Re: [Crash-utility] [PATCH] arm64: Fix for st->_stext_vmlinux not initialized when set VA_BITS_ACTUAL

Hi, Kazu and Qianli On Tue, Jun 28, 2022 at 9:17 AM HAGIO KAZUHITO(萩尾 一仁) <k-hagio-ab(a)nec.com&gt; wrote: > 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? OK, I will have a look and give feedback later.

> Kazu > > > > > qianli zhao <zhaoqianligood(a)gmail.com&gt; 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(a)gmail.com&gt; 于2022年6月24日周五 00:14写道： > >>> > >>> From: Qianli Zhao <qianli.zhao(a)horizon.ai&gt; > >>> > >>> 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(a)horizon.ai&gt; > >>> --- > >>> 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 > >>>