[Pdbg] [PATCH v1] sbefifo: fix sbefifo_register_get with multiple registers

[Amitay Isaacs]

On Tue, 2021-11-16 at 01:47 +0000, Joel Stanley wrote:
> On Fri, 12 Nov 2021 at 07:10, Nicholas Piggin <npiggin at gmail.com>
> wrote:
> > 
> > sbefifo_register_get_pull is not indexing the result buffer
> > correctly
> > for > 1 returned register.
> > 
> > Signed-off-by: Nicholas Piggin <npiggin at gmail.com>
> > ---
> >  libsbefifo/cmd_register.c | 5 +++--
> >  1 file changed, 3 insertions(+), 2 deletions(-)
> > 
> > diff --git a/libsbefifo/cmd_register.c b/libsbefifo/cmd_register.c
> > index 6c3f336..1e74b6e 100644
> > --- a/libsbefifo/cmd_register.c
> > +++ b/libsbefifo/cmd_register.c
> > @@ -57,6 +57,7 @@ static int sbefifo_register_get_push(uint8_t
> > core_id, uint8_t thread_id, uint8_t
> >  static int sbefifo_register_get_pull(uint8_t *buf, uint32_t
> > buflen, uint8_t reg_count, uint64_t **value)
> >  {
> >         uint32_t i;
> > +       uint32_t *b = (uint32_t *)buf;
> > 
> >         if (buflen != reg_count * 8)
> >                 return EPROTO;
> > @@ -68,8 +69,8 @@ static int sbefifo_register_get_pull(uint8_t
> > *buf, uint32_t buflen, uint8_t reg_
> >         for (i=0; i<reg_count; i++) {
> >                 uint32_t val1, val2;
> > 
> > -               val1 = be32toh(*(uint32_t *) &buf[i*4]);
> > -               val2 = be32toh(*(uint32_t *) &buf[i*4+4]);
> > +               val1 = be32toh(b[i*2]);
> > +               val2 = be32toh(b[i*2+1]);
> 
> Just to clarify, this is what the code was doing before:
> 
>                val1 = be32toh(b[i]);
>                val2 = be32toh(b[i + 1]);
> 
> Which would read out from the buffer:
> 
> value = 0 | 1
> value = 1 | 2
> value = 2 | 3
> 
> And your fix is to add i*2:
> 
> value = 0 | 1
> value = 2 | 3
> value = 4 | 5
> 
> Looks good to me!
> 
> Reviewed-by: Joel Stanley <joel at jms.id.au>
> 
> 
> > 
> >                 (*value)[i] = ((uint64_t)val1 << 32) |
> > (uint64_t)val2;
> >         }
> > --
> > 2.23.0
> > 
> > --
> > Pdbg mailing list
> > Pdbg at lists.ozlabs.org
> > https://lists.ozlabs.org/listinfo/pdbg

Good catch. Pushed upstream.


Amitay.
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