6.11-stable review patch. If anyone has any objections, please let me know.
------------------
From: Breno Leitao <leitao@xxxxxxxxxx>
[ Upstream commit d94785bb46b6167382b1de3290eccc91fa98df53 ]
A warning is triggered when there is insufficient space in the buffer
for userdata. However, this is not an issue since userdata will be sent
in the next iteration.
Current warning message:
------------[ cut here ]------------
WARNING: CPU: 13 PID: 3013042 at drivers/net/netconsole.c:1122 write_ext_msg+0x3b6/0x3d0
? write_ext_msg+0x3b6/0x3d0
console_flush_all+0x1e9/0x330
The code incorrectly issues a warning when this_chunk is zero, which is
a valid scenario. The warning should only be triggered when this_chunk
is negative.
Fixes: 1ec9daf95093 ("net: netconsole: append userdata to fragmented netconsole messages")
Signed-off-by: Breno Leitao <leitao@xxxxxxxxxx>
Reviewed-by: Simon Horman <horms@xxxxxxxxxx>
Link: https://patch.msgid.link/20241008094325.896208-1-leitao@xxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/net/netconsole.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c
index 9c09293b52588..3e68f7a6e0abe 100644
--- a/drivers/net/netconsole.c
+++ b/drivers/net/netconsole.c
@@ -1118,8 +1118,14 @@ static void send_ext_msg_udp(struct netconsole_target *nt, const char *msg,
this_chunk = min(userdata_len - sent_userdata,
MAX_PRINT_CHUNK - preceding_bytes);
- if (WARN_ON_ONCE(this_chunk <= 0))
+ if (WARN_ON_ONCE(this_chunk < 0))
+ /* this_chunk could be zero if all the previous
+ * message used all the buffer. This is not a
+ * problem, userdata will be sent in the next
+ * iteration
+ */
return;
+
memcpy(buf + this_header + this_offset,
userdata + sent_userdata,
this_chunk);
--
2.43.0
