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Re: [Qemu-trivial] [PATCH] hw/i386/pc: fix possible segment fault for po
From: |
Paolo Bonzini |
Subject: |
Re: [Qemu-trivial] [PATCH] hw/i386/pc: fix possible segment fault for port92_write |
Date: |
Fri, 22 Mar 2013 12:07:15 +0100 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130311 Thunderbird/17.0.4 |
Il 22/03/2013 10:12, liguang ha scritto:
> e.g.
> $qemu-system-x86_64 -device port92
> will report segment fault,
> for port92_write try a un-allocated
> assignment for a20_out.
> so check before this assignment.
>
> Signed-off-by: liguang <address@hidden>
> ---
> hw/i386/pc.c | 3 ++-
> 1 files changed, 2 insertions(+), 1 deletions(-)
>
> diff --git a/hw/i386/pc.c b/hw/i386/pc.c
> index ed7d9ba..a0e8ee0 100644
> --- a/hw/i386/pc.c
> +++ b/hw/i386/pc.c
> @@ -440,7 +440,8 @@ static void port92_write(void *opaque, hwaddr addr,
> uint64_t val,
>
> DPRINTF("port92: write 0x%02x\n", val);
> s->outport = val;
> - qemu_set_irq(*s->a20_out, (val >> 1) & 1);
> + if (s->a20_out)
> + qemu_set_irq(*s->a20_out, (val >> 1) & 1);
> if (val & 1) {
> qemu_system_reset_request();
> }
>
Unfortunately, this is a very common problem. The correct fix is to
change port92 to use the GPIO mechanism instead.
Paolo