From: Stefan Hajnoczi <stefanha@gmail.com>
To: "Oleinik, Alexander" <alxndr@bu.edu>
Cc: "qemu-devel@nongnu.org" <qemu-devel@nongnu.org>
Subject: Re: [PATCH v4 19/20] fuzz: add virtio-net fuzz target
Date: Thu, 7 Nov 2019 14:36:41 +0100 [thread overview]
Message-ID: <20191107133641.GE365089@stefanha-x1.localdomain> (raw)
In-Reply-To: <20191030144926.11873-20-alxndr@bu.edu>
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On Wed, Oct 30, 2019 at 02:50:03PM +0000, Oleinik, Alexander wrote:
> +static void virtio_net_fuzz_multi(QTestState *s,
> + const unsigned char *Data, size_t Size)
> +{
> + typedef struct vq_action {
> + uint8_t queue;
> + uint8_t length;
> + uint8_t write;
> + uint8_t next;
> + bool kick;
> + } vq_action;
> +
> + uint64_t req_addr[10];
> + int reqi = 0;
> + uint32_t free_head = 0;
> +
> + QGuestAllocator *t_alloc = fuzz_qos_alloc;
> +
> + QVirtioNet *net_if = fuzz_qos_obj;
> + QVirtioDevice *dev = net_if->vdev;
> + QVirtQueue *q;
> + vq_action vqa;
> + int iters = 0;
> + while (true) {
> + if (Size < sizeof(vqa)) {
> + break;
> + }
More concisely:
while (Size < sizeof(vqa)) {
> + memcpy(&vqa, Data, sizeof(vqa));
> + vqa = *((vq_action *)Data);
The assignment is redundant after the memcpy.
> + Data += sizeof(vqa);
> + Size -= sizeof(vqa);
> +
> + q = net_if->queues[vqa.queue % 3];
> +
> + vqa.length = vqa.length >= Size ? Size : vqa.length;
> +
> + req_addr[reqi] = guest_alloc(t_alloc, vqa.length);
> + qtest_memwrite(s, req_addr[reqi], Data, vqa.length);
> + if (iters == 0) {
What is the difference between iters and reqi? The values of these
variables are always identical so I think only one of them is needed.
> + free_head = qvirtqueue_add(s, q, req_addr[reqi], vqa.length,
> + vqa.write, vqa.next);
> + } else {
> + qvirtqueue_add(s, q,
> + req_addr[reqi], vqa.length, vqa.write , vqa.next);
> + }
> + iters++;
> + reqi++;
> + if (iters == 10) {
> + break;
> + }
> + Data += vqa.length;
> + Size -= vqa.length;
> + }
> + if (iters) {
> + qvirtqueue_kick(s, dev, q, free_head);
> + qtest_clock_step_next(s);
Here we could run the main loop until free_head appears in the used
ring. That should allow the request processing code path to be explored
more fully, but this it's okay to leave it like this for now.
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next prev parent reply other threads:[~2019-11-07 13:37 UTC|newest]
Thread overview: 57+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-30 14:49 [PATCH v4 00/20] Add virtual device fuzzing support Oleinik, Alexander
2019-10-30 14:49 ` [PATCH v4 01/20] softmmu: split off vl.c:main() into main.c Oleinik, Alexander
2019-11-05 16:41 ` Darren Kenny
2019-11-12 16:46 ` Alexander Bulekov
2019-11-06 15:01 ` Stefan Hajnoczi
2019-10-30 14:49 ` [PATCH v4 02/20] libqos: Rename i2c_send and i2c_recv Oleinik, Alexander
2019-11-06 15:17 ` Stefan Hajnoczi
2019-10-30 14:49 ` [PATCH v4 03/20] fuzz: Add FUZZ_TARGET module type Oleinik, Alexander
2019-11-06 13:17 ` Darren Kenny
2019-11-06 15:18 ` Stefan Hajnoczi
2019-10-30 14:49 ` [PATCH v4 04/20] qtest: add qtest_server_send abstraction Oleinik, Alexander
2019-11-06 13:29 ` Darren Kenny
2019-11-06 15:19 ` Stefan Hajnoczi
2019-10-30 14:49 ` [PATCH v4 06/20] module: check module wasn't already initialized Oleinik, Alexander
2019-11-06 15:26 ` Stefan Hajnoczi
2019-11-06 17:40 ` Darren Kenny
2019-10-30 14:49 ` [PATCH v4 05/20] libqtest: Add a layer of abstraciton to send/recv Oleinik, Alexander
2019-11-06 16:22 ` Stefan Hajnoczi
2019-10-30 14:49 ` [PATCH v4 07/20] qtest: add in-process incoming command handler Oleinik, Alexander
2019-11-06 16:33 ` Stefan Hajnoczi
2019-10-30 14:49 ` [PATCH v4 08/20] tests: provide test variables to other targets Oleinik, Alexander
2019-11-07 14:32 ` Darren Kenny
2019-10-30 14:49 ` [PATCH v4 09/20] libqos: split qos-test and libqos makefile vars Oleinik, Alexander
2019-11-07 14:03 ` Darren Kenny
2019-10-30 14:49 ` [PATCH v4 10/20] libqos: move useful qos-test funcs to qos_external Oleinik, Alexander
2019-11-06 16:41 ` Stefan Hajnoczi
2019-10-30 14:49 ` [PATCH v4 11/20] libqtest: make qtest_bufwrite send "atomic" Oleinik, Alexander
2019-11-06 16:44 ` Stefan Hajnoczi
2019-10-30 14:49 ` [PATCH v4 12/20] libqtest: add in-process qtest.c tx/rx handlers Oleinik, Alexander
2019-11-06 16:56 ` Stefan Hajnoczi
2019-11-12 17:38 ` Alexander Bulekov
2019-10-30 14:49 ` [PATCH v4 13/20] fuzz: add configure flag --enable-fuzzing Oleinik, Alexander
2019-11-06 16:57 ` Stefan Hajnoczi
2019-10-30 14:50 ` [PATCH v4 15/20] fuzz: add fuzzer skeleton Oleinik, Alexander
2019-11-07 12:55 ` Stefan Hajnoczi
2019-11-12 19:04 ` Alexander Bulekov
2019-10-30 14:50 ` [PATCH v4 14/20] fuzz: Add target/fuzz makefile rules Oleinik, Alexander
2019-11-07 14:31 ` Darren Kenny
2019-10-30 14:50 ` [PATCH v4 16/20] fuzz: add support for fork-based fuzzing Oleinik, Alexander
2019-11-07 13:17 ` Stefan Hajnoczi
2019-10-30 14:50 ` [PATCH v4 17/20] fuzz: add support for qos-assisted fuzz targets Oleinik, Alexander
2019-11-07 13:22 ` Stefan Hajnoczi
2019-10-30 14:50 ` [PATCH v4 18/20] fuzz: add i440fx " Oleinik, Alexander
2019-11-07 13:26 ` Stefan Hajnoczi
2019-10-30 14:50 ` [PATCH v4 19/20] fuzz: add virtio-net fuzz target Oleinik, Alexander
2019-11-07 13:36 ` Stefan Hajnoczi [this message]
2019-11-07 13:42 ` Jason Wang
2019-11-07 15:41 ` Stefan Hajnoczi
2019-10-30 14:50 ` [PATCH v4 20/20] fuzz: add documentation to docs/devel/ Oleinik, Alexander
2019-11-07 13:40 ` Stefan Hajnoczi
2019-11-07 15:02 ` Alexander Oleinik
2019-10-30 15:23 ` [PATCH v4 00/20] Add virtual device fuzzing support no-reply
2019-11-06 15:27 ` Stefan Hajnoczi
2019-11-05 13:57 ` Darren Kenny
2019-11-05 16:28 ` Alexander Oleinik
2019-11-05 16:47 ` Darren Kenny
2019-11-07 13:41 ` Stefan Hajnoczi
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