linux-stable/arch/x86/kernel/asm-offsets.c
Andy Lutomirski c482feefe1 x86/entry/64: Make cpu_entry_area.tss read-only
The TSS is a fairly juicy target for exploits, and, now that the TSS
is in the cpu_entry_area, it's no longer protected by kASLR.  Make it
read-only on x86_64.

On x86_32, it can't be RO because it's written by the CPU during task
switches, and we use a task gate for double faults.  I'd also be
nervous about errata if we tried to make it RO even on configurations
without double fault handling.

[ tglx: AMD confirmed that there is no problem on 64-bit with TSS RO.  So
  	it's probably safe to assume that it's a non issue, though Intel
  	might have been creative in that area. Still waiting for
  	confirmation. ]

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bpetkov@suse.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Link: https://lkml.kernel.org/r/20171204150606.733700132@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-17 14:27:52 +01:00

102 lines
3.1 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Generate definitions needed by assembly language modules.
* This code generates raw asm output which is post-processed to extract
* and format the required data.
*/
#define COMPILE_OFFSETS
#include <linux/crypto.h>
#include <linux/sched.h>
#include <linux/stddef.h>
#include <linux/hardirq.h>
#include <linux/suspend.h>
#include <linux/kbuild.h>
#include <asm/processor.h>
#include <asm/thread_info.h>
#include <asm/sigframe.h>
#include <asm/bootparam.h>
#include <asm/suspend.h>
#ifdef CONFIG_XEN
#include <xen/interface/xen.h>
#endif
#ifdef CONFIG_X86_32
# include "asm-offsets_32.c"
#else
# include "asm-offsets_64.c"
#endif
void common(void) {
BLANK();
OFFSET(TASK_threadsp, task_struct, thread.sp);
#ifdef CONFIG_CC_STACKPROTECTOR
OFFSET(TASK_stack_canary, task_struct, stack_canary);
#endif
BLANK();
OFFSET(TASK_TI_flags, task_struct, thread_info.flags);
OFFSET(TASK_addr_limit, task_struct, thread.addr_limit);
BLANK();
OFFSET(crypto_tfm_ctx_offset, crypto_tfm, __crt_ctx);
BLANK();
OFFSET(pbe_address, pbe, address);
OFFSET(pbe_orig_address, pbe, orig_address);
OFFSET(pbe_next, pbe, next);
#if defined(CONFIG_X86_32) || defined(CONFIG_IA32_EMULATION)
BLANK();
OFFSET(IA32_SIGCONTEXT_ax, sigcontext_32, ax);
OFFSET(IA32_SIGCONTEXT_bx, sigcontext_32, bx);
OFFSET(IA32_SIGCONTEXT_cx, sigcontext_32, cx);
OFFSET(IA32_SIGCONTEXT_dx, sigcontext_32, dx);
OFFSET(IA32_SIGCONTEXT_si, sigcontext_32, si);
OFFSET(IA32_SIGCONTEXT_di, sigcontext_32, di);
OFFSET(IA32_SIGCONTEXT_bp, sigcontext_32, bp);
OFFSET(IA32_SIGCONTEXT_sp, sigcontext_32, sp);
OFFSET(IA32_SIGCONTEXT_ip, sigcontext_32, ip);
BLANK();
OFFSET(IA32_RT_SIGFRAME_sigcontext, rt_sigframe_ia32, uc.uc_mcontext);
#endif
#ifdef CONFIG_PARAVIRT
BLANK();
OFFSET(PARAVIRT_PATCH_pv_cpu_ops, paravirt_patch_template, pv_cpu_ops);
OFFSET(PARAVIRT_PATCH_pv_irq_ops, paravirt_patch_template, pv_irq_ops);
OFFSET(PV_IRQ_irq_disable, pv_irq_ops, irq_disable);
OFFSET(PV_IRQ_irq_enable, pv_irq_ops, irq_enable);
OFFSET(PV_CPU_iret, pv_cpu_ops, iret);
OFFSET(PV_CPU_read_cr0, pv_cpu_ops, read_cr0);
OFFSET(PV_MMU_read_cr2, pv_mmu_ops, read_cr2);
#endif
#ifdef CONFIG_XEN
BLANK();
OFFSET(XEN_vcpu_info_mask, vcpu_info, evtchn_upcall_mask);
OFFSET(XEN_vcpu_info_pending, vcpu_info, evtchn_upcall_pending);
#endif
BLANK();
OFFSET(BP_scratch, boot_params, scratch);
OFFSET(BP_secure_boot, boot_params, secure_boot);
OFFSET(BP_loadflags, boot_params, hdr.loadflags);
OFFSET(BP_hardware_subarch, boot_params, hdr.hardware_subarch);
OFFSET(BP_version, boot_params, hdr.version);
OFFSET(BP_kernel_alignment, boot_params, hdr.kernel_alignment);
OFFSET(BP_init_size, boot_params, hdr.init_size);
OFFSET(BP_pref_address, boot_params, hdr.pref_address);
OFFSET(BP_code32_start, boot_params, hdr.code32_start);
BLANK();
DEFINE(PTREGS_SIZE, sizeof(struct pt_regs));
/* Layout info for cpu_entry_area */
OFFSET(CPU_ENTRY_AREA_tss, cpu_entry_area, tss);
OFFSET(CPU_ENTRY_AREA_entry_trampoline, cpu_entry_area, entry_trampoline);
OFFSET(CPU_ENTRY_AREA_SYSENTER_stack, cpu_entry_area, SYSENTER_stack_page);
DEFINE(SIZEOF_SYSENTER_stack, sizeof(struct SYSENTER_stack));
}