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.
110 lines
5.1 KiB
C
110 lines
5.1 KiB
C
/*
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* Copyright (C) 2015, Intel Corporation. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* 3. Neither the name of the copyright holder nor the names of its
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* contributors may be used to endorse or promote products derived
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* from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
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* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
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* OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#ifndef CPU_X86_MM_SYSCALLS_INT_H_
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#define CPU_X86_MM_SYSCALLS_INT_H_
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/** Software interrupt number for dispatching a system call */
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#define PROT_DOMAINS_SYSCALL_DISPATCH_INT 100
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/** Software interrupt number for returning from a system call */
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#define PROT_DOMAINS_SYSRET_DISPATCH_INT 101
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#if !__ASSEMBLER__
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#include <stdint.h>
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extern dom_id_t cur_dom;
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#define SYSCALLS_STUB_EPILOGUE(nm) \
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/* Load the system call identifier into EAX, as required by */ \
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/* prot_domains_syscall_dispatcher: */ \
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" mov $" EXP_STRINGIFY(_syscall_ent_##nm) ", %eax\n\t" \
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/* Check whether the server protection domain is already active: */ \
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" cmp %edx, cur_dom\n\t" \
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/* If so, skip the system call dispatcher and directly invoke the */ \
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/* system call body: */ \
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" je _syscall_" #nm "\n\t" \
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" int $" EXP_STRINGIFY(PROT_DOMAINS_SYSCALL_DISPATCH_INT) "\n\t"
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#define SYSCALLS_STUB(nm) \
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SYSCALLS_ALLOC_ENTRYPOINT(nm); \
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asm ( \
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".text\n\t" \
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".global " #nm "\n\t" \
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#nm ":\n\t" \
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/* First, load server protection domain ID into EDX, as required by */ \
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/* prot_domains_syscall_dispatcher: */ \
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/* Skip past return address on stack to obtain address of protection */ \
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/* domain ID parameter: */ \
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" mov 4(%esp), %edx\n\t" \
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SYSCALLS_STUB_EPILOGUE(nm))
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#define SYSCALLS_STUB_SINGLETON(nm, dcd) \
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SYSCALLS_ALLOC_ENTRYPOINT(nm); \
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asm ( \
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".text\n\t" \
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".global " #nm "\n\t" \
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#nm ":\n\t" \
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/* First, load server protection domain ID into EDX, as required by */ \
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/* prot_domains_syscall_dispatcher: */ \
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" mov %" SEG_KERN "s:" #dcd ", %edx\n\t" \
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SYSCALLS_STUB_EPILOGUE(nm))
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void syscalls_int_init(void);
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void prot_domains_sysret_stub(void);
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/* Inter-privilege level interrupt stack with no error code. */
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typedef struct interrupt_stack {
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uint32_t eip;
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uint32_t cs;
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uint32_t eflags;
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uint32_t esp;
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uint32_t ss;
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} interrupt_stack_t;
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#if 0
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/* Declaration only included for documentation purposes: */
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/**
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* \brief Switch to a different protection domain.
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* \param from_id Origin protection domain.
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* \param to_id Destination protection domain.
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* \return Segment selector for kernel data access (only used for
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* multi-segment implementations).
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*/
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uint32_t prot_domains_switch(dom_id_t from_id,
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dom_id_t to_id,
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interrupt_stack_t *intr_stk);
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#endif
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#endif
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#endif /* CPU_X86_MM_SYSCALLS_INT_H_ */
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