Re: Google Container OS and crash 8.0.4
                                
                                
                                
                                    
                                        by Matt Suiche
                                    
                                
                                
                                        Apparently, CONFIG_KALLSYMS_ALL is not set in COS kernel
Sent from my mobile device.
________________________________
From: Matt Suiche <matt.suiche(a)magnetforensics.com>
Sent: Wednesday, November 29, 2023 4:40:55 PM
To: HAGIO KAZUHITO(萩尾 一仁) <k-hagio-ab(a)nec.com>; devel(a)lists.crash-utility.osci.io <devel(a)lists.crash-utility.osci.io>
Subject: Re: [Crash-utility] Google Container OS and crash 8.0.4
Yes, it would probably make more sense. You can also probably use _stext instead of module_load_offset too to compare the values as an assertion check.
Sent from my mobile device.
________________________________
From: HAGIO KAZUHITO(萩尾 一仁) <k-hagio-ab(a)nec.com>
Sent: Wednesday, November 29, 2023 4:29 AM
To: Matt Suiche <matt.suiche(a)magnetforensics.com>; devel(a)lists.crash-utility.osci.io <devel(a)lists.crash-utility.osci.io>
Subject: Re: [Crash-utility] Google Container OS and crash 8.0.4
On 2023/11/22 18:04, Matt Suiche wrote:
> Sounds like this is the issue. Module_load_offset is not present, same
> with init_task though.
>
> root@instance-2:~# grep -e _stext -e module_load_offset -e init_task
> /proc/kallsyms
> ffffffff89000000 T _stext
> ffffffff8909e280 t ptrace_init_task
> ffffffff891c6af0 T ftrace_graph_init_task
> ffffffff89245ea0 T perf_event_init_task
> ffffffff8aba3b46 T rcu_init_tasks_generic
> root@instance-2:~#
Yes, but I don't see the reason why it's not present in /proc/kallsyms,
although it's present in the vmlinux..
Recent kernels have vmcoreinfo in /proc/kcore, maybe we can use the
KERNELOFFSET value instead of the module_load_offset symbol to determine
whether KASLR is enabled.  I might try it when I have time.
Thanks,
Kazu
>
> *From: *HAGIO KAZUHITO(萩尾 一仁) <k-hagio-ab(a)nec.com>
> *Date: *Wednesday, November 22, 2023 at 12:01 PM
> *To: *Matt Suiche <matt.suiche(a)magnetforensics.com>,
> devel(a)lists.crash-utility.osci.io <devel(a)lists.crash-utility.osci.io>
> *Subject: *EXTERNAL SENDER Re: [Crash-utility] Google Container OS and
> crash 8.0.4
>
> On 2023/11/22 15:41, Matt Suiche wrote:
>> Good point, enough the –kaslr=auto option worked well. Same when I passed --kaslr=0x8000000
>
> Good news.
>
> apparently module_load_offset symbol is needed in /proc/kallsyms to
> enable the KASLR detection.  I see it in the vmlinux.
>
> $ nm vmlinux-cos-5.15.133+ | grep module_load_offset
> ffffffff82d83350 b module_load_offset
>
> Is it (and _stext) found in /proc/kallsyms? like
>
> # grep -e _stext -e module_load_offset /proc/kallsyms
> ffffffffa0e00000 T _stext
> ffffffffa3aafab8 b module_load_offset
>
>
> PS. I will be out for the rest of this week, back next week.
>
> Thanks,
> Kazu
>
> This email including any attachments may contain confidential material
> for the sole use of the intended recipient. If you are not the intended
> recipient please immediately notify the sender by reply email,
> permanently delete this message and do not forward it or any part of it
> to anyone else.
>
This email including any attachments may contain confidential material for the sole use of the intended recipient. If you are not the intended recipient please immediately notify the sender by reply email, permanently delete this message and do not forward it or any part of it to anyone else.
                                
                         
                        
                                
                                1 year, 11 months
                        
                        
                 
         
 
        
            
        
        
        
                
                        
                                
                                
                                        
                                
                         
                        
                                
                                
                                        
                                                
                                        
                                        
                                        Re: Google Container OS and crash 8.0.4
                                
                                
                                
                                    
                                        by HAGIO KAZUHITO(萩尾 一仁)
                                    
                                
                                
                                        On 2023/11/22 18:04, Matt Suiche wrote:
> Sounds like this is the issue. Module_load_offset is not present, same 
> with init_task though.
> 
> root@instance-2:~# grep -e _stext -e module_load_offset -e init_task 
> /proc/kallsyms
> ffffffff89000000 T _stext
> ffffffff8909e280 t ptrace_init_task
> ffffffff891c6af0 T ftrace_graph_init_task
> ffffffff89245ea0 T perf_event_init_task
> ffffffff8aba3b46 T rcu_init_tasks_generic
> root@instance-2:~#
Yes, but I don't see the reason why it's not present in /proc/kallsyms, 
although it's present in the vmlinux..
Recent kernels have vmcoreinfo in /proc/kcore, maybe we can use the 
KERNELOFFSET value instead of the module_load_offset symbol to determine 
whether KASLR is enabled.  I might try it when I have time.
Thanks,
Kazu
> 
> *From: *HAGIO KAZUHITO(萩尾 一仁) <k-hagio-ab(a)nec.com>
> *Date: *Wednesday, November 22, 2023 at 12:01 PM
> *To: *Matt Suiche <matt.suiche(a)magnetforensics.com>, 
> devel(a)lists.crash-utility.osci.io <devel(a)lists.crash-utility.osci.io>
> *Subject: *EXTERNAL SENDER Re: [Crash-utility] Google Container OS and 
> crash 8.0.4
> 
> On 2023/11/22 15:41, Matt Suiche wrote:
>> Good point, enough the –kaslr=auto option worked well. Same when I passed --kaslr=0x8000000
> 
> Good news.
> 
> apparently module_load_offset symbol is needed in /proc/kallsyms to
> enable the KASLR detection.  I see it in the vmlinux.
> 
> $ nm vmlinux-cos-5.15.133+ | grep module_load_offset
> ffffffff82d83350 b module_load_offset
> 
> Is it (and _stext) found in /proc/kallsyms? like
> 
> # grep -e _stext -e module_load_offset /proc/kallsyms
> ffffffffa0e00000 T _stext
> ffffffffa3aafab8 b module_load_offset
> 
> 
> PS. I will be out for the rest of this week, back next week.
> 
> Thanks,
> Kazu
> 
> This email including any attachments may contain confidential material 
> for the sole use of the intended recipient. If you are not the intended 
> recipient please immediately notify the sender by reply email, 
> permanently delete this message and do not forward it or any part of it 
> to anyone else.
> 
                                
                         
                        
                                
                                1 year, 11 months
                        
                        
                 
         
 
        
            
        
        
        
                
                        
                                
                                
                                        
                                
                         
                        
                                
                                
                                        
                                                
                                        
                                        
                                        Re: [PATCH v2] symbols: skip load .init.* sections if module was  successfully initialized
                                
                                
                                
                                    
                                        by lijiang
                                    
                                
                                
                                        On Wed, Nov 15, 2023 at 4:00 PM <devel-request(a)lists.crash-utility.osci.io>
wrote:
> Date: Tue, 14 Nov 2023 16:32:07 +0800
> From: Tao Liu <ltao(a)redhat.com>
> Subject: [Crash-utility] [PATCH v2] symbols: skip load .init.*
>         sections if module was successfully initialized
> To: devel(a)lists.crash-utility.osci.io
> Cc: Tao Liu <ltao(a)redhat.com>
> Message-ID: <20231114083206.11202-1-ltao(a)redhat.com>
> Content-Type: text/plain; charset="US-ASCII"; x-default=true
>
> There might be address overlap of one module's .init.text symbols and
> another module's .text symbols. As a result, gdb fails to translate the
> address to symbol name correctly:
>
> crash> sym -m virtio_blk | grep MODULE
> ffffffffc00a4000 MODULE START: virtio_blk
> ffffffffc00a86ec MODULE END: virtio_blk
> crash> gdb info address floppy_module_init
> Symbol "floppy_module_init" is a function at address 0xffffffffc00a4131.
>
> Since the .init.* sections of a module had been freed by kernel if the
> module was initialized successfully, there is no need to load the .init.*
> sections data from "*.ko.debug" in gdb to create such an overlap.
> lm->mod_init_module_ptr is used as a flag of whether module is freed.
>
>
Good findings, Tao.
The v2 looks good to me. So: Ack.
Thanks
Lianbo
Without the patch:
> crash> mod -S
> crash> struct blk_mq_ops 0xffffffffc00a7160
> struct blk_mq_ops {
>   queue_rq = 0xffffffffc00a45b0 <floppy_module_init+1151>, <-- symbol
> translated from module floppy
>   map_queue = 0xffffffff813015c0 <blk_mq_map_queue>,
>   ...snip...
>   complete = 0xffffffffc00a4370 <floppy_module_init+575>,
>   init_request = 0xffffffffc00a4260 <floppy_module_init+303>,
>   ...snip...
> }
>
> With the patch:
> crash> mod -S
> crash> struct blk_mq_ops 0xffffffffc00a7160
> struct blk_mq_ops {
>   queue_rq = 0xffffffffc00a45b0 <virtio_queue_rq>, <-- symbol translated
> from module virtio_blk
>   map_queue = 0xffffffff813015c0 <blk_mq_map_queue>,
>   ...snip...
>   complete = 0xffffffffc00a4370 <virtblk_request_done>,
>   init_request = 0xffffffffc00a4260 <virtblk_init_request>,
>   ...snip...
> }
>
> Signed-off-by: Tao Liu <ltao(a)redhat.com>
> ---
>
> v1: [PATCH 1/2] symbols: expand kernel modules symtable before symbols
> translation
>     [PATCH 2/2] symbols: fix the error belonging of the kernel modules
> symbols
> v2 -> v1: Used different solution, re-drafted patch based on Kazu's
> comments,
>           so v1 can be discarded.
>
> ---
>  symbols.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/symbols.c b/symbols.c
> index 8e8b4c3..dae5b04 100644
> --- a/symbols.c
> +++ b/symbols.c
> @@ -13283,7 +13283,7 @@ add_symbol_file_kallsyms(struct load_module *lm,
> struct gnu_request *req)
>                         shift_string_right(req->buf, strlen(buf));
>                         BCOPY(buf, req->buf, strlen(buf));
>                         retval = TRUE;
> -               } else {
> +               } else if (lm->mod_init_module_ptr ||
> !STRNEQ(section_name, ".init.")) {
>                         sprintf(buf, " -s %s 0x%lx", section_name,
> section_vaddr);
>                         while ((len + strlen(buf)) >= buflen) {
>                                 RESIZEBUF(req->buf, buflen, buflen * 2);
> --
> 2.40.1
>
                                
                         
                        
                                
                                1 year, 11 months
                        
                        
                 
         
 
        
            
        
        
        
                
                        
                                
                                
                                        
                                
                         
                        
                                
                                
                                        
                                                
                                        
                                        
                                        Re: Crash preview with gdb-13.2 support
                                
                                
                                
                                    
                                        by lijiang
                                    
                                
                                
                                        On Tue, Nov 28, 2023 at 9:44 AM <devel-request(a)lists.crash-utility.osci.io>
wrote:
> Date: Mon, 27 Nov 2023 16:31:40 +0800
> From: Tao Liu <ltao(a)redhat.com>
> Subject: [Crash-utility] Crash preview with gdb-13.2 support
> To: devel(a)lists.crash-utility.osci.io
> Message-ID:
>         <CAO7dBbXPyiw0JxpyEDo7=
> K4S2k4JExaQrQwmMWSYf7oTeLFaGg(a)mail.gmail.com>
> Content-Type: text/plain; charset="UTF-8"
>
> Hi,
>
> Recently I created a repo as crash-preview[1], which forks from
> upstream crash utility but provides a higher gdb version support. The
> purpose of the repo is to ease the work of gdb upgrading for upstream
> crash utility by doing the gdb upgrading & testing tasks ahead of
> upstream.
>
> Currently gdb-13.2 is enabled for crash-preview. Any suggestions or
> comments are welcomed!
>
>
Thank you for the work, Tao.
That would be helpful for us, when the gdb version needs to be upgraded in
crash-utility. It will really save time for us, and prevent some risks, etc.
Anyway, I think that this should be a long term task.
Thanks.
Lianbo
> [1]: https://github.com/liutgnu/crash-preview
>
> Thanks,
> Tao Liu
>
                                
                         
                        
                                
                                1 year, 11 months
                        
                        
                 
         
 
        
            
        
        
        
                
                        
                        
                                
                                
                                        
                                                
                                        
                                        
                                        Crash preview with gdb-13.2 support
                                
                                
                                
                                    
                                        by Tao Liu
                                    
                                
                                
                                        Hi,
Recently I created a repo as crash-preview[1], which forks from
upstream crash utility but provides a higher gdb version support. The
purpose of the repo is to ease the work of gdb upgrading for upstream
crash utility by doing the gdb upgrading & testing tasks ahead of
upstream.
Currently gdb-13.2 is enabled for crash-preview. Any suggestions or
comments are welcomed!
[1]: https://github.com/liutgnu/crash-preview
Thanks,
Tao Liu
                                
                         
                        
                                
                                1 year, 11 months
                        
                        
                 
         
 
        
            
        
        
        
                
                        
                                
                                
                                        
                                
                         
                        
                                
                                
                                        
                                                
                                        
                                        
                                        Re: Patches for zram, swap cache fixes
                                
                                
                                
                                    
                                        by HAGIO KAZUHITO(萩尾 一仁)
                                    
                                
                                
                                        On 2023/11/21 17:42, Johan.Erlandsson(a)sony.com wrote:
>>>>> Hi
>>>>> Sharing 3 changes for zram regarding swap cache handling. Please have a look.
>>>>>
>>>>> Subject: [PATCH 1/3] zram, swap cache missing page tree offset
>>>>> Subject: [PATCH 2/3] zram, swap cache entries are pointer to struct page
>>>>> Subject: [PATCH 3/3] zram, exclude shadow entries from swap cache lookup
>>>>
>>>> Thank you for the patches.
>>>>
>>>>    > /* this already exists in maple_tree.h add to defs.h ? */
>>>>
>>>> Is it ok to add '#include maple_tree.h' ?
>>>
>>> Yes, that should work perfectly for 'xa_is_value'.
>>
>> Thanks for the reply.
>>
>> I'd like to squash the patches into a patch and add our signed-off-by
>> tags.  Please let me know if there is any trouble with the attached patch.
> 
> All looks good, verified.
> 
>>
>> One more thing, do you have any error message without the patch?  I'd
>> like to add it to the commit log, if possible.
> 
> No, I haven't seen any error messages. Short description what happens:
> 
> - lookup_swap_cache() return NULL since do_xarray() call return FALSE
> - in try_zram_decompress(), since 'entry' is NULL, page is filled with 00
> 	if (!entry || (flags & ZRAM_FLAG_SAME_BIT)) {
> 
> So without the patch, pages in swap cache will be seen to be a 'zero' page.
Thanks for the description, added.
Linabo, I updated the attached patch.
Thanks,
Kazu
                                
                         
                        
                                
                                1 year, 11 months
                        
                        
                 
         
 
        
            
        
        
        
                
                        
                                
                                
                                        
                                
                         
                        
                                
                                
                                        
                                                
                                        
                                        
                                        [PATCH v2] Fix 'rd' command for zram data display in Linux 6.2+
                                
                                
                                
                                    
                                        by Chengen Du
                                    
                                
                                
                                        A kernel commit 7ac07a26dea7 (zram: preparation for multi-zcomp support)
in Linux replaces "compressor" with "comp_algs" in the zram struct.
If not fixed, the issue triggers the following error:
  rd: WARNING: Some pages are swapped out to zram. Please run mod -s zram.
  rd: invalid user virtual address: ffff7d23f010  type: "64-bit UVADDR"
Signed-off-by: Chengen Du <chengen.du(a)canonical.com>
---
 defs.h     |  1 +
 diskdump.c | 56 +++++++++++++++++++++++++++++++++++-------------------
 2 files changed, 37 insertions(+), 20 deletions(-)
diff --git a/defs.h b/defs.h
index 788f63a..2cae5b6 100644
--- a/defs.h
+++ b/defs.h
@@ -2227,6 +2227,7 @@ struct offset_table {                    /* stash of commonly-used offsets */
 	long module_memory_size;
 	long irq_data_irq;
 	long zspage_huge;
+	long zram_comp_algs;
 };
 
 struct size_table {         /* stash of commonly-used sizes */
diff --git a/diskdump.c b/diskdump.c
index 0fe46f4..d7e4380 100644
--- a/diskdump.c
+++ b/diskdump.c
@@ -2757,6 +2757,8 @@ diskdump_device_dump_info(FILE *ofp)
 
 static ulong ZRAM_FLAG_SHIFT;
 static ulong ZRAM_FLAG_SAME_BIT;
+static ulong ZRAM_COMP_PRIORITY_BIT1;
+static ulong ZRAM_COMP_PRIORITY_MASK;
 
 static void
 zram_init(void)
@@ -2765,6 +2767,8 @@ zram_init(void)
 
 	MEMBER_OFFSET_INIT(zram_mempoll, "zram", "mem_pool");
 	MEMBER_OFFSET_INIT(zram_compressor, "zram", "compressor");
+	if (INVALID_MEMBER(zram_compressor))
+		MEMBER_OFFSET_INIT(zram_comp_algs, "zram", "comp_algs");
 	MEMBER_OFFSET_INIT(zram_table_flag, "zram_table_entry", "flags");
 	if (INVALID_MEMBER(zram_table_flag))
 		MEMBER_OFFSET_INIT(zram_table_flag, "zram_table_entry", "value");
@@ -2782,6 +2786,8 @@ zram_init(void)
 
 	ZRAM_FLAG_SHIFT = 1 << zram_flag_shift;
 	ZRAM_FLAG_SAME_BIT = 1 << (zram_flag_shift+1);
+	ZRAM_COMP_PRIORITY_BIT1 = ZRAM_FLAG_SHIFT + 7;
+	ZRAM_COMP_PRIORITY_MASK = 0x3;
 
 	if (CRASHDEBUG(1))
 		fprintf(fp, "zram_flag_shift: %ld\n", zram_flag_shift);
@@ -2980,13 +2986,15 @@ try_zram_decompress(ulonglong pte_val, unsigned char *buf, ulong len, ulonglong
 	unsigned char *outbuf = NULL;
 	ulong zram, zram_table_entry, sector, index, entry, flags, size,
 		outsize, off;
+	int comp_alg_unavail;
 
-	if (INVALID_MEMBER(zram_compressor)) {
+	comp_alg_unavail = INVALID_MEMBER(zram_compressor) && INVALID_MEMBER(zram_comp_algs);
+	if (comp_alg_unavail) {
 		zram_init();
-		if (INVALID_MEMBER(zram_compressor)) {
-			error(WARNING,
-			      "Some pages are swapped out to zram. "
-			      "Please run mod -s zram.\n");
+		comp_alg_unavail = INVALID_MEMBER(zram_compressor) && INVALID_MEMBER(zram_comp_algs);
+		if (comp_alg_unavail) {
+			error(WARNING, "some pages are swapped out to zram. "
+				"please run mod -s zram.\n");
 			return 0;
 		}
 	}
@@ -2997,8 +3005,29 @@ try_zram_decompress(ulonglong pte_val, unsigned char *buf, ulong len, ulonglong
 	if (!get_disk_name_private_data(pte_val, vaddr, NULL, &zram))
 		return 0;
 
-	readmem(zram + OFFSET(zram_compressor), KVADDR, name,
-		sizeof(name), "zram compressor", FAULT_ON_ERROR);
+	if (THIS_KERNEL_VERSION >= LINUX(2, 6, 0)) {
+		swp_offset = (ulonglong)__swp_offset(pte_val);
+	} else {
+		swp_offset = (ulonglong)SWP_OFFSET(pte_val);
+	}
+
+	sector = swp_offset << (PAGESHIFT() - 9);
+	index = sector >> SECTORS_PER_PAGE_SHIFT;
+	readmem(zram, KVADDR, &zram_table_entry,
+		sizeof(void *), "zram_table_entry", FAULT_ON_ERROR);
+	zram_table_entry += (index * SIZE(zram_table_entry));
+	readmem(zram_table_entry + OFFSET(zram_table_flag), KVADDR, &flags,
+		sizeof(void *), "zram_table_flag", FAULT_ON_ERROR);
+	if (VALID_MEMBER(zram_compressor)) {
+		readmem(zram + OFFSET(zram_compressor), KVADDR, name, sizeof(name),
+			"zram compressor", FAULT_ON_ERROR);
+	} else {
+		ulong comp_alg_addr;
+		uint32_t prio = (flags >> ZRAM_COMP_PRIORITY_BIT1) & ZRAM_COMP_PRIORITY_MASK;
+		readmem(zram + OFFSET(zram_comp_algs) + sizeof(const char *) * prio, KVADDR,
+			&comp_alg_addr, sizeof(comp_alg_addr), "zram comp_algs", FAULT_ON_ERROR);
+		read_string(comp_alg_addr, name, sizeof(name));
+	}
 	if (STREQ(name, "lzo")) {
 #ifdef LZO
 		if (!(dd->flags & LZO_SUPPORTED)) {
@@ -3019,12 +3048,6 @@ try_zram_decompress(ulonglong pte_val, unsigned char *buf, ulong len, ulonglong
 		return 0;
 	}
 
-	if (THIS_KERNEL_VERSION >= LINUX(2, 6, 0)) {
-		swp_offset = (ulonglong)__swp_offset(pte_val);
-	} else {
-		swp_offset = (ulonglong)SWP_OFFSET(pte_val);
-	}
-
 	zram_buf = (unsigned char *)GETBUF(PAGESIZE());
 	/* lookup page from swap cache */
 	off = PAGEOFFSET(vaddr);
@@ -3034,15 +3057,8 @@ try_zram_decompress(ulonglong pte_val, unsigned char *buf, ulong len, ulonglong
 		goto out;
 	}
 
-	sector = swp_offset << (PAGESHIFT() - 9);
-	index = sector >> SECTORS_PER_PAGE_SHIFT;
-	readmem(zram, KVADDR, &zram_table_entry,
-		sizeof(void *), "zram_table_entry", FAULT_ON_ERROR);
-	zram_table_entry += (index * SIZE(zram_table_entry));
 	readmem(zram_table_entry, KVADDR, &entry,
 		sizeof(void *), "entry of table", FAULT_ON_ERROR);
-	readmem(zram_table_entry + OFFSET(zram_table_flag), KVADDR, &flags,
-		sizeof(void *), "zram_table_flag", FAULT_ON_ERROR);
 	if (!entry || (flags & ZRAM_FLAG_SAME_BIT)) {
 		int count;
 		ulong *same_buf = (ulong *)GETBUF(PAGESIZE());
-- 
2.40.1
                                
                         
                        
                                
                                1 year, 11 months
                        
                        
                 
         
 
        
            
        
        
        
                
                        
                        
                                
                                
                                        
                                                
                                        
                                        
                                        Re: Google Container OS and crash 8.0.4
                                
                                
                                
                                    
                                        by HAGIO KAZUHITO(萩尾 一仁)
                                    
                                
                                
                                        On 2023/11/22 15:41, Matt Suiche wrote:
> Good point, enough the –kaslr=auto option worked well. Same when I passed --kaslr=0x8000000
Good news.
apparently module_load_offset symbol is needed in /proc/kallsyms to 
enable the KASLR detection.  I see it in the vmlinux.
$ nm vmlinux-cos-5.15.133+ | grep module_load_offset
ffffffff82d83350 b module_load_offset
Is it (and _stext) found in /proc/kallsyms? like
# grep -e _stext -e module_load_offset /proc/kallsyms
ffffffffa0e00000 T _stext
ffffffffa3aafab8 b module_load_offset
PS. I will be out for the rest of this week, back next week.
Thanks,
Kazu
                                
                         
                        
                                
                                1 year, 11 months
                        
                        
                 
         
 
        
            
        
        
        
                
                        
                                
                                
                                        
                                
                         
                        
                                
                                
                                        
                                                
                                        
                                        
                                        Re: Google Container OS and crash 8.0.4
                                
                                
                                
                                    
                                        by HAGIO KAZUHITO(萩尾 一仁)
                                    
                                
                                
                                        Hi Matt,
Thank you for trying the latest.
>        SYMBOL(_stext)=ffffffff89000000
>        KERNELOFFSET=8000000
> <readmem: ffffffff82239750, KVADDR, "page_offset_base", 8, (FOE|Q), 
5642aae35c08>
$ curl -O https://storage.googleapis.com/cos-tools/17162.336.25/vmlinux
$ nm vmlinux | grep -e ' _stext' -e ' page_offset_base'
ffffffff81000000 T _stext
ffffffff82239750 R page_offset_base
To me, it looks like KASLR detection doesn't work.  The randomized 
offset of the page_offset_base should be 0xffffffff82239750 + 0x8000000 
= 0xffffffff8a239750, but crash is trying to read 0xffffffff82239750.
We need to look into why it doesn't work, firstly does this option work? 
  If this works, I think it will be a clue.
# crash --kaslr=auto vmlinux /proc/kcore
   or
# crash --kaslr=<KERNELOFFSET value> vmlinux /proc/kcore
   i.e. --kaslr=8000000 during that system session.
   (this will vary after system reboot)
Thanks,
Kazu
On 2023/11/21 23:21, Matt Suiche wrote:
> Dear,
> 
> I tried to use crash 8.0.4 on Google Container OS (17162.336.25) but for some reason there is resistance.
> 
> Step to reproduce:
> 
>    1.  Create a Virtual Machine in Google Cloud using Google Container OS as a base image
>    2.  Run “toolkit”
>    3.  Download the vmlinux symbols for the current base image
>       *   curl https://storage.googleapis.com/cos-tools/$container_host_build_id/vmlinux > symbols/vmlinux-$container_host_build_id
>    4.  Run crash on /proc/kcore
> 
> Thanks,
> 
> Logs:
> 
> root@instance-2:~# crash /proc/kcore vmlinux-17162.336.25 -d 99
> 
> 
> 
> crash 8.0.4
> 
> 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.
> 
> 
> 
> get_live_memory_source: /proc/kcore
> 
> proc_kcore_data:
> 
>             flags: 500 (KCORE_LOCAL|KCORE_ELF64)
> 
>          segments: 12
> 
>        elf_header: 5642ab6d3f40
> 
>       header_size: 8636
> 
>           notes64: 5642ab6d3f80
> 
>            load64: 5642ab6d3fb8
> 
>           notes32: 0
> 
>            load32: 0
> 
>        vmcoreinfo: 0
> 
>   size_vmcoreinfo: 0
> 
> 
> 
>    Elf64_Phdr:
> 
>          p_type: 4 (PT_NOTE)
> 
>         p_flags: 0
> 
>        p_offset: 318
> 
>         p_vaddr: 0
> 
>         p_paddr: 0
> 
>        p_filesz: 7844
> 
>         p_memsz: 0
> 
>         p_align: 0
> 
> 
> 
>    Elf64_Phdr:
> 
>          p_type: 1 (PT_LOAD)
> 
>         p_flags: 7
> 
>        p_offset: 7fff89003000
> 
>         p_vaddr: ffffffff89000000
> 
>         p_paddr: 13a000000
> 
>        p_filesz: 35831808
> 
>         p_memsz: 35831808
> 
>         p_align: 4096
> 
> 
> 
>    Elf64_Phdr:
> 
>          p_type: 1 (PT_LOAD)
> 
>         p_flags: 7
> 
>        p_offset: 130900003000
> 
>         p_vaddr: ffff930900000000
> 
>         p_paddr: ffffffffffffffff
> 
>        p_filesz: 35184372088831
> 
>         p_memsz: 35184372088831
> 
>         p_align: 4096
> 
> 
> 
>    Elf64_Phdr:
> 
>          p_type: 1 (PT_LOAD)
> 
>         p_flags: 7
> 
>        p_offset: 7fffc0003000
> 
>         p_vaddr: ffffffffc0000000
> 
>         p_paddr: ffffffffffffffff
> 
>        p_filesz: 1056964608
> 
>         p_memsz: 1056964608
> 
>         p_align: 4096
> 
> 
> 
>    Elf64_Phdr:
> 
>          p_type: 1 (PT_LOAD)
> 
>         p_flags: 7
> 
>        p_offset: ec140004000
> 
>         p_vaddr: ffff8ec140001000
> 
>         p_paddr: 1000
> 
>        p_filesz: 344064
> 
>         p_memsz: 344064
> 
>         p_align: 4096
> 
> 
> 
>    Elf64_Phdr:
> 
>          p_type: 1 (PT_LOAD)
> 
>         p_flags: 7
> 
>        p_offset: 7be8c0003000
> 
>         p_vaddr: fffffbe8c0000000
> 
>         p_paddr: ffffffffffffffff
> 
>        p_filesz: 8192
> 
>         p_memsz: 8192
> 
>         p_align: 4096
> 
> 
> 
>    Elf64_Phdr:
> 
>          p_type: 1 (PT_LOAD)
> 
>         p_flags: 7
> 
>        p_offset: ec140063000
> 
>         p_vaddr: ffff8ec140060000
> 
>         p_paddr: 60000
> 
>        p_filesz: 229376
> 
>         p_memsz: 229376
> 
>         p_align: 4096
> 
> 
> 
>    Elf64_Phdr:
> 
>          p_type: 1 (PT_LOAD)
> 
>         p_flags: 7
> 
>        p_offset: ec140103000
> 
>         p_vaddr: ffff8ec140100000
> 
>         p_paddr: 100000
> 
>        p_filesz: 3212759040
> 
>         p_memsz: 3212759040
> 
>         p_align: 4096
> 
> 
> 
>    Elf64_Phdr:
> 
>          p_type: 1 (PT_LOAD)
> 
>         p_flags: 7
> 
>        p_offset: 7be8c0007000
> 
>         p_vaddr: fffffbe8c0004000
> 
>         p_paddr: ffffffffffffffff
> 
>        p_filesz: 50200576
> 
>         p_memsz: 50200576
> 
>         p_align: 4096
> 
> 
> 
>    Elf64_Phdr:
> 
>          p_type: 1 (PT_LOAD)
> 
>         p_flags: 7
> 
>        p_offset: ec1ffc02000
> 
>         p_vaddr: ffff8ec1ffbff000
> 
>         p_paddr: bfbff000
> 
>        p_filesz: 4067328
> 
>         p_memsz: 4067328
> 
>         p_align: 4096
> 
> 
> 
>    Elf64_Phdr:
> 
>          p_type: 1 (PT_LOAD)
> 
>         p_flags: 7
> 
>        p_offset: 7be8c2ff2000
> 
>         p_vaddr: fffffbe8c2fef000
> 
>         p_paddr: ffffffffffffffff
> 
>        p_filesz: 69632
> 
>         p_memsz: 69632
> 
>         p_align: 4096
> 
> 
> 
>    Elf64_Phdr:
> 
>          p_type: 1 (PT_LOAD)
> 
>         p_flags: 7
> 
>        p_offset: ec240003000
> 
>         p_vaddr: ffff8ec240000000
> 
>         p_paddr: 100000000
> 
>        p_filesz: 1073741824
> 
>         p_memsz: 1073741824
> 
>         p_align: 4096
> 
> 
> 
>    Elf64_Phdr:
> 
>          p_type: 1 (PT_LOAD)
> 
>         p_flags: 7
> 
>        p_offset: 7be8c4003000
> 
>         p_vaddr: fffffbe8c4000000
> 
>         p_paddr: ffffffffffffffff
> 
>        p_filesz: 16777216
> 
>         p_memsz: 16777216
> 
>         p_align: 4096
> 
> 
> 
>    Elf64_Nhdr:
> 
>        n_namesz: 5 ("CORE")
> 
>        n_descsz: 336
> 
>          n_type: 1 (NT_PRSTATUS)
> 
> 
> 
>    Elf64_Nhdr:
> 
>        n_namesz: 5 ("CORE")
> 
>        n_descsz: 136
> 
>          n_type: 3 (NT_PRPSINFO)
> 
> 
> 
>    Elf64_Nhdr:
> 
>        n_namesz: 5 ("CORE")
> 
>        n_descsz: 4288
> 
>          n_type: 4 (NT_TASKSTRUCT)
> 
> 
> 
>    Elf64_Nhdr:
> 
>        n_namesz: 11 ("VMCOREINFO")
> 
>        n_descsz: 3000
> 
>          n_type: 0 (unknown)
> 
> 
> 
>        OSRELEASE=5.15.133+
> 
>        BUILD-ID=f16c9f1b53617d7b151c4d18d79c6ccbb44ea6d6
> 
>        PAGESIZE=4096
> 
>        SYMBOL(init_uts_ns)=ffffffff8a615698
> 
>        OFFSET(uts_namespace.name)=0
> 
>        SYMBOL(node_online_map)=ffffffff8a85d638
> 
>        SYMBOL(swapper_pg_dir)=ffffffff8a60c000
> 
>        SYMBOL(_stext)=ffffffff89000000
> 
>        SYMBOL(vmap_area_list)=ffffffff8a774208
> 
>        SYMBOL(mem_section)=ffff8ec27fff8000
> 
>        LENGTH(mem_section)=2048
> 
>        SIZE(mem_section)=16
> 
>        OFFSET(mem_section.section_mem_map)=0
> 
>        NUMBER(SECTION_SIZE_BITS)=27
> 
>        NUMBER(MAX_PHYSMEM_BITS)=46
> 
>        SIZE(page)=64
> 
>        SIZE(pglist_data)=15616
> 
>        SIZE(zone)=1664
> 
>        SIZE(free_area)=104
> 
>        SIZE(list_head)=16
> 
>        SIZE(nodemask_t)=8
> 
>        OFFSET(page.flags)=0
> 
>        OFFSET(page._refcount)=52
> 
>        OFFSET(page.mapping)=24
> 
>        OFFSET(page.lru)=8
> 
>        OFFSET(page._mapcount)=48
> 
>        OFFSET(page.private)=40
> 
>        OFFSET(page.compound_dtor)=16
> 
>        OFFSET(page.compound_order)=17
> 
>        OFFSET(page.compound_head)=8
> 
>        OFFSET(pglist_data.node_zones)=0
> 
>        OFFSET(pglist_data.nr_zones)=14880
> 
>        OFFSET(pglist_data.node_start_pfn)=14888
> 
>        OFFSET(pglist_data.node_spanned_pages)=14904
> 
>        OFFSET(pglist_data.node_id)=14912
> 
>        OFFSET(zone.free_area)=192
> 
>        OFFSET(zone.vm_stat)=1472
> 
>        OFFSET(zone.spanned_pages)=128
> 
>        OFFSET(free_area.free_list)=0
> 
>        OFFSET(list_head.next)=0
> 
>        OFFSET(list_head.prev)=8
> 
>        OFFSET(vmap_area.va_start)=0
> 
>        OFFSET(vmap_area.list)=40
> 
>        LENGTH(zone.free_area)=11
> 
>        SYMBOL(prb)=ffffffff8a662318
> 
>        SYMBOL(printk_rb_static)=ffffffff8a662320
> 
>        SYMBOL(clear_seq)=ffffffff8ad8c0d8
> 
>        SIZE(printk_ringbuffer)=80
> 
>        OFFSET(printk_ringbuffer.desc_ring)=0
> 
>        OFFSET(printk_ringbuffer.text_data_ring)=40
> 
>        OFFSET(printk_ringbuffer.fail)=72
> 
>        SIZE(prb_desc_ring)=40
> 
>        OFFSET(prb_desc_ring.count_bits)=0
> 
>        OFFSET(prb_desc_ring.descs)=8
> 
>        OFFSET(prb_desc_ring.infos)=16
> 
>        OFFSET(prb_desc_ring.head_id)=24
> 
>        OFFSET(prb_desc_ring.tail_id)=32
> 
>        SIZE(prb_desc)=24
> 
>        OFFSET(prb_desc.state_var)=0
> 
>        OFFSET(prb_desc.text_blk_lpos)=8
> 
>        SIZE(prb_data_blk_lpos)=16
> 
>        OFFSET(prb_data_blk_lpos.begin)=0
> 
>        OFFSET(prb_data_blk_lpos.next)=8
> 
>        SIZE(printk_info)=88
> 
>        OFFSET(printk_info.seq)=0
> 
>        OFFSET(printk_info.ts_nsec)=8
> 
>        OFFSET(printk_info.text_len)=16
> 
>        OFFSET(printk_info.caller_id)=20
> 
>        OFFSET(printk_info.dev_info)=24
> 
>        SIZE(dev_printk_info)=64
> 
>        OFFSET(dev_printk_info.subsystem)=0
> 
>        LENGTH(printk_info_subsystem)=16
> 
>        OFFSET(dev_printk_info.device)=16
> 
>        LENGTH(printk_info_device)=48
> 
>        SIZE(prb_data_ring)=32
> 
>        OFFSET(prb_data_ring.size_bits)=0
> 
>        OFFSET(prb_data_ring.data)=8
> 
>        OFFSET(prb_data_ring.head_lpos)=16
> 
>        OFFSET(prb_data_ring.tail_lpos)=24
> 
>        SIZE(atomic_long_t)=8
> 
>        OFFSET(atomic_long_t.counter)=0
> 
>        SIZE(latched_seq)=24
> 
>        OFFSET(latched_seq.val)=8
> 
>        LENGTH(free_area.free_list)=6
> 
>        NUMBER(NR_FREE_PAGES)=0
> 
>        NUMBER(PG_lru)=4
> 
>        NUMBER(PG_private)=13
> 
>        NUMBER(PG_swapcache)=10
> 
>        NUMBER(PG_swapbacked)=19
> 
>        NUMBER(PG_slab)=9
> 
>        NUMBER(PG_hwpoison)=23
> 
>        NUMBER(PG_head_mask)=65536
> 
>        NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE)=-129
> 
>        NUMBER(HUGETLB_PAGE_DTOR)=2
> 
>        NUMBER(PAGE_OFFLINE_MAPCOUNT_VALUE)=-257
> 
>        NUMBER(phys_base)=5117050880
> 
>        SYMBOL(init_top_pgt)=ffffffff8a60c000
> 
>        NUMBER(pgtable_l5_enabled)=0
> 
>        SYMBOL(node_data)=ffffffff8a85c5d0
> 
>        LENGTH(node_data)=64
> 
>        KERNELOFFSET=8000000
> 
>        NUMBER(KERNEL_IMAGE_SIZE)=1073741824
> 
>        NUMBER(sme_mask)=0
> 
> 
> 
> /proc/version:
> 
> Linux version 5.15.133+ (builder@localhost) (Chromium OS 14.0_pre445002_p20220217-r3 clang version 14.0.0 (/var/tmp/portage/sys-devel/llvm-14.0_pre445002_p20220217-r3/work/llvm-14.0_pre445002_p20220217/clang 18308e171b5b1dd99627a4d88c7d6c5ff21b8c96), LLD 14.0.0) #1 SMP Sat Nov 11 11:15:28 UTC 2023
> 
> vmlinux-17162.336.25:
> 
> Linux version 5.15.133+ (builder@localhost) (Chromium OS 14.0_pre445002_p20220217-r3 clang version 14.0.0 (/var/tmp/portage/sys-devel/llvm-14.0_pre445002_p20220217-r3/work/llvm-14.0_pre445002_p20220217/clang 18308e171b5b1dd99627a4d88c7d6c5ff21b8c96), LLD 14.0.0) #1 SMP Sat Nov 11 11:15:28 UTC 2023
> 
> readmem: read_proc_kcore() -> /proc/kcore
> 
> crash: pv_ops exists: ARCH_PVOPS
> 
> VMCOREINFO: NUMBER(phys_base): 5117050880 -> 131000000
> 
> gdb vmlinux-17162.336.25
> 
> 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 "x86_64-pc-linux-gnu".
> 
> 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"...
> 
> GETBUF(344 -> 0)
> 
>    GETBUF(1500 -> 1)
> 
> 
> 
>    FREEBUF(1)
> 
> FREEBUF(0)
> 
> <readmem: ffffffff82239750, KVADDR, "page_offset_base", 8, (FOE|Q), 5642aae35c08>
> 
> <read_proc_kcore: addr: ffffffff82239750 paddr: 133239750 cnt: 8>
> 
> crash: seek error: kernel virtual address: ffffffff82239750  type: "page_offset_base"
> 
> 
> 
> root@instance-2:~# env
> 
> container_host_version_id=101
> 
> PWD=/root
> 
> LOGNAME=root
> 
> container=systemd-nspawn
> 
> HOME=/root
> 
> TERM=xterm-256color
> 
> USER=root
> 
> NOTIFY_SOCKET=/run/host/notify
> 
> SHLVL=1
> 
> container_host_id=cos
> 
> container_host_build_id=17162.336.25
> 
> PATH=/root/.cargo/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
> 
> container_uuid=d8282d15-c11a-416b-9371-94db01a7ca15
> 
> _=/usr/bin/env
> 
> OLDPWD=/
> 
> 
> This email including any attachments may contain confidential material for the sole use of the intended recipient. If you are not the intended recipient please immediately notify the sender by reply email, permanently delete this message and do not forward it or any part of it to anyone else.
> 
                                
                         
                        
                                
                                1 year, 11 months
                        
                        
                 
         
 
        
            
        
        
        
                
                        
                                
                                
                                        
                                
                         
                        
                                
                                
                                        
                                                
                                        
                                        
                                        Google Container OS and crash 8.0.4
                                
                                
                                
                                    
                                        by Matt Suiche
                                    
                                
                                
                                        Dear,
I tried to use crash 8.0.4 on Google Container OS (17162.336.25) but for some reason there is resistance.
Step to reproduce:
  1.  Create a Virtual Machine in Google Cloud using Google Container OS as a base image
  2.  Run “toolkit”
  3.  Download the vmlinux symbols for the current base image
     *   curl https://storage.googleapis.com/cos-tools/$container_host_build_id/vmlinux > symbols/vmlinux-$container_host_build_id
  4.  Run crash on /proc/kcore
Thanks,
Logs:
root@instance-2:~# crash /proc/kcore vmlinux-17162.336.25 -d 99
crash 8.0.4
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.
get_live_memory_source: /proc/kcore
proc_kcore_data:
           flags: 500 (KCORE_LOCAL|KCORE_ELF64)
        segments: 12
      elf_header: 5642ab6d3f40
     header_size: 8636
         notes64: 5642ab6d3f80
          load64: 5642ab6d3fb8
         notes32: 0
          load32: 0
      vmcoreinfo: 0
 size_vmcoreinfo: 0
  Elf64_Phdr:
        p_type: 4 (PT_NOTE)
       p_flags: 0
      p_offset: 318
       p_vaddr: 0
       p_paddr: 0
      p_filesz: 7844
       p_memsz: 0
       p_align: 0
  Elf64_Phdr:
        p_type: 1 (PT_LOAD)
       p_flags: 7
      p_offset: 7fff89003000
       p_vaddr: ffffffff89000000
       p_paddr: 13a000000
      p_filesz: 35831808
       p_memsz: 35831808
       p_align: 4096
  Elf64_Phdr:
        p_type: 1 (PT_LOAD)
       p_flags: 7
      p_offset: 130900003000
       p_vaddr: ffff930900000000
       p_paddr: ffffffffffffffff
      p_filesz: 35184372088831
       p_memsz: 35184372088831
       p_align: 4096
  Elf64_Phdr:
        p_type: 1 (PT_LOAD)
       p_flags: 7
      p_offset: 7fffc0003000
       p_vaddr: ffffffffc0000000
       p_paddr: ffffffffffffffff
      p_filesz: 1056964608
       p_memsz: 1056964608
       p_align: 4096
  Elf64_Phdr:
        p_type: 1 (PT_LOAD)
       p_flags: 7
      p_offset: ec140004000
       p_vaddr: ffff8ec140001000
       p_paddr: 1000
      p_filesz: 344064
       p_memsz: 344064
       p_align: 4096
  Elf64_Phdr:
        p_type: 1 (PT_LOAD)
       p_flags: 7
      p_offset: 7be8c0003000
       p_vaddr: fffffbe8c0000000
       p_paddr: ffffffffffffffff
      p_filesz: 8192
       p_memsz: 8192
       p_align: 4096
  Elf64_Phdr:
        p_type: 1 (PT_LOAD)
       p_flags: 7
      p_offset: ec140063000
       p_vaddr: ffff8ec140060000
       p_paddr: 60000
      p_filesz: 229376
       p_memsz: 229376
       p_align: 4096
  Elf64_Phdr:
        p_type: 1 (PT_LOAD)
       p_flags: 7
      p_offset: ec140103000
       p_vaddr: ffff8ec140100000
       p_paddr: 100000
      p_filesz: 3212759040
       p_memsz: 3212759040
       p_align: 4096
  Elf64_Phdr:
        p_type: 1 (PT_LOAD)
       p_flags: 7
      p_offset: 7be8c0007000
       p_vaddr: fffffbe8c0004000
       p_paddr: ffffffffffffffff
      p_filesz: 50200576
       p_memsz: 50200576
       p_align: 4096
  Elf64_Phdr:
        p_type: 1 (PT_LOAD)
       p_flags: 7
      p_offset: ec1ffc02000
       p_vaddr: ffff8ec1ffbff000
       p_paddr: bfbff000
      p_filesz: 4067328
       p_memsz: 4067328
       p_align: 4096
  Elf64_Phdr:
        p_type: 1 (PT_LOAD)
       p_flags: 7
      p_offset: 7be8c2ff2000
       p_vaddr: fffffbe8c2fef000
       p_paddr: ffffffffffffffff
      p_filesz: 69632
       p_memsz: 69632
       p_align: 4096
  Elf64_Phdr:
        p_type: 1 (PT_LOAD)
       p_flags: 7
      p_offset: ec240003000
       p_vaddr: ffff8ec240000000
       p_paddr: 100000000
      p_filesz: 1073741824
       p_memsz: 1073741824
       p_align: 4096
  Elf64_Phdr:
        p_type: 1 (PT_LOAD)
       p_flags: 7
      p_offset: 7be8c4003000
       p_vaddr: fffffbe8c4000000
       p_paddr: ffffffffffffffff
      p_filesz: 16777216
       p_memsz: 16777216
       p_align: 4096
  Elf64_Nhdr:
      n_namesz: 5 ("CORE")
      n_descsz: 336
        n_type: 1 (NT_PRSTATUS)
  Elf64_Nhdr:
      n_namesz: 5 ("CORE")
      n_descsz: 136
        n_type: 3 (NT_PRPSINFO)
  Elf64_Nhdr:
      n_namesz: 5 ("CORE")
      n_descsz: 4288
        n_type: 4 (NT_TASKSTRUCT)
  Elf64_Nhdr:
      n_namesz: 11 ("VMCOREINFO")
      n_descsz: 3000
        n_type: 0 (unknown)
      OSRELEASE=5.15.133+
      BUILD-ID=f16c9f1b53617d7b151c4d18d79c6ccbb44ea6d6
      PAGESIZE=4096
      SYMBOL(init_uts_ns)=ffffffff8a615698
      OFFSET(uts_namespace.name)=0
      SYMBOL(node_online_map)=ffffffff8a85d638
      SYMBOL(swapper_pg_dir)=ffffffff8a60c000
      SYMBOL(_stext)=ffffffff89000000
      SYMBOL(vmap_area_list)=ffffffff8a774208
      SYMBOL(mem_section)=ffff8ec27fff8000
      LENGTH(mem_section)=2048
      SIZE(mem_section)=16
      OFFSET(mem_section.section_mem_map)=0
      NUMBER(SECTION_SIZE_BITS)=27
      NUMBER(MAX_PHYSMEM_BITS)=46
      SIZE(page)=64
      SIZE(pglist_data)=15616
      SIZE(zone)=1664
      SIZE(free_area)=104
      SIZE(list_head)=16
      SIZE(nodemask_t)=8
      OFFSET(page.flags)=0
      OFFSET(page._refcount)=52
      OFFSET(page.mapping)=24
      OFFSET(page.lru)=8
      OFFSET(page._mapcount)=48
      OFFSET(page.private)=40
      OFFSET(page.compound_dtor)=16
      OFFSET(page.compound_order)=17
      OFFSET(page.compound_head)=8
      OFFSET(pglist_data.node_zones)=0
      OFFSET(pglist_data.nr_zones)=14880
      OFFSET(pglist_data.node_start_pfn)=14888
      OFFSET(pglist_data.node_spanned_pages)=14904
      OFFSET(pglist_data.node_id)=14912
      OFFSET(zone.free_area)=192
      OFFSET(zone.vm_stat)=1472
      OFFSET(zone.spanned_pages)=128
      OFFSET(free_area.free_list)=0
      OFFSET(list_head.next)=0
      OFFSET(list_head.prev)=8
      OFFSET(vmap_area.va_start)=0
      OFFSET(vmap_area.list)=40
      LENGTH(zone.free_area)=11
      SYMBOL(prb)=ffffffff8a662318
      SYMBOL(printk_rb_static)=ffffffff8a662320
      SYMBOL(clear_seq)=ffffffff8ad8c0d8
      SIZE(printk_ringbuffer)=80
      OFFSET(printk_ringbuffer.desc_ring)=0
      OFFSET(printk_ringbuffer.text_data_ring)=40
      OFFSET(printk_ringbuffer.fail)=72
      SIZE(prb_desc_ring)=40
      OFFSET(prb_desc_ring.count_bits)=0
      OFFSET(prb_desc_ring.descs)=8
      OFFSET(prb_desc_ring.infos)=16
      OFFSET(prb_desc_ring.head_id)=24
      OFFSET(prb_desc_ring.tail_id)=32
      SIZE(prb_desc)=24
      OFFSET(prb_desc.state_var)=0
      OFFSET(prb_desc.text_blk_lpos)=8
      SIZE(prb_data_blk_lpos)=16
      OFFSET(prb_data_blk_lpos.begin)=0
      OFFSET(prb_data_blk_lpos.next)=8
      SIZE(printk_info)=88
      OFFSET(printk_info.seq)=0
      OFFSET(printk_info.ts_nsec)=8
      OFFSET(printk_info.text_len)=16
      OFFSET(printk_info.caller_id)=20
      OFFSET(printk_info.dev_info)=24
      SIZE(dev_printk_info)=64
      OFFSET(dev_printk_info.subsystem)=0
      LENGTH(printk_info_subsystem)=16
      OFFSET(dev_printk_info.device)=16
      LENGTH(printk_info_device)=48
      SIZE(prb_data_ring)=32
      OFFSET(prb_data_ring.size_bits)=0
      OFFSET(prb_data_ring.data)=8
      OFFSET(prb_data_ring.head_lpos)=16
      OFFSET(prb_data_ring.tail_lpos)=24
      SIZE(atomic_long_t)=8
      OFFSET(atomic_long_t.counter)=0
      SIZE(latched_seq)=24
      OFFSET(latched_seq.val)=8
      LENGTH(free_area.free_list)=6
      NUMBER(NR_FREE_PAGES)=0
      NUMBER(PG_lru)=4
      NUMBER(PG_private)=13
      NUMBER(PG_swapcache)=10
      NUMBER(PG_swapbacked)=19
      NUMBER(PG_slab)=9
      NUMBER(PG_hwpoison)=23
      NUMBER(PG_head_mask)=65536
      NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE)=-129
      NUMBER(HUGETLB_PAGE_DTOR)=2
      NUMBER(PAGE_OFFLINE_MAPCOUNT_VALUE)=-257
      NUMBER(phys_base)=5117050880
      SYMBOL(init_top_pgt)=ffffffff8a60c000
      NUMBER(pgtable_l5_enabled)=0
      SYMBOL(node_data)=ffffffff8a85c5d0
      LENGTH(node_data)=64
      KERNELOFFSET=8000000
      NUMBER(KERNEL_IMAGE_SIZE)=1073741824
      NUMBER(sme_mask)=0
/proc/version:
Linux version 5.15.133+ (builder@localhost) (Chromium OS 14.0_pre445002_p20220217-r3 clang version 14.0.0 (/var/tmp/portage/sys-devel/llvm-14.0_pre445002_p20220217-r3/work/llvm-14.0_pre445002_p20220217/clang 18308e171b5b1dd99627a4d88c7d6c5ff21b8c96), LLD 14.0.0) #1 SMP Sat Nov 11 11:15:28 UTC 2023
vmlinux-17162.336.25:
Linux version 5.15.133+ (builder@localhost) (Chromium OS 14.0_pre445002_p20220217-r3 clang version 14.0.0 (/var/tmp/portage/sys-devel/llvm-14.0_pre445002_p20220217-r3/work/llvm-14.0_pre445002_p20220217/clang 18308e171b5b1dd99627a4d88c7d6c5ff21b8c96), LLD 14.0.0) #1 SMP Sat Nov 11 11:15:28 UTC 2023
readmem: read_proc_kcore() -> /proc/kcore
crash: pv_ops exists: ARCH_PVOPS
VMCOREINFO: NUMBER(phys_base): 5117050880 -> 131000000
gdb vmlinux-17162.336.25
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 "x86_64-pc-linux-gnu".
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"...
GETBUF(344 -> 0)
  GETBUF(1500 -> 1)
  FREEBUF(1)
FREEBUF(0)
<readmem: ffffffff82239750, KVADDR, "page_offset_base", 8, (FOE|Q), 5642aae35c08>
<read_proc_kcore: addr: ffffffff82239750 paddr: 133239750 cnt: 8>
crash: seek error: kernel virtual address: ffffffff82239750  type: "page_offset_base"
root@instance-2:~# env
container_host_version_id=101
PWD=/root
LOGNAME=root
container=systemd-nspawn
HOME=/root
TERM=xterm-256color
USER=root
NOTIFY_SOCKET=/run/host/notify
SHLVL=1
container_host_id=cos
container_host_build_id=17162.336.25
PATH=/root/.cargo/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
container_uuid=d8282d15-c11a-416b-9371-94db01a7ca15
_=/usr/bin/env
OLDPWD=/
This email including any attachments may contain confidential material for the sole use of the intended recipient. If you are not the intended recipient please immediately notify the sender by reply email, permanently delete this message and do not forward it or any part of it to anyone else.
                                
                         
                        
                                
                                1 year, 11 months