From 86a8623692b1b559a419a92eb8b6897c221bca74 Mon Sep 17 00:00:00 2001 From: Avi Kivity Date: Tue, 30 Oct 2012 13:47:45 +0200 Subject: [PATCH] memory: limit sections in the radix tree to the actual address space size 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 Signed-off-by: Avi Kivity [ Fail the build if TARGET_PHYS_ADDR_SPACE_BITS is too large - Paolo ] Signed-off-by: Paolo Bonzini --- exec.c | 13 ++++++++++++- include/exec/memory.h | 3 +++ 2 files changed, 15 insertions(+), 1 deletion(-) diff --git a/exec.c b/exec.c index 8562fcac9c..3fdca46a6a 100644 --- a/exec.c +++ b/exec.c @@ -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)) { diff --git a/include/exec/memory.h b/include/exec/memory.h index 91be2a3c7a..fdf55feea1 100644 --- a/include/exec/memory.h +++ b/include/exec/memory.h @@ -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;