Re: [PULL 23/35] hw/intc: Rework Loongson LIOINTC

["Jiaxun Yang" <jiaxun.yang@flygoat.com>]

On Mon, Jan 11, 2021, at 8:36 AM, Huacai Chen wrote:
> I think R_END should be 0x60, Jiaxun, what do you think?

U r right.
The manual is misleading.

Thanks.

- Jiaxun

> 
> Huacai
> 
> On Mon, Jan 11, 2021 at 5:51 AM BALATON Zoltan <balaton@eik.bme.hu> wrote:
> >
> > On Sun, 10 Jan 2021, Philippe Mathieu-Daudé wrote:
> > > Hi Peter, Huacai,
> > >
> > > On 1/10/21 8:49 PM, Peter Maydell wrote:
> > >> On Sun, 3 Jan 2021 at 21:11, Philippe Mathieu-Daudé <f4bug@amsat.org> wrote:
> > >>>
> > >>> From: Huacai Chen <chenhuacai@kernel.org>
> > >>>
> > >>> As suggested by Philippe Mathieu-Daudé, rework Loongson's liointc:
> > >>> 1, Move macro definitions to loongson_liointc.h;
> > >>> 2, Remove magic values and use macros instead;
> > >>> 3, Replace dead D() code by trace events.
> > >>>
> > >>> Suggested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> > >>> Signed-off-by: Huacai Chen <chenhuacai@kernel.org>
> > >>> Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> > >>> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> > >>> Message-Id: <20201221110538.3186646-2-chenhuacai@kernel.org>
> > >>> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> > >>> ---
> > >>>  include/hw/intc/loongson_liointc.h | 22 ++++++++++++++++++
> > >>>  hw/intc/loongson_liointc.c         | 36 +++++++++++++-----------------
> > >>>  2 files changed, 38 insertions(+), 20 deletions(-)
> > >>>  create mode 100644 include/hw/intc/loongson_liointc.h
> > >>
> > >> Hi; Coverity complains about a possible array overrun
> > >> in this commit:
> > >>
> > >>
> > >>> @@ -40,13 +39,10 @@
> > >>>  #define R_IEN                   0x24
> > >>>  #define R_IEN_SET               0x28
> > >>>  #define R_IEN_CLR               0x2c
> > >>> -#define R_PERCORE_ISR(x)        (0x40 + 0x8 * x)
> > >>> +#define R_ISR_SIZE              0x8
> > >>> +#define R_START                 0x40
> > >>>  #define R_END                   0x64
> > >>>
> > >>> -#define TYPE_LOONGSON_LIOINTC "loongson.liointc"
> > >>> -DECLARE_INSTANCE_CHECKER(struct loongson_liointc, LOONGSON_LIOINTC,
> > >>> -                         TYPE_LOONGSON_LIOINTC)
> > >>> -
> > >>>  struct loongson_liointc {
> > >>>      SysBusDevice parent_obj;
> > >>>
> > >>> @@ -123,14 +119,13 @@ liointc_read(void *opaque, hwaddr addr, unsigned int size)
> > >>>          goto out;
> > >>>      }
> > >>>
> > >>> -    /* Rest is 4 byte */
> > >>> +    /* Rest are 4 bytes */
> > >>>      if (size != 4 || (addr % 4)) {
> > >>>          goto out;
> > >>>      }
> > >>>
> >
> > Expanding macros in the following:
> >
> > >>> -    if (addr >= R_PERCORE_ISR(0) &&
> > >>> -        addr < R_PERCORE_ISR(NUM_CORES)) {
> > >>> -        int core = (addr - R_PERCORE_ISR(0)) / 8;
> >
> > if (addr >= (0x40 + 0x8 * 0) && addr < (0x40 + 0x8 * 4))
> > ->
> > if (addr >= 0x40 && addr < 0x60)
> > int core = (addr - 0x40) / 8;
> >
> >
> > >>> +    if (addr >= R_START && addr < R_END) {
> > >>> +        int core = (addr - R_START) / R_ISR_SIZE;
> >
> > if (addr >= 0x40 && addr < 0x64)
> > int core = (addr - 0x40) / 0x8;
> >
> > R_END seems to be off by 4 in the above. Should it be 0x60?
> >
> > Regards,
> > BALATON Zoltan
> >
> > >> R_END is 0x64 and R_START is 0x40, so if addr is 0x60
> > >> then addr - R_START is 0x32 and so core here is 4.
> > >> However p->per_core_isr[] only has 4 entries, so this will
> > >> be off the end of the array.
> > >>
> > >> This is CID 1438965.
> > >>
> > >>>          r = p->per_core_isr[core];
> > >>>          goto out;
> > >>>      }
> > >>
> > >>> -    if (addr >= R_PERCORE_ISR(0) &&
> > >>> -        addr < R_PERCORE_ISR(NUM_CORES)) {
> > >>> -        int core = (addr - R_PERCORE_ISR(0)) / 8;
> > >>> +    if (addr >= R_START && addr < R_END) {
> > >>> +        int core = (addr - R_START) / R_ISR_SIZE;
> > >>>          p->per_core_isr[core] = value;
> > >>>          goto out;
> > >>>      }
> > >>
> > >> Same thing here, CID 1438967.
> > >
> > > Thanks Peter.
> > >
> > > Huacai, can you have a look please?
> > >
> > > Thanks,
> > >
> > > Phil.
> > >
> > >
>

-- 
- Jiaxun