linux/arch/arm/kernel/asm-offsets.c
Ard Biesheuvel 189af46571 ARM: smp: add support for per-task stack canaries
On ARM, we currently only change the value of the stack canary when
switching tasks if the kernel was built for UP. On SMP kernels, this
is impossible since the stack canary value is obtained via a global
symbol reference, which means
a) all running tasks on all CPUs must use the same value
b) we can only modify the value when no kernel stack frames are live
   on any CPU, which is effectively never.

So instead, use a GCC plugin to add a RTL pass that replaces each
reference to the address of the __stack_chk_guard symbol with an
expression that produces the address of the 'stack_canary' field
that is added to struct thread_info. This way, each task will use
its own randomized value.

Cc: Russell King <linux@armlinux.org.uk>
Cc: Kees Cook <keescook@chromium.org>
Cc: Emese Revfy <re.emese@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Laura Abbott <labbott@redhat.com>
Cc: kernel-hardening@lists.openwall.com
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
2018-12-12 13:20:07 -08:00

198 lines
7.8 KiB
C

/*
* Copyright (C) 1995-2003 Russell King
* 2001-2002 Keith Owens
*
* Generate definitions needed by assembly language modules.
* This code generates raw asm output which is post-processed to extract
* and format the required data.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/compiler.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/dma-mapping.h>
#ifdef CONFIG_KVM_ARM_HOST
#include <linux/kvm_host.h>
#endif
#include <asm/cacheflush.h>
#include <asm/glue-df.h>
#include <asm/glue-pf.h>
#include <asm/mach/arch.h>
#include <asm/thread_info.h>
#include <asm/memory.h>
#include <asm/mpu.h>
#include <asm/procinfo.h>
#include <asm/suspend.h>
#include <asm/vdso_datapage.h>
#include <asm/hardware/cache-l2x0.h>
#include <linux/kbuild.h>
#include "signal.h"
/*
* Make sure that the compiler and target are compatible.
*/
#if defined(__APCS_26__)
#error Sorry, your compiler targets APCS-26 but this kernel requires APCS-32
#endif
/*
* GCC 4.8.0-4.8.2: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58854
* miscompiles find_get_entry(), and can result in EXT3 and EXT4
* filesystem corruption (possibly other FS too).
*/
#if defined(GCC_VERSION) && GCC_VERSION >= 40800 && GCC_VERSION < 40803
#error Your compiler is too buggy; it is known to miscompile kernels
#error and result in filesystem corruption and oopses.
#endif
int main(void)
{
DEFINE(TSK_ACTIVE_MM, offsetof(struct task_struct, active_mm));
#ifdef CONFIG_STACKPROTECTOR
DEFINE(TSK_STACK_CANARY, offsetof(struct task_struct, stack_canary));
#endif
BLANK();
DEFINE(TI_FLAGS, offsetof(struct thread_info, flags));
DEFINE(TI_PREEMPT, offsetof(struct thread_info, preempt_count));
DEFINE(TI_ADDR_LIMIT, offsetof(struct thread_info, addr_limit));
DEFINE(TI_TASK, offsetof(struct thread_info, task));
DEFINE(TI_CPU, offsetof(struct thread_info, cpu));
DEFINE(TI_CPU_DOMAIN, offsetof(struct thread_info, cpu_domain));
DEFINE(TI_CPU_SAVE, offsetof(struct thread_info, cpu_context));
DEFINE(TI_USED_CP, offsetof(struct thread_info, used_cp));
DEFINE(TI_TP_VALUE, offsetof(struct thread_info, tp_value));
DEFINE(TI_FPSTATE, offsetof(struct thread_info, fpstate));
#ifdef CONFIG_VFP
DEFINE(TI_VFPSTATE, offsetof(struct thread_info, vfpstate));
#ifdef CONFIG_SMP
DEFINE(VFP_CPU, offsetof(union vfp_state, hard.cpu));
#endif
#endif
#ifdef CONFIG_ARM_THUMBEE
DEFINE(TI_THUMBEE_STATE, offsetof(struct thread_info, thumbee_state));
#endif
#ifdef CONFIG_IWMMXT
DEFINE(TI_IWMMXT_STATE, offsetof(struct thread_info, fpstate.iwmmxt));
#endif
#ifdef CONFIG_CRUNCH
DEFINE(TI_CRUNCH_STATE, offsetof(struct thread_info, crunchstate));
#endif
#ifdef CONFIG_STACKPROTECTOR_PER_TASK
DEFINE(TI_STACK_CANARY, offsetof(struct thread_info, stack_canary));
#endif
DEFINE(THREAD_SZ_ORDER, THREAD_SIZE_ORDER);
BLANK();
DEFINE(S_R0, offsetof(struct pt_regs, ARM_r0));
DEFINE(S_R1, offsetof(struct pt_regs, ARM_r1));
DEFINE(S_R2, offsetof(struct pt_regs, ARM_r2));
DEFINE(S_R3, offsetof(struct pt_regs, ARM_r3));
DEFINE(S_R4, offsetof(struct pt_regs, ARM_r4));
DEFINE(S_R5, offsetof(struct pt_regs, ARM_r5));
DEFINE(S_R6, offsetof(struct pt_regs, ARM_r6));
DEFINE(S_R7, offsetof(struct pt_regs, ARM_r7));
DEFINE(S_R8, offsetof(struct pt_regs, ARM_r8));
DEFINE(S_R9, offsetof(struct pt_regs, ARM_r9));
DEFINE(S_R10, offsetof(struct pt_regs, ARM_r10));
DEFINE(S_FP, offsetof(struct pt_regs, ARM_fp));
DEFINE(S_IP, offsetof(struct pt_regs, ARM_ip));
DEFINE(S_SP, offsetof(struct pt_regs, ARM_sp));
DEFINE(S_LR, offsetof(struct pt_regs, ARM_lr));
DEFINE(S_PC, offsetof(struct pt_regs, ARM_pc));
DEFINE(S_PSR, offsetof(struct pt_regs, ARM_cpsr));
DEFINE(S_OLD_R0, offsetof(struct pt_regs, ARM_ORIG_r0));
DEFINE(PT_REGS_SIZE, sizeof(struct pt_regs));
DEFINE(SVC_DACR, offsetof(struct svc_pt_regs, dacr));
DEFINE(SVC_ADDR_LIMIT, offsetof(struct svc_pt_regs, addr_limit));
DEFINE(SVC_REGS_SIZE, sizeof(struct svc_pt_regs));
BLANK();
DEFINE(SIGFRAME_RC3_OFFSET, offsetof(struct sigframe, retcode[3]));
DEFINE(RT_SIGFRAME_RC3_OFFSET, offsetof(struct rt_sigframe, sig.retcode[3]));
BLANK();
#ifdef CONFIG_CACHE_L2X0
DEFINE(L2X0_R_PHY_BASE, offsetof(struct l2x0_regs, phy_base));
DEFINE(L2X0_R_AUX_CTRL, offsetof(struct l2x0_regs, aux_ctrl));
DEFINE(L2X0_R_TAG_LATENCY, offsetof(struct l2x0_regs, tag_latency));
DEFINE(L2X0_R_DATA_LATENCY, offsetof(struct l2x0_regs, data_latency));
DEFINE(L2X0_R_FILTER_START, offsetof(struct l2x0_regs, filter_start));
DEFINE(L2X0_R_FILTER_END, offsetof(struct l2x0_regs, filter_end));
DEFINE(L2X0_R_PREFETCH_CTRL, offsetof(struct l2x0_regs, prefetch_ctrl));
DEFINE(L2X0_R_PWR_CTRL, offsetof(struct l2x0_regs, pwr_ctrl));
BLANK();
#endif
#ifdef CONFIG_CPU_HAS_ASID
DEFINE(MM_CONTEXT_ID, offsetof(struct mm_struct, context.id.counter));
BLANK();
#endif
DEFINE(VMA_VM_MM, offsetof(struct vm_area_struct, vm_mm));
DEFINE(VMA_VM_FLAGS, offsetof(struct vm_area_struct, vm_flags));
BLANK();
DEFINE(VM_EXEC, VM_EXEC);
BLANK();
DEFINE(PAGE_SZ, PAGE_SIZE);
BLANK();
DEFINE(SYS_ERROR0, 0x9f0000);
BLANK();
DEFINE(SIZEOF_MACHINE_DESC, sizeof(struct machine_desc));
DEFINE(MACHINFO_TYPE, offsetof(struct machine_desc, nr));
DEFINE(MACHINFO_NAME, offsetof(struct machine_desc, name));
BLANK();
DEFINE(PROC_INFO_SZ, sizeof(struct proc_info_list));
DEFINE(PROCINFO_INITFUNC, offsetof(struct proc_info_list, __cpu_flush));
DEFINE(PROCINFO_MM_MMUFLAGS, offsetof(struct proc_info_list, __cpu_mm_mmu_flags));
DEFINE(PROCINFO_IO_MMUFLAGS, offsetof(struct proc_info_list, __cpu_io_mmu_flags));
BLANK();
#ifdef MULTI_DABORT
DEFINE(PROCESSOR_DABT_FUNC, offsetof(struct processor, _data_abort));
#endif
#ifdef MULTI_PABORT
DEFINE(PROCESSOR_PABT_FUNC, offsetof(struct processor, _prefetch_abort));
#endif
#ifdef MULTI_CPU
DEFINE(CPU_SLEEP_SIZE, offsetof(struct processor, suspend_size));
DEFINE(CPU_DO_SUSPEND, offsetof(struct processor, do_suspend));
DEFINE(CPU_DO_RESUME, offsetof(struct processor, do_resume));
#endif
#ifdef MULTI_CACHE
DEFINE(CACHE_FLUSH_KERN_ALL, offsetof(struct cpu_cache_fns, flush_kern_all));
#endif
#ifdef CONFIG_ARM_CPU_SUSPEND
DEFINE(SLEEP_SAVE_SP_SZ, sizeof(struct sleep_save_sp));
DEFINE(SLEEP_SAVE_SP_PHYS, offsetof(struct sleep_save_sp, save_ptr_stash_phys));
DEFINE(SLEEP_SAVE_SP_VIRT, offsetof(struct sleep_save_sp, save_ptr_stash));
#endif
BLANK();
DEFINE(DMA_BIDIRECTIONAL, DMA_BIDIRECTIONAL);
DEFINE(DMA_TO_DEVICE, DMA_TO_DEVICE);
DEFINE(DMA_FROM_DEVICE, DMA_FROM_DEVICE);
BLANK();
DEFINE(CACHE_WRITEBACK_ORDER, __CACHE_WRITEBACK_ORDER);
DEFINE(CACHE_WRITEBACK_GRANULE, __CACHE_WRITEBACK_GRANULE);
BLANK();
#ifdef CONFIG_KVM_ARM_HOST
DEFINE(VCPU_GUEST_CTXT, offsetof(struct kvm_vcpu, arch.ctxt));
DEFINE(VCPU_HOST_CTXT, offsetof(struct kvm_vcpu, arch.host_cpu_context));
DEFINE(CPU_CTXT_VFP, offsetof(struct kvm_cpu_context, vfp));
DEFINE(CPU_CTXT_GP_REGS, offsetof(struct kvm_cpu_context, gp_regs));
DEFINE(GP_REGS_USR, offsetof(struct kvm_regs, usr_regs));
#endif
BLANK();
#ifdef CONFIG_VDSO
DEFINE(VDSO_DATA_SIZE, sizeof(union vdso_data_store));
#endif
BLANK();
#ifdef CONFIG_ARM_MPU
DEFINE(MPU_RNG_INFO_RNGS, offsetof(struct mpu_rgn_info, rgns));
DEFINE(MPU_RNG_INFO_USED, offsetof(struct mpu_rgn_info, used));
DEFINE(MPU_RNG_SIZE, sizeof(struct mpu_rgn));
DEFINE(MPU_RGN_DRBAR, offsetof(struct mpu_rgn, drbar));
DEFINE(MPU_RGN_DRSR, offsetof(struct mpu_rgn, drsr));
DEFINE(MPU_RGN_DRACR, offsetof(struct mpu_rgn, dracr));
DEFINE(MPU_RGN_PRBAR, offsetof(struct mpu_rgn, prbar));
DEFINE(MPU_RGN_PRLAR, offsetof(struct mpu_rgn, prlar));
#endif
return 0;
}