[Crash-utility] arm64: doesn't work for kernel v5.4?

[AKASHI Takahiro]

On Wed, Oct 09, 2019 at 09:03:25AM -0400, Dave Anderson wrote:
> 
> 
> ----- Original Message -----
> > On Tue, Oct 08, 2019 at 04:55:48PM -0400, Dave Anderson wrote:
> > > 
> > > > ----- Original Message -----
> > > > > Hi Dave,
> > > > > 
> > > > > I tried to use crash v7.2.7 with kernel v5.4-rc1 on arm64.
> > > > > 
> > > > > 1. VA_BITS_ACTUAL is missing in vmcoreinfo.
> > > > >    Does anyone work on fixing it on kernel side?
> > > > >    (just adding one or two lines though)
> > > > > 
> > > > > 2. With a tweak above, I still fail to run crash with vmcore
> > > > >    seeing the following errors;
> > > > >    (I didn't dig into details)
> > > > > 
> > > > >    crash-arm64: invalid kernel virtual address: ffff800010c689a8  type:
> > > > >    "kernel_config_data"
> > > > >    WARNING: cannot read kernel_config_data
> > > > >    crash-arm64: invalid kernel virtual address: ffff80001177a160  type:
> > > > >    "possible"
> > > > >    WARNING: cannot read cpu_possible_map
> > > > >    crash-arm64: invalid kernel virtual address: ffff80001177a140  type:
> > > > >    "present"
> > > > >    WARNING: cannot read cpu_present_map
> > > > >    crash-arm64: invalid kernel virtual address: ffff80001177a120  type:
> > > > >    "online"
> > > > >    WARNING: cannot read cpu_online_map
> > > > >    crash-arm64: invalid kernel virtual address: ffff80001177a188  type:
> > > > >    "active"
> > > > >    WARNING: cannot read cpu_active_map
> > > > >    crash-arm64: invalid kernel virtual address: ffff80001196afe0  type:
> > > > >    "shadow_timekeeper xtime_sec"
> > > > >    crash-arm64: invalid kernel virtual address: ffff800011782b3c  type:
> > > > >    "init_uts_ns"
> > > > >    WARNING: invalid linux_banner pointer: ffff800010c500e8
> > > > >    crash: vmlinux.1003 and vmcore.1003 do not match!
> > > > > 
> > > > > Have you noticed this issue?
> > > > 
> > > > I have been waiting for our internal 5.4-rc1 based ARK kernel to be
> > > > built,
> > > > and it looks like it should be available soon.  But I did not expect
> > > > crash
> > > > to work on arm64 in 5.4.
> > > > 
> > > > I put in a bunch of 52-bit support into the crash utility last spring,
> > > > but
> > > > it was based upon an early proposed patch-set from Steve Capper that
> > > > Chris
> > > > von Recklinghausen backported to our 4.18.0-80.el8 kernel at the time.
> > > > I believe Chris may have added the VA_BITS_ACTUAL vmcoreinfo entry (?),
> > > > and I'm presuming there will be other VM-related things that are
> > > > different from that original kernel patch.
> > > > 
> > > > Thanks,
> > > >   Dave
> > > 
> > > I still haven't got a 5.4-rc1 kernel to test with, but Chris Von
> > > Recklinghausen
> > > has backported the latest upstream 52-bit patch-set to a 4.18-based kernel.
> > > However, it did require one additional patch needed for crash to run live
> > > on /proc/kcore, which he posted on the arm list today:
> > > 
> > >   [PATCH] arm64: remove arm64 definitions of kc_vaddr_to_offset and
> > >   kc_offset_to_vaddr.
> > >   http://lists.infradead.org/pipermail/linux-arm-kernel/2019-October/685109.html
> > > 
> > > With his patch-set (including the above), crash-7.2.7 comes up unmodified
> > > on
> > > a live system -- albeit one which downgrades from 52 bits to 48 bits. Chris is
> > > going to test crash running live on a 52 bit simulator tomorrow.
> > 
> > I may misunderstand something, but even after applying this patch,
> > nothing has changed, at least, against /proc/vmcore. (I see the same errors.)
> 
> The patch has nothing to do with /proc/vmcore -- did you mean /proc/kcore?

That's why I said that I might misunderstand something.
I have concerns on /proc/vmcore as I'm now pushing my kexec_file_load-
based kdump patch.

Thanks,
-Takahiro Akashi

> Dave
> 
> 
> > 
> > Thanks,
> > -Takahiro Akashi
> > 
> > 
> > > Dave
> > > 
> > > --
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> > 
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