commit bfa6d75c60704e73b204b9ddcccd443e862ffa34
author Hung-ying Tyan <tyanh@google.com> Tue May 17 18:49:10 2016 +0800
committer Hung-ying Tyan <tyanh@google.com> Fri Jun 24 11:10:46 2016 +0800
tree 8cfc0613c4cb72556a37a6b338ff1ee81b0dced8
parent 59e6afc617bf5ce341de4f3d0428c2b1a79879ee

Add -f to insmod

When the flag is on, insmod will bypass vermagic and symbol version
checking in the kernel. This is to make it possible to update kernel
without recompiling kernel modules.

BUG=28803994

Change-Id: Ib4be6999ef52baefd4210ee0d242360e43318907

init/builtins.cpp

diff --git a/init/builtins.cpp b/init/builtins.cpp
index 89f6c68..98595da 100644
--- a/init/builtins.cpp
+++ b/init/builtins.cpp
@@ -36,6 +36,7 @@
 #include <sys/wait.h>
 #include <unistd.h>
 #include <linux/loop.h>
+#include <linux/module.h>
 #include <ext4_crypt_init_extensions.h>
 
 #include <selinux/selinux.h>
@@ -44,6 +45,7 @@
 #include <fs_mgr.h>
 #include <android-base/file.h>
 #include <android-base/parseint.h>
+#include <android-base/strings.h>
 #include <android-base/stringprintf.h>
 #include <cutils/partition_utils.h>
 #include <cutils/android_reboot.h>
@@ -66,13 +68,13 @@
 
 static const int kTerminateServiceDelayMicroSeconds = 50000;
 
-static int insmod(const char *filename, const char *options) {
+static int insmod(const char *filename, const char *options, int flags) {
     int fd = open(filename, O_RDONLY | O_NOFOLLOW | O_CLOEXEC);
     if (fd == -1) {
         ERROR("insmod: open(\"%s\") failed: %s", filename, strerror(errno));
         return -1;
     }
-    int rc = syscall(__NR_finit_module, fd, options, 0);
+    int rc = syscall(__NR_finit_module, fd, options, flags);
     if (rc == -1) {
         ERROR("finit_module for \"%s\" failed: %s", filename, strerror(errno));
     }
@@ -269,17 +271,17 @@
 }
 
 static int do_insmod(const std::vector<std::string>& args) {
-    std::string options;
+    int flags = 0;
+    auto it = args.begin() + 1;
 
-    if (args.size() > 2) {
-        options += args[2];
-        for (std::size_t i = 3; i < args.size(); ++i) {
-            options += ' ';
-            options += args[i];
-        }
+    if (!(*it).compare("-f")) {
+        flags = MODULE_INIT_IGNORE_VERMAGIC | MODULE_INIT_IGNORE_MODVERSIONS;
+        it++;
     }
 
-    return insmod(args[1].c_str(), options.c_str());
+    std::string filename = *it++;
+    std::string options = android::base::Join(std::vector<std::string>(it, args.end()), ' ');
+    return insmod(filename.c_str(), options.c_str(), flags);
 }
 
 static int do_mkdir(const std::vector<std::string>& args) {