The DMA engine is started by I/O access and then itself accesses the
I/O registers, triggering a reentrancy bug.
The following log can reveal it:
==5637==ERROR: AddressSanitizer: stack-overflow
#0 0x5595435f6078 in tulip_xmit_list_update qemu/hw/net/tulip.c:673
#1 0x5595435f204a in tulip_write qemu/hw/net/tulip.c:805:13
#2 0x559544637f86 in memory_region_write_accessor qemu/softmmu/memory.c:492:5
#3 0x5595446379fa in access_with_adjusted_size qemu/softmmu/memory.c:554:18
#4 0x5595446372fa in memory_region_dispatch_write qemu/softmmu/memory.c
#5 0x55954468b74c in flatview_write_continue qemu/softmmu/physmem.c:2825:23
#6 0x559544683662 in flatview_write qemu/softmmu/physmem.c:2867:12
#7 0x5595446833f3 in address_space_write qemu/softmmu/physmem.c:2963:18
#8 0x5595435fb082 in dma_memory_rw_relaxed qemu/include/sysemu/dma.h:87:12
#9 0x5595435fb082 in dma_memory_rw qemu/include/sysemu/dma.h:130:12
#10 0x5595435fb082 in dma_memory_write qemu/include/sysemu/dma.h:171:12
#11 0x5595435fb082 in stl_le_dma qemu/include/sysemu/dma.h:272:1
#12 0x5595435fb082 in stl_le_pci_dma qemu/include/hw/pci/pci.h:910:1
#13 0x5595435fb082 in tulip_desc_write qemu/hw/net/tulip.c:101:9
#14 0x5595435f7e3d in tulip_xmit_list_update qemu/hw/net/tulip.c:706:9
#15 0x5595435f204a in tulip_write qemu/hw/net/tulip.c:805:13
Fix this bug by restricting the DMA engine to memories regions.
Signed-off-by: Zheyu Ma <zheyuma97@gmail.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
36a894aeb6