From 73188068d7ba40c8a37b4763db38bb1ce24ca07d Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Tue, 23 Jul 2024 18:05:13 +0100 Subject: system/physmem: Where we assume we have a RAM MR, assert it In the functions invalidate_and_set_dirty() and cpu_physical_memory_snapshot_and_clear_dirty(), we assume that we are dealing with RAM memory regions. In this case we know that memory_region_get_ram_addr() will succeed. Assert this before we use the returned ram_addr_t in arithmetic. This makes Coverity happier about these functions: it otherwise complains that we might have an arithmetic overflow that stems from the possible -1 return from memory_region_get_ram_addr(). Resolves: Coverity CID 1547629, 1547715 Signed-off-by: Peter Maydell Reviewed-by: Peter Xu Reviewed-by: David Hildenbrand Message-id: 20240723170513.1676453-1-peter.maydell@linaro.org --- system/physmem.c | 18 ++++++++++++++---- 1 file changed, 14 insertions(+), 4 deletions(-) (limited to 'system/physmem.c') diff --git a/system/physmem.c b/system/physmem.c index 0e19186e1b..94600a33ec 100644 --- a/system/physmem.c +++ b/system/physmem.c @@ -923,13 +923,19 @@ DirtyBitmapSnapshot *cpu_physical_memory_snapshot_and_clear_dirty (MemoryRegion *mr, hwaddr offset, hwaddr length, unsigned client) { DirtyMemoryBlocks *blocks; - ram_addr_t start = memory_region_get_ram_addr(mr) + offset; + ram_addr_t start, first, last; unsigned long align = 1UL << (TARGET_PAGE_BITS + BITS_PER_LEVEL); - ram_addr_t first = QEMU_ALIGN_DOWN(start, align); - ram_addr_t last = QEMU_ALIGN_UP(start + length, align); DirtyBitmapSnapshot *snap; unsigned long page, end, dest; + start = memory_region_get_ram_addr(mr); + /* We know we're only called for RAM MemoryRegions */ + assert(start != RAM_ADDR_INVALID); + start += offset; + + first = QEMU_ALIGN_DOWN(start, align); + last = QEMU_ALIGN_UP(start + length, align); + snap = g_malloc0(sizeof(*snap) + ((last - first) >> (TARGET_PAGE_BITS + 3))); snap->start = first; @@ -2659,7 +2665,11 @@ static void invalidate_and_set_dirty(MemoryRegion *mr, hwaddr addr, hwaddr length) { uint8_t dirty_log_mask = memory_region_get_dirty_log_mask(mr); - addr += memory_region_get_ram_addr(mr); + ram_addr_t ramaddr = memory_region_get_ram_addr(mr); + + /* We know we're only called for RAM MemoryRegions */ + assert(ramaddr != RAM_ADDR_INVALID); + addr += ramaddr; /* No early return if dirty_log_mask is or becomes 0, because * cpu_physical_memory_set_dirty_range will still call -- cgit v1.2.3