[PATCH] kdb: Fix btc (backtrace on each cpu) crash

From: Douglas Anderson
Date: Tue Oct 30 2018 - 16:54:04 EST


Typing 'btc' on kdb doing all sorts of fail. Sometimes it would
crash, sometimes display nothing, and sometimes hang.

Bisect tracked this down to the commit ad67b74d2469 ("printk: hash
addresses printed with %p"), suggesting an obvious fix. The pointer
used internally in kdb shouldn't be hashed, so switch it to %px.

Fixes: ad67b74d2469 ("printk: hash addresses printed with %p")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
---

kernel/debug/kdb/kdb_bt.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/debug/kdb/kdb_bt.c b/kernel/debug/kdb/kdb_bt.c
index 6ad4a9fcbd6f..7921ae4fca8d 100644
--- a/kernel/debug/kdb/kdb_bt.c
+++ b/kernel/debug/kdb/kdb_bt.c
@@ -179,14 +179,14 @@ kdb_bt(int argc, const char **argv)
kdb_printf("no process for cpu %ld\n", cpu);
return 0;
}
- sprintf(buf, "btt 0x%p\n", KDB_TSK(cpu));
+ sprintf(buf, "btt 0x%px\n", KDB_TSK(cpu));
kdb_parse(buf);
return 0;
}
kdb_printf("btc: cpu status: ");
kdb_parse("cpu\n");
for_each_online_cpu(cpu) {
- sprintf(buf, "btt 0x%p\n", KDB_TSK(cpu));
+ sprintf(buf, "btt 0x%px\n", KDB_TSK(cpu));
kdb_parse(buf);
touch_nmi_watchdog();
}
--
2.19.1.568.g152ad8e336-goog