contiki/cpu/x86/mm/syscalls-int.h
Michael LeMay 3908253038 x86: Add support for (paging-based) protection domains
This patch implements a simple, lightweight form of protection domains
using a pluggable framework.  Currently, the following plugin is
available:

 - Flat memory model with paging.

The overall goal of a protection domain implementation within this
framework is to define a set of resources that should be accessible to
each protection domain and to prevent that protection domain from
accessing other resources.  The details of each implementation of
protection domains may differ substantially, but they should all be
guided by the principle of least privilege.  However, that idealized
principle is balanced against the practical objectives of limiting the
number of relatively time-consuming context switches and minimizing
changes to existing code.

For additional information, please refer to cpu/x86/mm/README.md.

This patch also causes the C compiler to be used as the default linker
and assembler.
2016-03-21 17:18:06 -07:00

110 lines
5.1 KiB
C

/*
* 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.
*/
#ifndef CPU_X86_MM_SYSCALLS_INT_H_
#define CPU_X86_MM_SYSCALLS_INT_H_
/** Software interrupt number for dispatching a system call */
#define PROT_DOMAINS_SYSCALL_DISPATCH_INT 100
/** Software interrupt number for returning from a system call */
#define PROT_DOMAINS_SYSRET_DISPATCH_INT 101
#if !__ASSEMBLER__
#include <stdint.h>
extern dom_id_t cur_dom;
#define SYSCALLS_STUB_EPILOGUE(nm) \
/* Load the system call identifier into EAX, as required by */ \
/* prot_domains_syscall_dispatcher: */ \
" mov $" EXP_STRINGIFY(_syscall_ent_##nm) ", %eax\n\t" \
/* Check whether the server protection domain is already active: */ \
" cmp %edx, cur_dom\n\t" \
/* If so, skip the system call dispatcher and directly invoke the */ \
/* system call body: */ \
" je _syscall_" #nm "\n\t" \
" int $" EXP_STRINGIFY(PROT_DOMAINS_SYSCALL_DISPATCH_INT) "\n\t"
#define SYSCALLS_STUB(nm) \
SYSCALLS_ALLOC_ENTRYPOINT(nm); \
asm ( \
".text\n\t" \
".global " #nm "\n\t" \
#nm ":\n\t" \
/* First, load server protection domain ID into EDX, as required by */ \
/* prot_domains_syscall_dispatcher: */ \
/* Skip past return address on stack to obtain address of protection */ \
/* domain ID parameter: */ \
" mov 4(%esp), %edx\n\t" \
SYSCALLS_STUB_EPILOGUE(nm))
#define SYSCALLS_STUB_SINGLETON(nm, dcd) \
SYSCALLS_ALLOC_ENTRYPOINT(nm); \
asm ( \
".text\n\t" \
".global " #nm "\n\t" \
#nm ":\n\t" \
/* First, load server protection domain ID into EDX, as required by */ \
/* prot_domains_syscall_dispatcher: */ \
" mov " #dcd ", %edx\n\t" \
SYSCALLS_STUB_EPILOGUE(nm))
void syscalls_int_init(void);
void prot_domains_sysret_stub(void);
/* Inter-privilege level interrupt stack with no error code. */
typedef struct interrupt_stack {
uint32_t eip;
uint32_t cs;
uint32_t eflags;
uint32_t esp;
uint32_t ss;
} interrupt_stack_t;
#if 0
/* Declaration only included for documentation purposes: */
/**
* \brief Switch to a different protection domain.
* \param from_id Origin protection domain.
* \param to_id Destination protection domain.
* \return Segment selector for kernel data access (only used for
* multi-segment implementations).
*/
uint32_t prot_domains_switch(dom_id_t from_id,
dom_id_t to_id,
interrupt_stack_t *intr_stk);
#endif
#endif
#endif /* CPU_X86_MM_SYSCALLS_INT_H_ */