1 files changed, 170 insertions, 3 deletions

diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 26f9923baddc..b0d4ab4dfd3d 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -120,7 +120,7 @@ int ptrace_check_attach(struct task_struct *child, int kill)
         return ret;
 }
 
-static int may_attach(struct task_struct *task)
+int __ptrace_may_attach(struct task_struct *task)
 {
         /* May we inspect the given task?
          * This check is used both for attaching with ptrace
@@ -154,7 +154,7 @@ int ptrace_may_attach(struct task_struct *task)
 {
         int err;
         task_lock(task);
-        err = may_attach(task);
+        err = __ptrace_may_attach(task);
         task_unlock(task);
         return !err;
 }
@@ -196,7 +196,7 @@ repeat:
         /* the same process cannot be attached many times */
         if (task->ptrace & PT_PTRACED)
                 goto bad;
-        retval = may_attach(task);
+        retval = __ptrace_may_attach(task);
         if (retval)
                 goto bad;
 
@@ -366,12 +366,73 @@ static int ptrace_setsiginfo(struct task_struct *child, siginfo_t __user * data)
         return error;
 }
 
+
+#ifdef PTRACE_SINGLESTEP
+#define is_singlestep(request)          ((request) == PTRACE_SINGLESTEP)
+#else
+#define is_singlestep(request)          0
+#endif
+
+#ifdef PTRACE_SINGLEBLOCK
+#define is_singleblock(request)         ((request) == PTRACE_SINGLEBLOCK)
+#else
+#define is_singleblock(request)         0
+#endif
+
+#ifdef PTRACE_SYSEMU
+#define is_sysemu_singlestep(request)   ((request) == PTRACE_SYSEMU_SINGLESTEP)
+#else
+#define is_sysemu_singlestep(request)   0
+#endif
+
+static int ptrace_resume(struct task_struct *child, long request, long data)
+{
+        if (!valid_signal(data))
+                return -EIO;
+
+        if (request == PTRACE_SYSCALL)
+                set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
+        else
+                clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
+
+#ifdef TIF_SYSCALL_EMU
+        if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP)
+                set_tsk_thread_flag(child, TIF_SYSCALL_EMU);
+        else
+                clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
+#endif
+
+        if (is_singleblock(request)) {
+                if (unlikely(!arch_has_block_step()))
+                        return -EIO;
+                user_enable_block_step(child);
+        } else if (is_singlestep(request) || is_sysemu_singlestep(request)) {
+                if (unlikely(!arch_has_single_step()))
+                        return -EIO;
+                user_enable_single_step(child);
+        }
+        else
+                user_disable_single_step(child);
+
+        child->exit_code = data;
+        wake_up_process(child);
+
+        return 0;
+}
+
 int ptrace_request(struct task_struct *child, long request,
                    long addr, long data)
 {
         int ret = -EIO;
 
         switch (request) {
+        case PTRACE_PEEKTEXT:
+        case PTRACE_PEEKDATA:
+                return generic_ptrace_peekdata(child, addr, data);
+        case PTRACE_POKETEXT:
+        case PTRACE_POKEDATA:
+                return generic_ptrace_pokedata(child, addr, data);
+
 #ifdef PTRACE_OLDSETOPTIONS
         case PTRACE_OLDSETOPTIONS:
 #endif
@@ -390,6 +451,26 @@ int ptrace_request(struct task_struct *child, long request,
         case PTRACE_DETACH:      /* detach a process that was attached. */
                 ret = ptrace_detach(child, data);
                 break;
+
+#ifdef PTRACE_SINGLESTEP
+        case PTRACE_SINGLESTEP:
+#endif
+#ifdef PTRACE_SINGLEBLOCK
+        case PTRACE_SINGLEBLOCK:
+#endif
+#ifdef PTRACE_SYSEMU
+        case PTRACE_SYSEMU:
+        case PTRACE_SYSEMU_SINGLESTEP:
+#endif
+        case PTRACE_SYSCALL:
+        case PTRACE_CONT:
+                return ptrace_resume(child, request, data);
+
+        case PTRACE_KILL:
+                if (child->exit_state)  /* already dead */
+                        return 0;
+                return ptrace_resume(child, request, SIGKILL);
+
         default:
                 break;
         }
@@ -470,6 +551,8 @@ asmlinkage long sys_ptrace(long request, long pid, long addr, long data)
         lock_kernel();
         if (request == PTRACE_TRACEME) {
                 ret = ptrace_traceme();
+                if (!ret)
+                        arch_ptrace_attach(current);
                 goto out;
         }
 
@@ -524,3 +607,87 @@ int generic_ptrace_pokedata(struct task_struct *tsk, long addr, long data)
         copied = access_process_vm(tsk, addr, &data, sizeof(data), 1);
         return (copied == sizeof(data)) ? 0 : -EIO;
 }
+
+#ifdef CONFIG_COMPAT
+#include <linux/compat.h>
+
+int compat_ptrace_request(struct task_struct *child, compat_long_t request,
+                          compat_ulong_t addr, compat_ulong_t data)
+{
+        compat_ulong_t __user *datap = compat_ptr(data);
+        compat_ulong_t word;
+        int ret;
+
+        switch (request) {
+        case PTRACE_PEEKTEXT:
+        case PTRACE_PEEKDATA:
+                ret = access_process_vm(child, addr, &word, sizeof(word), 0);
+                if (ret != sizeof(word))
+                        ret = -EIO;
+                else
+                        ret = put_user(word, datap);
+                break;
+
+        case PTRACE_POKETEXT:
+        case PTRACE_POKEDATA:
+                ret = access_process_vm(child, addr, &data, sizeof(data), 1);
+                ret = (ret != sizeof(data) ? -EIO : 0);
+                break;
+
+        case PTRACE_GETEVENTMSG:
+                ret = put_user((compat_ulong_t) child->ptrace_message, datap);
+                break;
+
+        default:
+                ret = ptrace_request(child, request, addr, data);
+        }
+
+        return ret;
+}
+
+#ifdef __ARCH_WANT_COMPAT_SYS_PTRACE
+asmlinkage long compat_sys_ptrace(compat_long_t request, compat_long_t pid,
+                                  compat_long_t addr, compat_long_t data)
+{
+        struct task_struct *child;
+        long ret;
+
+        /*
+         * This lock_kernel fixes a subtle race with suid exec
+         */
+        lock_kernel();
+        if (request == PTRACE_TRACEME) {
+                ret = ptrace_traceme();
+                goto out;
+        }
+
+        child = ptrace_get_task_struct(pid);
+        if (IS_ERR(child)) {
+                ret = PTR_ERR(child);
+                goto out;
+        }
+
+        if (request == PTRACE_ATTACH) {
+                ret = ptrace_attach(child);
+                /*
+                 * Some architectures need to do book-keeping after
+                 * a ptrace attach.
+                 */
+                if (!ret)
+                        arch_ptrace_attach(child);
+                goto out_put_task_struct;
+        }
+
+        ret = ptrace_check_attach(child, request == PTRACE_KILL);
+        if (!ret)
+                ret = compat_arch_ptrace(child, request, addr, data);
+
+ out_put_task_struct:
+        put_task_struct(child);
+ out:
+        unlock_kernel();
+        return ret;
+}
+#endif /* __ARCH_WANT_COMPAT_SYS_PTRACE */
+
+#endif  /* CONFIG_COMPAT */