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/99bb57ac98afd89fcf23f0c8bc637821dcbd278f > > On Wed, Sep 10, 2025 at 2:33 PM Tao Liu <[email protected]> wrote: >> >> Hi lianbo, >> >> Thanks for the v2, LGTM, ack. >> >> >> On Mon, Sep 8, 2025 at 8:42 PM Lianbo Jiang <[email protected]> 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 <[email protected]> >>> --- >>> 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} >>> ${WARNING_ERROR} >>> diff --git a/printk.c b/printk.c >>> index 95db7e607e4c..ae28c4fa0b21 100644 >>> --- a/printk.c >>> +++ b/printk.c >>> @@ -1,5 +1,6 @@ >>> #include "defs.h" >>> #include <ctype.h> >>> +#include "demangle.h" >>> >>> /* convenience struct for passing many values to helper functions */ >>> struct prb_map { >>> @@ -201,14 +202,44 @@ dump_record(struct prb_map *m, unsigned long id, int >>> msg_flags) >>> >>> text = m->text_data + begin; >>> >>> + if (text_len > BUFSIZE) { >>> + error(WARNING, "\nThe messages could be truncated!\n"); >>> + text_len = BUFSIZE; >>> + } >>> + >>> for (i = 0, p = text; i < text_len; i++, p++) { >>> if (*p == '\n') >>> fprintf(fp, "\n%s", space(ilen)); >>> else if (isprint(*p) || isspace(*p)) >>> - fputc(*p, fp); >>> + sprintf(&buf[i], "%c", *p); >>> else >>> fputc('.', fp); >>> } >>> + /* >>> + * Try to demangle a mangled Rust symbol(calltrace) from log buffer >>> + */ >>> + char *p1 = strstr(buf, "_R"); >>> + if (!p1) >>> + p1 = strstr(buf, "_ZN"); >>> + char *p2 = strchrnul(buf, '+'); >>> + if (p1 && p2) { >>> + char mangled[BUFSIZE] = {0}; >>> + char demangled[BUFSIZE] = {0}; >>> + char *res; >>> + size_t slen = p1 - buf; >>> + >>> + if (slen) >>> + memcpy(demangled, buf, slen); >>> + >>> + memcpy(mangled, p1, p2-p1); >>> + res = rust_demangle(mangled, DMGL_RUST); >>> + if (res) { >>> + snprintf(demangled+slen, BUFSIZE-slen, "%s%s", res, >>> p2); >>> + fprintf(fp, "%s",demangled); >>> + free(res); >>> + } >>> + } else >>> + fprintf(fp, "%s", buf); >>> >>> if (msg_flags & SHOW_LOG_DICT) { >>> text = info + OFFSET(printk_info_dev_info) + >>> -- >>> 2.50.1 >>> > -- > Crash-utility mailing list -- [email protected] > To unsubscribe send an email to [email protected] > https://${domain_name}/admin/lists/devel.lists.crash-utility.osci.io/ > Contribution Guidelines: https://github.com/crash-utility/crash/wiki -- Crash-utility mailing list -- [email protected] To unsubscribe send an email to [email protected] https://${domain_name}/admin/lists/devel.lists.crash-utility.osci.io/ Contribution Guidelines: https://github.com/crash-utility/crash/wiki
