android/SukiSU-Ultra
1
0
Fork 0
Code Issues Pull Requests Actions 1 Packages Projects Releases Wiki Activity

kernel: rework umount with task_work

Browse Source 
Co-authored-by: weishu <twsxtd@gmail.com>
This commit is contained in:
ShirkNeko
2025-11-04 22:24:00 +08:00
parent fa229b23a4
commit 1a70506f0e
1 changed files with 68 additions and 53 deletions
Download Patch File Download Diff File Expand all files Collapse all files

121
kernel/core_hook.c
View File

@@ -1,4 +1,6 @@
#include "linux/slab.h"
#include <linux/slab.h>
#include <linux/task_work.h>
#include <linux/thread_info.h>
#include <linux/seccomp.h>
#include <linux/bpf.h>
#include <linux/capability.h>
@@ -25,7 +27,6 @@
#include <linux/uaccess.h>
#include <linux/uidgid.h>
#include <linux/version.h>
#include <linux/workqueue.h>
#include <linux/lsm_hooks.h>
#include <linux/binfmts.h>
#include <linux/tty.h>
@@ -163,13 +164,6 @@ static void ksu_try_escalate_for_uid(uid_t uid)
remove_pending_root(uid);
}
static struct workqueue_struct *ksu_workqueue;
struct ksu_umount_work {
struct work_struct work;
struct mnt_namespace *mnt_ns;
};
static bool ksu_kernel_umount_enabled = true;
static int kernel_umount_feature_get(u64 *value)
@@ -979,15 +973,23 @@ void susfs_try_umount_all(uid_t uid) {
#endif
#ifdef CONFIG_KSU_SUSFS_TRY_UMOUNT
static void do_umount_work(struct work_struct *work)
struct umount_tw {
struct callback_head cb;
const struct cred *old_cred;
};
static void umount_tw_func(struct callback_head *cb)
{
struct ksu_umount_work *umount_work = container_of(work, struct ksu_umount_work, work);
struct mnt_namespace *old_mnt_ns = current->nsproxy->mnt_ns;
current->nsproxy->mnt_ns = umount_work->mnt_ns;
struct umount_tw *tw = container_of(cb, struct umount_tw, cb);
const struct cred *saved = NULL;
if (tw->old_cred) {
saved = override_creds(tw->old_cred);
}
uid_t uid = current_uid().val;
// fixme: use `collect_mounts` and `iterate_mount` to iterate all mountpoint and
// filter the mountpoint whose target is `/data/adb`
try_umount("/odm", true, 0, uid);
try_umount("/system", true, 0, uid);
try_umount("/vendor", true, 0, uid);
@@ -1007,19 +1009,29 @@ static void do_umount_work(struct work_struct *work)
try_umount("/apex/com.android.art/bin/dex2oat64", false, MNT_DETACH, uid);
try_umount("/apex/com.android.art/bin/dex2oat32", false, MNT_DETACH, uid);
// fixme: dec refcount
current->nsproxy->mnt_ns = old_mnt_ns;
if (saved)
revert_creds(saved);
kfree(umount_work);
if (tw->old_cred)
put_cred(tw->old_cred);
kfree(tw);
}
#else
static void do_umount_work(struct work_struct *work)
struct umount_tw {
struct callback_head cb;
const struct cred *old_cred;
};
static void umount_tw_func(struct callback_head *cb)
{
struct ksu_umount_work *umount_work = container_of(work, struct ksu_umount_work, work);
struct mnt_namespace *old_mnt_ns = current->nsproxy->mnt_ns;
current->nsproxy->mnt_ns = umount_work->mnt_ns;
struct umount_tw *tw = container_of(cb, struct umount_tw, cb);
const struct cred *saved = NULL;
if (tw->old_cred) {
saved = override_creds(tw->old_cred);
}
// fixme: use `collect_mounts` and `iterate_mount` to iterate all mountpoint and
// filter the mountpoint whose target is `/data/adb`
try_umount("/odm", true, 0);
try_umount("/system", true, 0);
try_umount("/vendor", true, 0);
@@ -1036,16 +1048,20 @@ static void do_umount_work(struct work_struct *work)
try_umount("/apex/com.android.art/bin/dex2oat64", false, MNT_DETACH);
try_umount("/apex/com.android.art/bin/dex2oat32", false, MNT_DETACH);
// fixme: dec refcount
current->nsproxy->mnt_ns = old_mnt_ns;
if (saved)
revert_creds(saved);
kfree(umount_work);
if (tw->old_cred)
put_cred(tw->old_cred);
kfree(tw);
}
#endif
#ifdef CONFIG_KSU_SUSFS
int ksu_handle_setuid(struct cred *new, const struct cred *old)
{
struct umount_tw *tw;
if (!new || !old) {
return 0;
}
@@ -1130,16 +1146,21 @@ do_umount:
// susfs come first, and lastly umount by ksu, make sure umount in reversed order
susfs_try_umount_all(new_uid.val);
#else
// fixme: use `collect_mounts` and `iterate_mount` to iterate all mountpoint and
// filter the mountpoint whose target is `/data/adb`
struct work_struct *work = kmalloc(sizeof(struct work_struct), GFP_ATOMIC);
if (!work) {
pr_err("Failed to allocate work\n");
tw = kmalloc(sizeof(*tw), GFP_ATOMIC);
if (!tw)
return 0;
}
INIT_WORK(work, do_umount_work);
queue_work(ksu_workqueue, work);
tw->old_cred = get_current_cred();
tw->cb.func = umount_tw_func;
int err = task_work_add(current, &tw->cb, TWA_RESUME);
if (err) {
if (tw->old_cred) {
put_cred(tw->old_cred);
}
kfree(tw);
pr_warn("unmount add task_work failed\n");
}
#endif // #ifdef CONFIG_KSU_SUSFS_TRY_UMOUNT
@@ -1163,6 +1184,7 @@ do_umount:
#else
int ksu_handle_setuid(struct cred *new, const struct cred *old)
{
struct umount_tw *tw;
if (!new || !old) {
return 0;
}
@@ -1239,21 +1261,22 @@ int ksu_handle_setuid(struct cred *new, const struct cred *old)
current->pid);
#endif
// fixme: use `collect_mounts` and `iterate_mount` to iterate all mountpoint and
// filter the mountpoint whose target is `/data/adb`
struct ksu_umount_work *umount_work = kmalloc(sizeof(struct ksu_umount_work), GFP_ATOMIC);
if (!umount_work) {
pr_err("Failed to allocate umount_work\n");
tw = kmalloc(sizeof(*tw), GFP_ATOMIC);
if (!tw)
return 0;
tw->old_cred = get_current_cred();
tw->cb.func = umount_tw_func;
int err = task_work_add(current, &tw->cb, TWA_RESUME);
if (err) {
if (tw->old_cred) {
put_cred(tw->old_cred);
}
kfree(tw);
pr_warn("unmount add task_work failed\n");
}
// fixme: inc refcount
umount_work->mnt_ns = current->nsproxy->mnt_ns;
INIT_WORK(&umount_work->work, do_umount_work);
queue_work(ksu_workqueue, &umount_work->work);
return 0;
}
@@ -1597,10 +1620,6 @@ void __init ksu_core_init(void)
if (ksu_register_feature_handler(&kernel_umount_handler)) {
pr_err("Failed to register kernel_umount feature handler\n");
}
ksu_workqueue = alloc_workqueue("ksu_umount", WQ_UNBOUND, 0);
if (!ksu_workqueue) {
pr_err("Failed to create ksu workqueue\n");
}
ksu_lsm_hook_init();
#ifdef CONFIG_KSU_KPROBES_HOOK
int rc = ksu_kprobe_init();
@@ -1622,8 +1641,4 @@ void ksu_core_exit(void)
pr_info("ksu_core_kprobe_exit\n");
ksu_kprobe_exit();
#endif
if (ksu_workqueue) {
flush_workqueue(ksu_workqueue);
destroy_workqueue(ksu_workqueue);
}
}