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From:   Guo Ren <guoren@kernel.org>
Date:   Fri, 22 Jul 2022 15:51:12 +0800
Message-ID: <CAJF2gTSYp4-2VLq4HmvcdDWq3ygkHiXpDfTyocYStxGpejx7jg@mail.gmail.com>
Subject: Re: [PATCH 4/5] riscv: Add modules to virtual kernel memory layout dump
To:     =?UTF-8?Q?Heiko_St=C3=BCbner?= <heiko@sntech.de>
Cc:     Paul Walmsley <paul.walmsley@sifive.com>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        Albert Ou <aou@eecs.berkeley.edu>,
        Anup Patel <anup@brainfault.org>,
        Nick Kossifidis <mick@ics.forth.gr>,
        Alexandre Ghiti <alexandre.ghiti@canonical.com>,
        Xianting Tian <xianting.tian@linux.alibaba.com>,
        linux-riscv <linux-riscv@lists.infradead.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        crash-utility@redhat.com, huanyi.xj@alibaba-inc.com,
        Heinrich Schuchardt <heinrich.schuchardt@canonical.com>,
        k-hagio-ab@nec.com, hschauhan@nulltrace.org
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On Fri, Jul 22, 2022 at 3:24 PM Heiko St=C3=BCbner <heiko@sntech.de> wrote:
>
> Am Sonntag, 17. Juli 2022, 12:13:22 CEST schrieb Xianting Tian:
> > Modules always live before the kernel, MODULES_END is fixed but
> > MODULES_VADDR isn't fixed, it depends on the kernel size.
> > Let's add it to virtual kernel memory layout dump.
> >
> > As MODULES is only defined for CONFIG_64BIT, so we dump it when
> > CONFIG_64BIT=3Dy.
> >
> > eg,
> > MODULES_VADDR - MODULES_END
> > 0xffffffff01133000 - 0xffffffff80000000
> >
> > Signed-off-by: Xianting Tian <xianting.tian@linux.alibaba.com>
>
> I'm still not sure if it would be better to define MODULES_* constants
> even on 32bit (with their VMALLOC_START etc values) and prevent
> needing the CONFIG_64BIT ifdef, but that's for others to decide :-)
There is no MODULES_VADDR for 32-bit, because it reuses vmalloc area.

We should print MODULES_VADDR here to make people clear to know.

Reviewed-by: Guo Ren <guoren@kernel.org>

>
> The below also looks good, so
> Reviewed-by: Heiko Stuebner <heiko@sntech.de>
>
> > ---
> >  arch/riscv/mm/init.c | 4 ++++
> >  1 file changed, 4 insertions(+)
> >
> > diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
> > index d466ec670e1f..2c4a64e97aec 100644
> > --- a/arch/riscv/mm/init.c
> > +++ b/arch/riscv/mm/init.c
> > @@ -135,6 +135,10 @@ static void __init print_vm_layout(void)
> >               (unsigned long)VMEMMAP_END);
> >       print_ml("vmalloc", (unsigned long)VMALLOC_START,
> >               (unsigned long)VMALLOC_END);
> > +#ifdef CONFIG_64BIT
> > +     print_ml("modules", (unsigned long)MODULES_VADDR,
> > +             (unsigned long)MODULES_END);
> > +#endif
> >       print_ml("lowmem", (unsigned long)PAGE_OFFSET,
> >               (unsigned long)high_memory);
> >       if (IS_ENABLED(CONFIG_64BIT)) {
> >
>
>
>
>


--=20
Best Regards
 Guo Ren