[PATCH 4.9 18/45] scripts/gdb: lx-dmesg: cast log_buf to void* for addr fetch

Greg Kroah-Hartman
2021-01-11T14:04:35Z

From: Leonard Crestez <leonard.crestez@nxp.com>

commit c454756f47277b651ad41a5a163499294529e35d upstream

In some cases it is possible for the str() conversion here to throw
encoding errors because log_buf might not point to valid ascii. For
example:

(gdb) python print str(gdb.parse_and_eval("log_buf"))
Traceback (most recent call last):
File "<string>", line 1, in <module>
UnicodeEncodeError: 'ascii' codec can't encode character u'\u0303' in
position 24: ordinal not in range(128)

Avoid this by explicitly casting to (void *) inside the gdb expression.

Link: http://lkml.kernel.org/r/ba6f85dbb02ca980ebd0e2399b0649423399b565.1498481469.git.leonard.crestez@nxp.com
Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Reviewed-by: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Kieran Bingham <kieran@ksquared.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
scripts/gdb/linux/dmesg.py | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scripts/gdb/linux/dmesg.py b/scripts/gdb/linux/dmesg.py
index 5afd1098e33a1..f5a030333dfd8 100644
--- a/scripts/gdb/linux/dmesg.py
+++ b/scripts/gdb/linux/dmesg.py
@@ -24,7 +24,7 @@ class LxDmesg(gdb.Command):

def invoke(self, arg, from_tty):
log_buf_addr = int(str(gdb.parse_and_eval(
- "'printk.c'::log_buf")).split()[0], 16)
+ "(void *)'printk.c'::log_buf")).split()[0], 16)
log_first_idx = int(gdb.parse_and_eval("'printk.c'::log_first_idx"))
log_next_idx = int(gdb.parse_and_eval("'printk.c'::log_next_idx"))
log_buf_len = int(gdb.parse_and_eval("'printk.c'::log_buf_len"))
--
2.27.0