ptrace: do_wait(traced_leader_killed_by_mt_exec) can block forever

[pandora-kernel.git] / fs / exec.c

diff --git a/fs/exec.c b/fs/exec.c
index 936f577..d219541 100644 (file)
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -42,7 +42,6 @@
 #include <linux/pid_namespace.h>
 #include <linux/module.h>
 #include <linux/namei.h>
-#include <linux/proc_fs.h>
 #include <linux/mount.h>
 #include <linux/security.h>
 #include <linux/syscalls.h>
@@ -964,9 +963,18 @@ static int de_thread(struct task_struct *tsk)
                leader->group_leader = tsk;
 
                tsk->exit_signal = SIGCHLD;
+               leader->exit_signal = -1;
 
                BUG_ON(leader->exit_state != EXIT_ZOMBIE);
                leader->exit_state = EXIT_DEAD;
+
+               /*
+                * We are going to release_task()->ptrace_unlink() silently,
+                * the tracer can sleep in do_wait(). EXIT_DEAD guarantees
+                * the tracer wont't block again waiting for this thread.
+                */
+               if (unlikely(leader->ptrace))
+                       __wake_up_parent(leader, leader->parent);
                write_unlock_irq(&tasklist_lock);
 
                release_task(leader);
@@ -1225,7 +1233,12 @@ int check_unsafe_exec(struct linux_binprm *bprm)
        unsigned n_fs;
        int res = 0;
 
-       bprm->unsafe = tracehook_unsafe_exec(p);
+       if (p->ptrace) {
+               if (p->ptrace & PT_PTRACE_CAP)
+                       bprm->unsafe |= LSM_UNSAFE_PTRACE_CAP;
+               else
+                       bprm->unsafe |= LSM_UNSAFE_PTRACE;
+       }
 
        n_fs = 1;
        spin_lock(&p->fs->lock);
@@ -1353,6 +1366,7 @@ int search_binary_handler(struct linux_binprm *bprm,struct pt_regs *regs)
        unsigned int depth = bprm->recursion_depth;
        int try,retval;
        struct linux_binfmt *fmt;
+       pid_t old_pid;
 
        retval = security_bprm_check(bprm);
        if (retval)
@@ -1366,6 +1380,11 @@ int search_binary_handler(struct linux_binprm *bprm,struct pt_regs *regs)
        if (retval)
                return retval;
 
+       /* Need to fetch pid before load_binary changes it */
+       rcu_read_lock();
+       old_pid = task_pid_nr_ns(current, task_active_pid_ns(current->parent));
+       rcu_read_unlock();
+
        retval = -ENOENT;
        for (try=0; try<2; try++) {
                read_lock(&binfmt_lock);
@@ -1385,7 +1404,8 @@ int search_binary_handler(struct linux_binprm *bprm,struct pt_regs *regs)
                        bprm->recursion_depth = depth;
                        if (retval >= 0) {
                                if (depth == 0)
-                                       tracehook_report_exec(fmt, bprm, regs);
+                                       ptrace_event(PTRACE_EVENT_EXEC,
+                                                       old_pid);
                                put_binfmt(fmt);
                                allow_write_access(bprm->file);
                                if (bprm->file)
@@ -1624,6 +1644,41 @@ expand_fail:
        return ret;
 }
 
+static int cn_print_exe_file(struct core_name *cn)
+{
+       struct file *exe_file;
+       char *pathbuf, *path, *p;
+       int ret;
+
+       exe_file = get_mm_exe_file(current->mm);
+       if (!exe_file)
+               return cn_printf(cn, "(unknown)");
+
+       pathbuf = kmalloc(PATH_MAX, GFP_TEMPORARY);
+       if (!pathbuf) {
+               ret = -ENOMEM;
+               goto put_exe_file;
+       }
+
+       path = d_path(&exe_file->f_path, pathbuf, PATH_MAX);
+       if (IS_ERR(path)) {
+               ret = PTR_ERR(path);
+               goto free_buf;
+       }
+
+       for (p = path; *p; p++)
+               if (*p == '/')
+                       *p = '!';
+
+       ret = cn_printf(cn, "%s", path);
+
+free_buf:
+       kfree(pathbuf);
+put_exe_file:
+       fput(exe_file);
+       return ret;
+}
+
 /* format_corename will inspect the pattern parameter, and output a
  * name into corename, which must have space for at least
  * CORENAME_MAX_SIZE bytes plus one byte for the zero terminator.
@@ -1695,6 +1750,9 @@ static int format_corename(struct core_name *cn, long signr)
                        case 'e':
                                err = cn_printf(cn, "%s", current->comm);
                                break;
+                       case 'E':
+                               err = cn_print_exe_file(cn);
+                               break;
                        /* core limit size */
                        case 'c':
                                err = cn_printf(cn, "%lu",
@@ -1735,7 +1793,7 @@ static int zap_process(struct task_struct *start, int exit_code)
 
        t = start;
        do {
-               task_clear_group_stop_pending(t);
+               task_clear_jobctl_pending(t, JOBCTL_PENDING_MASK);
                if (t != current && t->mm) {
                        sigaddset(&t->pending.signal, SIGKILL);
                        signal_wake_up(t, 1);