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osd-contiki/cpu/x86/mm/gdt-layout.h

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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.
2015-08-10 17:34:02 +02:00
/*
* 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_GDT_LAYOUT_H_
#define CPU_X86_MM_GDT_LAYOUT_H_
#include "prot-domains.h"
#if X86_CONF_PROT_DOMAINS == X86_CONF_PROT_DOMAINS__PAGING
/**
* Number of fixed GDT descriptors. Additional descriptors may be defined
* outside of gdt.c.
*/
#define GDT_NUM_FIXED_DESC 7
x86: Add TSS-based protection domain support This patch extends the protection domain framework with an additional plugin to use Task-State Segment (TSS) structures to offload much of the work of switching protection domains to the CPU. This can save space compared to paging, since paging requires two 4KiB page tables and one 32-byte page table plus one whole-system TSS and an additional 32-byte data structure for each protection domain, whereas the approach implemented by this patch just requires a 128-byte data structure for each protection domain. Only a small number of protection domains will typically be used, so n * 128 < 8328 + (n * 32). For additional information, please refer to cpu/x86/mm/README.md. GCC 6 is introducing named address spaces for the FS and GS segments [1]. LLVM Clang also provides address spaces for the FS and GS segments [2]. This patch also adds support to the multi-segment X86 memory management subsystem for using these features instead of inline assembly blocks, which enables type checking to detect some address space mismatches. [1] https://gcc.gnu.org/onlinedocs/gcc/Named-Address-Spaces.html [2] http://llvm.org/releases/3.3/tools/clang/docs/LanguageExtensions.html#target-specific-extensions
2015-08-08 00:43:10 +02:00
#elif X86_CONF_PROT_DOMAINS_MULTI_SEG
#define GDT_NUM_FIXED_DESC 11
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.
2015-08-10 17:34:02 +02:00
#else
#define GDT_NUM_FIXED_DESC 3
#endif
#define GDT_IDX_NULL 0
/**
* Flat code segment, used at boot and also for the rest of the system's
* runtime when protection domains are disabled
*/
#define GDT_IDX_CODE_FLAT 1
/**
* Flat data segment, used at boot and also for the rest of the system's
* runtime when protection domains are disabled
*/
#define GDT_IDX_DATA_FLAT 2
#if X86_CONF_PROT_DOMAINS != X86_CONF_PROT_DOMAINS__NONE
/** Default (post-boot) code segment */
#define GDT_IDX_CODE 3
/**
* Same bounds and permissions as default code segment, but at the interrupt
* handler privilege level
*/
#define GDT_IDX_CODE_INT 4
/** Stack segment for interrupt handlers */
#define GDT_IDX_STK_INT 5
x86: Add TSS-based protection domain support This patch extends the protection domain framework with an additional plugin to use Task-State Segment (TSS) structures to offload much of the work of switching protection domains to the CPU. This can save space compared to paging, since paging requires two 4KiB page tables and one 32-byte page table plus one whole-system TSS and an additional 32-byte data structure for each protection domain, whereas the approach implemented by this patch just requires a 128-byte data structure for each protection domain. Only a small number of protection domains will typically be used, so n * 128 < 8328 + (n * 32). For additional information, please refer to cpu/x86/mm/README.md. GCC 6 is introducing named address spaces for the FS and GS segments [1]. LLVM Clang also provides address spaces for the FS and GS segments [2]. This patch also adds support to the multi-segment X86 memory management subsystem for using these features instead of inline assembly blocks, which enables type checking to detect some address space mismatches. [1] https://gcc.gnu.org/onlinedocs/gcc/Named-Address-Spaces.html [2] http://llvm.org/releases/3.3/tools/clang/docs/LanguageExtensions.html#target-specific-extensions
2015-08-08 00:43:10 +02:00
#if X86_CONF_PROT_DOMAINS == X86_CONF_PROT_DOMAINS__PAGING
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.
2015-08-10 17:34:02 +02:00
#define GDT_IDX_CODE_EXC GDT_IDX_CODE_FLAT
/** Default data segment used by code at all privilege levels */
#define GDT_IDX_DATA 6
#define GDT_IDX_STK GDT_IDX_DATA
#define GDT_IDX_STK_EXC GDT_IDX_DATA_FLAT
#else
x86: Add TSS-based protection domain support This patch extends the protection domain framework with an additional plugin to use Task-State Segment (TSS) structures to offload much of the work of switching protection domains to the CPU. This can save space compared to paging, since paging requires two 4KiB page tables and one 32-byte page table plus one whole-system TSS and an additional 32-byte data structure for each protection domain, whereas the approach implemented by this patch just requires a 128-byte data structure for each protection domain. Only a small number of protection domains will typically be used, so n * 128 < 8328 + (n * 32). For additional information, please refer to cpu/x86/mm/README.md. GCC 6 is introducing named address spaces for the FS and GS segments [1]. LLVM Clang also provides address spaces for the FS and GS segments [2]. This patch also adds support to the multi-segment X86 memory management subsystem for using these features instead of inline assembly blocks, which enables type checking to detect some address space mismatches. [1] https://gcc.gnu.org/onlinedocs/gcc/Named-Address-Spaces.html [2] http://llvm.org/releases/3.3/tools/clang/docs/LanguageExtensions.html#target-specific-extensions
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/**
* Same bounds and permissions as default code segment, but at the exception
* handler privilege level
*/
#define GDT_IDX_CODE_EXC 6
/** R/W kernel data descriptor used during boot stage 1 */
#define GDT_IDX_DATA_KERN_EXC 7
/** Default data segment used by code at all privilege levels */
#define GDT_IDX_DATA 8
/**
* Default stack segment, which overlaps with the beginning of the default data
* segment
*/
#define GDT_IDX_STK 9
/** Stack segment for exception handlers */
#define GDT_IDX_STK_EXC 10
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.
2015-08-07 20:51:04 +02:00
#if X86_CONF_PROT_DOMAINS == X86_CONF_PROT_DOMAINS__TSS
x86: Add TSS-based protection domain support This patch extends the protection domain framework with an additional plugin to use Task-State Segment (TSS) structures to offload much of the work of switching protection domains to the CPU. This can save space compared to paging, since paging requires two 4KiB page tables and one 32-byte page table plus one whole-system TSS and an additional 32-byte data structure for each protection domain, whereas the approach implemented by this patch just requires a 128-byte data structure for each protection domain. Only a small number of protection domains will typically be used, so n * 128 < 8328 + (n * 32). For additional information, please refer to cpu/x86/mm/README.md. GCC 6 is introducing named address spaces for the FS and GS segments [1]. LLVM Clang also provides address spaces for the FS and GS segments [2]. This patch also adds support to the multi-segment X86 memory management subsystem for using these features instead of inline assembly blocks, which enables type checking to detect some address space mismatches. [1] https://gcc.gnu.org/onlinedocs/gcc/Named-Address-Spaces.html [2] http://llvm.org/releases/3.3/tools/clang/docs/LanguageExtensions.html#target-specific-extensions
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#define GDT_IDX_TSS(dom_id) (GDT_NUM_FIXED_DESC + (2 * (dom_id)))
#define GDT_IDX_LDT(dom_id) (GDT_NUM_FIXED_DESC + (2 * (dom_id)) + 1)
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.
2015-08-07 20:51:04 +02:00
#else
#define GDT_IDX_LDT(dom_id) (GDT_NUM_FIXED_DESC + (dom_id))
#endif
x86: Add TSS-based protection domain support This patch extends the protection domain framework with an additional plugin to use Task-State Segment (TSS) structures to offload much of the work of switching protection domains to the CPU. This can save space compared to paging, since paging requires two 4KiB page tables and one 32-byte page table plus one whole-system TSS and an additional 32-byte data structure for each protection domain, whereas the approach implemented by this patch just requires a 128-byte data structure for each protection domain. Only a small number of protection domains will typically be used, so n * 128 < 8328 + (n * 32). For additional information, please refer to cpu/x86/mm/README.md. GCC 6 is introducing named address spaces for the FS and GS segments [1]. LLVM Clang also provides address spaces for the FS and GS segments [2]. This patch also adds support to the multi-segment X86 memory management subsystem for using these features instead of inline assembly blocks, which enables type checking to detect some address space mismatches. [1] https://gcc.gnu.org/onlinedocs/gcc/Named-Address-Spaces.html [2] http://llvm.org/releases/3.3/tools/clang/docs/LanguageExtensions.html#target-specific-extensions
2015-08-08 00:43:10 +02:00
#endif
#else
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.
2015-08-10 17:34:02 +02:00
#define GDT_IDX_CODE GDT_IDX_CODE_FLAT
#define GDT_IDX_CODE_INT GDT_IDX_CODE_FLAT
#define GDT_IDX_CODE_EXC GDT_IDX_CODE_FLAT
#define GDT_IDX_DATA GDT_IDX_DATA_FLAT
#define GDT_IDX_STK GDT_IDX_DATA_FLAT
#define GDT_IDX_STK_INT GDT_IDX_DATA_FLAT
#define GDT_IDX_STK_EXC GDT_IDX_DATA_FLAT
#endif
#define GDT_SEL(idx, rpl) (((idx) << 3) | (rpl))
#define DT_SEL_GET_IDX(sel) ((sel) >> 3)
#define DT_SEL_GET_RPL(sel) ((sel) & 3)
#define GDT_SEL_NULL GDT_SEL(GDT_IDX_NULL, 0)
#define GDT_SEL_CODE_FLAT GDT_SEL(GDT_IDX_CODE_FLAT, PRIV_LVL_EXC)
#define GDT_SEL_DATA_FLAT GDT_SEL(GDT_IDX_DATA_FLAT, PRIV_LVL_EXC)
#define GDT_SEL_CODE GDT_SEL(GDT_IDX_CODE, PRIV_LVL_USER)
#define GDT_SEL_CODE_INT GDT_SEL(GDT_IDX_CODE_INT, PRIV_LVL_INT)
#define GDT_SEL_CODE_EXC GDT_SEL(GDT_IDX_CODE_EXC, PRIV_LVL_EXC)
#define GDT_SEL_DATA GDT_SEL(GDT_IDX_DATA, PRIV_LVL_EXC)
x86: Add TSS-based protection domain support This patch extends the protection domain framework with an additional plugin to use Task-State Segment (TSS) structures to offload much of the work of switching protection domains to the CPU. This can save space compared to paging, since paging requires two 4KiB page tables and one 32-byte page table plus one whole-system TSS and an additional 32-byte data structure for each protection domain, whereas the approach implemented by this patch just requires a 128-byte data structure for each protection domain. Only a small number of protection domains will typically be used, so n * 128 < 8328 + (n * 32). For additional information, please refer to cpu/x86/mm/README.md. GCC 6 is introducing named address spaces for the FS and GS segments [1]. LLVM Clang also provides address spaces for the FS and GS segments [2]. This patch also adds support to the multi-segment X86 memory management subsystem for using these features instead of inline assembly blocks, which enables type checking to detect some address space mismatches. [1] https://gcc.gnu.org/onlinedocs/gcc/Named-Address-Spaces.html [2] http://llvm.org/releases/3.3/tools/clang/docs/LanguageExtensions.html#target-specific-extensions
2015-08-08 00:43:10 +02:00
#define GDT_SEL_DATA_KERN_EXC GDT_SEL(GDT_IDX_DATA_KERN_EXC, PRIV_LVL_EXC)
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.
2015-08-10 17:34:02 +02:00
#define GDT_SEL_STK GDT_SEL(GDT_IDX_STK, PRIV_LVL_USER)
#define GDT_SEL_STK_INT GDT_SEL(GDT_IDX_STK_INT, PRIV_LVL_INT)
#define GDT_SEL_STK_EXC GDT_SEL(GDT_IDX_STK_EXC, PRIV_LVL_EXC)
x86: Add TSS-based protection domain support This patch extends the protection domain framework with an additional plugin to use Task-State Segment (TSS) structures to offload much of the work of switching protection domains to the CPU. This can save space compared to paging, since paging requires two 4KiB page tables and one 32-byte page table plus one whole-system TSS and an additional 32-byte data structure for each protection domain, whereas the approach implemented by this patch just requires a 128-byte data structure for each protection domain. Only a small number of protection domains will typically be used, so n * 128 < 8328 + (n * 32). For additional information, please refer to cpu/x86/mm/README.md. GCC 6 is introducing named address spaces for the FS and GS segments [1]. LLVM Clang also provides address spaces for the FS and GS segments [2]. This patch also adds support to the multi-segment X86 memory management subsystem for using these features instead of inline assembly blocks, which enables type checking to detect some address space mismatches. [1] https://gcc.gnu.org/onlinedocs/gcc/Named-Address-Spaces.html [2] http://llvm.org/releases/3.3/tools/clang/docs/LanguageExtensions.html#target-specific-extensions
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#define GDT_SEL_TSS(dom_id) GDT_SEL(GDT_IDX_TSS(dom_id), PRIV_LVL_USER)
#define GDT_SEL_LDT(dom_id) GDT_SEL(GDT_IDX_LDT(dom_id), PRIV_LVL_USER)
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.
2015-08-10 17:34:02 +02:00
#endif /* CPU_X86_MM_GDT_LAYOUT_H_ */
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