Re: [PATCH v3 3/5] RISC-V: Improve init_resources

[Nick Kossifidis]

Hello Geert,

Στις 2021-04-06 10:19, Geert Uytterhoeven έγραψε:
> Hi Nick,
>
> Thanks for your patch!
>
> On Mon, Apr 5, 2021 at 10:57 AM Nick Kossifidis <mick@xxxxxxxxxxxx> 
> wrote:
> > * Kernel region is always present and we know where it is, no
> > need to look for it inside the loop, just ignore it like the
> > rest of the reserved regions within system's memory.
> >
> > * Don't call memblock_free inside the loop, if called it'll split
> > the region of pre-allocated resources in two parts, messing things
> > up, just re-use the previous pre-allocated resource and free any
> > unused resources after both loops finish.
> >
> > * memblock_alloc may add a region when called, so increase the
> > number of pre-allocated regions by one to be on the safe side
> > (reported and patched by Geert Uytterhoeven)
> >
> > Signed-off-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
>
> Where does this SoB come from?
>
> > Signed-off-by: Nick Kossifidis <mick@xxxxxxxxxxxx>
>
> > --- a/arch/riscv/kernel/setup.c
> > +++ b/arch/riscv/kernel/setup.c
>
> > @@ -129,53 +139,42 @@ static void __init init_resources(void)
> >         struct resource *res = NULL;
> >         struct resource *mem_res = NULL;
> >         size_t mem_res_sz = 0;
> > -       int ret = 0, i = 0;
> > -
> > -       code_res.start = __pa_symbol(_text);
> > -       code_res.end = __pa_symbol(_etext) - 1;
> > -       code_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
> > -
> > -       rodata_res.start = __pa_symbol(__start_rodata);
> > -       rodata_res.end = __pa_symbol(__end_rodata) - 1;
> > -       rodata_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
> > -
> > -       data_res.start = __pa_symbol(_data);
> > -       data_res.end = __pa_symbol(_edata) - 1;
> > -       data_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
> > +       int num_resources = 0, res_idx = 0;
> > +       int ret = 0;
> >
> > -       bss_res.start = __pa_symbol(__bss_start);
> > -       bss_res.end = __pa_symbol(__bss_stop) - 1;
> > -       bss_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
> > +       /* + 1 as memblock_alloc() might increase 
> > memblock.reserved.cnt */
> > +       num_resources = memblock.memory.cnt + memblock.reserved.cnt + 
> > 1;
> > +       res_idx = num_resources - 1;
> >
> > -       mem_res_sz = (memblock.memory.cnt + memblock.reserved.cnt) * 
> > sizeof(*mem_res);
>
> Oh, you incorporated my commit ce989f1472ae350e ("RISC-V: Fix 
> out-of-bounds
> accesses in init_resources()") (from v5.12-rc4) into your patch.
> Why? This means your patch does not apply against upstream.

Sorry if this looks awkward, I'm under the impression that new features 
go on for-next instead of fixes and your patch hasn't been merged on 
for-next yet. I thought it would be cleaner to have one patch to merge 
for init_resources instead of two, and simpler for people to test the 
series. I can rebase this on top of fixes if that works better for you 
or Palmer.

Regards,
Nick