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memory: limit sections in the radix tree to the actual address space size

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The radix tree is statically sized to fit TARGET_PHYS_ADDR_SPACE_BITS.
If a larger memory region is registered, it will overflow.

Fix by limiting any section in the radix tree to the supported size.

This problem was not observed earlier since artificial regions (containers
and aliases) are eliminated by the memory core, leaving only device regions
which have reasonable sizes.  An IOMMU however cannot be eliminated by the
memory core, and may have an artificial size.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Avi Kivity <avi.kivity@gmail.com>
[ Fail the build if TARGET_PHYS_ADDR_SPACE_BITS is too large - Paolo ]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Avi Kivity 2012-10-30 13:47:45 +02:00 committed by Paolo Bonzini
parent 311f83ca08
commit 86a8623692
2 changed files with 15 additions and 1 deletions
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13
exec.c
View File

@ -775,10 +775,21 @@ static void register_multipage(AddressSpaceDispatch *d, MemoryRegionSection *sec
section_index);
}
QEMU_BUILD_BUG_ON(TARGET_PHYS_ADDR_SPACE_BITS > MAX_PHYS_ADDR_SPACE_BITS)
static MemoryRegionSection limit(MemoryRegionSection section)
{
section.size = MIN(section.offset_within_address_space + section.size,
MAX_PHYS_ADDR + 1)
- section.offset_within_address_space;
return section;
}
static void mem_add(MemoryListener *listener, MemoryRegionSection *section)
{
AddressSpaceDispatch *d = container_of(listener, AddressSpaceDispatch, listener);
MemoryRegionSection now = *section, remain = *section;
MemoryRegionSection now = limit(*section), remain = limit(*section);
if ((now.offset_within_address_space & ~TARGET_PAGE_MASK)
|| (now.size < TARGET_PAGE_SIZE)) {

3
include/exec/memory.h
View File

@ -26,6 +26,9 @@
#include "exec/ioport.h"
#include "qemu/int128.h"
#define MAX_PHYS_ADDR_SPACE_BITS 62
#define MAX_PHYS_ADDR (((hwaddr)1 << MAX_PHYS_ADDR_SPACE_BITS) - 1)
typedef struct MemoryRegionOps MemoryRegionOps;
typedef struct MemoryRegionPortio MemoryRegionPortio;
typedef struct MemoryRegionMmio MemoryRegionMmio;