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hw: avoid address overflow in Tlb::remove_region() 

ref #589
This commit is contained in:
Martin Stein 2013-09-16 15:35:00 +02:00 committed by Norman Feske
parent 909c2dbc95
commit de87fa1b5c
1 changed files with 51 additions and 63 deletions
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114
base-hw/src/core/tlb/arm.h
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@ -398,47 +398,43 @@ namespace Arm
}
/**
* Remove translations, wich overlap with a given virtual region
* Remove translations that overlap with a given virtual region
*
* \param vo offset of the virtual region within the region
* represented by this table
* \param vo region offset within the tables virtual region
* \param size region size
*/
void remove_region(addr_t const vo, size_t const size)
void remove_region(addr_t vo, size_t const size)
{
/* traverse all possibly affected entries */
addr_t residual_vo = vo;
addr_t const ve = vo + size;
unsigned i;
while (1)
{
/* check if anything is left over to remove */
if (residual_vo >= vo + size) return;
/* check if residual region overlaps with table */
if (_index_by_vo(i, residual_vo)) return;
/* update current entry and recalculate residual region */
if (vo >= ve) { return; }
if (_index_by_vo(i, vo)) { return; }
addr_t next_vo;
switch (Descriptor::type(_entries[i])) {
case Descriptor::FAULT: {
residual_vo = (residual_vo & Fault::VIRT_BASE_MASK)
+ Fault::VIRT_SIZE;
vo &= Fault::VIRT_BASE_MASK;
next_vo = vo + Fault::VIRT_SIZE;
break; }
case Descriptor::SMALL_PAGE: {
residual_vo = (residual_vo & Small_page::VIRT_BASE_MASK)
+ Small_page::VIRT_SIZE;
vo &= Small_page::VIRT_BASE_MASK;
Descriptor::invalidate(_entries[i]);
next_vo = vo + Small_page::VIRT_SIZE;
break; }
case Descriptor::LARGE_PAGE: {
PDBG("Removal of large pages not implemented");
PDBG("large pages not supported by now");
while (1) ;
break; }
}
if (next_vo < vo) { return; }
vo = next_vo;
}
}
@ -800,63 +796,55 @@ namespace Arm
}
/**
* Remove translations, wich overlap with a given virtual region
* Remove translations that overlap with a given virtual region
*
* \param vo offset of the virtual region within the region
* represented by this table
* \param vo region offset within the tables virtual region
* \param size region size
*/
void remove_region(addr_t const vo, size_t const size)
void remove_region(addr_t vo, size_t const size)
{
/* traverse all possibly affected entries */
addr_t residual_vo = vo;
addr_t const ve = vo + size;
unsigned i;
while (1)
{
/* check if anything is left over to remove */
if (residual_vo >= vo + size) return;
if (vo >= ve) { return; }
if (_index_by_vo(i, vo)) { return; }
addr_t next_vo;
switch (Descriptor::type(_entries[i])) {
/* check if the residual region overlaps with this table */
if (_index_by_vo(i, residual_vo)) return;
case Descriptor::FAULT: {
/* update current entry and recalculate residual region */
switch (Descriptor::type(_entries[i]))
{
case Descriptor::FAULT:
{
residual_vo = (residual_vo & Fault::VIRT_BASE_MASK)
+ Fault::VIRT_SIZE;
break;
}
case Descriptor::PAGE_TABLE:
{
/* instruct page table to remove residual region */
Page_table * const pt = (Page_table *)
(addr_t)Page_table_descriptor::Pa_31_10::masked(_entries[i]);
size_t const residual_size = vo + size - residual_vo;
addr_t const pt_vo = residual_vo
- Section::Pa_31_20::masked(residual_vo);
pt->remove_region(pt_vo, residual_size);
vo &= Fault::VIRT_BASE_MASK;
next_vo = vo + Fault::VIRT_SIZE;
break; }
/* recalculate residual region */
residual_vo = (residual_vo & Page_table::VIRT_BASE_MASK)
+ Page_table::VIRT_SIZE;
break;
}
case Descriptor::SECTION:
{
case Descriptor::PAGE_TABLE: {
typedef Page_table_descriptor Ptd;
typedef Page_table Pt;
vo &= Pt::VIRT_BASE_MASK;
Pt * const pt = (Pt *)Ptd::Pa_31_10::masked(_entries[i]);
addr_t const pt_vo = vo - Section::Pa_31_20::masked(vo);
pt->remove_region(pt_vo, ve - vo);
next_vo = vo + Pt::VIRT_SIZE;
break; }
case Descriptor::SECTION: {
vo &= Section::VIRT_BASE_MASK;
Descriptor::invalidate(_entries[i]);
residual_vo = (residual_vo & Section::VIRT_BASE_MASK)
+ Section::VIRT_SIZE;
break;
}
case Descriptor::SUPERSECTION:
{
PDBG("Removal of supersections not implemented");
while (1);
break;
}
next_vo = vo + Section::VIRT_SIZE;
break; }
case Descriptor::SUPERSECTION: {
PDBG("supersections not supported by now");
while (1) { }
break; }
}
if (next_vo < vo) { return; }
vo = next_vo;
}
}