lkml.org 
[lkml]   [2021]   [Jul]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
SubjectRe: [PATCH -next v2] riscv: add VMAP_STACK overflow detection
On Thu, 22 Jul 2021 01:35:23 -0700
Atish Patra <atishp@atishpatra.org> wrote:

> On Wed, Jul 21, 2021 at 11:12 PM Palmer Dabbelt <palmer@dabbelt.com> wrote:
> >
> > On Mon, 19 Jul 2021 00:23:06 PDT (-0700), schwab@linux-m68k.org wrote:
> > > On Jul 19 2021, tongtiangen wrote:
> > >
> > >> On 2021/7/17 14:55, Andreas Schwab wrote:
> > >>> Please use
> > >>> https://download.opensuse.org/repositories/home:/Andreas_Schwab:/riscv:/jeos/images/openSUSE-Tumbleweed-RISC-V-JeOS-efi.riscv64.raw.xz
> > >>> and run it in qemu with u-boot as kernel.
> > >>>
> > >>> Andreas.
> > >>>
> > >>
> > >> Hi andreas:
> > >> I used today's latest mainline code and .config provided by you, and I
> > >> can't reproduce this panic.
> > >
> > > Did you test it like I said above?
> > >
> > > Andreas.
> >
> > I'm getting this on and off, with just
> >
> > CONFIG_VMAP_STACK=y
> >
> > on top of defconfig, when running on QEMU. It's not showing up right
> > now: I'd thought it was an issue with that initrd patch, but it went
> > away when I re-ran the tests so I'm guessing it's something
> > non-deterministic. I'll try to take a look if it comes back.
> >
>
> I got it very frequently on beagleV with the following branch & config.
> https://github.com/esmil/linux/commits/beaglev
>
> beaglev_defconfig
>
> Disabling CONFIG_VMAP_STACK avoids the crash.

Hi all,

I think we need to pin the stack before calling get_wchan(), could you please
try below patch?

Thanks

diff --git a/arch/riscv/kernel/stacktrace.c b/arch/riscv/kernel/stacktrace.c
index ff467b98c3e3..ac7593607fa6 100644
--- a/arch/riscv/kernel/stacktrace.c
+++ b/arch/riscv/kernel/stacktrace.c
@@ -132,8 +132,12 @@ unsigned long get_wchan(struct task_struct *task)
{
unsigned long pc = 0;

- if (likely(task && task != current && !task_is_running(task)))
+ if (likely(task && task != current && !task_is_running(task))) {
+ if (!try_get_task_stack(task))
+ return 0;
walk_stackframe(task, NULL, save_wchan, &pc);
+ put_task_stack(task);
+ }
return pc;
}


>
> > _______________________________________________
> > linux-riscv mailing list
> > linux-riscv@lists.infradead.org
> > http://lists.infradead.org/mailman/listinfo/linux-riscv
>
>
>


\
 
 \ /
  Last update: 2021-07-22 19:36    [W:0.068 / U:0.300 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site