As of commit 2277b492582d ("kdb: Fix stack crawling on 'running' CPUs
that aren't the master") we no longer need any special case for doing
stack dumps on CPUs that are not the kdb master. Let's remove.
Signed-off-by: Douglas Anderson <[email protected]>
---
I have no way to test this personally, so hopefully someone who uses
kdb/kgdb on MIPS can.
Ideally this patch should be Acked by MIPS folks and then land through
the kdb/kgdb tree since the next patch in the series, ("kdb:
kdb_current_regs should be private") depends on it.
arch/mips/kernel/traps.c | 5 -----
1 file changed, 5 deletions(-)
diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index 342e41de9d64..46fbcfeaae9a 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -210,11 +210,6 @@ void show_stack(struct task_struct *task, unsigned long *sp)
regs.regs[29] = task->thread.reg29;
regs.regs[31] = 0;
regs.cp0_epc = task->thread.reg31;
-#ifdef CONFIG_KGDB_KDB
- } else if (atomic_read(&kgdb_active) != -1 &&
- kdb_current_regs) {
- memcpy(®s, kdb_current_regs, sizeof(regs));
-#endif /* CONFIG_KGDB_KDB */
} else {
prepare_frametrace(®s);
}
--
2.24.0.432.g9d3f5f5b63-goog
On Sat, Nov 09, 2019 at 11:16:40AM -0800, Douglas Anderson wrote:
> As of commit 2277b492582d ("kdb: Fix stack crawling on 'running' CPUs
> that aren't the master") we no longer need any special case for doing
> stack dumps on CPUs that are not the kdb master. Let's remove.
>
> Signed-off-by: Douglas Anderson <[email protected]>
> ---
> I have no way to test this personally, so hopefully someone who uses
> kdb/kgdb on MIPS can.
I took this as a hint to add mips support to kgdbtest ;-)
Support is added and working well. Unfortunately lack of familiarity
with mips means I have not yet figured out which mips defconfig gives
us working SMP (and what the corresponding qemu invocation should be).
I think that means I still can't (quite) exercise this code fully.
The most appropriate test is bta on an SMP system, right?
> Ideally this patch should be Acked by MIPS folks and then land through
> the kdb/kgdb tree since the next patch in the series, ("kdb:
> kdb_current_regs should be private") depends on it.
An Acked-by from a MIPS maintainer would be very welcome. Perhaps
with a bit of extra work on the above I might be able to provide
a Tested-by:.
I didn't see anything that particularly bothered me in the patches but
given we're already at -rc7 I'm inclined to target this patchset for 5.6
rather than 5.5.
Daniel.
Hi,
On Thu, Nov 14, 2019 at 2:51 AM Daniel Thompson
<[email protected]> wrote:
>
> On Sat, Nov 09, 2019 at 11:16:40AM -0800, Douglas Anderson wrote:
> > As of commit 2277b492582d ("kdb: Fix stack crawling on 'running' CPUs
> > that aren't the master") we no longer need any special case for doing
> > stack dumps on CPUs that are not the kdb master. Let's remove.
> >
> > Signed-off-by: Douglas Anderson <[email protected]>
> > ---
> > I have no way to test this personally, so hopefully someone who uses
> > kdb/kgdb on MIPS can.
>
> I took this as a hint to add mips support to kgdbtest ;-)
>
> Support is added and working well. Unfortunately lack of familiarity
> with mips means I have not yet figured out which mips defconfig gives
> us working SMP (and what the corresponding qemu invocation should be).
Nice!
> I think that means I still can't (quite) exercise this code fully.
> The most appropriate test is bta on an SMP system, right?
Yeah, or at least "btc".
> > Ideally this patch should be Acked by MIPS folks and then land through
> > the kdb/kgdb tree since the next patch in the series, ("kdb:
> > kdb_current_regs should be private") depends on it.
>
> An Acked-by from a MIPS maintainer would be very welcome. Perhaps
> with a bit of extra work on the above I might be able to provide
> a Tested-by:.
>
> I didn't see anything that particularly bothered me in the patches but
> given we're already at -rc7 I'm inclined to target this patchset for 5.6
> rather than 5.5.
That's fine. This is all just cleanup stuff so targeting 5.6 is fine.
-Doug
Hi Daniel,
On Thu, Nov 14, 2019 at 10:51:25AM +0000, Daniel Thompson wrote:
> On Sat, Nov 09, 2019 at 11:16:40AM -0800, Douglas Anderson wrote:
> > As of commit 2277b492582d ("kdb: Fix stack crawling on 'running' CPUs
> > that aren't the master") we no longer need any special case for doing
> > stack dumps on CPUs that are not the kdb master. Let's remove.
> >
> > Signed-off-by: Douglas Anderson <[email protected]>
> > ---
> > I have no way to test this personally, so hopefully someone who uses
> > kdb/kgdb on MIPS can.
>
> I took this as a hint to add mips support to kgdbtest ;-)
Wonderful! :)
> Support is added and working well. Unfortunately lack of familiarity
> with mips means I have not yet figured out which mips defconfig gives
> us working SMP (and what the corresponding qemu invocation should be).
You can build 64r6el_defconfig & boot it something like this:
$ qemu-system-mips64el \
-M boston -cpu I6500 -smp 4 \
-kernel arch/mips/boot/vmlinux.gz.itb \
-serial stdio \
-hda my-disk-image.bin \
-append "root=/dev/sda"
Linux should see the system as a single core with 4 hardware threads
(VPs or Virtual Processors in MIPS terminology).
> > Ideally this patch should be Acked by MIPS folks and then land through
> > the kdb/kgdb tree since the next patch in the series, ("kdb:
> > kdb_current_regs should be private") depends on it.
>
> An Acked-by from a MIPS maintainer would be very welcome. Perhaps
> with a bit of extra work on the above I might be able to provide
> a Tested-by:.
The patches look reasonable to me; I was hoping to test them before
giving an ack but haven't had the time yet. It seems you may be making
that easier :)
Thanks,
Paul