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x86: Add support for (paging-based) protection domains

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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.
This commit is contained in:
Michael LeMay 2015-08-10 08:34:02 -07:00
parent b0de416682
commit 3908253038
48 changed files with 3558 additions and 295 deletions
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19
cpu/x86/init/common/idt.c
View file

@ -28,9 +28,13 @@
* OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "gdt-layout.h"
#include "prot-domains.h"
#include <stdint.h>
#include "helpers.h"
#include "segmentation.h"
#include "idt.h"
#define NUM_DESC 256
@ -55,22 +59,27 @@ typedef struct intr_gate_desc {
* of the IDT should be aligned on an 8-byte boundary to maximize performance
* of cache line fills.
*/
static intr_gate_desc_t idt[NUM_DESC] __attribute__ ((aligned(8)));
static intr_gate_desc_t __attribute__((aligned(8))) ATTR_BSS_KERN
idt[NUM_DESC];
/*---------------------------------------------------------------------------*/
/* XXX: If you change this function prototype, make sure you fix the assembly
* code in SET_INTERRUPT_HANDLER macro in interrupt.h. Otherwise, you might
* code in SET_INT_EXC_HANDLER macro in interrupt.h. Otherwise, you might
* face a very-hard-to-find bug in the interrupt handling system.
*/
void
idt_set_intr_gate_desc(int intr_num, uint32_t offset)
idt_set_intr_gate_desc(int intr_num,
uint32_t offset,
uint16_t cs,
uint16_t dpl)
{
intr_gate_desc_t *desc = &idt[intr_num];
desc->offset_low = offset & 0xFFFF;
desc->selector = 0x08; /* Offset in GDT for code segment */
desc->selector = cs;
desc->fixed = BIT(9) | BIT(10);
desc->d = 1;
desc->dpl = 0;
desc->dpl = dpl;
desc->p = 1;
desc->offset_high = (offset >> 16) & 0xFFFF;
}