osd-contiki/cpu/x86/mm/tss-prot-domains.h

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/*
* Copyright (C) 2015-2016, 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.
*/
#ifndef CPU_X86_MM_TSS_PROT_DOMAINS_H_
#define CPU_X86_MM_TSS_PROT_DOMAINS_H_
#include <stdbool.h>
#include <stdint.h>
#include <stdlib.h>
#include "ldt-layout.h"
#include "segmentation.h"
#include "tss.h"
struct dom_kern_data {
/** Task State Segment */
tss_t tss;
/** Local Descriptor Table with per-domain descriptors */
segment_desc_t ldt[LDT_NUM_DESC];
} __attribute__((packed));
/* relies on dom_kern_data: */
#include "multi-segment.h"
/* relies on ATTR_KERN_ADDR_SPACE: */
#include "syscalls.h"
/**
* Data associated with each protection domain that is owned by clients of that
* domain and used to identify the domain.
*/
struct dom_client_data {
dom_id_t dom_id;
/** The selector is only 16 bits, but it is padded to 32 bits. */
uint32_t tss_sel;
};
extern uint32_t prot_domains_main_esp;
#define SYSCALLS_STUB_MIDDLE(nm) \
/* If already in the callee protection domain, skip the protection */ \
/* domain switch and directly invoke the system call body */ \
" je _syscall_" #nm "\n\t" \
" movl $" EXP_STRINGIFY(_syscall_ent_##nm) ", prot_domains_syscall\n\t" \
" mov %esp, prot_domains_main_esp\n\t"
#define SYSCALLS_STUB(nm) \
SYSCALLS_ALLOC_ENTRYPOINT(nm); \
asm ( \
".text\n\t" \
".global " #nm "\n\t" \
#nm ":\n\t" \
" str %ax\n\t" \
/* Compare current Task Register selector to selector for callee */ \
/* protection domain, in tss_sel field of dom_client_data */ \
" cmpw %ax, 8(%esp)\n\t" \
SYSCALLS_STUB_MIDDLE(nm) \
/* This will treat the dom_id field as the offset for the call, but */ \
/* that is ignored when performing a far call to a task */ \
" lcall *4(%esp)\n\t" \
" ret\n\t")
#define SYSCALLS_STUB_SINGLETON(nm, dcd) \
SYSCALLS_ALLOC_ENTRYPOINT(nm); \
asm ( \
".text\n\t" \
".global " #nm "\n\t" \
#nm ":\n\t" \
" str %ax\n\t" \
/* Compare current Task Register selector to selector for callee */ \
/* protection domain, in tss_sel field of dom_client_data */ \
" cmpw %ax, %" SEG_KERN "s:(4 + " #dcd ")\n\t" \
SYSCALLS_STUB_MIDDLE(nm) \
/* This will treat the dom_id field as the offset for the call, but */ \
/* that is ignored when performing a far call to a task */ \
" lcall *%" SEG_KERN "s:" #dcd "\n\t" \
" ret\n\t")
#define PROT_DOMAINS_ENTER_ISR(exc) \
MULTI_SEGMENT_ENTER_ISR(exc) \
/* It is possible that the system call dispatcher is being interrupted, */ \
/* and some interrupt handlers perform system calls. Thus, it is */ \
/* necessary to save and restore the system call dispatcher parameters */ \
/* (in callee-saved registers). */ \
"mov prot_domains_main_esp, %%esi\n\t" \
"mov prot_domains_syscall, %%edi\n\t" \
PROT_DOMAINS_ENTER_ISR_COMMON(exc)
#define PROT_DOMAINS_LEAVE_ISR(exc) \
PROT_DOMAINS_LEAVE_ISR_COMMON(exc) \
"mov %%edi, prot_domains_syscall\n\t" \
"mov %%esi, prot_domains_main_esp\n\t" \
MULTI_SEGMENT_LEAVE_ISR(exc)
/* Allocate two additional GDT entries for each protection domain. Note that
* the particular storage allocated by this statement may actually be used for
* some other protection domain, depending on how the linker happens to arrange
* all of the GDT storage. The GDT_IDX_TSS and GDT_IDX_LDT macros in
* gdt-layout.h determine which storage is used for each protection domain.
* Thus, this storage should not be referenced directly by its variable name.
*/
#define PROT_DOMAINS_ALLOC_IMPL(nm) \
static segment_desc_t ATTR_BSS_GDT_MID _gdt_storage_##nm[2]
#endif /* CPU_X86_MM_TSS_PROT_DOMAINS_H_ */