7.9 KiB
7.9 KiB
Tracepoint Hook Integration
Introduction
Since commit 49b01aad, SukiSU has introduced Tracepoint Hook
This Hook theoretically has lower performance overhead compared to Kprobes Hook, but is inferior to Manual Hook / Syscall Hook
Note
This tutorial references the syscall hook v1.4 version from backslashxx/KernelSU#5, as well as the original KernelSU's Manual Hook
Guide
execve Hook (exec.c)
Generally need to modify the do_execve and compat_do_execve methods in fs/exec.c
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -78,6 +78,10 @@
#include <trace/hooks/sched.h>
#endif
+#if defined(CONFIG_KSU) && defined(CONFIG_KSU_TRACEPOINT_HOOK)
+#include <../drivers/kernelsu/ksu_trace.h>
+#endif
+
EXPORT_TRACEPOINT_SYMBOL_GPL(task_rename);
static int bprm_creds_from_file(struct linux_binprm *bprm);
@@ -2037,6 +2041,9 @@ static int do_execve(struct filename *filename,
{
struct user_arg_ptr argv = { .ptr.native = __argv };
struct user_arg_ptr envp = { .ptr.native = __envp };
+#if defined(CONFIG_KSU) && defined(CONFIG_KSU_TRACEPOINT_HOOK)
+ trace_ksu_trace_execveat_hook((int *)AT_FDCWD, &filename, &argv, &envp, 0);
+#endif
return do_execveat_common(AT_FDCWD, filename, argv, envp, 0);
}
@@ -2064,6 +2071,9 @@ static int compat_do_execve(struct filename *filename,
.is_compat = true,
.ptr.compat = __envp,
};
+#if defined(CONFIG_KSU) && defined(CONFIG_KSU_TRACEPOINT_HOOK)
+ trace_ksu_trace_execveat_sucompat_hook((int *)AT_FDCWD, &filename, NULL, NULL, NULL); /* 32-bit su */
+#endif
return do_execveat_common(AT_FDCWD, filename, argv, envp, 0);
}
faccessat Hook (open.c)
Generally need to modify the do_faccessat method in /fs/open.c
--- a/fs/open.c
+++ b/fs/open.c
@@ -37,6 +37,10 @@
#include "internal.h"
#include <trace/hooks/syscall_check.h>
+#if defined(CONFIG_KSU) && defined(CONFIG_KSU_TRACEPOINT_HOOK)
+#include <../drivers/kernelsu/ksu_trace.h>
+#endif
+
int do_truncate(struct user_namespace *mnt_userns, struct dentry *dentry,
loff_t length, unsigned int time_attrs, struct file *filp)
{
@@ -468,6 +472,9 @@ static long do_faccessat(int dfd, const char __user *filename, int mode, int fla
SYSCALL_DEFINE3(faccessat, int, dfd, const char __user *, filename, int, mode)
{
+#if defined(CONFIG_KSU) && defined(CONFIG_KSU_TRACEPOINT_HOOK)
+ trace_ksu_trace_faccessat_hook(&dfd, &filename, &mode, NULL);
+#endif
return do_faccessat(dfd, filename, mode, 0);
}
If there's no do_faccessat method, you can find the faccessat SYSCALL definition (for kernels earlier than 4.17)
--- a/fs/open.c
+++ b/fs/open.c
@@ -31,6 +31,9 @@
#include <linux/ima.h>
#include <linux/dnotify.h>
#include <linux/compat.h>
+#if defined(CONFIG_KSU) && defined(CONFIG_KSU_TRACEPOINT_HOOK)
+#include <../drivers/kernelsu/ksu_trace.h>
+#endif
#include "internal.h"
@@ -369,6 +372,9 @@ SYSCALL_DEFINE3(faccessat, int, dfd, const char __user *, filename, int, mode)
int res;
unsigned int lookup_flags = LOOKUP_FOLLOW;
+#if defined(CONFIG_KSU) && defined(CONFIG_KSU_TRACEPOINT_HOOK)
+ trace_ksu_trace_faccessat_hook(&dfd, &filename, &mode, NULL);
+#endif
if (mode & ~S_IRWXO) /* where's F_OK, X_OK, W_OK, R_OK? */
return -EINVAL;
sys_read Hook (read_write.c)
Need to modify the sys_read method in fs/read_write.c (4.19 and above)
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -25,6 +25,10 @@
#include <linux/uaccess.h>
#include <asm/unistd.h>
+#if defined(CONFIG_KSU) && defined(CONFIG_KSU_TRACEPOINT_HOOK)
+#include <../drivers/kernelsu/ksu_trace.h>
+#endif
+
const struct file_operations generic_ro_fops = {
.llseek = generic_file_llseek,
.read_iter = generic_file_read_iter,
@@ -630,6 +634,9 @@ ssize_t ksys_read(unsigned int fd, char __user *buf, size_t count)
SYSCALL_DEFINE3(read, unsigned int, fd, char __user *, buf, size_t, count)
{
+#if defined(CONFIG_KSU) && defined(CONFIG_KSU_TRACEPOINT_HOOK)
+ trace_ksu_trace_sys_read_hook(fd, &buf, &count);
+#endif
return ksys_read(fd, buf, count);
}
Or the read SYSCALL definition (4.14 and below)
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -25,6 +25,11 @@
#include <linux/uaccess.h>
#include <asm/unistd.h>
+#if defined(CONFIG_KSU) && defined(CONFIG_KSU_TRACEPOINT_HOOK)
+#include <../drivers/kernelsu/ksu_trace.h>
+#endif
+
+
const struct file_operations generic_ro_fops = {
.llseek = generic_file_llseek,
.read_iter = generic_file_read_iter,
@@ -575,6 +580,9 @@ SYSCALL_DEFINE3(read, unsigned int, fd, char __user *, buf, size_t, count)
if (f.file) {
loff_t pos = file_pos_read(f.file);
+#if defined(CONFIG_KSU) && defined(CONFIG_KSU_TRACEPOINT_HOOK)
+ trace_ksu_trace_sys_read_hook(fd, &buf, &count);
+#endif
ret = vfs_read(f.file, buf, count, &pos);
if (ret >= 0)
file_pos_write(f.file, pos);
fstatat Hook (stat.c)
Need to modify the newfstatat SYSCALL definition in stat.c
If 32-bit support is needed, also need to modify the statat64 SYSCALL definition
--- a/fs/stat.c
+++ b/fs/stat.c
@@ -24,6 +24,10 @@
#include "internal.h"
#include "mount.h"
+#if defined(CONFIG_KSU) && defined(CONFIG_KSU_TRACEPOINT_HOOK)
+#include <../drivers/kernelsu/ksu_trace.h>
+#endif
+
/**
* generic_fillattr - Fill in the basic attributes from the inode struct
* @mnt_userns: user namespace of the mount the inode was found from
@@ -408,6 +412,10 @@ SYSCALL_DEFINE4(newfstatat, int, dfd, const char __user *, filename,
struct kstat stat;
int error;
+#if defined(CONFIG_KSU) && defined(CONFIG_KSU_TRACEPOINT_HOOK)
+ trace_ksu_trace_stat_hook(&dfd, &filename, &flag);
+#endif
+
error = vfs_fstatat(dfd, filename, &stat, flag);
if (error)
return error;
@@ -559,6 +567,10 @@ SYSCALL_DEFINE4(fstatat64, int, dfd, const char __user *, filename,
struct kstat stat;
int error;
+#if defined(CONFIG_KSU) && defined(CONFIG_KSU_TRACEPOINT_HOOK)
+ trace_ksu_trace_stat_hook(&dfd, &filename, &flag); /* 32-bit su support */
+#endif
+
error = vfs_fstatat(dfd, filename, &stat, flag);
if (error)
return error;
input Hook (input.c, for entering KSU built-in security mode)
Need to modify the input_event method in drivers/input/input.c, not input_handle_event
--- a/drivers/input/input.c
+++ b/drivers/input/input.c
@@ -26,6 +26,10 @@
#include "input-compat.h"
#include "input-poller.h"
+#if defined(CONFIG_KSU) && defined(CONFIG_KSU_TRACEPOINT_HOOK)
+#include <../../drivers/kernelsu/ksu_trace.h>
+#endif
+
MODULE_AUTHOR("Vojtech Pavlik <vojtech@suse.cz>");
MODULE_DESCRIPTION("Input core");
MODULE_LICENSE("GPL");
@@ -451,6 +455,10 @@ void input_event(struct input_dev *dev,
{
unsigned long flags;
+#if defined(CONFIG_KSU) && defined(CONFIG_KSU_TRACEPOINT_HOOK)
+ trace_ksu_trace_input_hook(&type, &code, &value);
+#endif
+
if (is_event_supported(type, dev->evbit, EV_MAX)) {
spin_lock_irqsave(&dev->event_lock, flags);
devpts Hook (pty.c)
Need to modify the pts_unix98_lookup method in drivers/tty/pty.c
--- a/drivers/tty/pty.c
+++ b/drivers/tty/pty.c
@@ -31,6 +31,10 @@
#include <linux/compat.h>
#include "tty.h"
+#if defined(CONFIG_KSU) && defined(CONFIG_KSU_TRACEPOINT_HOOK)
+#include <../../drivers/kernelsu/ksu_trace.h>
+#endif
+
#undef TTY_DEBUG_HANGUP
#ifdef TTY_DEBUG_HANGUP
# define tty_debug_hangup(tty, f, args...) tty_debug(tty, f, ##args)
@@ -707,6 +711,10 @@ static struct tty_struct *pts_unix98_lookup(struct tty_driver *driver,
{
struct tty_struct *tty;
+#if defined(CONFIG_KSU) && defined(CONFIG_KSU_TRACEPOINT_HOOK)
+ trace_ksu_trace_devpts_hook((struct inode *)file->f_path.dentry->d_inode);
+#endif
+
mutex_lock(&devpts_mutex);
tty = devpts_get_priv(file->f_path.dentry);
mutex_unlock(&devpts_mutex);