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

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(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 >>>