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From: Alexander Bulekov <alxndr@bu.edu>
To: qemu-devel@nongnu.org
Cc: darren.kenny@oracle.com, Alexander Bulekov <alxndr@bu.edu>,
	bsd@redhat.com, stefanha@redhat.com, pbonzini@redhat.com,
	Richard Henderson <rth@twiddle.net>
Subject: [PATCH v9 14/23] exec: keep ram block across fork when using qtest
Date: Tue, 11 Feb 2020 15:35:01 -0500	[thread overview]
Message-ID: <20200211203510.3534-15-alxndr@bu.edu> (raw)
In-Reply-To: <20200211203510.3534-1-alxndr@bu.edu>

Ram blocks were marked MADV_DONTFORK breaking fuzzing-tests which
execute each test-input in a forked process.

Signed-off-by: Alexander Bulekov <alxndr@bu.edu>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
---
 exec.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/exec.c b/exec.c
index 67e520d18e..43f6659d12 100644
--- a/exec.c
+++ b/exec.c
@@ -35,6 +35,7 @@
 #include "sysemu/kvm.h"
 #include "sysemu/sysemu.h"
 #include "sysemu/tcg.h"
+#include "sysemu/qtest.h"
 #include "qemu/timer.h"
 #include "qemu/config-file.h"
 #include "qemu/error-report.h"
@@ -2306,8 +2307,15 @@ static void ram_block_add(RAMBlock *new_block, Error **errp, bool shared)
     if (new_block->host) {
         qemu_ram_setup_dump(new_block->host, new_block->max_length);
         qemu_madvise(new_block->host, new_block->max_length, QEMU_MADV_HUGEPAGE);
-        /* MADV_DONTFORK is also needed by KVM in absence of synchronous MMU */
-        qemu_madvise(new_block->host, new_block->max_length, QEMU_MADV_DONTFORK);
+        /*
+         * MADV_DONTFORK is also needed by KVM in absence of synchronous MMU
+         * Configure it unless the machine is a qtest server, in which case
+         * KVM is not used and it may be forked (eg for fuzzing purposes).
+         */
+        if (!qtest_enabled()) {
+            qemu_madvise(new_block->host, new_block->max_length,
+                         QEMU_MADV_DONTFORK);
+        }
         ram_block_notify_add(new_block->host, new_block->max_length);
     }
 }
-- 
2.25.0



  parent reply	other threads:[~2020-02-11 20:49 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-11 20:34 [PATCH v9 00/23] Add virtual device fuzzing support Alexander Bulekov
2020-02-11 20:34 ` [PATCH v9 01/23] checkpatch: replace vl.c in the top of repo check Alexander Bulekov
2020-02-13 11:55   ` Stefan Hajnoczi
2020-02-11 20:34 ` [PATCH v9 02/23] softmmu: move vl.c to softmmu/ Alexander Bulekov
2020-02-13 11:58   ` Stefan Hajnoczi
2020-02-11 20:34 ` [PATCH v9 03/23] softmmu: split off vl.c:main() into main.c Alexander Bulekov
2020-02-11 20:34 ` [PATCH v9 04/23] module: check module wasn't already initialized Alexander Bulekov
2020-02-11 20:34 ` [PATCH v9 05/23] fuzz: add FUZZ_TARGET module type Alexander Bulekov
2020-02-11 20:34 ` [PATCH v9 06/23] qtest: add qtest_server_send abstraction Alexander Bulekov
2020-02-11 20:34 ` [PATCH v9 07/23] libqtest: add a layer of abstraction to send/recv Alexander Bulekov
2020-02-11 20:34 ` [PATCH v9 08/23] libqtest: make bufwrite rely on the TransportOps Alexander Bulekov
2020-02-11 20:34 ` [PATCH v9 09/23] qtest: add in-process incoming command handler Alexander Bulekov
2020-02-11 20:34 ` [PATCH v9 10/23] libqos: rename i2c_send and i2c_recv Alexander Bulekov
2020-02-11 20:34 ` [PATCH v9 11/23] libqos: split qos-test and libqos makefile vars Alexander Bulekov
2020-02-11 20:34 ` [PATCH v9 12/23] libqos: move useful qos-test funcs to qos_external Alexander Bulekov
2020-02-11 20:35 ` [PATCH v9 13/23] fuzz: add fuzzer skeleton Alexander Bulekov
2020-02-11 20:35 ` Alexander Bulekov [this message]
2020-02-11 20:35 ` [PATCH v9 15/23] main: keep rcu_atfork callback enabled for qtest Alexander Bulekov
2020-02-11 20:35 ` [PATCH v9 16/23] fuzz: support for fork-based fuzzing Alexander Bulekov
2020-02-11 20:35 ` [PATCH v9 17/23] fuzz: add support for qos-assisted fuzz targets Alexander Bulekov
2020-02-11 20:35 ` [PATCH v9 18/23] fuzz: add target/fuzz makefile rules Alexander Bulekov
2020-02-11 20:35 ` [PATCH v9 19/23] fuzz: add configure flag --enable-fuzzing Alexander Bulekov
2020-02-11 20:35 ` [PATCH v9 20/23] fuzz: add i440fx fuzz targets Alexander Bulekov
2020-02-11 20:35 ` [PATCH v9 21/23] fuzz: add virtio-net fuzz target Alexander Bulekov
2020-02-11 20:35 ` [PATCH v9 22/23] fuzz: add virtio-scsi " Alexander Bulekov
2020-02-13 13:42   ` Stefan Hajnoczi
2020-02-11 20:35 ` [PATCH v9 23/23] fuzz: add documentation to docs/devel/ Alexander Bulekov

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