| Message ID | 1307129824-8396-2-git-send-email-penberg@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, Jun 03, 2011 at 10:37:04PM +0300, Pekka Enberg wrote: > This patch fixes access to 'ah' in int10_vesa() by masking the high bits. > > Cc: Ingo Molnar <mingo@elte.hu> > Cc: Cyrill Gorcunov <gorcunov@gmail.com> > Cc: John Floren <john@jfloren.net> > Cc: Sasha Levin <levinsasha928@gmail.com> > Signed-off-by: Pekka Enberg <penberg@kernel.org> > --- ... Ack, thanks Pekka! Cyrill -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 06/03/2011 10:37 PM, Pekka Enberg wrote: > This patch fixes access to 'ah' in int10_vesa() by masking the high bits. > > @@ -131,7 +131,7 @@ static void int10_vesa(struct int10_args *args) > { > u8 al; > > - al = args->eax; > + al = args->eax& 0xff; Isn't this reading %al? And the high bits are masked by the type of the variable?
On Mon, Jun 06, 2011 at 11:28:56AM +0300, Avi Kivity wrote: > On 06/03/2011 10:37 PM, Pekka Enberg wrote: > >This patch fixes access to 'ah' in int10_vesa() by masking the high bits. > > > >@@ -131,7 +131,7 @@ static void int10_vesa(struct int10_args *args) > > { > > u8 al; > > > >- al = args->eax; > >+ al = args->eax& 0xff; > > Isn't this reading %al? And the high bits are masked by the type of > the variable? > Type conversion will do the work but having explicit masking is a way better I believe, at least it makes this code snippet notable. Cyrill -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, Jun 6, 2011 at 11:37 AM, Cyrill Gorcunov <gorcunov@gmail.com> wrote: > On Mon, Jun 06, 2011 at 11:28:56AM +0300, Avi Kivity wrote: >> On 06/03/2011 10:37 PM, Pekka Enberg wrote: >> >This patch fixes access to 'ah' in int10_vesa() by masking the high bits. >> > >> >@@ -131,7 +131,7 @@ static void int10_vesa(struct int10_args *args) >> > { >> > u8 al; >> > >> >- al = args->eax; >> >+ al = args->eax& 0xff; >> >> Isn't this reading %al? And the high bits are masked by the type of >> the variable? >> > > Type conversion will do the work but having explicit masking is > a way better I believe, at least it makes this code snippet notable. True but the patch description is bogus as it really doesn't _fix_ anything. Pekka -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, Jun 06, 2011 at 12:09:25PM +0300, Pekka Enberg wrote: ... > > Type conversion will do the work but having explicit masking is > > a way better I believe, at least it makes this code snippet notable. > > True but the patch description is bogus as it really doesn't _fix_ anything. > > Pekka Yup, I somehow missed 'fix' word in log, looked only in patch body, sorry. Cyrill -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/tools/kvm/bios/int10.c b/tools/kvm/bios/int10.c index f7fecac..498a93a 100644 --- a/tools/kvm/bios/int10.c +++ b/tools/kvm/bios/int10.c @@ -131,7 +131,7 @@ static void int10_vesa(struct int10_args *args) { u8 al; - al = args->eax; + al = args->eax & 0xff; switch (al) { case 0x00:
This patch fixes access to 'ah' in int10_vesa() by masking the high bits. Cc: Ingo Molnar <mingo@elte.hu> Cc: Cyrill Gorcunov <gorcunov@gmail.com> Cc: John Floren <john@jfloren.net> Cc: Sasha Levin <levinsasha928@gmail.com> Signed-off-by: Pekka Enberg <penberg@kernel.org> --- tools/kvm/bios/int10.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-)