Alexander Bulekov <alx...@bu.edu> 于2021年2月19日周五 上午10:15写道: > > On 210219 1006, Li Qiang wrote: > > Alexander Bulekov <alx...@bu.edu> 于2021年2月19日周五 上午9:56写道: > > > > > > On 210218 1441, Peter Maydell wrote: > > > > On Thu, 18 Feb 2021 at 14:13, P J P <ppan...@redhat.com> wrote: > > > > > > > > > > From: Prasad J Pandit <p...@fedoraproject.org> > > > > > > > > > > While processing controller commands, eepro100 emulator gets > > > > > command unit(CU) base address OR receive unit (RU) base address > > > > > OR command block (CB) address from guest. If these values are not > > > > > checked, it may lead to an infinite loop kind of issues. Add checks > > > > > to avoid it. > > > > > > So could you please provide a backtrack? > > > > I don't know if you are asking me or Prasad, but here is the stacktrace
Yes, a typical DMA reentry issue. Any progress to solve these DMA reentry issues? seems more and more this kind of issues. Just return from the busy things as a new father and not focus this quite a time. Thanks, Li Qiang > for the one I provided: > ==2715275==ERROR: AddressSanitizer: stack-overflow on address > 0x7ffc5262ba28 (pc 0x55d83b103ac6 bp 0x7ffc5262c270 sp 0x7ffc5262ba30 > T0) > #0 in __asan_memcpy (qemu-system-i386+0x2aa3ac6) > #1 in flatview_do_translate ../softmmu/physmem.c:518:12 > #2 in flatview_translate ../softmmu/physmem.c:568:15 > #3 in flatview_read ../softmmu/physmem.c:2878:10 > #4 in address_space_read_full ../softmmu/physmem.c:2892:18 > #5 in dma_memory_rw_relaxed include/sysemu/dma.h:88:12 > #6 in dma_memory_rw include/sysemu/dma.h:127:12 > #7 in pci_dma_rw include/hw/pci/pci.h:803:12 > #8 in pci_dma_read include/hw/pci/pci.h:821:12 > #9 in read_cb ../hw/net/eepro100.c:726:5 > #10 in action_command ../hw/net/eepro100.c:847:9 > #11 in eepro100_cu_command ../hw/net/eepro100.c:969:13 > #12 in eepro100_write_command ../hw/net/eepro100.c:1063:5 > #13 in eepro100_write2 ../hw/net/eepro100.c:1510:9 > #14 in eepro100_write ../hw/net/eepro100.c:1593:9 > #15 in memory_region_write_accessor ../softmmu/memory.c:491:5 > #16 in access_with_adjusted_size ../softmmu/memory.c:552:18 > #17 in memory_region_dispatch_write ../softmmu/memory.c > #18 in flatview_write_continue ../softmmu/physmem.c:2776:23 > #19 in flatview_write ../softmmu/physmem.c:2816:14 > #20 in address_space_write ../softmmu/physmem.c:2908:18 > #21 in dma_memory_rw_relaxed include/sysemu/dma.h:88:12 > #22 in dma_memory_rw include/sysemu/dma.h:127:12 > #23 in dma_memory_write include/sysemu/dma.h:163:12 > #24 in stw_le_dma include/sysemu/dma.h:259:1 > #25 in stw_le_pci_dma include/hw/pci/pci.h:855:1 > #26 in action_command ../hw/net/eepro100.c:913:9 > #27 in eepro100_cu_command ../hw/net/eepro100.c:969:13 > #28 in eepro100_write_command ../hw/net/eepro100.c:1063:5 > #29 in eepro100_write2 ../hw/net/eepro100.c:1510:9 > #30 in eepro100_write ../hw/net/eepro100.c:1593:9 > ... till there's no more stack ... > > > > > Thanks, > > Li Qiang > > > > > > > > > > > > Reported-by: Ruhr-University Bochum <bugs-sys...@rub.de> > > > > > Signed-off-by: Prasad J Pandit <p...@fedoraproject.org> > > > > > --- > > > > > hw/net/eepro100.c | 8 +++++++- > > > > > 1 file changed, 7 insertions(+), 1 deletion(-) > > > > > > > > > > diff --git a/hw/net/eepro100.c b/hw/net/eepro100.c > > > > > index 16e95ef9cc..afa1c9b2aa 100644 > > > > > --- a/hw/net/eepro100.c > > > > > +++ b/hw/net/eepro100.c > > > > > @@ -843,7 +843,8 @@ static void action_command(EEPRO100State *s) > > > > > bool bit_i; > > > > > bool bit_nc; > > > > > uint16_t ok_status = STATUS_OK; > > > > > - s->cb_address = s->cu_base + s->cu_offset; > > > > > + s->cb_address = s->cu_base + s->cu_offset; /* uint32_t > > > > > overflow */ > > > > > + assert (s->cb_address >= s->cu_base); > > > > > > > > We get these values from the guest; you can't just assert() on them. > > > > You need to do something else. > > > > > > > > My reading of the 8255x data sheet is that there is nothing > > > > in the hardware that forbids the guest from programming the > > > > device such that the cu_base + cu_offset wraps around: > > > > http://www.intel.com/content/dam/doc/manual/8255x-10-100-mbps-ethernet-controller-software-dev-manual.pdf > > > > -- page 30 says that this is all doing 32-bit arithmetic > > > > on addresses and doesn't say that there is any special case > > > > handling by the device of overflow of that addition. > > > > > > > > Your commit message isn't very clear about what the failure > > > > case is here, but I think the fix has to be something > > > > different from this. > > > > > > Maybe the infinite loop mentioned in the commit message is actually a > > > DMA recursion issue? I'm providing a reproducer for a DMA re-entracy > > > issue below. With this patch applied, the reproducer triggers the > > > assert(), rather than overflowing the stack, so maybe it is the same > > > issue? > > > -Alex > > > > > > cat << EOF | ./qemu-system-i386 -display none -machine accel=qtest, -m \ > > > 512M -device i82559er,netdev=net0 -netdev user,id=net0 -nodefaults \ > > > -qtest stdio > > > outl 0xcf8 0x80001014 > > > outl 0xcfc 0xc000 > > > outl 0xcf8 0x80001010 > > > outl 0xcfc 0xe0020000 > > > outl 0xcf8 0x80001004 > > > outw 0xcfc 0x7 > > > write 0x1ffffc0b 0x1 0x55 > > > write 0x1ffffc0c 0x1 0xfc > > > write 0x1ffffc0d 0x1 0x46 > > > write 0x1ffffc0e 0x1 0x07 > > > write 0x746fc59 0x1 0x02 > > > write 0x746fc5b 0x1 0x02 > > > write 0x746fc5c 0x1 0xe0 > > > write 0x4 0x1 0x07 > > > write 0x5 0x1 0xfc > > > write 0x6 0x1 0xff > > > write 0x7 0x1 0x1f > > > outw 0xc002 0x20 > > > EOF > > > > > > Formatted for committing a regression-test: > > > > > > static void test_fuzz(void) > > > { > > > QTestState *s = > > > qtest_init("-display none , -m 512M -device i82559er,netdev=net0 " > > > "-netdev user,id=net0 -nodefaults"); > > > qtest_outl(s, 0xcf8, 0x80001014); > > > qtest_outl(s, 0xcfc, 0xc000); > > > qtest_outl(s, 0xcf8, 0x80001010); > > > qtest_outl(s, 0xcfc, 0xe0020000); > > > qtest_outl(s, 0xcf8, 0x80001004); > > > qtest_outw(s, 0xcfc, 0x7); > > > qtest_bufwrite(s, 0x1ffffc0b, "\x55", 0x1); > > > qtest_bufwrite(s, 0x1ffffc0c, "\xfc", 0x1); > > > qtest_bufwrite(s, 0x1ffffc0d, "\x46", 0x1); > > > qtest_bufwrite(s, 0x1ffffc0e, "\x07", 0x1); > > > qtest_bufwrite(s, 0x746fc59, "\x02", 0x1); > > > qtest_bufwrite(s, 0x746fc5b, "\x02", 0x1); > > > qtest_bufwrite(s, 0x746fc5c, "\xe0", 0x1); > > > qtest_bufwrite(s, 0x4, "\x07", 0x1); > > > qtest_bufwrite(s, 0x5, "\xfc", 0x1); > > > qtest_bufwrite(s, 0x6, "\xff", 0x1); > > > qtest_bufwrite(s, 0x7, "\x1f", 0x1); > > > qtest_outw(s, 0xc002, 0x20); > > > qtest_quit(s); > > > } > > > > > > > > > > > > > > thanks > > > > -- PMM > > > > > > >