Hi Qianli,

thanks for the patch and explanation.  I was off.

On 2022/06/27 11:24, qianli zhao wrote:
> Hi,Kazu
>
> Would you like to help review this patch?

Sure, I think I can review it this week.

Lianbo, can you possibly reproduce and test this?

Kazu

>
> qianli zhao <zhaoqianligood@gmail.com> 于2022年6月24日周五 10:56写道：
>
>>
>> Hi,all
>>
>> Here's some explanation for this patch
>>
>> Without patch:
>> Consider the following scenario
>> ->arm64_init(PRE_GDB)
>> case PRE_GDB:
>> ...
>>   292                         } else if (ms->VA_BITS_ACTUAL) {
>>   293                                 ms->modules_vaddr =
>> (st->_stext_vmlinux & TEXT_OFFSET_MASK) -
>> ARM64_MODULES_VSIZE;-->//ms->modules_vaddr=0xfffffffff8000000
>>   294                                 ms->modules_end =
>> ms->modules_vaddr + ARM64_MODULES_VSIZE
>> -1;--->//ms->modules_end=0xffffffffffffffff
>>   295                                 ms->vmalloc_start_addr =
>> ms->modules_end + 1;--->//ms->vmalloc_start_addr=0
>> 296                         } else {
>>                                 ....
>>                                 }
>>                                 arm64_calc_kimage_voffset();
>> .....
>>
>> Since arm64_calc_kimage_voffset() depends on vmalloc_start_addr,
>> kimage_voffset cannot be calculated correctly.
>>
>> st->_stext_vmlinux can be initialized in numeric_forward(),just set
>> st->_stext_vmlinux to UNINITIALIZED.
>>
>> ============
>> log as below:
>>
>> $ ~/crash/crash/crash vmlinux DDRCS0.bin@0x80000000 --machdep vabits_actual=48
>>
>> crash 8.0.1++
>> Copyright (C) 2002-2022  Red Hat, Inc.
>> Copyright (C) 2004, 2005, 2006, 2010  IBM Corporation
>> Copyright (C) 1999-2006  Hewlett-Packard Co
>> Copyright (C) 2005, 2006, 2011, 2012  Fujitsu Limited
>> Copyright (C) 2006, 2007  VA Linux Systems Japan K.K.
>> Copyright (C) 2005, 2011, 2020-2022  NEC Corporation
>> Copyright (C) 1999, 2002, 2007  Silicon Graphics, Inc.
>> Copyright (C) 1999, 2000, 2001, 2002  Mission Critical Linux, Inc.
>> Copyright (C) 2015, 2021  VMware, Inc.
>> This program is free software, covered by the GNU General Public License,
>> and you are welcome to change it and/or distribute copies of it under
>> certain conditions.  Enter "help copying" to see the conditions.
>> This program has absolutely no warranty.  Enter "help warranty" for details.
>>
>> NOTE: setting vabits_actual to: 48
>>
>> WARNING: kimage_voffset cannot be determined from the dumpfile.
>>         Try using the command line option: --machdep kimage_voffset=<addr>
>> GNU gdb (GDB) 10.2
>> Copyright (C) 2021 Free Software Foundation, Inc.
>> License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
>> This is free software: you are free to change and redistribute it.
>> There is NO WARRANTY, to the extent permitted by law.
>> Type "show copying" and "show warranty" for details.
>> This GDB was configured as "--host=x86_64-pc-linux-gnu
>> --target=aarch64-elf-linux".
>> Type "show configuration" for configuration details.
>> Find the GDB manual and other documentation resources online at:
>>      <http://www.gnu.org/software/gdb/documentation/>.
>>
>> For help, type "help".
>> Type "apropos word" to search for commands related to "word"...
>>
>> crash: read error: kernel virtual address: ffff80001083d4a0  type:
>> "kernel_config_data"
>> WARNING: cannot read kernel_config_data
>> crash: read error: kernel virtual address: ffff80001170e798  type: "possible"
>> WARNING: cannot read cpu_possible_map
>> crash: read error: kernel virtual address: ffff80001170e7a8  type: "present"
>> WARNING: cannot read cpu_present_map
>> crash: read error: kernel virtual address: ffff80001170e788  type: "online"
>> WARNING: cannot read cpu_online_map
>> crash: read error: kernel virtual address: ffff80001170e7c0  type: "active"
>> WARNING: cannot read cpu_active_map
>> crash: read error: kernel virtual address: ffff8000122e00f0  type:
>> "shadow_timekeeper xtime_sec"
>> crash: read error: kernel virtual address: ffff80001171dc04  type: "init_uts_ns"
>> crash: vmlinux and /var/tmp/ramdump_elf_m2ivkg do not match!
>>
>> Usage:
>>
>>    crash [OPTION]... NAMELIST MEMORY-IMAGE[@ADDRESS]     (dumpfile form)
>>    crash [OPTION]... [NAMELIST]                          (live system form)
>>
>> Enter "crash -h" for details.
>>
>> Qianli Zhao <zhaoqianligood@gmail.com> 于2022年6月24日周五 00:14写道：
>>>
>>> From: Qianli Zhao <qianli.zhao@horizon.ai>
>>>
>>> Setting st->_stext_vmlinux to UNINITIALIZED to search for "_stext" from the vmlinux
>>> Without the patch, if we do not enable kaslr, will get the wrong
>>> MODULES/VMALLOC ranges, cause parsing dump failure
>>>
>>> Signed-off-by: Qianli Zhao <qianli.zhao@horizon.ai>
>>> ---
>>>   arm64.c | 3 +++
>>>   1 file changed, 3 insertions(+)
>>>
>>> diff --git a/arm64.c b/arm64.c
>>> index 0f615cf..4458a66 100644
>>> --- a/arm64.c
>>> +++ b/arm64.c
>>> @@ -149,6 +149,9 @@ arm64_init(int when)
>>>
>>>                  ms = machdep->machspec;
>>>
>>> +               if (ms->VA_BITS_ACTUAL)
>>> +                       st->_stext_vmlinux = UNINITIALIZED;
>>> +
>>>                  if (!ms->kimage_voffset && STREQ(pc->live_memsrc, "/dev/crash"))
>>>                          ioctl(pc->mfd, DEV_CRASH_ARCH_DATA, &ms->kimage_voffset);
>>>
>>> --
>>> 2.17.1
>>>