e0aefd11d9
This patch extends the protection domain framework with a third plugin that is a hybrid of the previous two. The hardware task switching mechanism has a strictly-defined format for TSS data structures that causes more space to be consumed than would otherwise be required. This patch defines a smaller data structure that is allocated for each protection domain, only requiring 32 bytes instead of 128 bytes. It uses the same multi-segment memory layout as the TSS-based plugin and leaves paging disabled. However, it uses a similar mechanism as the paging plugin to perform system call dispatches and returns. For additional information, please refer to cpu/x86/mm/README.md.
134 lines
4.3 KiB
ArmAsm
134 lines
4.3 KiB
ArmAsm
/*
|
|
* Copyright (C) 2015, Intel Corporation. All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
*
|
|
* 3. Neither the name of the copyright holder nor the names of its
|
|
* contributors may be used to endorse or promote products derived
|
|
* from this software without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
|
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
|
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
|
|
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
|
|
* COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
|
|
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
|
|
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
|
|
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
|
|
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
|
|
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
|
|
* OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
*/
|
|
|
|
#include "syscalls-int.h"
|
|
#include "prot-domains.h"
|
|
#include "gdt-layout.h"
|
|
#include "stacks.h"
|
|
|
|
/* Must match definitions (plus the trailing 's') in multi-segment.h */
|
|
#define SEG_MMIO fs
|
|
#define SEG_KERN fs
|
|
|
|
.text
|
|
|
|
/* Invoke the system call return dispatcher from the default privilege
|
|
* level
|
|
*/
|
|
.global prot_domains_sysret_stub
|
|
prot_domains_sysret_stub:
|
|
int $PROT_DOMAINS_SYSRET_DISPATCH_INT
|
|
|
|
.macro save_segs
|
|
#if X86_CONF_PROT_DOMAINS == X86_CONF_PROT_DOMAINS__SWSEG
|
|
/* Save (and restore, in restore_segs) MMIO segment register into
|
|
* callee-saved register in case a system call was invoked from a region in
|
|
* which MMIO is enabled.
|
|
*/
|
|
push %SEG_MMIO
|
|
#endif
|
|
.endm
|
|
|
|
.macro restore_segs
|
|
#if X86_CONF_PROT_DOMAINS == X86_CONF_PROT_DOMAINS__SWSEG
|
|
pop %SEG_MMIO
|
|
#endif
|
|
.endm
|
|
|
|
/* Refresh most of the segment registers in case they were corrupted by
|
|
* userspace code to prevent that from corrupting the operation of the
|
|
* privileged code.
|
|
*/
|
|
.macro load_kern_segs
|
|
#if X86_CONF_PROT_DOMAINS == X86_CONF_PROT_DOMAINS__SWSEG
|
|
mov $GDT_SEL_DATA, %eax
|
|
mov %eax, %ds
|
|
mov %eax, %es
|
|
mov $GDT_SEL_DATA_KERN_EXC, %eax
|
|
mov %eax, %SEG_KERN
|
|
#endif
|
|
.endm
|
|
|
|
/* Invoke the system call dispatcher C routine */
|
|
.global prot_domains_syscall_dispatcher
|
|
prot_domains_syscall_dispatcher:
|
|
mov %esp, %ecx /*< interrupt_stack_t *intr_stk */
|
|
/* EDX already set to "dom_client_data_t to_dcd" by syscall stub */
|
|
save_segs
|
|
push %eax /*< syscalls_entrypoint_t *syscall */
|
|
load_kern_segs
|
|
call prot_domains_syscall_dispatcher_impl
|
|
/* fastcall convention, so callee pops arguments */
|
|
restore_segs
|
|
iret
|
|
|
|
/* Invoke the system call return dispatcher C routine */
|
|
.global prot_domains_sysret_dispatcher
|
|
prot_domains_sysret_dispatcher:
|
|
mov %esp, %ecx /*< interrupt_stack_t *intr_stk */
|
|
save_segs
|
|
load_kern_segs
|
|
call prot_domains_sysret_dispatcher_impl
|
|
restore_segs
|
|
/* Zero caller-saved registers in case they contain secrets. The system call
|
|
* handlers and dispatchers need to preserve the callee-saved registers.
|
|
*/
|
|
xor %eax, %eax
|
|
xor %ecx, %ecx
|
|
xor %edx, %edx
|
|
iret
|
|
|
|
.global prot_domains_launch_kernel
|
|
prot_domains_launch_kernel:
|
|
#if X86_CONF_PROT_DOMAINS == X86_CONF_PROT_DOMAINS__PAGING
|
|
mov $GDT_SEL_DATA, %eax
|
|
mov %eax, %ds
|
|
mov %eax, %es
|
|
mov %eax, %fs
|
|
mov %eax, %gs
|
|
#else
|
|
mov $GDT_SEL_LDT(DOM_ID_kern), %eax
|
|
lldt %ax
|
|
call multi_segment_launch_kernel
|
|
#endif
|
|
/* init interrupt return stack: */
|
|
pushl $GDT_SEL_STK
|
|
lea stacks_main, %eax
|
|
/* matches STACKS_INIT_TOP, plus 4 since an address has been consumed: */
|
|
add $(STACKS_SIZE_MAIN - 4), %eax
|
|
pushl %eax
|
|
pushl $EFLAGS_IOPL(PRIV_LVL_INT)
|
|
pushl $GDT_SEL_CODE
|
|
pushl $0 /* will be overwritten by syscall_dispatcher_impl */
|
|
/* fastcall convention: */
|
|
mov %esp, %ecx
|
|
call prot_domains_launch_kernel_impl
|
|
iretl
|