[Crash-utility] [PATCH v2 3/3] Enable resolving mangled Rust symbol in lockless ring buffer
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