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hw: PD in extra header with asserts reviewed

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ref #528
This commit is contained in:
Martin Stein 2013-09-06 17:37:09 +02:00 committed by Norman Feske
parent 5f64411ad7
commit 1843f10c62
5 changed files with 241 additions and 178 deletions
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12
base-hw/src/core/arm_v6/mode_transition.s
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@ -118,8 +118,8 @@
* region, thus one should map it solely accessable for privileged modes.
*/
.p2align 12
.global _mode_transition_begin
_mode_transition_begin:
.global _mt_begin
_mt_begin:
/*
* On user exceptions the CPU has to jump to one of the following
@ -225,10 +225,10 @@
_mt_buffer: .long 0
.p2align 2
.global _mode_transition_end
_mode_transition_end:
.global _mt_end
_mt_end:
/* FIXME this exists only because _vm_mon_entry pollutes kernel.cc */
.global _mon_vm_entry
_mon_vm_entry:
.global _mt_vm_entry_pic
_mt_vm_entry_pic:
1: b 1b

12
base-hw/src/core/arm_v7/mode_transition.s
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@ -248,8 +248,8 @@
* region, thus one should map it solely accessable for privileged modes.
*/
.p2align 12 /* page-aligned */
.global _mode_transition_begin
_mode_transition_begin:
.global _mt_begin
_mt_begin:
/*
* On user exceptions the CPU has to jump to one of the following
@ -299,8 +299,8 @@
.global _mt_buffer
_mt_buffer: .long 0
.global _mode_transition_end
_mode_transition_end:
.global _mt_end
_mt_end:
/*
* On vm exceptions the CPU has to jump to one of the following
@ -328,6 +328,6 @@
/* kernel must jump to this point to switch to a vm */
.p2align 2
.global _mon_vm_entry
_mon_vm_entry:
.global _mt_vm_entry_pic
_mt_vm_entry_pic:
_kernel_to_vm

188
base-hw/src/core/kernel.cc
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@ -27,9 +27,9 @@
#include <base/thread_state.h>
/* core includes */
#include <kernel/pd.h>
#include <platform_thread.h>
#include <platform_pd.h>
#include <tlb.h>
#include <trustzone.h>
/* base-hw includes */
@ -42,15 +42,6 @@ extern Genode::Native_utcb * _main_utcb;
extern int _kernel_stack_high;
extern "C" void CORE_MAIN();
/* get structure of mode transition PIC */
extern int _mode_transition_begin;
extern int _mode_transition_end;
extern int _mt_user_entry_pic;
extern int _mon_vm_entry;
extern Genode::addr_t _mt_client_context_ptr;
extern Genode::addr_t _mt_master_context_begin;
extern Genode::addr_t _mt_master_context_end;
namespace Kernel
{
/* import Genode types */
@ -58,138 +49,6 @@ namespace Kernel
typedef Genode::umword_t umword_t;
class Schedule_context;
/**
* Controls the mode transition code
*
* The code that switches between kernel/user mode must not exceed the
* smallest page size supported by the MMU. The Code must be position
* independent. This code has to be mapped in every PD, to ensure
* appropriate kernel invokation on CPU interrupts.
* This class controls the settings like kernel, user, and VM states
* that are handled by the mode transition PIC.
*/
struct Mode_transition_control
{
enum {
SIZE_LOG2 = Tlb::MIN_PAGE_SIZE_LOG2,
SIZE = 1 << SIZE_LOG2,
VIRT_BASE = Cpu::EXCEPTION_ENTRY,
VIRT_END = VIRT_BASE + SIZE,
ALIGNM_LOG2 = SIZE_LOG2,
};
addr_t const _virt_user_entry;
/**
* Constructor
*/
Mode_transition_control() :
_virt_user_entry(VIRT_BASE + ((addr_t)&_mt_user_entry_pic -
(addr_t)&_mode_transition_begin))
{
/* check if mode transition PIC fits into aligned region */
addr_t const pic_begin = (addr_t)&_mode_transition_begin;
addr_t const pic_end = (addr_t)&_mode_transition_end;
size_t const pic_size = pic_end - pic_begin;
assert(pic_size <= SIZE);
/* check if kernel context fits into the mode transition */
addr_t const kc_begin = (addr_t)&_mt_master_context_begin;
addr_t const kc_end = (addr_t)&_mt_master_context_end;
size_t const kc_size = kc_end - kc_begin;
assert(sizeof(Cpu::Context) <= kc_size);
}
/**
* Fetch next kernelmode context
*/
void fetch_master_context(Cpu::Context * const c) {
memcpy(&_mt_master_context_begin, c, sizeof(Cpu::Context)); }
/**
* Page aligned physical base of the mode transition PIC
*/
addr_t phys_base() { return (addr_t)&_mode_transition_begin; }
/**
* Jump to the usermode entry PIC
*/
void virt_user_entry() {
((void(*)(void))_virt_user_entry)(); }
};
/**
* Static mode transition control
*/
static Mode_transition_control * mtc()
{ return unsynchronized_singleton<Mode_transition_control>(); }
/**
* Kernel object that represents a Genode PD
*/
class Pd : public Object<Pd, MAX_PDS>
{
Tlb * const _tlb;
Platform_pd * const _platform_pd;
/* keep ready memory for size aligned extra costs at construction */
enum { EXTRA_SPACE_SIZE = 2*Tlb::MAX_COSTS_PER_TRANSLATION };
char _extra_space[EXTRA_SPACE_SIZE];
public:
/**
* Constructor
*/
Pd(Tlb * const t, Platform_pd * const platform_pd)
: _tlb(t), _platform_pd(platform_pd)
{
/* try to add translation for mode transition region */
Page_flags::access_t const flags = Page_flags::mode_transition();
unsigned const slog2 =
tlb()->insert_translation(mtc()->VIRT_BASE,
mtc()->phys_base(),
mtc()->SIZE_LOG2, flags);
/* extra space needed to translate mode transition region */
if (slog2)
{
/* Get size aligned extra space */
addr_t const es = (addr_t)&_extra_space;
addr_t const es_end = es + sizeof(_extra_space);
addr_t const aligned_es = (es_end - (1<<slog2)) &
~((1<<slog2)-1);
addr_t const aligned_es_end = aligned_es + (1<<slog2);
/* check attributes of aligned extra space */
assert(aligned_es >= es && aligned_es_end <= es_end)
/* translate mode transition region globally */
tlb()->insert_translation(mtc()->VIRT_BASE,
mtc()->phys_base(),
mtc()->SIZE_LOG2, flags,
(void *)aligned_es);
}
}
/**
* Add the CPU context 'c' to this PD
*/
void append_context(Cpu::Context * const c)
{
c->protection_domain(id());
c->tlb(tlb()->base());
}
/***************
** Accessors **
***************/
Tlb * const tlb() { return _tlb; }
Platform_pd * const platform_pd() { return _platform_pd; }
};
}
namespace Kernel
@ -229,7 +88,6 @@ namespace Kernel
return pd;
}
/**
* Get core attributes
*/
@ -325,8 +183,7 @@ void Kernel::Thread::handle_exception()
void Kernel::Thread::proceed()
{
_mt_client_context_ptr = (addr_t)static_cast<Genode::Cpu_state*>(this);
mtc()->virt_user_entry();
mtc()->continue_user(static_cast<Cpu::Context *>(this));
}
@ -353,7 +210,6 @@ void Kernel::Thread::_awaits_irq()
namespace Kernel
{
void deliver_signal(Signal_handler * const dst,
void * const base,
size_t const size)
@ -406,14 +262,7 @@ namespace Kernel
}
}
void proceed()
{
/* set context pointer for mode switch */
_mt_client_context_ptr = (addr_t)_state;
/* jump to assembler path */
((void(*)(void))&_mon_vm_entry)();
}
void proceed() { mtc()->continue_vm(_state); }
};
@ -1109,17 +958,6 @@ extern "C" void kernel()
/* enable kernel timer */
pic()->unmask(Timer::IRQ);
/* compose kernel CPU context */
static Cpu::Context kernel_context;
kernel_context.ip = (addr_t)kernel;
kernel_context.sp = (addr_t)&_kernel_stack_high;
/* add kernel to the core PD */
core()->append_context(&kernel_context);
/* offer the final kernel context to the mode transition page */
mtc()->fetch_master_context(&kernel_context);
/* TrustZone initialization code */
trustzone_initialization(pic());
@ -1272,3 +1110,23 @@ void Thread::kill_signal_context_done()
user_arg_0(1);
_schedule();
}
static Kernel::Mode_transition_control * Kernel::mtc()
{
/* compose CPU context for kernel entry */
struct Kernel_context : Cpu::Context
{
/**
* Constructor
*/
Kernel_context()
{
ip = (addr_t)kernel;
sp = (addr_t)&_kernel_stack_high;
core()->admit(this);
}
} * const k = unsynchronized_singleton<Kernel_context>();
/* initialize mode transition page */
return unsynchronized_singleton<Mode_transition_control>(k);
}

206
base-hw/src/core/kernel/pd.h Normal file
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@ -0,0 +1,206 @@
/*
* \brief Kernel backend for protection domains
* \author Martin Stein
* \date 2012-11-30
*/
/*
* Copyright (C) 2012-2013 Genode Labs GmbH
*
* This file is part of the Genode OS framework, which is distributed
* under the terms of the GNU General Public License version 2.
*/
#ifndef _KERNEL__PD_H_
#define _KERNEL__PD_H_
/* core includes */
#include <kernel/configuration.h>
#include <kernel/object.h>
#include <tlb.h>
#include <cpu.h>
#include <assert.h>
/* structure of the mode transition */
extern int _mt_begin;
extern int _mt_end;
extern int _mt_user_entry_pic;
extern int _mt_vm_entry_pic;
extern Genode::addr_t _mt_client_context_ptr;
extern Genode::addr_t _mt_master_context_begin;
extern Genode::addr_t _mt_master_context_end;
namespace Kernel
{
/**
* Controls the mode-transition page
*
* The mode transition page is a small memory region that is mapped by
* every PD to the same virtual address. It contains code that acts as a
* link between high privileged CPU mode (often called kernel) and low
* privileged CPU mode (often called userland). The mode transition
* control provides a simple interface to access the code from within
* the kernel.
*/
struct Mode_transition_control;
/**
* Return the system wide mode-transition control
*/
static Mode_transition_control * mtc();
/**
* Kernel backend of protection domains
*/
class Pd;
}
class Kernel::Mode_transition_control
{
friend class Pd;
private:
typedef Genode::Cpu Cpu;
typedef Genode::Cpu_state_modes Cpu_state_modes;
typedef Genode::Page_flags Page_flags;
addr_t const _virt_user_entry;
public:
enum {
SIZE_LOG2 = Tlb::MIN_PAGE_SIZE_LOG2,
SIZE = 1 << SIZE_LOG2,
VIRT_BASE = Cpu::EXCEPTION_ENTRY,
VIRT_END = VIRT_BASE + SIZE,
ALIGNM_LOG2 = SIZE_LOG2,
};
/**
* Constructor
*
* \param c CPU context for kernel mode entry
*/
Mode_transition_control(Cpu::Context * const c)
:
_virt_user_entry(VIRT_BASE + ((addr_t)&_mt_user_entry_pic -
(addr_t)&_mt_begin))
{
/* check if mode transition fits into aligned region */
addr_t const mt_begin = (addr_t)&_mt_begin;
addr_t const mt_end = (addr_t)&_mt_end;
size_t const mt_size = mt_end - mt_begin;
assert(mt_size <= SIZE);
/* check if kernel context fits into the mode transition */
addr_t const kc_begin = (addr_t)&_mt_master_context_begin;
addr_t const kc_end = (addr_t)&_mt_master_context_end;
size_t const kc_size = kc_end - kc_begin;
assert(sizeof(Cpu::Context) <= kc_size);
/* fetch kernel-mode context */
Genode::memcpy(&_mt_master_context_begin, c, sizeof(Cpu::Context));
}
/**
* Map the mode transition page to a virtual address space
*
* \param tlb translation buffer of the address space
* \param ram RAM donation for mapping (first try without)
*
* \return RAM-donation size that is needed to do the mapping
*/
size_t map(Tlb * tlb, addr_t ram = 0)
{
Page_flags::access_t const flags = Page_flags::mode_transition();
addr_t const phys_base = (addr_t)&_mt_begin;
return tlb->insert_translation(VIRT_BASE, phys_base, SIZE_LOG2,
flags, (void *)ram);
}
/**
* Continue user-mode execution with CPU context 'c'
*/
void continue_user(Cpu::Context * const c)
{
_mt_client_context_ptr = (addr_t)c;
((void(*)(void))_virt_user_entry)();
}
/**
* Continue VM execution with CPU state 's'
*/
void continue_vm(Cpu_state_modes * s)
{
_mt_client_context_ptr = (addr_t)s;
((void(*)(void))&_mt_vm_entry_pic)();
}
};
class Kernel::Pd : public Object<Pd, MAX_PDS>
{
private:
typedef Genode::Cpu Cpu;
Tlb * const _tlb;
Platform_pd * const _platform_pd;
/* keep ready memory for size-aligned extra costs at construction */
enum { EXTRA_RAM_SIZE = 2 * Tlb::MAX_COSTS_PER_TRANSLATION };
char _extra_ram[EXTRA_RAM_SIZE];
public:
/**
* Constructor
*
* \param tlb translation lookaside buffer of the PD
* \param platform_pd core object of the PD
*/
Pd(Tlb * const tlb, Platform_pd * const platform_pd)
:
_tlb(tlb), _platform_pd(platform_pd)
{
/* try to add translation for mode transition region */
unsigned const slog2 = mtc()->map(tlb);
/* extra ram needed to translate mode transition region */
if (slog2)
{
/* get size aligned extra ram */
addr_t const ram = (addr_t)&_extra_ram;
addr_t const ram_end = ram + sizeof(_extra_ram);
addr_t const aligned_ram = (ram_end - (1 << slog2)) &
~((1 << slog2) - 1);
addr_t const aligned_ram_end = aligned_ram + (1 << slog2);
/* check attributes of aligned extra ram */
assert(aligned_ram >= ram && aligned_ram_end <= ram_end)
/* translate mode transition region globally */
mtc()->map(tlb, aligned_ram);
}
}
/**
* Let the CPU context 'c' join the PD
*/
void admit(Cpu::Context * const c)
{
c->protection_domain(id());
c->tlb(tlb()->base());
}
/***************
** Accessors **
***************/
Tlb * tlb() const { return _tlb; }
Platform_pd * platform_pd() const { return _platform_pd; }
};
#endif /* _KERNEL__PD_H_ */

1
base-hw/src/core/kernel/thread.h
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@ -33,7 +33,6 @@ namespace Genode
namespace Kernel
{
typedef Genode::Cpu Cpu;
typedef Genode::Page_flags Page_flags;
typedef Genode::Core_tlb Core_tlb;
typedef Genode::Pagefault Pagefault;
typedef Genode::Native_utcb Native_utcb;