When calculating the size of the buffer required for the VGA/VBE state,
round up rather than truncating when dividing the number of bytes to get
the number of 64-byte blocks. Without this modification, the save state
function will write past the end of a buffer of the size requested.

Signed-off-by: Daniel Verkamp <daniel@drv.nu>
---

V2: apply the fix to VGA function 101c as well

 vgasrc/vbe.c     | 2 +-
 vgasrc/vgabios.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/vgasrc/vbe.c b/vgasrc/vbe.c
index 66afb011..1a0948cf 100644
--- a/vgasrc/vbe.c
+++ b/vgasrc/vbe.c
@@ -242,7 +242,7 @@ vbe_104f04(struct bregs *regs)
     if (ret < 0)
         goto fail;
     if (cmd == 0)
-        regs->bx = ret / 64;
+        regs->bx = DIV_ROUND_UP(ret, 64);
     regs->ax = 0x004f;
     return;
 fail:
diff --git a/vgasrc/vgabios.c b/vgasrc/vgabios.c
index 198ee555..73ba1c3d 100644
--- a/vgasrc/vgabios.c
+++ b/vgasrc/vgabios.c
@@ -1081,7 +1081,7 @@ handle_101c(struct bregs *regs)
     if (ret < 0)
         goto fail;
     if (cmd == 0)
-        regs->bx = ret / 64;
+        regs->bx = DIV_ROUND_UP(ret, 64);
     regs->al = 0x1c;
 fail:
     return;
-- 
2.43.0

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On Mon, Mar 11, 2024 at 5:57 PM Daniel Verkamp <daniel@drv.nu> wrote:
>
> When calculating the size of the buffer required for the VGA/VBE state,
> round up rather than truncating when dividing the number of bytes to get
> the number of 64-byte blocks. Without this modification, the save state
> function will write past the end of a buffer of the size requested.
>
> Signed-off-by: Daniel Verkamp <daniel@drv.nu>

Sorry, I forgot to include Reviewed-by: Philippe Mathieu-Daudé
<philmd@linaro.org> from the previous version.
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On Mon, Mar 11, 2024 at 06:09:58PM -0700, Daniel Verkamp wrote:
> On Mon, Mar 11, 2024 at 5:57 PM Daniel Verkamp <daniel@drv.nu> wrote:
> >
> > When calculating the size of the buffer required for the VGA/VBE state,
> > round up rather than truncating when dividing the number of bytes to get
> > the number of 64-byte blocks. Without this modification, the save state
> > function will write past the end of a buffer of the size requested.
> >
> > Signed-off-by: Daniel Verkamp <daniel@drv.nu>

Thanks, I committed this change.

> Sorry, I forgot to include Reviewed-by: Philippe Mathieu-Daudé
> <philmd@linaro.org> from the previous version.

Ah - I missed this as well.  Sorry about that.

-Kevin
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On 12/3/24 15:30, Kevin O'Connor wrote:
> On Mon, Mar 11, 2024 at 06:09:58PM -0700, Daniel Verkamp wrote:
>> On Mon, Mar 11, 2024 at 5:57 PM Daniel Verkamp <daniel@drv.nu> wrote:
>>>
>>> When calculating the size of the buffer required for the VGA/VBE state,
>>> round up rather than truncating when dividing the number of bytes to get
>>> the number of 64-byte blocks. Without this modification, the save state
>>> function will write past the end of a buffer of the size requested.
>>>
>>> Signed-off-by: Daniel Verkamp <daniel@drv.nu>
> 
> Thanks, I committed this change.
> 
>> Sorry, I forgot to include Reviewed-by: Philippe Mathieu-Daudé
>> <philmd@linaro.org> from the previous version.
> 
> Ah - I missed this as well.  Sorry about that.

Not a big deal ;)

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