From ed1a203f6f2c4a2fc4a2d9135cd9669aef23e428 Mon Sep 17 00:00:00 2001 From: Laura Abbott Date: Wed, 13 Aug 2014 15:24:38 -0700 Subject: [PATCH] soc: qcom: Add better support for early random numbers The existing support for generating random numbers relied on a hacked up version of CONFIG_ARCH_RANDOM and was prone to scheduling while atomic bugs due to needing to take a mutex. We don't actually need the additional randomness all the time, the pool just needs to be initialized with some amount of random data to avoid getting the same result each time. Switch to this method for initializing the random pool. Change-Id: I804ec7556cbd18ff2d9869a03069fda1dd519a79 Signed-off-by: Laura Abbott [ohaugan@codeaurora.org: Fixed trivial merge conflicts] Signed-off-by: Olav Haugan --- arch/arm/include/asm/archrandom.h | 20 --------- drivers/soc/qcom/Kconfig | 8 ++++ drivers/soc/qcom/Makefile | 1 + .../soc/qcom}/early_random.c | 44 +++---------------- 4 files changed, 16 insertions(+), 57 deletions(-) delete mode 100644 arch/arm/include/asm/archrandom.h rename {arch/arm/mach-msm => drivers/soc/qcom}/early_random.c (57%) diff --git a/arch/arm/include/asm/archrandom.h b/arch/arm/include/asm/archrandom.h deleted file mode 100644 index 5530d450a098..000000000000 --- a/arch/arm/include/asm/archrandom.h +++ /dev/null @@ -1,20 +0,0 @@ -/* Copyright (c) 2013, The Linux Foundation. All rights reserved. - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 and - * only version 2 as published by the Free Software Foundation. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - */ - -#ifndef ARM_ASM_ARCHRANDOM_H -#define ARM_ASM_ARCHRANDOM_H - -extern int arch_get_random_long(unsigned long *v); -extern int arch_get_random_int(unsigned int *v); - -#endif diff --git a/drivers/soc/qcom/Kconfig b/drivers/soc/qcom/Kconfig index 2bc74941abc8..8c43effadc70 100644 --- a/drivers/soc/qcom/Kconfig +++ b/drivers/soc/qcom/Kconfig @@ -821,4 +821,12 @@ config QCOM_SMCINVOKE Enable SMCInvoke driver which supports capability based secure communication between QSEE and HLOS. +config QCOM_EARLY_RANDOM + bool "Initialize random pool very early" + help + The standard random pool may not initialize until late in the boot + process which means that any calls to get random numbers before then + may not be truly random. Select this option to make an early call + to get some random data to put in the pool. If unsure, say N. + source "drivers/soc/qcom/memshare/Kconfig" diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile index 434a114c000f..0105e03b082d 100644 --- a/drivers/soc/qcom/Makefile +++ b/drivers/soc/qcom/Makefile @@ -99,3 +99,4 @@ obj-$(CONFIG_MSM_RPM_LOG) += rpm_log.o obj-$(CONFIG_QSEE_IPC_IRQ_BRIDGE) += qsee_ipc_irq_bridge.o obj-$(CONFIG_WCD_DSP_GLINK) += wcd-dsp-glink.o obj-$(CONFIG_QCOM_SMCINVOKE) += smcinvoke.o +obj-$(CONFIG_QCOM_EARLY_RANDOM) += early_random.o diff --git a/arch/arm/mach-msm/early_random.c b/drivers/soc/qcom/early_random.c similarity index 57% rename from arch/arm/mach-msm/early_random.c rename to drivers/soc/qcom/early_random.c index e315b86a4315..de38fc04676c 100644 --- a/arch/arm/mach-msm/early_random.c +++ b/drivers/soc/qcom/early_random.c @@ -1,4 +1,4 @@ -/* Copyright (c) 2013, The Linux Foundation. All rights reserved. +/* Copyright (c) 2013-2014, 2016, The Linux Foundation. All rights reserved. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 and @@ -12,8 +12,9 @@ */ #include +#include -#include +#include #include #include @@ -21,32 +22,24 @@ #define TZ_SVC_CRYPTO 10 #define PRNG_CMD_ID 0x01 -static int use_arch_random = 1; struct tz_prng_data { uint8_t *out_buf; uint32_t out_buf_sz; } __packed; DEFINE_SCM_BUFFER(common_scm_buf) -DEFINE_MUTEX(arch_random_lock); #define RANDOM_BUFFER_SIZE PAGE_SIZE char random_buffer[RANDOM_BUFFER_SIZE] __aligned(PAGE_SIZE); -int arch_get_random_common(void *v, size_t size) +void __init init_random_pool(void) { struct tz_prng_data data; int ret; u32 resp; - if (!use_arch_random) - return 0; - - if (size > sizeof(random_buffer)) - return 0; - - mutex_lock(&arch_random_lock); data.out_buf = (uint8_t *) virt_to_phys(random_buffer); - data.out_buf_sz = size; + data.out_buf_sz = SZ_512; + dmac_flush_range(random_buffer, random_buffer + RANDOM_BUFFER_SIZE); ret = scm_call_noalloc(TZ_SVC_CRYPTO, PRNG_CMD_ID, &data, sizeof(data), &resp, sizeof(resp), @@ -54,30 +47,7 @@ int arch_get_random_common(void *v, size_t size) if (!ret) { dmac_inv_range(random_buffer, random_buffer + RANDOM_BUFFER_SIZE); - outer_inv_range( - (unsigned long) virt_to_phys(random_buffer), - (unsigned long) virt_to_phys(random_buffer) + - RANDOM_BUFFER_SIZE); - memcpy(v, random_buffer, size); + add_device_randomness(random_buffer, SZ_512); } - mutex_unlock(&arch_random_lock); - return !ret; } -int arch_get_random_long(unsigned long *v) -{ - return arch_get_random_common(v, sizeof(unsigned long)); -} - -int arch_get_random_int(unsigned int *v) -{ - return arch_get_random_common(v, sizeof(unsigned int)); -} - -int arch_random_init(void) -{ - use_arch_random = 0; - - return 0; -} -module_init(arch_random_init);