SKAS4 - Host get_mm and switch_mm

index cd2327d..6b55c52 100644
@@ -7,7 +7,9 @@
 #define __SKAS_PTRACE_H
 
 #define PTRACE_FAULTINFO 52
-#define PTRACE_SWITCH_MM 55
+#ifndef OLD_PTRACE_SWITCH_MM
+#define OLD_PTRACE_SWITCH_MM 55
+#endif
 
 #include "sysdep/skas_ptrace.h"
 

index 47b57b4..36f8ae5 100644
@@ -192,7 +192,7 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 	}
 #endif
 #ifdef CONFIG_PROC_MM
-	case PTRACE_SWITCH_MM: {
+	case OLD_PTRACE_SWITCH_MM: {
 		struct mm_struct *old = child->mm;
 		struct mm_struct *new = proc_mm_get_mm(data);
 

index 82a0780..522d0f1 100644
@@ -627,7 +627,7 @@ void __switch_mm(struct mm_id *mm_idp)
 
 	/* FIXME: need cpu pid in __switch_mm */
 	if (proc_mm) {
-		err = ptrace(PTRACE_SWITCH_MM, userspace_pid[0], 0,
+		err = ptrace(OLD_PTRACE_SWITCH_MM, userspace_pid[0], 0,
 			     mm_idp->u.mm_fd);
 		if (err)
 			panic("__switch_mm - PTRACE_SWITCH_MM failed, "

index e2d1426..85621a2 100644
@@ -200,3 +200,11 @@ long sys_sigaction(int sig, const struct old_sigaction __user *act,
 
 	return ret;
 }
+
+extern long do_switch_mm(int fd, int flags, long __user *new,
+			 long __user *save, struct pt_regs *regs);
+
+long sys_switch_mm(int fd, int flags, long __user *new, long __user *save)
+{
+	return do_switch_mm(fd, flags, new, save, &current->thread.regs);
+}

index 86f6b18..ff012ba 100644
@@ -112,3 +112,11 @@ void arch_switch_to(struct task_struct *from, struct task_struct *to)
 
 	arch_prctl(to, ARCH_SET_FS, (void __user *) to->thread.arch.fs);
 }
+
+extern long do_switch_mm(int fd, int flags, long __user *new,
+			 long __user *save, struct pt_regs *regs);
+
+long stub_switch_mm(int fd, int flags, long __user *new, long __user *save)
+{
+	return do_switch_mm(fd, flags, new, save, &current->thread.regs);
+}

index 4a233ad..5c0caa4 100644
@@ -38,7 +38,7 @@
 #define R32(l,q) \
 	case offsetof(struct user32, regs.l): stack[offsetof(struct pt_regs, q)/8] = val; break
 
-static int putreg32(struct task_struct *child, unsigned regno, u32 val)
+int putreg32(struct task_struct *child, unsigned regno, u32 val)
 {
 	int i;
 	__u64 *stack = (__u64 *)task_pt_regs(child);

@@ -139,7 +139,7 @@ static int putreg32(struct task_struct *child, unsigned regno, u32 val)
 #define R32(l,q) \
 	case offsetof(struct user32, regs.l): *val = stack[offsetof(struct pt_regs, q)/8]; break
 
-static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
+int getreg32(struct task_struct *child, unsigned regno, u32 *val)
 {
 	__u64 *stack = (__u64 *)task_pt_regs(child);
 

@@ -248,6 +248,7 @@ asmlinkage long sys32_ptrace(long request, u32 pid, u32 addr, u32 data)
 	case PTRACE_SETOPTIONS:
 	case PTRACE_SET_THREAD_AREA:
 	case PTRACE_GET_THREAD_AREA:
+	case PTRACE_SWITCH_MM:
 		return sys_ptrace(request, pid, addr, data); 
 
 	default:

index ff5431c..c3bd8cd 100644
@@ -83,8 +83,8 @@ static inline int put_stack_long(struct task_struct *task, int offset,
 	return 0;
 }
 
-static int putreg(struct task_struct *child,
-	unsigned long regno, unsigned long value)
+int putreg(struct task_struct *child,
+	   unsigned long regno, unsigned long value)
 {
 	switch (regno >> 2) {
 		case GS:

@@ -116,7 +116,7 @@ static int putreg(struct task_struct *child,
 	return 0;
 }
 
-static unsigned long getreg(struct task_struct *child,
+unsigned long getreg(struct task_struct *child,
 	unsigned long regno)
 {
 	unsigned long retval = ~0UL;

index 607085f..a568429 100644
@@ -226,7 +226,7 @@ void ptrace_disable(struct task_struct *child)
 	clear_singlestep(child);
 }
 
-static int putreg(struct task_struct *child,
+int putreg(struct task_struct *child,
 	unsigned long regno, unsigned long value)
 {
 	unsigned long tmp; 

@@ -283,7 +283,7 @@ static int putreg(struct task_struct *child,
 	return 0;
 }
 
-static unsigned long getreg(struct task_struct *child, unsigned long regno)
+unsigned long getreg(struct task_struct *child, unsigned long regno)
 {
 	unsigned long val;
 	switch (regno) {

index a86d26f..7b9d43b 100644
@@ -261,3 +261,12 @@ int kernel_execve(const char *filename, char *const argv[], char *const envp[])
 	: "0" (__NR_execve),"ri" (filename),"c" (argv), "d" (envp) : "memory");
 	return __res;
 }
+
+extern long do_switch_mm(int fd, int flags, long __user *new, long __user *save,
+			 struct pt_regs *regs);
+
+asmlinkage long sys_switch_mm(struct pt_regs regs)
+{
+	return do_switch_mm(regs.ebx, regs.ecx, (long __user *) regs.edx,
+			    (long __user *) regs.esi, &regs);
+}

index 907942e..ddc1c98 100644
@@ -153,3 +153,12 @@ asmlinkage long sys_uname(struct new_utsname __user * name)
 		err |= copy_to_user(&name->machine, "i686", 5); 		
 	return err ? -EFAULT : 0;
 }
+
+extern long do_switch_mm(int fd, int flags, long __user *new,
+			 long __user *save, struct pt_regs *regs);
+
+asmlinkage long sys_switch_mm(int fd, int flags, long __user *new,
+			      long __user *save, struct pt_regs *regs)
+{
+	return do_switch_mm(fd, flags, new, save, regs);
+}

index 7411bfb..6dd8e34 100644
@@ -2187,6 +2187,34 @@ static int proc_pid_io_accounting(struct task_struct *task, char *buffer)
 }
 #endif
 
+static int proc_pid_mm_open(struct inode *inode, struct file *file)
+{
+	struct task_struct *task = pid_task(proc_pid(inode), PIDTYPE_PID);
+
+	if (task == NULL)
+		return -ENOENT;
+
+	if(task->mm != NULL)
+		atomic_inc(&task->mm->mm_users);
+	file->private_data = task->mm;
+	return 0;
+}
+
+static int proc_pid_mm_release(struct inode *inode, struct file *file)
+{
+	struct mm_struct *mm = file->private_data;
+
+	if(mm != NULL)
+		mmput(mm);
+
+	return 0;
+}
+
+const struct file_operations proc_pid_mm_operations = {
+	.open		= proc_pid_mm_open,
+	.release	= proc_pid_mm_release,
+};
+
 /*
  * Thread groups
  */

@@ -2250,6 +2278,7 @@ static const struct pid_entry tgid_base_stuff[] = {
 #ifdef CONFIG_TASK_IO_ACCOUNTING
 	INF("io",	S_IRUGO, pid_io_accounting),
 #endif
+	REG("mm", S_IRUSR | S_IWUSR, pid_mm),
 };
 
 static int proc_tgid_base_readdir(struct file * filp,

index 9b15545..3477555 100644
@@ -330,10 +330,12 @@
 #define __NR_timerfd		322
 #define __NR_eventfd		323
 #define __NR_fallocate		324
+#define __NR_new_mm		325
+#define __NR_switch_mm		326
 
 #ifdef __KERNEL__
 
-#define NR_syscalls 325
+#define NR_syscalls 327
 
 #define __ARCH_WANT_IPC_PARSE_VERSION
 #define __ARCH_WANT_OLD_READDIR

index 5ff4d3e..baf4c0c 100644
@@ -635,6 +635,10 @@ __SYSCALL(__NR_timerfd, sys_timerfd)
 __SYSCALL(__NR_eventfd, sys_eventfd)
 #define __NR_fallocate				285
 __SYSCALL(__NR_fallocate, sys_fallocate)
+#define __NR_new_mm				286
+__SYSCALL(__NR_new_mm, sys_new_mm)
+#define __NR_switch_mm				287
+__SYSCALL(__NR_switch_mm, stub_switch_mm)
 
 #ifndef __NO_STUBS
 #define __ARCH_WANT_OLD_READDIR

index 3ea5750..6758e86 100644
@@ -21,6 +21,8 @@
 
 #define PTRACE_SYSCALL		  24
 
+#define PTRACE_SWITCH_MM	  33
+
 /* 0x4200-0x4300 are reserved for architecture-independent additions.  */
 #define PTRACE_SETOPTIONS	0x4200
 #define PTRACE_GETEVENTMSG	0x4201

index ac3d496..7707a43 100644
@@ -1665,6 +1665,7 @@ static inline int sas_ss_flags(unsigned long sp)
  * Routines for handling mm_structs
  */
 extern struct mm_struct * mm_alloc(void);
+extern struct mm_struct *dup_mm(struct task_struct *tsk);
 
 /* mmdrop drops the mm and the page tables */
 extern void FASTCALL(__mmdrop(struct mm_struct *));

index 8dd8ff2..bd9afde 100644
@@ -491,7 +491,7 @@ void mm_release(struct task_struct *tsk, struct mm_struct *mm)
  * Allocate a new mm structure and copy contents from the
  * mm structure of the passed in task structure.
  */
-static struct mm_struct *dup_mm(struct task_struct *tsk)
+struct mm_struct *dup_mm(struct task_struct *tsk)
 {
 	struct mm_struct *mm, *oldmm = current->mm;
 	int err;

446 lines not on this page · raw message

index c25db86..317e888 100644
@@ -366,6 +366,29 @@ static int ptrace_setsiginfo(struct task_struct *child, siginfo_t __user * data)
 	return error;
 }
 
+extern struct mm_struct *fd_to_mm(int fd);
+
+static int ptrace_switch_mm(struct task_struct *child, int mm_fd)
+{
+	struct mm_struct *old = child->mm;
+	struct mm_struct *new = fd_to_mm(mm_fd);
+
+	if (IS_ERR(new))
+		return PTR_ERR(new);
+
+	task_lock(child);
+
+	atomic_inc(&new->mm_users);
+
+	child->mm = new;
+	child->active_mm = new;
+
+	task_unlock(child);
+	mmput(old);
+
+	return 0;
+}
+
 int ptrace_request(struct task_struct *child, long request,
 		   long addr, long data)
 {

@@ -390,6 +413,9 @@ int ptrace_request(struct task_struct *child, long request,
 	case PTRACE_DETACH:	 /* detach a process that was attached. */
 		ret = ptrace_detach(child, data);
 		break;
+	case PTRACE_SWITCH_MM:
+		ret = ptrace_switch_mm(child, data);
+		break;
 	default:
 		break;
 	}