[Crash-utility] Crash utility with RT patchset

[Abhishek Shah]

Hi Ron,

> I guess the address convention seems x8664 when looking at  0xffffffxxxxxxxx type sort of 64 bit virtual address.

arm64 also has a similar range of virtual addresses (see
"Documentation/arm64/memory.rst" in Linux),
currently my target is using 39-bits (as specified in crash command
used below) and 4 kB page table.

I see below address range being used, when giving "-d 1" to enable debug prints:

crash: get_cpus_present: present: 8
hypervisor: (undetermined)
ikconfig: 1616 valid configs.
SECTION_SIZE_BITS: 30
CONFIG_ARM64_VA_BITS: 39
      VA_BITS_ACTUAL: 39
(calculated) VA_BITS: 39
 PAGE_OFFSET: ffffff8000000000
    VA_START: ffffffc000000000
     modules: ffffffc008000000 - ffffffc00fffffff
     vmalloc: ffffffc010000000 - fffffffebffeffff
kernel image: fffffff009680000 - fffffff00b194000
     vmemmap: fffffffeffe00000 - ffffffffffffffff


Also ,There is no issue with crash (compiled for arm64) or vmlinux (arm64) type.

> Either that or possibly the offset at which you are trying to load.
Are you referring to kaslr offset? Without that in place, I get a
vmlinux/ramdump mismatch error.
So I am confident that it is correct.

Can anyone suggest whether any change is required in either crash utility or
RT Linux to make use of crash utility to analyze ramdump with RT Linux?


Regards,
Abhishek

On Thu, Jul 8, 2021 at 7:49 AM Ron HM <gpl.positron at gmail.com> wrote:
>
> Either that or possibly the offset at which you are trying to load.
>
> On Thu, 8 Jul 2021, 9:28 am Ron HM, <gpl.positron at gmail.com> wrote:
>>
>> Hi Abhishek,
>> I guess the address convention seems x8664 when looking at  0xffffffxxxxxxxx type sort of 64 bit virtual address.
>>
>> ------
>> crash: invalid kernel virtual address: fffffff791ff5a5f  type: "64-bit KVADDR"
>> -----
>>
>> For arm64 bit the addressing would more be sort of 0xCCAbxxxxxxx sorts. Due to the convention of memory addressing start addresses.
>>
>> As a first check confirm if your crash and vmlinuz file is x8664 type
>> # file vmlinux
>> # file crash
>>
>>
>>
>>
>> On Wed, 7 Jul 2021, 3:53 pm Abhishek Shah, <abrs612 at gmail.com> wrote:
>>>
>>> Hi All,
>>>
>>> I was wondering if there is any change required in either crash utility or
>>> RT Linux to make use of crash utility to analyze ramdump with RT Linux.
>>>
>>> I am using crash 7.3.0++ and Linux - 5.4.61-rt37 on arm64 target.
>>> I see the below error:
>>> ../crash DDR0.BIN at 0x80000000,DDR1.BIN at 0x100000000 vmlinux
>>> --machdep vabits_actual=39 --kaslr 0x2ff9600000
>>> ......
>>> crash: invalid kernel virtual address: fffffff791ff5a5f  type: "64-bit KVADDR"
>>>
>>>
>>> Regards,
>>> Abhishek
>>>
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