From 26670c8260a03add519ee26d3da7ac2bce64ee1e Mon Sep 17 00:00:00 2001 From: Varun Wadekar <vwadekar@nvidia.com> Date: Tue, 7 Jun 2016 21:21:59 -0700 Subject: [PATCH] tlkd: execute standard SMC calls on the boot CPU This patch checks if standard SMC calls, meant for TLK, are issued only on the boot CPU. TLK is UP Trusted OS stack and so we need this check to avoid the NS world calling into TLK from any other CPU. The previous check tied TLK to CPU0, but the boot CPU can be other than CPU0 in some scenarios. Change-Id: I75eaafa32471ce19e9920433c2f97b6b5fc02d86 Signed-off-by: Varun Wadekar <vwadekar@nvidia.com> --- services/spd/tlkd/tlkd_main.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) diff --git a/services/spd/tlkd/tlkd_main.c b/services/spd/tlkd/tlkd_main.c index 0fddcb27d..5ebe4fdd1 100644 --- a/services/spd/tlkd/tlkd_main.c +++ b/services/spd/tlkd/tlkd_main.c @@ -1,5 +1,5 @@ /* - * Copyright (c) 2015, ARM Limited and Contributors. All rights reserved. + * Copyright (c) 2015-2016, ARM Limited and Contributors. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: @@ -58,6 +58,11 @@ extern const spd_pm_ops_t tlkd_pm_ops; ******************************************************************************/ tlk_context_t tlk_ctx; +/******************************************************************************* + * CPU number on which TLK booted up + ******************************************************************************/ +static int boot_cpu; + /* TLK UID: RFC-4122 compliant UUID (version-5, sha-1) */ DEFINE_SVC_UUID(tlk_uuid, 0xbd11e9c9, 0x2bba, 0x52ee, 0xb1, 0x72, @@ -132,6 +137,12 @@ int32_t tlkd_init(void) cm_init_my_context(tlk_entry_point); + /* + * TLK runs only on a single CPU. Store the value of the boot + * CPU for sanity checking later. + */ + boot_cpu = plat_my_core_pos(); + /* * Arrange for an entry into the test secure payload. */ @@ -163,8 +174,8 @@ uint64_t tlkd_smc_handler(uint32_t smc_fid, /* Passing a NULL context is a critical programming error */ assert(handle); - /* These SMCs are only supported by CPU0 */ - if ((read_mpidr() & MPIDR_CPU_MASK) != 0) + /* These SMCs are only supported by a single CPU */ + if (boot_cpu != plat_my_core_pos()) SMC_RET1(handle, SMC_UNK); /* Determine which security state this SMC originated from */ -- GitLab