logic@nexus-software.ie> Sender: linux-crypto-owner@vger.kernel.org List-ID: commit 1005bccd7a4a ("crypto: caam - enable instantiation of all RNG4 state handles") introduces a control when incrementing ent_delay which contains the following comment above it: /* * If either SH were instantiated by somebody else * (e.g. u-boot) then it is assumed that the entropy * parameters are properly set and thus the function * setting these (kick_trng(...)) is skipped. * Also, if a handle was instantiated, do not change * the TRNG parameters. */ The problem is if u-boot has already instantiated the RNG and TEE/OPTEE is running then instantiate_rng() will always return -EAGAIN and ent_delay will never increment causing the loop to never break. This patch fixes commit 1005bccd7a4a ("crypto: caam - enable instantiation of all RNG4 state handles") by always incrementing ent_delay if and only if both rng4_sh_init and inst_handles are non-zero for a given loop. This should allow the current behavior to continue while allowing the loop to break should (rng4_sh_init=1 && inst_handles 1) be true and instantiate_rng() return -EAGAIN forever. Fixes: 1005bccd7a4a ("crypto: caam - enable instantiation of all RNG4 state handles") Reported-by: Ryan Harkin Signed-off-by: Bryan O'Donoghue Cc: "Horia Geantă" Cc: Aymen Sghaier Cc: Fabio Estevam Cc: Peng Fan Cc: Herbert Xu Cc: "David S. Miller" Cc: Lukas Auer --- drivers/crypto/caam/ctrl.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/crypto/caam/ctrl.c b/drivers/crypto/caam/ctrl.c index 98986d3..0a1e96b 100644 --- a/drivers/crypto/caam/ctrl.c +++ b/drivers/crypto/caam/ctrl.c @@ -704,7 +704,10 @@ static int caam_probe(struct platform_device *pdev) ent_delay); kick_trng(pdev, ent_delay); ent_delay += 400; + } else if (ctrlpriv->rng4_sh_init && inst_handles) { + ent_delay += 400; } + /* * if instantiate_rng(...) fails, the loop will rerun * and the kick_trng(...) function will modfiy the -- 2.7.4