diff options
Diffstat (limited to 'drivers/soc/qcom/kernel_protect.c')
| -rw-r--r-- | drivers/soc/qcom/kernel_protect.c | 38 |
1 files changed, 34 insertions, 4 deletions
diff --git a/drivers/soc/qcom/kernel_protect.c b/drivers/soc/qcom/kernel_protect.c index 73192971..b48cd0bf 100644 --- a/drivers/soc/qcom/kernel_protect.c +++ b/drivers/soc/qcom/kernel_protect.c @@ -1,4 +1,4 @@ -/* Copyright (c) 2015, The Linux Foundation. All rights reserved. +/* Copyright (c) 2015,2016 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 @@ -14,10 +14,12 @@ #include <linux/printk.h> #include <linux/init.h> #include <linux/gfp.h> +#include <soc/qcom/scm.h> #include <soc/qcom/secure_buffer.h> #include <asm/sections.h> #include <asm/cacheflush.h> +#define KERNEL_PROTECT_MPU 0x24 #ifdef CONFIG_MSM_KERNEL_PROTECT_TEST @@ -38,6 +40,10 @@ static void msm_protect_kernel_test(void) */ char *addr = (char *)__alloc_pages_nodemask; + if (IS_ENABLED(CONFIG_MSM_KERNEL_PROTECT_MPU)) { + pr_err("MPU protected kernel code is HLOS writable\n"); + return; + } pr_err("Checking whether the kernel text is writable...\n"); pr_err("A BUG means it is writable (this is bad)\n"); pr_err("A stage-2 fault means it's not writable (this is good, but we'll still crash)\n"); @@ -84,9 +90,33 @@ static int __init msm_protect_kernel(void) pr_debug("assigning from phys: %pa to %pa\n", &kernel_x_start_rounded, &kernel_x_end); pr_debug("virtual: %p to %p\n", virt_start, virt_end); - ret = hyp_assign_phys(kernel_x_start_rounded, - kernel_x_end - kernel_x_start_rounded, - &vmid_hlos, 1, &vmid_hlos, &dest_perms, 1); + + if (IS_ENABLED(CONFIG_MSM_KERNEL_PROTECT_MPU)) { + struct scm_desc desc = {0}; + + if (!scm_is_call_available(SCM_SVC_MP, KERNEL_PROTECT_MPU)) + return 0; + + desc.args[0] = kernel_x_start_rounded; + desc.args[1] = kernel_x_end - kernel_x_start_rounded; + desc.arginfo = SCM_ARGS(2); + + ret = scm_call2(SCM_SIP_FNID(SCM_SVC_MP, + KERNEL_PROTECT_MPU), &desc); + if (ret) { + /* + * must not proceed if failed to MPU protect kernel + * text region + */ + panic("Failed to protect kernel region %pa -- %pa\n", + &kernel_x_start_rounded, + &kernel_x_end); + } + } else { + ret = hyp_assign_phys(kernel_x_start_rounded, + kernel_x_end - kernel_x_start_rounded, + &vmid_hlos, 1, &vmid_hlos, &dest_perms, 1); + } if (ret) /* * We want to fail relatively silently since not all |