11:51 p.m.
Hi Lianbo, Tao,
Just a report, with this patch (99bb57ac98af), I observed that
the log command printed a couple of empty lines (only timestamps).
Could you reproduce this at your end?
$ diff -u log.pre log.cur
--- log.pre 2025-09-16 13:14:31.022206514 +0900
+++ log.cur 2025-09-16 13:14:56.220390987 +0900
@@ -210,7 +210,7 @@
[ 0.169375] clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff,
max_idle_ns: 1911260446275000 ns
[ 0.169375] futex hash table entries: 1024 (order: 4, 65536 bytes, linear)
[ 0.169375] pinctrl core: initialized pinctrl subsystem
-[ 0.172925] NET: Registered PF_NETLINK/PF_ROUTE protocol family
+[ 0.172925]
[ 0.172983] DMA: preallocated 512 KiB GFP_KERNEL pool for atomic allocations
[ 0.172986] DMA: preallocated 512 KiB GFP_KERNEL|GFP_DMA pool for atomic
allocations
[ 0.172988] DMA: preallocated 512 KiB GFP_KERNEL|GFP_DMA32 pool for atomic
allocations
@@ -807,7 +807,7 @@
[771438.513231] entry_SYSCALL_64_after_hwframe+0x72/0xdc
[771438.513423] RIP: 0033:0x7fbd9f8fda57
[771438.513576] Code: 0f 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 f3 0f 1e
fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77
51 c3 48 83 ec 28 48 89 54 24 18 48 89 74 24
-[771438.514251] RSP: 002b:00007ffee0de2b98 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
+[771438.514251]
[771438.514534] RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007fbd9f8fda57
[771438.514800] RDX: 0000000000000002 RSI: 00005647ccc0a330 RDI: 0000000000000001
[771438.515066] RBP: 00005647ccc0a330 R08: 0000000000000003 R09: 0000000000000000
log.cur: 99bb57ac98afd89fcf23f0c8bc637821dcbd278f
log.pre: a5942e3acfd9330d101cc65ef2e19e627233ddf6
vmcore: panic by sysrq-trigger on 5.14.0-427.13.1.el9_4.x86_64
(found also on 6.17-rc6)
Thanks,
Kazu
On 2025/09/15 10:19, Tao Liu wrote:
> applied:
https://github.com/crash-utility/crash/commit/99bb57ac98afd89fcf23f0c8bc6...
>
> On Wed, Sep 10, 2025 at 2:33 PM Tao Liu <ltao(a)redhat.com> wrote:
>>
>> Hi lianbo,
>>
>> Thanks for the v2, LGTM, ack.
>>
>>
>> On Mon, Sep 8, 2025 at 8:42 PM Lianbo Jiang <lijiang(a)redhat.com> wrote:
>>>
>>> Without the patch:
>>> crash> log
>>> ...
>>> [ 2174.308966] Call Trace:
>>> [ 2174.311693] <TASK>
>>> [ 2174.314033] dump_stack_lvl+0x5d/0x80
>>> [ 2174.318125] panic+0x156/0x32a
>>> [ 2174.321539] _RNvCscb18lrEyTSA_10rust_panic10area_in_hp+0xf7/0x120
[rust_panic]
>>> [ 2174.329700] ? console_unlock+0x9c/0x140
>>> [ 2174.334080] ? irq_work_queue+0x2d/0x50
>>> [ 2174.338352] ? __pfx_init_module+0x10/0x10 [rust_panic]
>>> [ 2174.344183]
_RNvMCscb18lrEyTSA_10rust_panicNtB2_10HelloPanic8step_two+0x20/0xe0 [rust_panic]
>>> [ 2174.353698] ? _printk+0x6b/0x90
>>> ...
>>>
>>> With the patch:
>>> crash> log
>>> ...
>>> [ 2174.308966] Call Trace:
>>> [ 2174.311693] <TASK>
>>> [ 2174.314033] dump_stack_lvl+0x5d/0x80
>>> [ 2174.318125] panic+0x156/0x32a
>>> [ 2174.321539] rust_panic::area_in_hp+0xf7/0x120 [rust_panic]
>>> [ 2174.329700] ? console_unlock+0x9c/0x140
>>> [ 2174.334080] ? irq_work_queue+0x2d/0x50
>>> [ 2174.338352] ? __pfx_init_module+0x10/0x10 [rust_panic]
>>> [ 2174.344183] <rust_panic::HelloPanic>::step_two+0x20/0xe0
[rust_panic]
>>> [ 2174.353698] ? _printk+0x6b/0x90
>>> ...
>>>
>>> Signed-off-by: Lianbo Jiang <lijiang(a)redhat.com>
>>> ---
>>> Note:
>>> 1. Add some checks to avoid the risk of buffer overflow.
>>>
>>> Makefile | 2 +-
>>> printk.c | 33 ++++++++++++++++++++++++++++++++-
>>> 2 files changed, 33 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/Makefile b/Makefile
>>> index fc1c9588dcfa..b277129f6df2 100644
>>> --- a/Makefile
>>> +++ b/Makefile
>>> @@ -421,7 +421,7 @@ kernel.o: ${GENERIC_HFILES} kernel.c
>>> ${CC} -c ${CRASH_CFLAGS} kernel.c -I${BFD_DIRECTORY}
-I${GDB_INCLUDE_DIRECTORY} ${WARNING_OPTIONS} ${WARNING_ERROR}
>>>
>>> printk.o: ${GENERIC_HFILES} printk.c
>>> - ${CC} -c ${CRASH_CFLAGS} printk.c ${WARNING_OPTIONS}
${WARNING_ERROR}
>>> + ${CC} -c ${CRASH_CFLAGS} printk.c -I${GDB_INCLUDE_DIRECTORY}
${WARNING_OPTIONS} ${WARNING_ERROR}
>>>
>>> gdb_interface.o: ${GENERIC_HFILES} gdb_interface.c
>>> ${CC} -c ${CRASH_CFLAGS} gdb_interface.c ${WARNING_OPTIONS}
${WARNING_ERROR}
>>> diff --git a/printk.c b/printk.c
>>> index 95db7e607e4c..ae28c4fa0b21 100644
>>> --- a/printk.c
>>> +++ b/printk.c
>>> @@ -1,5 +1,6 @@
>>> #include "defs.h"
>>> #include <ctype.h>
>>> +#include "demangle.h"
>>>
>>> /* convenience struct for passing many values to helper functions */
>>> struct prb_map {
>>> @@ -201,14 +202,44 @@ dump_record(struct prb_map *m, unsigned long id, int
msg_flags)
>>>
>>> text = m->text_data + begin;
>>>
>>> + if (text_len > BUFSIZE) {
>>> + error(WARNING, "\nThe messages could be
truncated!\n");
>>> + text_len = BUFSIZE;
>>> + }
>>> +
>>> for (i = 0, p = text; i < text_len; i++, p++) {
>>> if (*p == '\n')
>>> fprintf(fp, "\n%s", space(ilen));
>>> else if (isprint(*p) || isspace(*p))
>>> - fputc(*p, fp);
>>> + sprintf(&buf[i], "%c", *p);
>>> else
>>> fputc('.', fp);
>>> }
>>> + /*
>>> + * Try to demangle a mangled Rust symbol(calltrace) from log buffer
>>> + */
>>> + char *p1 = strstr(buf, "_R");
>>> + if (!p1)
>>> + p1 = strstr(buf, "_ZN");
>>> + char *p2 = strchrnul(buf, '+');
>>> + if (p1 && p2) {
>>> + char mangled[BUFSIZE] = {0};
>>> + char demangled[BUFSIZE] = {0};
>>> + char *res;
>>> + size_t slen = p1 - buf;
>>> +
>>> + if (slen)
>>> + memcpy(demangled, buf, slen);
>>> +
>>> + memcpy(mangled, p1, p2-p1);
>>> + res = rust_demangle(mangled, DMGL_RUST);
>>> + if (res) {
>>> + snprintf(demangled+slen, BUFSIZE-slen,
"%s%s", res, p2);
>>> + fprintf(fp, "%s",demangled);
>>> + free(res);
>>> + }
>>> + } else
>>> + fprintf(fp, "%s", buf);
>>>
>>> if (msg_flags & SHOW_LOG_DICT) {
>>> text = info + OFFSET(printk_info_dev_info) +
>>> --
>>> 2.50.1
>>>
> --
> Crash-utility mailing list -- devel(a)lists.crash-utility.osci.io
> To unsubscribe send an email to devel-leave(a)lists.crash-utility.osci.io
> https://${domain_name}/admin/lists/devel.lists.crash-utility.osci.io/
> Contribution Guidelines: https://github.com/crash-utility/crash/wiki