From 7d3c5c6ea26ba75b5a5a390619417519b915177f Mon Sep 17 00:00:00 2001
From: Suren Baghdasaryan <surenb@google.com>
Date: Fri, 18 Oct 2019 11:22:27 -0700
Subject: [PATCH] lmkd: Add library function to unregister a process

Introduce lmkd_unregister_proc helper function. Fix a bug where
lmkd_pack_set_procremove used a wrong structure as a parameter.

Bug: 129011369
Test: verify process record removal when it is manually killed
Change-Id: I7ab5a499f6b1c6eecfdba4d0a5ec916053e2726a
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
---
 include/liblmkd_utils.h |  8 ++++++++
 include/lmkd.h          |  2 +-
 liblmkd_utils.c         | 11 +++++++++++
 3 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/include/liblmkd_utils.h b/include/liblmkd_utils.h
index 72e3f4a..92e4d41 100644
--- a/include/liblmkd_utils.h
+++ b/include/liblmkd_utils.h
@@ -39,6 +39,14 @@ int lmkd_connect();
  */
 int lmkd_register_proc(int sock, struct lmk_procprio *params);
 
+/*
+ * Unregisters a process previously registered with lmkd.
+ * On success returns 0.
+ * On error, -1 is returned.
+ * In the case of error errno is set appropriately.
+ */
+int lmkd_unregister_proc(int sock, struct lmk_procremove *params);
+
 /*
  * Creates memcg directory for given process.
  * On success returns 0.
diff --git a/include/lmkd.h b/include/lmkd.h
index 59377dd..08805fb 100644
--- a/include/lmkd.h
+++ b/include/lmkd.h
@@ -135,7 +135,7 @@ static inline void lmkd_pack_get_procremove(LMKD_CTRL_PACKET packet,
  * Warning: no checks performed, caller should ensure valid parameters.
  */
 static inline size_t lmkd_pack_set_procremove(LMKD_CTRL_PACKET packet,
-                                              struct lmk_procprio* params) {
+                                              struct lmk_procremove* params) {
     packet[0] = htonl(LMK_PROCREMOVE);
     packet[1] = htonl(params->pid);
     return 2 * sizeof(int);
diff --git a/liblmkd_utils.c b/liblmkd_utils.c
index 980cd35..280c149 100644
--- a/liblmkd_utils.c
+++ b/liblmkd_utils.c
@@ -42,6 +42,17 @@ int lmkd_register_proc(int sock, struct lmk_procprio *params) {
     return (ret < 0) ? -1 : 0;
 }
 
+int lmkd_unregister_proc(int sock, struct lmk_procremove *params) {
+    LMKD_CTRL_PACKET packet;
+    size_t size;
+    int ret;
+
+    size = lmkd_pack_set_procremove(packet, params);
+    ret = TEMP_FAILURE_RETRY(write(sock, packet, size));
+
+    return (ret < 0) ? -1 : 0;
+}
+
 int create_memcg(uid_t uid, pid_t pid) {
     char buf[256];
     int tasks_file;