ExternalVendorCode/genode
1
0
Fork 0
mirror of https://github.com/genodelabs/genode.git synced 2025-02-20 17:52:52 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

Remove context area from physical RAM allocator

Browse Source 
In base-fiasco, base-foc and base-pistachio, physical memory gets mapped
1:1 to core virtual memory. When the 'Ram_session_component' allocates
physical memory for a client, it zeroes out the corresponding area in
core's virtual address space and then maps the area to the client. If this
area overlaps with core's virtual thread context area (usually at
0x40000000-0x4fffffff), the stack of one or more core threads can get
overwritten.

To avoid this problem, with this patch, the thread context area gets
removed from the physical RAM allocator on these platforms.

Fixes #660.
This commit is contained in:
Christian Prochaska 2013-02-21 17:47:15 +01:00 committed by Norman Feske
parent 439315d918
commit 2664afbd7d
4 changed files with 52 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

15
base-fiasco/src/core/platform.cc
View File

@ -187,6 +187,14 @@ struct Region
Region() : start(0), end(0) { }
Region(addr_t s, addr_t e) : start(s), end(e) { }
/**
* Returns true if the specified range intersects with the region
*/
bool intersects(addr_t base, size_t size) const
{
return (((base + size) > start) && (base < end));
}
};
@ -296,8 +304,11 @@ void Platform::_setup_mem_alloc()
}
region.start = addr; region.end = addr + size;
add_region(region, _ram_alloc);
add_region(region, _core_address_ranges());
if (!region.intersects(Native_config::context_area_virtual_base(),
Native_config::context_area_virtual_size())) {
add_region(region, _ram_alloc);
add_region(region, _core_address_ranges());
}
remove_region(region, _io_mem_alloc);
remove_region(region, _region_alloc);
}

15
base-foc/src/core/platform.cc
View File

@ -171,6 +171,14 @@ struct Region
Region() : start(0), end(0) { }
Region(addr_t s, addr_t e) : start(s), end(e) { }
/**
* Returns true if the specified range intersects with the region
*/
bool intersects(addr_t base, size_t size) const
{
return (((base + size) > start) && (base < end));
}
};
@ -308,8 +316,11 @@ void Platform::_setup_mem_alloc()
}
region.start = addr; region.end = addr + size;
add_region(region, _ram_alloc);
add_region(region, _core_address_ranges());
if (!region.intersects(Native_config::context_area_virtual_base(),
Native_config::context_area_virtual_size())) {
add_region(region, _ram_alloc);
add_region(region, _core_address_ranges());
}
remove_region(region, _io_mem_alloc);
remove_region(region, _region_alloc);
}

12
base-pistachio/src/core/include/map_local.h
View File

@ -20,6 +20,7 @@
/* Pistachio includes */
namespace Pistachio {
#include <l4/space.h>
#include <l4/types.h>
#include <l4/ipc.h>
#include <l4/kdebug.h>
@ -40,7 +41,7 @@ namespace Genode {
*/
inline static bool map_local(addr_t from_addr, addr_t to_addr, size_t num_pages)
{
Native_thread_id core_pager = platform_specific()->core_pager()->native_thread_id();
addr_t offset = 0;
@ -85,7 +86,14 @@ namespace Genode {
*/
inline void unmap_local(addr_t virt, size_t num_pages)
{
PERR("unmap_local() called - not implemented yet");
size_t page_size = get_page_size();
addr_t offset = 0;
for (unsigned i = 0; i < num_pages; i++, offset += page_size) {
using namespace Pistachio;
L4_Fpage_t fpage = L4_Fpage(virt + offset, page_size);
fpage += L4_FullyAccessible;
L4_Flush(fpage);
}
}
}

18
base-pistachio/src/core/platform.cc
View File

@ -21,6 +21,7 @@
/* core includes */
#include <core_parent.h>
#include <map_local.h>
#include <platform.h>
#include <platform_thread.h>
#include <platform_pd.h>
@ -247,6 +248,14 @@ struct Region
Region() : start(0), end(0) { }
Region(addr_t s, addr_t e) : start(s), end(e) { }
/**
* Returns true if the specified range intersects with the region
*/
bool intersects(addr_t base, size_t size) const
{
return (((base + size) > start) && (base < end));
}
};
@ -396,8 +405,13 @@ void Platform::_setup_mem_alloc()
} else {
region.start = addr; region.end = addr + size;
add_region(region, _ram_alloc);
add_region(region, _core_address_ranges());
if (!region.intersects(Native_config::context_area_virtual_base(),
Native_config::context_area_virtual_size())) {
add_region(region, _ram_alloc);
add_region(region, _core_address_ranges());
} else {
unmap_local(region.start, size >> get_page_size_log2());
}
remove_region(region, _io_mem_alloc);
remove_region(region, _region_alloc);
}