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[83.36.179.126]) by smtp.gmail.com with ESMTPSA id o2sm2879094wrj.21.2020.07.23.01.28.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 23 Jul 2020 01:28:26 -0700 (PDT) From: Jorge Ramirez-Ortiz To: jorge@foundries.io, sumit.garg@linaro.org, mpm@selenic.com, herbert@gondor.apana.org.au Cc: jens.wiklander@linaro.org, arnd@arndb.de, ricardo@foundries.io, mike@foundries.io, gregkh@linuxfoundation.org, op-tee@lists.trustedfirmware.org, linux-crypto@vger.kernel.org Subject: [PATCH 2/2] hwrng: optee: fix wait use case Date: Thu, 23 Jul 2020 10:28:21 +0200 Message-Id: <20200723082821.26237-2-jorge@foundries.io> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200723082821.26237-1-jorge@foundries.io> References: <20200723082821.26237-1-jorge@foundries.io> Sender: linux-crypto-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org The current code waits for data to be available before attempting a second read. However the second read would not be executed as the while loop exits. This fix does not wait if all data has been read and reads a second time if only partial data was retrieved on the first read. Signed-off-by: Jorge Ramirez-Ortiz --- drivers/char/hw_random/optee-rng.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/char/hw_random/optee-rng.c b/drivers/char/hw_random/optee-rng.c index 5bc4700c4dae..967d58bb9fda 100644 --- a/drivers/char/hw_random/optee-rng.c +++ b/drivers/char/hw_random/optee-rng.c @@ -122,13 +122,15 @@ static int optee_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait) if (max > MAX_ENTROPY_REQ_SZ) max = MAX_ENTROPY_REQ_SZ; - while (read == 0) { + for (;;) { rng_size = get_optee_rng_data(pvt_data, data, (max - read)); data += rng_size; read += rng_size; if (wait && pvt_data->data_rate) { + if (read == max) + return read; if (timeout-- == 0) return read; msleep((1000 * (max - read)) / pvt_data->data_rate); -- 2.17.1