contiki/cpu/x86/mm/syscalls-int.h
Michael LeMay e0aefd11d9 x86: Add support for SW-switched segment-based protection domains
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.
2016-04-22 08:16:43 -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 %" SEG_KERN "s:" #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_ */