Re: [PATCH] qtest: add fuzz test case

[Philippe Mathieu-Daudé]

On 8/19/20 4:15 PM, Li Qiang wrote:
> Currently the device fuzzer find a more and more issues.
> For every fuzz case, we need not only the fixes but also
> the coressponding test case. We can analysis the reproducer

Typo "corresponding"

> for every case and find what happened in where and write
> a beautiful test case. However the raw data of reproducer is not
> friendly to analysis. It will take a very long time, even far more
> than the fixes itself. So let's create a new file to hold all of
> the fuzz test cases and just use the raw data to act as the test
> case. This way nobody will be afraid of writing a test case for
> the fuzz reproducer.

Ahaha nice :)

> 
> This patch adds the issue LP#1878263 test case.
> 
> Signed-off-by: Li Qiang <liq3ea@163.com>
> ---
>  tests/qtest/Makefile.include |  2 ++
>  tests/qtest/fuzz-test.c      | 45 ++++++++++++++++++++++++++++++++++++
>  2 files changed, 47 insertions(+)
>  create mode 100644 tests/qtest/fuzz-test.c
> 
> diff --git a/tests/qtest/Makefile.include b/tests/qtest/Makefile.include
> index b0204e44f2..ff460179c5 100644
> --- a/tests/qtest/Makefile.include
> +++ b/tests/qtest/Makefile.include
> @@ -7,6 +7,7 @@ check-qtest-generic-y += machine-none-test
>  check-qtest-generic-y += qmp-test
>  check-qtest-generic-y += qmp-cmd-test
>  check-qtest-generic-y += qom-test
> +check-qtest-generic-y += fuzz-test

Maybe name that fuzzed-reproducers-test?

>  check-qtest-generic-$(CONFIG_MODULES) += modules-test
>  check-qtest-generic-y += test-hmp
>  
> @@ -272,6 +273,7 @@ tests/qtest/m25p80-test$(EXESUF): 
> tests/qtest/m25p80-test.o
>  tests/qtest/i440fx-test$(EXESUF): tests/qtest/i440fx-test.o 
> $(libqos-pc-obj-y)
>  tests/qtest/q35-test$(EXESUF): tests/qtest/q35-test.o $(libqos-pc-obj-y)
>  tests/qtest/fw_cfg-test$(EXESUF): tests/qtest/fw_cfg-test.o 
> $(libqos-pc-obj-y)
> +tests/qtest/fuzz-test$(EXESUF): tests/qtest/fuzz-test.o $(libqos-pc-obj-y)
>  tests/qtest/rtl8139-test$(EXESUF): tests/qtest/rtl8139-test.o 
> $(libqos-pc-obj-y)
>  tests/qtest/pnv-xscom-test$(EXESUF): tests/qtest/pnv-xscom-test.o
>  tests/qtest/wdt_ib700-test$(EXESUF): tests/qtest/wdt_ib700-test.o
> diff --git a/tests/qtest/fuzz-test.c b/tests/qtest/fuzz-test.c
> new file mode 100644
> index 0000000000..695c6dffb9
> --- /dev/null
> +++ b/tests/qtest/fuzz-test.c
> @@ -0,0 +1,45 @@
> +/*
> + * QTest testcase for fuzz case
> + *
> + * Copyright (c) 2020 Li Qiang <liq3ea@gmail.com>
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2 or later.
> + * See the COPYING file in the top-level directory.
> + */
> +
> +
> +#include "qemu/osdep.h"
> +
> +#include "libqtest.h"
> +
> +/*
> + * This used to trigger the assert in scsi_dma_complete
> + * https://bugs.launchpad.net/qemu/+bug/1878263
> + */
> +static void test_megasas_zero_iov_cnt(void)

I'd name it test_lp1878263_megasas_zero_iov_cnt()
or lp1878263_megasas_zero_iov_cnt().

> +{
> +    QTestState *s;
> +
> +    s = qtest_init("-nographic -monitor none -serial none "
> +                   "-M q35 -device megasas -device scsi-cd,drive=null0 "
> +                   "-blockdev 
> driver=null-co,read-zeroes=on,node-name=null0");
> +    qtest_outl(s, 0xcf8, 0x80001818);
> +    qtest_outl(s, 0xcfc, 0xc101);
> +    qtest_outl(s, 0xcf8, 0x8000181c);
> +    qtest_outl(s, 0xcf8, 0x80001804);
> +    qtest_outw(s, 0xcfc, 0x7);
> +    qtest_outl(s, 0xcf8, 0x8000186a);
> +    qtest_writeb(s, 0x14, 0xfe);
> +    qtest_writeb(s, 0x0, 0x02);
> +    qtest_outb(s, 0xc1c0, 0x17);
> +    qtest_quit(s);

Actually all the test body could be generated...
Alex, can you have a look at that?

> +}
> +
> +int main(int argc, char **argv)
> +{
> +    g_test_init(&argc, &argv, NULL);
> +
> +    qtest_add_func("fuzz/megasas_zero_iov_cnt", test_megasas_zero_iov_cnt);
> +
> +    return g_test_run();

The problem is now the test suite will fail because this test is not
fixed.

Good idea btw :)

> +}
>