[Devel] [RFC PATCH 2/2] autofs: sent 32-bit sized packet for 32-bit process

[Stanislav Kinsburskiy]

The structure autofs_v5_packet (except name) is not aligned by 8 bytes, which
lead to different sizes in 32 and 64-bit architectures.
Let's form 32-bit compatible packet when daemon has 32-bit addressation.

Signed-off-by: Stanislav Kinsburskiy <skinsbursky at virtuozzo.com>
---
 fs/autofs4/waitq.c |   11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/fs/autofs4/waitq.c b/fs/autofs4/waitq.c
index 309ca6b..484cf2e 100644
--- a/fs/autofs4/waitq.c
+++ b/fs/autofs4/waitq.c
@@ -153,12 +153,19 @@ static void autofs4_notify_daemon(struct autofs_sb_info *sbi,
 	{
 		struct autofs_v5_packet *packet = &pkt.v5_pkt.v5_packet;
 		struct user_namespace *user_ns = sbi->pipe->f_cred->user_ns;
+		size_t name_offset;
 
-		pktsz = sizeof(*packet);
+		if (sbi->is32bit)
+			name_offset = offsetof(struct autofs_v5_packet, len) +
+				      sizeof(packet->len);
+		else
+			name_offset = offsetof(struct autofs_v5_packet, name);
+
+		pktsz = name_offset + sizeof(packet->name);
 
 		packet->wait_queue_token = wq->wait_queue_token;
 		packet->len = wq->name.len;
-		memcpy(packet->name, wq->name.name, wq->name.len);
+		memcpy(packet + name_offset, wq->name.name, wq->name.len);
 		packet->name[wq->name.len] = '\0';
 		packet->dev = wq->dev;
 		packet->ino = wq->ino;