[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] [PATCH] kvmvapic: add read operation to the MemoryRegionOps
From: |
Tommi Rantala |
Subject: |
[Qemu-devel] [PATCH] kvmvapic: add read operation to the MemoryRegionOps to fix segfault |
Date: |
Sat, 16 Feb 2013 11:20:07 +0200 |
QEMU would occasionally segfault when fuzzing the linux kernel with
Trinity. Add a read op (copied from hw/kvm/apic.c) to vapic_ops to
prevent the crash.
Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x7fffeddcc700 (LWP 15999)]
0x0000000000000000 in ?? ()
(gdb) bt
#0 0x0000000000000000 in ?? ()
#1 0x00005555557bbd2d in memory_region_read_accessor (opaque=0x555556be77c8,
addr=<optimized out>, value=0x7fffeddcbaf0, size=1, shift=0, mask=255) at
/home/ttrantal/git/qemu/memory.c:316
#2 0x00005555557bb612 in access_with_adjusted_size (address@hidden,
address@hidden, size=1, access_size_min=<optimized out>,
access_size_max=<optimized out>, address@hidden 0x5555557bbcd0
<memory_region_read_accessor>, address@hidden) at
/home/ttrantal/git/qemu/memory.c:364
#3 0x00005555557bcde8 in memory_region_iorange_read (iorange=0x555556874d90,
offset=0, width=1, data=0x7fffeddcbaf0) at
/home/ttrantal/git/qemu/memory.c:409
#4 0x00005555557b6c37 in ioport_readb_thunk (opaque=<optimized out>,
addr=<optimized out>) at /home/ttrantal/git/qemu/ioport.c:186
#5 0x00005555557b74ee in ioport_read (address=0, index=0) at
/home/ttrantal/git/qemu/ioport.c:70
#6 cpu_inb (address@hidden) at /home/ttrantal/git/qemu/ioport.c:309
#7 0x00005555557b98a3 in kvm_handle_io (count=1, size=1, direction=0,
data=<optimized out>, port=126) at /home/ttrantal/git/qemu/kvm-all.c:1414
#8 kvm_cpu_exec (address@hidden) at
/home/ttrantal/git/qemu/kvm-all.c:1581
#9 0x0000555555763bb1 in qemu_kvm_cpu_thread_fn (arg=0x555556bcc870) at
/home/ttrantal/git/qemu/cpus.c:759
#10 0x00007ffff6487d15 in start_thread (arg=0x7fffeddcc700) at
pthread_create.c:308
#11 0x00007ffff297946d in clone () at
../sysdeps/unix/sysv/linux/x86_64/clone.S:114
(gdb)
Signed-off-by: Tommi Rantala <address@hidden>
---
hw/kvmvapic.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/hw/kvmvapic.c b/hw/kvmvapic.c
index 1b5f416..d4420fe 100644
--- a/hw/kvmvapic.c
+++ b/hw/kvmvapic.c
@@ -615,6 +615,12 @@ static int vapic_prepare(VAPICROMState *s)
return 0;
}
+static uint64_t vapic_read(void *opaque, hwaddr addr,
+ unsigned int size)
+{
+ return ~(uint64_t)0;
+}
+
static void vapic_write(void *opaque, hwaddr addr, uint64_t data,
unsigned int size)
{
@@ -683,6 +689,7 @@ static void vapic_write(void *opaque, hwaddr addr, uint64_t
data,
}
static const MemoryRegionOps vapic_ops = {
+ .read = vapic_read,
.write = vapic_write,
.endianness = DEVICE_NATIVE_ENDIAN,
};
--
1.8.1
- [Qemu-devel] [PATCH] kvmvapic: add read operation to the MemoryRegionOps to fix segfault,
Tommi Rantala <=