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From:   Douglas Anderson <dianders@chromium.org>
To:     Jason Wessel <jason.wessel@windriver.com>,
        Daniel Thompson <daniel.thompson@linaro.org>
Cc:     "Tobin C . Harding" <me@tobin.cc>, joe@perches.com,
        Douglas Anderson <dianders@chromium.org>,
        stable@vger.kernel.org, kgdb-bugreport@lists.sourceforge.net,
        linux-kernel@vger.kernel.org
Subject: [PATCH] kdb: Fix btc (backtrace on each cpu) crash
Date:   Tue, 30 Oct 2018 13:53:34 -0700
Message-Id: <20181030205334.148162-1-dianders@chromium.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

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@vger.kernel.org
Signed-off-by: Douglas Anderson <dianders@chromium.org>
---

 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