Merge branch 'ptrace' of git://git.kernel.org/pub/scm/linux/kernel/git/oleg/misc
* 'ptrace' of git://git.kernel.org/pub/scm/linux/kernel/git/oleg/misc: (39 commits)
ptrace: do_wait(traced_leader_killed_by_mt_exec) can block forever
ptrace: fix ptrace_signal() && STOP_DEQUEUED interaction
connector: add an event for monitoring process tracers
ptrace: dont send SIGSTOP on auto-attach if PT_SEIZED
ptrace: mv send-SIGSTOP from do_fork() to ptrace_init_task()
ptrace_init_task: initialize child->jobctl explicitly
has_stopped_jobs: s/task_is_stopped/SIGNAL_STOP_STOPPED/
ptrace: make former thread ID available via PTRACE_GETEVENTMSG after PTRACE_EVENT_EXEC stop
ptrace: wait_consider_task: s/same_thread_group/ptrace_reparented/
ptrace: kill real_parent_is_ptracer() in in favor of ptrace_reparented()
ptrace: ptrace_reparented() should check same_thread_group()
redefine thread_group_leader() as exit_signal >= 0
do not change dead_task->exit_signal
kill task_detached()
reparent_leader: check EXIT_DEAD instead of task_detached()
make do_notify_parent() __must_check, update the callers
__ptrace_detach: avoid task_detached(), check do_notify_parent()
kill tracehook_notify_death()
make do_notify_parent() return bool
ptrace: s/tracehook_tracer_task()/ptrace_parent()/
...
diff --git a/arch/s390/kernel/traps.c b/arch/s390/kernel/traps.c
index a65d2e8..a63d34c 100644
--- a/arch/s390/kernel/traps.c
+++ b/arch/s390/kernel/traps.c
@@ -331,7 +331,7 @@
{
if (notify_die(DIE_SSTEP, "sstep", regs, 0, 0, SIGTRAP) == NOTIFY_STOP)
return;
- if (tracehook_consider_fatal_signal(current, SIGTRAP))
+ if (current->ptrace)
force_sig(SIGTRAP, current);
}
@@ -425,7 +425,7 @@
if (get_user(*((__u16 *) opcode), (__u16 __user *) location))
return;
if (*((__u16 *) opcode) == S390_BREAKPOINT_U16) {
- if (tracehook_consider_fatal_signal(current, SIGTRAP))
+ if (current->ptrace)
force_sig(SIGTRAP, current);
else
signal = SIGILL;
diff --git a/drivers/connector/cn_proc.c b/drivers/connector/cn_proc.c
index 2b46a7e..281902d 100644
--- a/drivers/connector/cn_proc.c
+++ b/drivers/connector/cn_proc.c
@@ -28,6 +28,7 @@
#include <linux/init.h>
#include <linux/connector.h>
#include <linux/gfp.h>
+#include <linux/ptrace.h>
#include <asm/atomic.h>
#include <asm/unaligned.h>
@@ -166,6 +167,40 @@
cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
}
+void proc_ptrace_connector(struct task_struct *task, int ptrace_id)
+{
+ struct cn_msg *msg;
+ struct proc_event *ev;
+ struct timespec ts;
+ __u8 buffer[CN_PROC_MSG_SIZE];
+ struct task_struct *tracer;
+
+ if (atomic_read(&proc_event_num_listeners) < 1)
+ return;
+
+ msg = (struct cn_msg *)buffer;
+ ev = (struct proc_event *)msg->data;
+ get_seq(&msg->seq, &ev->cpu);
+ ktime_get_ts(&ts); /* get high res monotonic timestamp */
+ put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns);
+ ev->what = PROC_EVENT_PTRACE;
+ ev->event_data.ptrace.process_pid = task->pid;
+ ev->event_data.ptrace.process_tgid = task->tgid;
+ if (ptrace_id == PTRACE_ATTACH) {
+ ev->event_data.ptrace.tracer_pid = current->pid;
+ ev->event_data.ptrace.tracer_tgid = current->tgid;
+ } else if (ptrace_id == PTRACE_DETACH) {
+ ev->event_data.ptrace.tracer_pid = 0;
+ ev->event_data.ptrace.tracer_tgid = 0;
+ } else
+ return;
+
+ memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
+ msg->ack = 0; /* not used */
+ msg->len = sizeof(*ev);
+ cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
+}
+
void proc_exit_connector(struct task_struct *task)
{
struct cn_msg *msg;
diff --git a/fs/exec.c b/fs/exec.c
index 6075a1e..d9576f2 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -963,9 +963,18 @@
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 +1234,12 @@
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 +1367,7 @@
unsigned int depth = bprm->recursion_depth;
int try,retval;
struct linux_binfmt *fmt;
+ pid_t old_pid;
retval = security_bprm_check(bprm);
if (retval)
@@ -1362,6 +1377,11 @@
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);
@@ -1381,7 +1401,8 @@
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)
@@ -1769,7 +1790,7 @@
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);
diff --git a/fs/proc/array.c b/fs/proc/array.c
index 9b45ee8..3a1dafd 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -172,7 +172,7 @@
task_tgid_nr_ns(rcu_dereference(p->real_parent), ns) : 0;
tpid = 0;
if (pid_alive(p)) {
- struct task_struct *tracer = tracehook_tracer_task(p);
+ struct task_struct *tracer = ptrace_parent(p);
if (tracer)
tpid = task_pid_nr_ns(tracer, ns);
}
diff --git a/fs/proc/base.c b/fs/proc/base.c
index fc5bc27..c47719a 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -216,7 +216,7 @@
if (task_is_stopped_or_traced(task)) {
int match;
rcu_read_lock();
- match = (tracehook_tracer_task(task) == current);
+ match = (ptrace_parent(task) == current);
rcu_read_unlock();
if (match && ptrace_may_access(task, PTRACE_MODE_ATTACH))
return mm;
diff --git a/include/linux/cn_proc.h b/include/linux/cn_proc.h
index 47dac5e..12c517b 100644
--- a/include/linux/cn_proc.h
+++ b/include/linux/cn_proc.h
@@ -53,6 +53,7 @@
PROC_EVENT_UID = 0x00000004,
PROC_EVENT_GID = 0x00000040,
PROC_EVENT_SID = 0x00000080,
+ PROC_EVENT_PTRACE = 0x00000100,
/* "next" should be 0x00000400 */
/* "last" is the last process event: exit */
PROC_EVENT_EXIT = 0x80000000
@@ -95,6 +96,13 @@
__kernel_pid_t process_tgid;
} sid;
+ struct ptrace_proc_event {
+ __kernel_pid_t process_pid;
+ __kernel_pid_t process_tgid;
+ __kernel_pid_t tracer_pid;
+ __kernel_pid_t tracer_tgid;
+ } ptrace;
+
struct exit_proc_event {
__kernel_pid_t process_pid;
__kernel_pid_t process_tgid;
@@ -109,6 +117,7 @@
void proc_exec_connector(struct task_struct *task);
void proc_id_connector(struct task_struct *task, int which_id);
void proc_sid_connector(struct task_struct *task);
+void proc_ptrace_connector(struct task_struct *task, int which_id);
void proc_exit_connector(struct task_struct *task);
#else
static inline void proc_fork_connector(struct task_struct *task)
@@ -124,6 +133,10 @@
static inline void proc_sid_connector(struct task_struct *task)
{}
+static inline void proc_ptrace_connector(struct task_struct *task,
+ int ptrace_id)
+{}
+
static inline void proc_exit_connector(struct task_struct *task)
{}
#endif /* CONFIG_PROC_EVENTS */
diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h
index 9178d5c..800f113 100644
--- a/include/linux/ptrace.h
+++ b/include/linux/ptrace.h
@@ -47,6 +47,13 @@
#define PTRACE_GETREGSET 0x4204
#define PTRACE_SETREGSET 0x4205
+#define PTRACE_SEIZE 0x4206
+#define PTRACE_INTERRUPT 0x4207
+#define PTRACE_LISTEN 0x4208
+
+/* flags in @data for PTRACE_SEIZE */
+#define PTRACE_SEIZE_DEVEL 0x80000000 /* temp flag for development */
+
/* options set using PTRACE_SETOPTIONS */
#define PTRACE_O_TRACESYSGOOD 0x00000001
#define PTRACE_O_TRACEFORK 0x00000002
@@ -65,6 +72,7 @@
#define PTRACE_EVENT_EXEC 4
#define PTRACE_EVENT_VFORK_DONE 5
#define PTRACE_EVENT_EXIT 6
+#define PTRACE_EVENT_STOP 7
#include <asm/ptrace.h>
@@ -77,16 +85,22 @@
* flags. When the a task is stopped the ptracer owns task->ptrace.
*/
+#define PT_SEIZED 0x00010000 /* SEIZE used, enable new behavior */
#define PT_PTRACED 0x00000001
#define PT_DTRACE 0x00000002 /* delayed trace (used on m68k, i386) */
#define PT_TRACESYSGOOD 0x00000004
#define PT_PTRACE_CAP 0x00000008 /* ptracer can follow suid-exec */
-#define PT_TRACE_FORK 0x00000010
-#define PT_TRACE_VFORK 0x00000020
-#define PT_TRACE_CLONE 0x00000040
-#define PT_TRACE_EXEC 0x00000080
-#define PT_TRACE_VFORK_DONE 0x00000100
-#define PT_TRACE_EXIT 0x00000200
+
+/* PT_TRACE_* event enable flags */
+#define PT_EVENT_FLAG_SHIFT 4
+#define PT_EVENT_FLAG(event) (1 << (PT_EVENT_FLAG_SHIFT + (event) - 1))
+
+#define PT_TRACE_FORK PT_EVENT_FLAG(PTRACE_EVENT_FORK)
+#define PT_TRACE_VFORK PT_EVENT_FLAG(PTRACE_EVENT_VFORK)
+#define PT_TRACE_CLONE PT_EVENT_FLAG(PTRACE_EVENT_CLONE)
+#define PT_TRACE_EXEC PT_EVENT_FLAG(PTRACE_EVENT_EXEC)
+#define PT_TRACE_VFORK_DONE PT_EVENT_FLAG(PTRACE_EVENT_VFORK_DONE)
+#define PT_TRACE_EXIT PT_EVENT_FLAG(PTRACE_EVENT_EXIT)
#define PT_TRACE_MASK 0x000003f4
@@ -105,7 +119,7 @@
extern int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len);
extern int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len);
extern void ptrace_disable(struct task_struct *);
-extern int ptrace_check_attach(struct task_struct *task, int kill);
+extern int ptrace_check_attach(struct task_struct *task, bool ignore_state);
extern int ptrace_request(struct task_struct *child, long request,
unsigned long addr, unsigned long data);
extern void ptrace_notify(int exit_code);
@@ -122,7 +136,7 @@
static inline int ptrace_reparented(struct task_struct *child)
{
- return child->real_parent != child->parent;
+ return !same_thread_group(child->real_parent, child->parent);
}
static inline void ptrace_unlink(struct task_struct *child)
@@ -137,36 +151,56 @@
unsigned long data);
/**
- * task_ptrace - return %PT_* flags that apply to a task
- * @task: pointer to &task_struct in question
+ * ptrace_parent - return the task that is tracing the given task
+ * @task: task to consider
*
- * Returns the %PT_* flags that apply to @task.
+ * Returns %NULL if no one is tracing @task, or the &struct task_struct
+ * pointer to its tracer.
+ *
+ * Must called under rcu_read_lock(). The pointer returned might be kept
+ * live only by RCU. During exec, this may be called with task_lock() held
+ * on @task, still held from when check_unsafe_exec() was called.
*/
-static inline int task_ptrace(struct task_struct *task)
+static inline struct task_struct *ptrace_parent(struct task_struct *task)
{
- return task->ptrace;
+ if (unlikely(task->ptrace))
+ return rcu_dereference(task->parent);
+ return NULL;
+}
+
+/**
+ * ptrace_event_enabled - test whether a ptrace event is enabled
+ * @task: ptracee of interest
+ * @event: %PTRACE_EVENT_* to test
+ *
+ * Test whether @event is enabled for ptracee @task.
+ *
+ * Returns %true if @event is enabled, %false otherwise.
+ */
+static inline bool ptrace_event_enabled(struct task_struct *task, int event)
+{
+ return task->ptrace & PT_EVENT_FLAG(event);
}
/**
* ptrace_event - possibly stop for a ptrace event notification
- * @mask: %PT_* bit to check in @current->ptrace
- * @event: %PTRACE_EVENT_* value to report if @mask is set
+ * @event: %PTRACE_EVENT_* value to report
* @message: value for %PTRACE_GETEVENTMSG to return
*
- * This checks the @mask bit to see if ptrace wants stops for this event.
- * If so we stop, reporting @event and @message to the ptrace parent.
- *
- * Returns nonzero if we did a ptrace notification, zero if not.
+ * Check whether @event is enabled and, if so, report @event and @message
+ * to the ptrace parent.
*
* Called without locks.
*/
-static inline int ptrace_event(int mask, int event, unsigned long message)
+static inline void ptrace_event(int event, unsigned long message)
{
- if (mask && likely(!(current->ptrace & mask)))
- return 0;
- current->ptrace_message = message;
- ptrace_notify((event << 8) | SIGTRAP);
- return 1;
+ if (unlikely(ptrace_event_enabled(current, event))) {
+ current->ptrace_message = message;
+ ptrace_notify((event << 8) | SIGTRAP);
+ } else if (event == PTRACE_EVENT_EXEC && unlikely(current->ptrace)) {
+ /* legacy EXEC report via SIGTRAP */
+ send_sig(SIGTRAP, current, 0);
+ }
}
/**
@@ -183,16 +217,24 @@
{
INIT_LIST_HEAD(&child->ptrace_entry);
INIT_LIST_HEAD(&child->ptraced);
- child->parent = child->real_parent;
- child->ptrace = 0;
- if (unlikely(ptrace) && (current->ptrace & PT_PTRACED)) {
- child->ptrace = current->ptrace;
- __ptrace_link(child, current->parent);
- }
-
#ifdef CONFIG_HAVE_HW_BREAKPOINT
atomic_set(&child->ptrace_bp_refcnt, 1);
#endif
+ child->jobctl = 0;
+ child->ptrace = 0;
+ child->parent = child->real_parent;
+
+ if (unlikely(ptrace) && current->ptrace) {
+ child->ptrace = current->ptrace;
+ __ptrace_link(child, current->parent);
+
+ if (child->ptrace & PT_SEIZED)
+ task_set_jobctl_pending(child, JOBCTL_TRAP_STOP);
+ else
+ sigaddset(&child->pending.signal, SIGSTOP);
+
+ set_tsk_thread_flag(child, TIF_SIGPENDING);
+ }
}
/**
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 14a6c7b..f6ef727 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1292,7 +1292,7 @@
int exit_state;
int exit_code, exit_signal;
int pdeath_signal; /* The signal sent when the parent dies */
- unsigned int group_stop; /* GROUP_STOP_*, siglock protected */
+ unsigned int jobctl; /* JOBCTL_*, siglock protected */
/* ??? */
unsigned int personality;
unsigned did_exec:1;
@@ -1813,15 +1813,34 @@
#define used_math() tsk_used_math(current)
/*
- * task->group_stop flags
+ * task->jobctl flags
*/
-#define GROUP_STOP_SIGMASK 0xffff /* signr of the last group stop */
-#define GROUP_STOP_PENDING (1 << 16) /* task should stop for group stop */
-#define GROUP_STOP_CONSUME (1 << 17) /* consume group stop count */
-#define GROUP_STOP_TRAPPING (1 << 18) /* switching from STOPPED to TRACED */
-#define GROUP_STOP_DEQUEUED (1 << 19) /* stop signal dequeued */
+#define JOBCTL_STOP_SIGMASK 0xffff /* signr of the last group stop */
-extern void task_clear_group_stop_pending(struct task_struct *task);
+#define JOBCTL_STOP_DEQUEUED_BIT 16 /* stop signal dequeued */
+#define JOBCTL_STOP_PENDING_BIT 17 /* task should stop for group stop */
+#define JOBCTL_STOP_CONSUME_BIT 18 /* consume group stop count */
+#define JOBCTL_TRAP_STOP_BIT 19 /* trap for STOP */
+#define JOBCTL_TRAP_NOTIFY_BIT 20 /* trap for NOTIFY */
+#define JOBCTL_TRAPPING_BIT 21 /* switching to TRACED */
+#define JOBCTL_LISTENING_BIT 22 /* ptracer is listening for events */
+
+#define JOBCTL_STOP_DEQUEUED (1 << JOBCTL_STOP_DEQUEUED_BIT)
+#define JOBCTL_STOP_PENDING (1 << JOBCTL_STOP_PENDING_BIT)
+#define JOBCTL_STOP_CONSUME (1 << JOBCTL_STOP_CONSUME_BIT)
+#define JOBCTL_TRAP_STOP (1 << JOBCTL_TRAP_STOP_BIT)
+#define JOBCTL_TRAP_NOTIFY (1 << JOBCTL_TRAP_NOTIFY_BIT)
+#define JOBCTL_TRAPPING (1 << JOBCTL_TRAPPING_BIT)
+#define JOBCTL_LISTENING (1 << JOBCTL_LISTENING_BIT)
+
+#define JOBCTL_TRAP_MASK (JOBCTL_TRAP_STOP | JOBCTL_TRAP_NOTIFY)
+#define JOBCTL_PENDING_MASK (JOBCTL_STOP_PENDING | JOBCTL_TRAP_MASK)
+
+extern bool task_set_jobctl_pending(struct task_struct *task,
+ unsigned int mask);
+extern void task_clear_jobctl_trapping(struct task_struct *task);
+extern void task_clear_jobctl_pending(struct task_struct *task,
+ unsigned int mask);
#ifdef CONFIG_PREEMPT_RCU
@@ -2136,7 +2155,7 @@
spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
return ret;
-}
+}
extern void block_all_signals(int (*notifier)(void *priv), void *priv,
sigset_t *mask);
@@ -2151,7 +2170,7 @@
extern int kill_pgrp(struct pid *pid, int sig, int priv);
extern int kill_pid(struct pid *pid, int sig, int priv);
extern int kill_proc_info(int, struct siginfo *, pid_t);
-extern int do_notify_parent(struct task_struct *, int);
+extern __must_check bool do_notify_parent(struct task_struct *, int);
extern void __wake_up_parent(struct task_struct *p, struct task_struct *parent);
extern void force_sig(int, struct task_struct *);
extern int send_sig(int, struct task_struct *, int);
@@ -2275,8 +2294,10 @@
return tsk->signal->nr_threads;
}
-/* de_thread depends on thread_group_leader not being a pid based check */
-#define thread_group_leader(p) (p == p->group_leader)
+static inline bool thread_group_leader(struct task_struct *p)
+{
+ return p->exit_signal >= 0;
+}
/* Do to the insanities of de_thread it is possible for a process
* to have the pid of the thread group leader without actually being
@@ -2309,11 +2330,6 @@
#define delay_group_leader(p) \
(thread_group_leader(p) && !thread_group_empty(p))
-static inline int task_detached(struct task_struct *p)
-{
- return p->exit_signal == -1;
-}
-
/*
* Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
* subscriptions and synchronises with wait4(). Also used in procfs. Also
diff --git a/include/linux/tracehook.h b/include/linux/tracehook.h
index e95f523..a71a292 100644
--- a/include/linux/tracehook.h
+++ b/include/linux/tracehook.h
@@ -51,27 +51,12 @@
#include <linux/security.h>
struct linux_binprm;
-/**
- * tracehook_expect_breakpoints - guess if task memory might be touched
- * @task: current task, making a new mapping
- *
- * Return nonzero if @task is expected to want breakpoint insertion in
- * its memory at some point. A zero return is no guarantee it won't
- * be done, but this is a hint that it's known to be likely.
- *
- * May be called with @task->mm->mmap_sem held for writing.
- */
-static inline int tracehook_expect_breakpoints(struct task_struct *task)
-{
- return (task_ptrace(task) & PT_PTRACED) != 0;
-}
-
/*
* ptrace report for syscall entry and exit looks identical.
*/
static inline void ptrace_report_syscall(struct pt_regs *regs)
{
- int ptrace = task_ptrace(current);
+ int ptrace = current->ptrace;
if (!(ptrace & PT_PTRACED))
return;
@@ -145,229 +130,6 @@
}
/**
- * tracehook_unsafe_exec - check for exec declared unsafe due to tracing
- * @task: current task doing exec
- *
- * Return %LSM_UNSAFE_* bits applied to an exec because of tracing.
- *
- * @task->signal->cred_guard_mutex is held by the caller through the do_execve().
- */
-static inline int tracehook_unsafe_exec(struct task_struct *task)
-{
- int unsafe = 0;
- int ptrace = task_ptrace(task);
- if (ptrace & PT_PTRACED) {
- if (ptrace & PT_PTRACE_CAP)
- unsafe |= LSM_UNSAFE_PTRACE_CAP;
- else
- unsafe |= LSM_UNSAFE_PTRACE;
- }
- return unsafe;
-}
-
-/**
- * tracehook_tracer_task - return the task that is tracing the given task
- * @tsk: task to consider
- *
- * Returns NULL if no one is tracing @task, or the &struct task_struct
- * pointer to its tracer.
- *
- * Must called under rcu_read_lock(). The pointer returned might be kept
- * live only by RCU. During exec, this may be called with task_lock()
- * held on @task, still held from when tracehook_unsafe_exec() was called.
- */
-static inline struct task_struct *tracehook_tracer_task(struct task_struct *tsk)
-{
- if (task_ptrace(tsk) & PT_PTRACED)
- return rcu_dereference(tsk->parent);
- return NULL;
-}
-
-/**
- * tracehook_report_exec - a successful exec was completed
- * @fmt: &struct linux_binfmt that performed the exec
- * @bprm: &struct linux_binprm containing exec details
- * @regs: user-mode register state
- *
- * An exec just completed, we are shortly going to return to user mode.
- * The freshly initialized register state can be seen and changed in @regs.
- * The name, file and other pointers in @bprm are still on hand to be
- * inspected, but will be freed as soon as this returns.
- *
- * Called with no locks, but with some kernel resources held live
- * and a reference on @fmt->module.
- */
-static inline void tracehook_report_exec(struct linux_binfmt *fmt,
- struct linux_binprm *bprm,
- struct pt_regs *regs)
-{
- if (!ptrace_event(PT_TRACE_EXEC, PTRACE_EVENT_EXEC, 0) &&
- unlikely(task_ptrace(current) & PT_PTRACED))
- send_sig(SIGTRAP, current, 0);
-}
-
-/**
- * tracehook_report_exit - task has begun to exit
- * @exit_code: pointer to value destined for @current->exit_code
- *
- * @exit_code points to the value passed to do_exit(), which tracing
- * might change here. This is almost the first thing in do_exit(),
- * before freeing any resources or setting the %PF_EXITING flag.
- *
- * Called with no locks held.
- */
-static inline void tracehook_report_exit(long *exit_code)
-{
- ptrace_event(PT_TRACE_EXIT, PTRACE_EVENT_EXIT, *exit_code);
-}
-
-/**
- * tracehook_prepare_clone - prepare for new child to be cloned
- * @clone_flags: %CLONE_* flags from clone/fork/vfork system call
- *
- * This is called before a new user task is to be cloned.
- * Its return value will be passed to tracehook_finish_clone().
- *
- * Called with no locks held.
- */
-static inline int tracehook_prepare_clone(unsigned clone_flags)
-{
- if (clone_flags & CLONE_UNTRACED)
- return 0;
-
- if (clone_flags & CLONE_VFORK) {
- if (current->ptrace & PT_TRACE_VFORK)
- return PTRACE_EVENT_VFORK;
- } else if ((clone_flags & CSIGNAL) != SIGCHLD) {
- if (current->ptrace & PT_TRACE_CLONE)
- return PTRACE_EVENT_CLONE;
- } else if (current->ptrace & PT_TRACE_FORK)
- return PTRACE_EVENT_FORK;
-
- return 0;
-}
-
-/**
- * tracehook_finish_clone - new child created and being attached
- * @child: new child task
- * @clone_flags: %CLONE_* flags from clone/fork/vfork system call
- * @trace: return value from tracehook_prepare_clone()
- *
- * This is called immediately after adding @child to its parent's children list.
- * The @trace value is that returned by tracehook_prepare_clone().
- *
- * Called with current's siglock and write_lock_irq(&tasklist_lock) held.
- */
-static inline void tracehook_finish_clone(struct task_struct *child,
- unsigned long clone_flags, int trace)
-{
- ptrace_init_task(child, (clone_flags & CLONE_PTRACE) || trace);
-}
-
-/**
- * tracehook_report_clone - in parent, new child is about to start running
- * @regs: parent's user register state
- * @clone_flags: flags from parent's system call
- * @pid: new child's PID in the parent's namespace
- * @child: new child task
- *
- * Called after a child is set up, but before it has been started running.
- * This is not a good place to block, because the child has not started
- * yet. Suspend the child here if desired, and then block in
- * tracehook_report_clone_complete(). This must prevent the child from
- * self-reaping if tracehook_report_clone_complete() uses the @child
- * pointer; otherwise it might have died and been released by the time
- * tracehook_report_clone_complete() is called.
- *
- * Called with no locks held, but the child cannot run until this returns.
- */
-static inline void tracehook_report_clone(struct pt_regs *regs,
- unsigned long clone_flags,
- pid_t pid, struct task_struct *child)
-{
- if (unlikely(task_ptrace(child))) {
- /*
- * It doesn't matter who attached/attaching to this
- * task, the pending SIGSTOP is right in any case.
- */
- sigaddset(&child->pending.signal, SIGSTOP);
- set_tsk_thread_flag(child, TIF_SIGPENDING);
- }
-}
-
-/**
- * tracehook_report_clone_complete - new child is running
- * @trace: return value from tracehook_prepare_clone()
- * @regs: parent's user register state
- * @clone_flags: flags from parent's system call
- * @pid: new child's PID in the parent's namespace
- * @child: child task, already running
- *
- * This is called just after the child has started running. This is
- * just before the clone/fork syscall returns, or blocks for vfork
- * child completion if @clone_flags has the %CLONE_VFORK bit set.
- * The @child pointer may be invalid if a self-reaping child died and
- * tracehook_report_clone() took no action to prevent it from self-reaping.
- *
- * Called with no locks held.
- */
-static inline void tracehook_report_clone_complete(int trace,
- struct pt_regs *regs,
- unsigned long clone_flags,
- pid_t pid,
- struct task_struct *child)
-{
- if (unlikely(trace))
- ptrace_event(0, trace, pid);
-}
-
-/**
- * tracehook_report_vfork_done - vfork parent's child has exited or exec'd
- * @child: child task, already running
- * @pid: new child's PID in the parent's namespace
- *
- * Called after a %CLONE_VFORK parent has waited for the child to complete.
- * The clone/vfork system call will return immediately after this.
- * The @child pointer may be invalid if a self-reaping child died and
- * tracehook_report_clone() took no action to prevent it from self-reaping.
- *
- * Called with no locks held.
- */
-static inline void tracehook_report_vfork_done(struct task_struct *child,
- pid_t pid)
-{
- ptrace_event(PT_TRACE_VFORK_DONE, PTRACE_EVENT_VFORK_DONE, pid);
-}
-
-/**
- * tracehook_prepare_release_task - task is being reaped, clean up tracing
- * @task: task in %EXIT_DEAD state
- *
- * This is called in release_task() just before @task gets finally reaped
- * and freed. This would be the ideal place to remove and clean up any
- * tracing-related state for @task.
- *
- * Called with no locks held.
- */
-static inline void tracehook_prepare_release_task(struct task_struct *task)
-{
-}
-
-/**
- * tracehook_finish_release_task - final tracing clean-up
- * @task: task in %EXIT_DEAD state
- *
- * This is called in release_task() when @task is being in the middle of
- * being reaped. After this, there must be no tracing entanglements.
- *
- * Called with write_lock_irq(&tasklist_lock) held.
- */
-static inline void tracehook_finish_release_task(struct task_struct *task)
-{
- ptrace_release_task(task);
-}
-
-/**
* tracehook_signal_handler - signal handler setup is complete
* @sig: number of signal being delivered
* @info: siginfo_t of signal being delivered
@@ -390,151 +152,6 @@
ptrace_notify(SIGTRAP);
}
-/**
- * tracehook_consider_ignored_signal - suppress short-circuit of ignored signal
- * @task: task receiving the signal
- * @sig: signal number being sent
- *
- * Return zero iff tracing doesn't care to examine this ignored signal,
- * so it can short-circuit normal delivery and never even get queued.
- *
- * Called with @task->sighand->siglock held.
- */
-static inline int tracehook_consider_ignored_signal(struct task_struct *task,
- int sig)
-{
- return (task_ptrace(task) & PT_PTRACED) != 0;
-}
-
-/**
- * tracehook_consider_fatal_signal - suppress special handling of fatal signal
- * @task: task receiving the signal
- * @sig: signal number being sent
- *
- * Return nonzero to prevent special handling of this termination signal.
- * Normally handler for signal is %SIG_DFL. It can be %SIG_IGN if @sig is
- * ignored, in which case force_sig() is about to reset it to %SIG_DFL.
- * When this returns zero, this signal might cause a quick termination
- * that does not give the debugger a chance to intercept the signal.
- *
- * Called with or without @task->sighand->siglock held.
- */
-static inline int tracehook_consider_fatal_signal(struct task_struct *task,
- int sig)
-{
- return (task_ptrace(task) & PT_PTRACED) != 0;
-}
-
-/**
- * tracehook_force_sigpending - let tracing force signal_pending(current) on
- *
- * Called when recomputing our signal_pending() flag. Return nonzero
- * to force the signal_pending() flag on, so that tracehook_get_signal()
- * will be called before the next return to user mode.
- *
- * Called with @current->sighand->siglock held.
- */
-static inline int tracehook_force_sigpending(void)
-{
- return 0;
-}
-
-/**
- * tracehook_get_signal - deliver synthetic signal to traced task
- * @task: @current
- * @regs: task_pt_regs(@current)
- * @info: details of synthetic signal
- * @return_ka: sigaction for synthetic signal
- *
- * Return zero to check for a real pending signal normally.
- * Return -1 after releasing the siglock to repeat the check.
- * Return a signal number to induce an artificial signal delivery,
- * setting *@info and *@return_ka to specify its details and behavior.
- *
- * The @return_ka->sa_handler value controls the disposition of the
- * signal, no matter the signal number. For %SIG_DFL, the return value
- * is a representative signal to indicate the behavior (e.g. %SIGTERM
- * for death, %SIGQUIT for core dump, %SIGSTOP for job control stop,
- * %SIGTSTP for stop unless in an orphaned pgrp), but the signal number
- * reported will be @info->si_signo instead.
- *
- * Called with @task->sighand->siglock held, before dequeuing pending signals.
- */
-static inline int tracehook_get_signal(struct task_struct *task,
- struct pt_regs *regs,
- siginfo_t *info,
- struct k_sigaction *return_ka)
-{
- return 0;
-}
-
-/**
- * tracehook_finish_jctl - report about return from job control stop
- *
- * This is called by do_signal_stop() after wakeup.
- */
-static inline void tracehook_finish_jctl(void)
-{
-}
-
-#define DEATH_REAP -1
-#define DEATH_DELAYED_GROUP_LEADER -2
-
-/**
- * tracehook_notify_death - task is dead, ready to notify parent
- * @task: @current task now exiting
- * @death_cookie: value to pass to tracehook_report_death()
- * @group_dead: nonzero if this was the last thread in the group to die
- *
- * A return value >= 0 means call do_notify_parent() with that signal
- * number. Negative return value can be %DEATH_REAP to self-reap right
- * now, or %DEATH_DELAYED_GROUP_LEADER to a zombie without notifying our
- * parent. Note that a return value of 0 means a do_notify_parent() call
- * that sends no signal, but still wakes up a parent blocked in wait*().
- *
- * Called with write_lock_irq(&tasklist_lock) held.
- */
-static inline int tracehook_notify_death(struct task_struct *task,
- void **death_cookie, int group_dead)
-{
- if (task_detached(task))
- return task->ptrace ? SIGCHLD : DEATH_REAP;
-
- /*
- * If something other than our normal parent is ptracing us, then
- * send it a SIGCHLD instead of honoring exit_signal. exit_signal
- * only has special meaning to our real parent.
- */
- if (thread_group_empty(task) && !ptrace_reparented(task))
- return task->exit_signal;
-
- return task->ptrace ? SIGCHLD : DEATH_DELAYED_GROUP_LEADER;
-}
-
-/**
- * tracehook_report_death - task is dead and ready to be reaped
- * @task: @current task now exiting
- * @signal: return value from tracheook_notify_death()
- * @death_cookie: value passed back from tracehook_notify_death()
- * @group_dead: nonzero if this was the last thread in the group to die
- *
- * Thread has just become a zombie or is about to self-reap. If positive,
- * @signal is the signal number just sent to the parent (usually %SIGCHLD).
- * If @signal is %DEATH_REAP, this thread will self-reap. If @signal is
- * %DEATH_DELAYED_GROUP_LEADER, this is a delayed_group_leader() zombie.
- * The @death_cookie was passed back by tracehook_notify_death().
- *
- * If normal reaping is not inhibited, @task->exit_state might be changing
- * in parallel.
- *
- * Called without locks.
- */
-static inline void tracehook_report_death(struct task_struct *task,
- int signal, void *death_cookie,
- int group_dead)
-{
-}
-
#ifdef TIF_NOTIFY_RESUME
/**
* set_notify_resume - cause tracehook_notify_resume() to be called
diff --git a/kernel/exit.c b/kernel/exit.c
index f2b321b..73bb192 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -169,7 +169,6 @@
struct task_struct *leader;
int zap_leader;
repeat:
- tracehook_prepare_release_task(p);
/* don't need to get the RCU readlock here - the process is dead and
* can't be modifying its own credentials. But shut RCU-lockdep up */
rcu_read_lock();
@@ -179,7 +178,7 @@
proc_flush_task(p);
write_lock_irq(&tasklist_lock);
- tracehook_finish_release_task(p);
+ ptrace_release_task(p);
__exit_signal(p);
/*
@@ -190,22 +189,12 @@
zap_leader = 0;
leader = p->group_leader;
if (leader != p && thread_group_empty(leader) && leader->exit_state == EXIT_ZOMBIE) {
- BUG_ON(task_detached(leader));
- do_notify_parent(leader, leader->exit_signal);
/*
* If we were the last child thread and the leader has
* exited already, and the leader's parent ignores SIGCHLD,
* then we are the one who should release the leader.
- *
- * do_notify_parent() will have marked it self-reaping in
- * that case.
*/
- zap_leader = task_detached(leader);
-
- /*
- * This maintains the invariant that release_task()
- * only runs on a task in EXIT_DEAD, just for sanity.
- */
+ zap_leader = do_notify_parent(leader, leader->exit_signal);
if (zap_leader)
leader->exit_state = EXIT_DEAD;
}
@@ -277,18 +266,16 @@
return retval;
}
-static int has_stopped_jobs(struct pid *pgrp)
+static bool has_stopped_jobs(struct pid *pgrp)
{
- int retval = 0;
struct task_struct *p;
do_each_pid_task(pgrp, PIDTYPE_PGID, p) {
- if (!task_is_stopped(p))
- continue;
- retval = 1;
- break;
+ if (p->signal->flags & SIGNAL_STOP_STOPPED)
+ return true;
} while_each_pid_task(pgrp, PIDTYPE_PGID, p);
- return retval;
+
+ return false;
}
/*
@@ -751,7 +738,7 @@
{
list_move_tail(&p->sibling, &p->real_parent->children);
- if (task_detached(p))
+ if (p->exit_state == EXIT_DEAD)
return;
/*
* If this is a threaded reparent there is no need to
@@ -764,10 +751,9 @@
p->exit_signal = SIGCHLD;
/* If it has exited notify the new parent about this child's death. */
- if (!task_ptrace(p) &&
+ if (!p->ptrace &&
p->exit_state == EXIT_ZOMBIE && thread_group_empty(p)) {
- do_notify_parent(p, p->exit_signal);
- if (task_detached(p)) {
+ if (do_notify_parent(p, p->exit_signal)) {
p->exit_state = EXIT_DEAD;
list_move_tail(&p->sibling, dead);
}
@@ -794,7 +780,7 @@
do {
t->real_parent = reaper;
if (t->parent == father) {
- BUG_ON(task_ptrace(t));
+ BUG_ON(t->ptrace);
t->parent = t->real_parent;
}
if (t->pdeath_signal)
@@ -819,8 +805,7 @@
*/
static void exit_notify(struct task_struct *tsk, int group_dead)
{
- int signal;
- void *cookie;
+ bool autoreap;
/*
* This does two things:
@@ -851,26 +836,33 @@
* we have changed execution domain as these two values started
* the same after a fork.
*/
- if (tsk->exit_signal != SIGCHLD && !task_detached(tsk) &&
+ if (thread_group_leader(tsk) && tsk->exit_signal != SIGCHLD &&
(tsk->parent_exec_id != tsk->real_parent->self_exec_id ||
tsk->self_exec_id != tsk->parent_exec_id))
tsk->exit_signal = SIGCHLD;
- signal = tracehook_notify_death(tsk, &cookie, group_dead);
- if (signal >= 0)
- signal = do_notify_parent(tsk, signal);
+ if (unlikely(tsk->ptrace)) {
+ int sig = thread_group_leader(tsk) &&
+ thread_group_empty(tsk) &&
+ !ptrace_reparented(tsk) ?
+ tsk->exit_signal : SIGCHLD;
+ autoreap = do_notify_parent(tsk, sig);
+ } else if (thread_group_leader(tsk)) {
+ autoreap = thread_group_empty(tsk) &&
+ do_notify_parent(tsk, tsk->exit_signal);
+ } else {
+ autoreap = true;
+ }
- tsk->exit_state = signal == DEATH_REAP ? EXIT_DEAD : EXIT_ZOMBIE;
+ tsk->exit_state = autoreap ? EXIT_DEAD : EXIT_ZOMBIE;
/* mt-exec, de_thread() is waiting for group leader */
if (unlikely(tsk->signal->notify_count < 0))
wake_up_process(tsk->signal->group_exit_task);
write_unlock_irq(&tasklist_lock);
- tracehook_report_death(tsk, signal, cookie, group_dead);
-
/* If the process is dead, release it - nobody will wait for it */
- if (signal == DEATH_REAP)
+ if (autoreap)
release_task(tsk);
}
@@ -923,7 +915,7 @@
*/
set_fs(USER_DS);
- tracehook_report_exit(&code);
+ ptrace_event(PTRACE_EVENT_EXIT, code);
validate_creds_for_do_exit(tsk);
@@ -1235,9 +1227,9 @@
traced = ptrace_reparented(p);
/*
* It can be ptraced but not reparented, check
- * !task_detached() to filter out sub-threads.
+ * thread_group_leader() to filter out sub-threads.
*/
- if (likely(!traced) && likely(!task_detached(p))) {
+ if (likely(!traced) && thread_group_leader(p)) {
struct signal_struct *psig;
struct signal_struct *sig;
unsigned long maxrss;
@@ -1345,16 +1337,13 @@
/* We dropped tasklist, ptracer could die and untrace */
ptrace_unlink(p);
/*
- * If this is not a detached task, notify the parent.
- * If it's still not detached after that, don't release
- * it now.
+ * If this is not a sub-thread, notify the parent.
+ * If parent wants a zombie, don't release it now.
*/
- if (!task_detached(p)) {
- do_notify_parent(p, p->exit_signal);
- if (!task_detached(p)) {
- p->exit_state = EXIT_ZOMBIE;
- p = NULL;
- }
+ if (thread_group_leader(p) &&
+ !do_notify_parent(p, p->exit_signal)) {
+ p->exit_state = EXIT_ZOMBIE;
+ p = NULL;
}
write_unlock_irq(&tasklist_lock);
}
@@ -1367,7 +1356,8 @@
static int *task_stopped_code(struct task_struct *p, bool ptrace)
{
if (ptrace) {
- if (task_is_stopped_or_traced(p))
+ if (task_is_stopped_or_traced(p) &&
+ !(p->jobctl & JOBCTL_LISTENING))
return &p->exit_code;
} else {
if (p->signal->flags & SIGNAL_STOP_STOPPED)
@@ -1563,7 +1553,7 @@
* Notification and reaping will be cascaded to the real
* parent when the ptracer detaches.
*/
- if (likely(!ptrace) && unlikely(task_ptrace(p))) {
+ if (likely(!ptrace) && unlikely(p->ptrace)) {
/* it will become visible, clear notask_error */
wo->notask_error = 0;
return 0;
@@ -1606,8 +1596,7 @@
* own children, it should create a separate process which
* takes the role of real parent.
*/
- if (likely(!ptrace) && task_ptrace(p) &&
- same_thread_group(p->parent, p->real_parent))
+ if (likely(!ptrace) && p->ptrace && !ptrace_reparented(p))
return 0;
/*
diff --git a/kernel/fork.c b/kernel/fork.c
index 0276c30..4d4117e 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -37,7 +37,6 @@
#include <linux/swap.h>
#include <linux/syscalls.h>
#include <linux/jiffies.h>
-#include <linux/tracehook.h>
#include <linux/futex.h>
#include <linux/compat.h>
#include <linux/kthread.h>
@@ -1340,7 +1339,7 @@
}
if (likely(p->pid)) {
- tracehook_finish_clone(p, clone_flags, trace);
+ ptrace_init_task(p, (clone_flags & CLONE_PTRACE) || trace);
if (thread_group_leader(p)) {
if (is_child_reaper(pid))
@@ -1481,10 +1480,22 @@
}
/*
- * When called from kernel_thread, don't do user tracing stuff.
+ * Determine whether and which event to report to ptracer. When
+ * called from kernel_thread or CLONE_UNTRACED is explicitly
+ * requested, no event is reported; otherwise, report if the event
+ * for the type of forking is enabled.
*/
- if (likely(user_mode(regs)))
- trace = tracehook_prepare_clone(clone_flags);
+ if (likely(user_mode(regs)) && !(clone_flags & CLONE_UNTRACED)) {
+ if (clone_flags & CLONE_VFORK)
+ trace = PTRACE_EVENT_VFORK;
+ else if ((clone_flags & CSIGNAL) != SIGCHLD)
+ trace = PTRACE_EVENT_CLONE;
+ else
+ trace = PTRACE_EVENT_FORK;
+
+ if (likely(!ptrace_event_enabled(current, trace)))
+ trace = 0;
+ }
p = copy_process(clone_flags, stack_start, regs, stack_size,
child_tidptr, NULL, trace);
@@ -1508,26 +1519,26 @@
}
audit_finish_fork(p);
- tracehook_report_clone(regs, clone_flags, nr, p);
/*
* We set PF_STARTING at creation in case tracing wants to
* use this to distinguish a fully live task from one that
- * hasn't gotten to tracehook_report_clone() yet. Now we
- * clear it and set the child going.
+ * hasn't finished SIGSTOP raising yet. Now we clear it
+ * and set the child going.
*/
p->flags &= ~PF_STARTING;
wake_up_new_task(p);
- tracehook_report_clone_complete(trace, regs,
- clone_flags, nr, p);
+ /* forking complete and child started to run, tell ptracer */
+ if (unlikely(trace))
+ ptrace_event(trace, nr);
if (clone_flags & CLONE_VFORK) {
freezer_do_not_count();
wait_for_completion(&vfork);
freezer_count();
- tracehook_report_vfork_done(p, nr);
+ ptrace_event(PTRACE_EVENT_VFORK_DONE, nr);
}
} else {
nr = PTR_ERR(p);
diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 2df1157..9de3ecf 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -23,8 +23,15 @@
#include <linux/uaccess.h>
#include <linux/regset.h>
#include <linux/hw_breakpoint.h>
+#include <linux/cn_proc.h>
+static int ptrace_trapping_sleep_fn(void *flags)
+{
+ schedule();
+ return 0;
+}
+
/*
* ptrace a task: make the debugger its new parent and
* move it to the ptrace list.
@@ -77,13 +84,20 @@
spin_lock(&child->sighand->siglock);
/*
- * Reinstate GROUP_STOP_PENDING if group stop is in effect and
+ * Clear all pending traps and TRAPPING. TRAPPING should be
+ * cleared regardless of JOBCTL_STOP_PENDING. Do it explicitly.
+ */
+ task_clear_jobctl_pending(child, JOBCTL_TRAP_MASK);
+ task_clear_jobctl_trapping(child);
+
+ /*
+ * Reinstate JOBCTL_STOP_PENDING if group stop is in effect and
* @child isn't dead.
*/
if (!(child->flags & PF_EXITING) &&
(child->signal->flags & SIGNAL_STOP_STOPPED ||
child->signal->group_stop_count))
- child->group_stop |= GROUP_STOP_PENDING;
+ child->jobctl |= JOBCTL_STOP_PENDING;
/*
* If transition to TASK_STOPPED is pending or in TASK_TRACED, kick
@@ -91,16 +105,30 @@
* is in TASK_TRACED; otherwise, we might unduly disrupt
* TASK_KILLABLE sleeps.
*/
- if (child->group_stop & GROUP_STOP_PENDING || task_is_traced(child))
+ if (child->jobctl & JOBCTL_STOP_PENDING || task_is_traced(child))
signal_wake_up(child, task_is_traced(child));
spin_unlock(&child->sighand->siglock);
}
-/*
- * Check that we have indeed attached to the thing..
+/**
+ * ptrace_check_attach - check whether ptracee is ready for ptrace operation
+ * @child: ptracee to check for
+ * @ignore_state: don't check whether @child is currently %TASK_TRACED
+ *
+ * Check whether @child is being ptraced by %current and ready for further
+ * ptrace operations. If @ignore_state is %false, @child also should be in
+ * %TASK_TRACED state and on return the child is guaranteed to be traced
+ * and not executing. If @ignore_state is %true, @child can be in any
+ * state.
+ *
+ * CONTEXT:
+ * Grabs and releases tasklist_lock and @child->sighand->siglock.
+ *
+ * RETURNS:
+ * 0 on success, -ESRCH if %child is not ready.
*/
-int ptrace_check_attach(struct task_struct *child, int kill)
+int ptrace_check_attach(struct task_struct *child, bool ignore_state)
{
int ret = -ESRCH;
@@ -119,13 +147,14 @@
*/
spin_lock_irq(&child->sighand->siglock);
WARN_ON_ONCE(task_is_stopped(child));
- if (task_is_traced(child) || kill)
+ if (ignore_state || (task_is_traced(child) &&
+ !(child->jobctl & JOBCTL_LISTENING)))
ret = 0;
spin_unlock_irq(&child->sighand->siglock);
}
read_unlock(&tasklist_lock);
- if (!ret && !kill)
+ if (!ret && !ignore_state)
ret = wait_task_inactive(child, TASK_TRACED) ? 0 : -ESRCH;
/* All systems go.. */
@@ -182,11 +211,28 @@
return !err;
}
-static int ptrace_attach(struct task_struct *task)
+static int ptrace_attach(struct task_struct *task, long request,
+ unsigned long flags)
{
- bool wait_trap = false;
+ bool seize = (request == PTRACE_SEIZE);
int retval;
+ /*
+ * SEIZE will enable new ptrace behaviors which will be implemented
+ * gradually. SEIZE_DEVEL is used to prevent applications
+ * expecting full SEIZE behaviors trapping on kernel commits which
+ * are still in the process of implementing them.
+ *
+ * Only test programs for new ptrace behaviors being implemented
+ * should set SEIZE_DEVEL. If unset, SEIZE will fail with -EIO.
+ *
+ * Once SEIZE behaviors are completely implemented, this flag and
+ * the following test will be removed.
+ */
+ retval = -EIO;
+ if (seize && !(flags & PTRACE_SEIZE_DEVEL))
+ goto out;
+
audit_ptrace(task);
retval = -EPERM;
@@ -218,16 +264,21 @@
goto unlock_tasklist;
task->ptrace = PT_PTRACED;
+ if (seize)
+ task->ptrace |= PT_SEIZED;
if (task_ns_capable(task, CAP_SYS_PTRACE))
task->ptrace |= PT_PTRACE_CAP;
__ptrace_link(task, current);
- send_sig_info(SIGSTOP, SEND_SIG_FORCED, task);
+
+ /* SEIZE doesn't trap tracee on attach */
+ if (!seize)
+ send_sig_info(SIGSTOP, SEND_SIG_FORCED, task);
spin_lock(&task->sighand->siglock);
/*
- * If the task is already STOPPED, set GROUP_STOP_PENDING and
+ * If the task is already STOPPED, set JOBCTL_TRAP_STOP and
* TRAPPING, and kick it so that it transits to TRACED. TRAPPING
* will be cleared if the child completes the transition or any
* event which clears the group stop states happens. We'll wait
@@ -243,11 +294,9 @@
* The following task_is_stopped() test is safe as both transitions
* in and out of STOPPED are protected by siglock.
*/
- if (task_is_stopped(task)) {
- task->group_stop |= GROUP_STOP_PENDING | GROUP_STOP_TRAPPING;
+ if (task_is_stopped(task) &&
+ task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING))
signal_wake_up(task, 1);
- wait_trap = true;
- }
spin_unlock(&task->sighand->siglock);
@@ -257,9 +306,12 @@
unlock_creds:
mutex_unlock(&task->signal->cred_guard_mutex);
out:
- if (wait_trap)
- wait_event(current->signal->wait_chldexit,
- !(task->group_stop & GROUP_STOP_TRAPPING));
+ if (!retval) {
+ wait_on_bit(&task->jobctl, JOBCTL_TRAPPING_BIT,
+ ptrace_trapping_sleep_fn, TASK_UNINTERRUPTIBLE);
+ proc_ptrace_connector(task, PTRACE_ATTACH);
+ }
+
return retval;
}
@@ -322,25 +374,27 @@
*/
static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p)
{
+ bool dead;
+
__ptrace_unlink(p);
- if (p->exit_state == EXIT_ZOMBIE) {
- if (!task_detached(p) && thread_group_empty(p)) {
- if (!same_thread_group(p->real_parent, tracer))
- do_notify_parent(p, p->exit_signal);
- else if (ignoring_children(tracer->sighand)) {
- __wake_up_parent(p, tracer);
- p->exit_signal = -1;
- }
- }
- if (task_detached(p)) {
- /* Mark it as in the process of being reaped. */
- p->exit_state = EXIT_DEAD;
- return true;
+ if (p->exit_state != EXIT_ZOMBIE)
+ return false;
+
+ dead = !thread_group_leader(p);
+
+ if (!dead && thread_group_empty(p)) {
+ if (!same_thread_group(p->real_parent, tracer))
+ dead = do_notify_parent(p, p->exit_signal);
+ else if (ignoring_children(tracer->sighand)) {
+ __wake_up_parent(p, tracer);
+ dead = true;
}
}
-
- return false;
+ /* Mark it as in the process of being reaped. */
+ if (dead)
+ p->exit_state = EXIT_DEAD;
+ return dead;
}
static int ptrace_detach(struct task_struct *child, unsigned int data)
@@ -365,6 +419,7 @@
}
write_unlock_irq(&tasklist_lock);
+ proc_ptrace_connector(child, PTRACE_DETACH);
if (unlikely(dead))
release_task(child);
@@ -611,10 +666,12 @@
int ptrace_request(struct task_struct *child, long request,
unsigned long addr, unsigned long data)
{
+ bool seized = child->ptrace & PT_SEIZED;
int ret = -EIO;
- siginfo_t siginfo;
+ siginfo_t siginfo, *si;
void __user *datavp = (void __user *) data;
unsigned long __user *datalp = datavp;
+ unsigned long flags;
switch (request) {
case PTRACE_PEEKTEXT:
@@ -647,6 +704,62 @@
ret = ptrace_setsiginfo(child, &siginfo);
break;
+ case PTRACE_INTERRUPT:
+ /*
+ * Stop tracee without any side-effect on signal or job
+ * control. At least one trap is guaranteed to happen
+ * after this request. If @child is already trapped, the
+ * current trap is not disturbed and another trap will
+ * happen after the current trap is ended with PTRACE_CONT.
+ *
+ * The actual trap might not be PTRACE_EVENT_STOP trap but
+ * the pending condition is cleared regardless.
+ */
+ if (unlikely(!seized || !lock_task_sighand(child, &flags)))
+ break;
+
+ /*
+ * INTERRUPT doesn't disturb existing trap sans one
+ * exception. If ptracer issued LISTEN for the current
+ * STOP, this INTERRUPT should clear LISTEN and re-trap
+ * tracee into STOP.
+ */
+ if (likely(task_set_jobctl_pending(child, JOBCTL_TRAP_STOP)))
+ signal_wake_up(child, child->jobctl & JOBCTL_LISTENING);
+
+ unlock_task_sighand(child, &flags);
+ ret = 0;
+ break;
+
+ case PTRACE_LISTEN:
+ /*
+ * Listen for events. Tracee must be in STOP. It's not
+ * resumed per-se but is not considered to be in TRACED by
+ * wait(2) or ptrace(2). If an async event (e.g. group
+ * stop state change) happens, tracee will enter STOP trap
+ * again. Alternatively, ptracer can issue INTERRUPT to
+ * finish listening and re-trap tracee into STOP.
+ */
+ if (unlikely(!seized || !lock_task_sighand(child, &flags)))
+ break;
+
+ si = child->last_siginfo;
+ if (unlikely(!si || si->si_code >> 8 != PTRACE_EVENT_STOP))
+ break;
+
+ child->jobctl |= JOBCTL_LISTENING;
+
+ /*
+ * If NOTIFY is set, it means event happened between start
+ * of this trap and now. Trigger re-trap immediately.
+ */
+ if (child->jobctl & JOBCTL_TRAP_NOTIFY)
+ signal_wake_up(child, true);
+
+ unlock_task_sighand(child, &flags);
+ ret = 0;
+ break;
+
case PTRACE_DETACH: /* detach a process that was attached. */
ret = ptrace_detach(child, data);
break;
@@ -761,8 +874,8 @@
goto out;
}
- if (request == PTRACE_ATTACH) {
- ret = ptrace_attach(child);
+ if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) {
+ ret = ptrace_attach(child, request, data);
/*
* Some architectures need to do book-keeping after
* a ptrace attach.
@@ -772,7 +885,8 @@
goto out_put_task_struct;
}
- ret = ptrace_check_attach(child, request == PTRACE_KILL);
+ ret = ptrace_check_attach(child, request == PTRACE_KILL ||
+ request == PTRACE_INTERRUPT);
if (ret < 0)
goto out_put_task_struct;
@@ -903,8 +1017,8 @@
goto out;
}
- if (request == PTRACE_ATTACH) {
- ret = ptrace_attach(child);
+ if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) {
+ ret = ptrace_attach(child, request, data);
/*
* Some architectures need to do book-keeping after
* a ptrace attach.
@@ -914,7 +1028,8 @@
goto out_put_task_struct;
}
- ret = ptrace_check_attach(child, request == PTRACE_KILL);
+ ret = ptrace_check_attach(child, request == PTRACE_KILL ||
+ request == PTRACE_INTERRUPT);
if (!ret)
ret = compat_arch_ptrace(child, request, addr, data);
diff --git a/kernel/signal.c b/kernel/signal.c
index 415d85d..d7f70ae 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -87,7 +87,7 @@
/*
* Tracers may want to know about even ignored signals.
*/
- return !tracehook_consider_ignored_signal(t, sig);
+ return !t->ptrace;
}
/*
@@ -124,7 +124,7 @@
static int recalc_sigpending_tsk(struct task_struct *t)
{
- if ((t->group_stop & GROUP_STOP_PENDING) ||
+ if ((t->jobctl & JOBCTL_PENDING_MASK) ||
PENDING(&t->pending, &t->blocked) ||
PENDING(&t->signal->shared_pending, &t->blocked)) {
set_tsk_thread_flag(t, TIF_SIGPENDING);
@@ -150,9 +150,7 @@
void recalc_sigpending(void)
{
- if (unlikely(tracehook_force_sigpending()))
- set_thread_flag(TIF_SIGPENDING);
- else if (!recalc_sigpending_tsk(current) && !freezing(current))
+ if (!recalc_sigpending_tsk(current) && !freezing(current))
clear_thread_flag(TIF_SIGPENDING);
}
@@ -224,47 +222,93 @@
}
/**
- * task_clear_group_stop_trapping - clear group stop trapping bit
+ * task_set_jobctl_pending - set jobctl pending bits
+ * @task: target task
+ * @mask: pending bits to set
+ *
+ * Clear @mask from @task->jobctl. @mask must be subset of
+ * %JOBCTL_PENDING_MASK | %JOBCTL_STOP_CONSUME | %JOBCTL_STOP_SIGMASK |
+ * %JOBCTL_TRAPPING. If stop signo is being set, the existing signo is
+ * cleared. If @task is already being killed or exiting, this function
+ * becomes noop.
+ *
+ * CONTEXT:
+ * Must be called with @task->sighand->siglock held.
+ *
+ * RETURNS:
+ * %true if @mask is set, %false if made noop because @task was dying.
+ */
+bool task_set_jobctl_pending(struct task_struct *task, unsigned int mask)
+{
+ BUG_ON(mask & ~(JOBCTL_PENDING_MASK | JOBCTL_STOP_CONSUME |
+ JOBCTL_STOP_SIGMASK | JOBCTL_TRAPPING));
+ BUG_ON((mask & JOBCTL_TRAPPING) && !(mask & JOBCTL_PENDING_MASK));
+
+ if (unlikely(fatal_signal_pending(task) || (task->flags & PF_EXITING)))
+ return false;
+
+ if (mask & JOBCTL_STOP_SIGMASK)
+ task->jobctl &= ~JOBCTL_STOP_SIGMASK;
+
+ task->jobctl |= mask;
+ return true;
+}
+
+/**
+ * task_clear_jobctl_trapping - clear jobctl trapping bit
* @task: target task
*
- * If GROUP_STOP_TRAPPING is set, a ptracer is waiting for us. Clear it
- * and wake up the ptracer. Note that we don't need any further locking.
- * @task->siglock guarantees that @task->parent points to the ptracer.
+ * If JOBCTL_TRAPPING is set, a ptracer is waiting for us to enter TRACED.
+ * Clear it and wake up the ptracer. Note that we don't need any further
+ * locking. @task->siglock guarantees that @task->parent points to the
+ * ptracer.
*
* CONTEXT:
* Must be called with @task->sighand->siglock held.
*/
-static void task_clear_group_stop_trapping(struct task_struct *task)
+void task_clear_jobctl_trapping(struct task_struct *task)
{
- if (unlikely(task->group_stop & GROUP_STOP_TRAPPING)) {
- task->group_stop &= ~GROUP_STOP_TRAPPING;
- __wake_up_sync_key(&task->parent->signal->wait_chldexit,
- TASK_UNINTERRUPTIBLE, 1, task);
+ if (unlikely(task->jobctl & JOBCTL_TRAPPING)) {
+ task->jobctl &= ~JOBCTL_TRAPPING;
+ wake_up_bit(&task->jobctl, JOBCTL_TRAPPING_BIT);
}
}
/**
- * task_clear_group_stop_pending - clear pending group stop
+ * task_clear_jobctl_pending - clear jobctl pending bits
* @task: target task
+ * @mask: pending bits to clear
*
- * Clear group stop states for @task.
+ * Clear @mask from @task->jobctl. @mask must be subset of
+ * %JOBCTL_PENDING_MASK. If %JOBCTL_STOP_PENDING is being cleared, other
+ * STOP bits are cleared together.
+ *
+ * If clearing of @mask leaves no stop or trap pending, this function calls
+ * task_clear_jobctl_trapping().
*
* CONTEXT:
* Must be called with @task->sighand->siglock held.
*/
-void task_clear_group_stop_pending(struct task_struct *task)
+void task_clear_jobctl_pending(struct task_struct *task, unsigned int mask)
{
- task->group_stop &= ~(GROUP_STOP_PENDING | GROUP_STOP_CONSUME |
- GROUP_STOP_DEQUEUED);
+ BUG_ON(mask & ~JOBCTL_PENDING_MASK);
+
+ if (mask & JOBCTL_STOP_PENDING)
+ mask |= JOBCTL_STOP_CONSUME | JOBCTL_STOP_DEQUEUED;
+
+ task->jobctl &= ~mask;
+
+ if (!(task->jobctl & JOBCTL_PENDING_MASK))
+ task_clear_jobctl_trapping(task);
}
/**
* task_participate_group_stop - participate in a group stop
* @task: task participating in a group stop
*
- * @task has GROUP_STOP_PENDING set and is participating in a group stop.
+ * @task has %JOBCTL_STOP_PENDING set and is participating in a group stop.
* Group stop states are cleared and the group stop count is consumed if
- * %GROUP_STOP_CONSUME was set. If the consumption completes the group
+ * %JOBCTL_STOP_CONSUME was set. If the consumption completes the group
* stop, the appropriate %SIGNAL_* flags are set.
*
* CONTEXT:
@@ -277,11 +321,11 @@
static bool task_participate_group_stop(struct task_struct *task)
{
struct signal_struct *sig = task->signal;
- bool consume = task->group_stop & GROUP_STOP_CONSUME;
+ bool consume = task->jobctl & JOBCTL_STOP_CONSUME;
- WARN_ON_ONCE(!(task->group_stop & GROUP_STOP_PENDING));
+ WARN_ON_ONCE(!(task->jobctl & JOBCTL_STOP_PENDING));
- task_clear_group_stop_pending(task);
+ task_clear_jobctl_pending(task, JOBCTL_STOP_PENDING);
if (!consume)
return false;
@@ -449,7 +493,8 @@
return 1;
if (handler != SIG_IGN && handler != SIG_DFL)
return 0;
- return !tracehook_consider_fatal_signal(tsk, sig);
+ /* if ptraced, let the tracer determine */
+ return !tsk->ptrace;
}
/*
@@ -604,7 +649,7 @@
* is to alert stop-signal processing code when another
* processor has come along and cleared the flag.
*/
- current->group_stop |= GROUP_STOP_DEQUEUED;
+ current->jobctl |= JOBCTL_STOP_DEQUEUED;
}
if ((info->si_code & __SI_MASK) == __SI_TIMER && info->si_sys_private) {
/*
@@ -773,6 +818,32 @@
return security_task_kill(t, info, sig, 0);
}
+/**
+ * ptrace_trap_notify - schedule trap to notify ptracer
+ * @t: tracee wanting to notify tracer
+ *
+ * This function schedules sticky ptrace trap which is cleared on the next
+ * TRAP_STOP to notify ptracer of an event. @t must have been seized by
+ * ptracer.
+ *
+ * If @t is running, STOP trap will be taken. If trapped for STOP and
+ * ptracer is listening for events, tracee is woken up so that it can
+ * re-trap for the new event. If trapped otherwise, STOP trap will be
+ * eventually taken without returning to userland after the existing traps
+ * are finished by PTRACE_CONT.
+ *
+ * CONTEXT:
+ * Must be called with @task->sighand->siglock held.
+ */
+static void ptrace_trap_notify(struct task_struct *t)
+{
+ WARN_ON_ONCE(!(t->ptrace & PT_SEIZED));
+ assert_spin_locked(&t->sighand->siglock);
+
+ task_set_jobctl_pending(t, JOBCTL_TRAP_NOTIFY);
+ signal_wake_up(t, t->jobctl & JOBCTL_LISTENING);
+}
+
/*
* Handle magic process-wide effects of stop/continue signals. Unlike
* the signal actions, these happen immediately at signal-generation
@@ -809,9 +880,12 @@
rm_from_queue(SIG_KERNEL_STOP_MASK, &signal->shared_pending);
t = p;
do {
- task_clear_group_stop_pending(t);
+ task_clear_jobctl_pending(t, JOBCTL_STOP_PENDING);
rm_from_queue(SIG_KERNEL_STOP_MASK, &t->pending);
- wake_up_state(t, __TASK_STOPPED);
+ if (likely(!(t->ptrace & PT_SEIZED)))
+ wake_up_state(t, __TASK_STOPPED);
+ else
+ ptrace_trap_notify(t);
} while_each_thread(p, t);
/*
@@ -908,8 +982,7 @@
if (sig_fatal(p, sig) &&
!(signal->flags & (SIGNAL_UNKILLABLE | SIGNAL_GROUP_EXIT)) &&
!sigismember(&t->real_blocked, sig) &&
- (sig == SIGKILL ||
- !tracehook_consider_fatal_signal(t, sig))) {
+ (sig == SIGKILL || !t->ptrace)) {
/*
* This signal will be fatal to the whole group.
*/
@@ -925,7 +998,7 @@
signal->group_stop_count = 0;
t = p;
do {
- task_clear_group_stop_pending(t);
+ task_clear_jobctl_pending(t, JOBCTL_PENDING_MASK);
sigaddset(&t->pending.signal, SIGKILL);
signal_wake_up(t, 1);
} while_each_thread(p, t);
@@ -1160,7 +1233,7 @@
p->signal->group_stop_count = 0;
while_each_thread(p, t) {
- task_clear_group_stop_pending(t);
+ task_clear_jobctl_pending(t, JOBCTL_PENDING_MASK);
count++;
/* Don't bother with already dead threads */
@@ -1511,22 +1584,22 @@
* Let a parent know about the death of a child.
* For a stopped/continued status change, use do_notify_parent_cldstop instead.
*
- * Returns -1 if our parent ignored us and so we've switched to
- * self-reaping, or else @sig.
+ * Returns true if our parent ignored us and so we've switched to
+ * self-reaping.
*/
-int do_notify_parent(struct task_struct *tsk, int sig)
+bool do_notify_parent(struct task_struct *tsk, int sig)
{
struct siginfo info;
unsigned long flags;
struct sighand_struct *psig;
- int ret = sig;
+ bool autoreap = false;
BUG_ON(sig == -1);
/* do_notify_parent_cldstop should have been called instead. */
BUG_ON(task_is_stopped_or_traced(tsk));
- BUG_ON(!task_ptrace(tsk) &&
+ BUG_ON(!tsk->ptrace &&
(tsk->group_leader != tsk || !thread_group_empty(tsk)));
info.si_signo = sig;
@@ -1565,7 +1638,7 @@
psig = tsk->parent->sighand;
spin_lock_irqsave(&psig->siglock, flags);
- if (!task_ptrace(tsk) && sig == SIGCHLD &&
+ if (!tsk->ptrace && sig == SIGCHLD &&
(psig->action[SIGCHLD-1].sa.sa_handler == SIG_IGN ||
(psig->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT))) {
/*
@@ -1583,16 +1656,16 @@
* is implementation-defined: we do (if you don't want
* it, just use SIG_IGN instead).
*/
- ret = tsk->exit_signal = -1;
+ autoreap = true;
if (psig->action[SIGCHLD-1].sa.sa_handler == SIG_IGN)
- sig = -1;
+ sig = 0;
}
- if (valid_signal(sig) && sig > 0)
+ if (valid_signal(sig) && sig)
__group_send_sig_info(sig, &info, tsk->parent);
__wake_up_parent(tsk, tsk->parent);
spin_unlock_irqrestore(&psig->siglock, flags);
- return ret;
+ return autoreap;
}
/**
@@ -1665,7 +1738,7 @@
static inline int may_ptrace_stop(void)
{
- if (!likely(task_ptrace(current)))
+ if (!likely(current->ptrace))
return 0;
/*
* Are we in the middle of do_coredump?
@@ -1694,15 +1767,6 @@
}
/*
- * Test whether the target task of the usual cldstop notification - the
- * real_parent of @child - is in the same group as the ptracer.
- */
-static bool real_parent_is_ptracer(struct task_struct *child)
-{
- return same_thread_group(child->parent, child->real_parent);
-}
-
-/*
* This must be called with current->sighand->siglock held.
*
* This should be the path for all ptrace stops.
@@ -1739,31 +1803,34 @@
}
/*
- * If @why is CLD_STOPPED, we're trapping to participate in a group
- * stop. Do the bookkeeping. Note that if SIGCONT was delievered
- * while siglock was released for the arch hook, PENDING could be
- * clear now. We act as if SIGCONT is received after TASK_TRACED
- * is entered - ignore it.
+ * We're committing to trapping. TRACED should be visible before
+ * TRAPPING is cleared; otherwise, the tracer might fail do_wait().
+ * Also, transition to TRACED and updates to ->jobctl should be
+ * atomic with respect to siglock and should be done after the arch
+ * hook as siglock is released and regrabbed across it.
*/
- if (why == CLD_STOPPED && (current->group_stop & GROUP_STOP_PENDING))
- gstop_done = task_participate_group_stop(current);
+ set_current_state(TASK_TRACED);
current->last_siginfo = info;
current->exit_code = exit_code;
/*
- * TRACED should be visible before TRAPPING is cleared; otherwise,
- * the tracer might fail do_wait().
+ * If @why is CLD_STOPPED, we're trapping to participate in a group
+ * stop. Do the bookkeeping. Note that if SIGCONT was delievered
+ * across siglock relocks since INTERRUPT was scheduled, PENDING
+ * could be clear now. We act as if SIGCONT is received after
+ * TASK_TRACED is entered - ignore it.
*/
- set_current_state(TASK_TRACED);
+ if (why == CLD_STOPPED && (current->jobctl & JOBCTL_STOP_PENDING))
+ gstop_done = task_participate_group_stop(current);
- /*
- * We're committing to trapping. Clearing GROUP_STOP_TRAPPING and
- * transition to TASK_TRACED should be atomic with respect to
- * siglock. This hsould be done after the arch hook as siglock is
- * released and regrabbed across it.
- */
- task_clear_group_stop_trapping(current);
+ /* any trap clears pending STOP trap, STOP trap clears NOTIFY */
+ task_clear_jobctl_pending(current, JOBCTL_TRAP_STOP);
+ if (info && info->si_code >> 8 == PTRACE_EVENT_STOP)
+ task_clear_jobctl_pending(current, JOBCTL_TRAP_NOTIFY);
+
+ /* entering a trap, clear TRAPPING */
+ task_clear_jobctl_trapping(current);
spin_unlock_irq(¤t->sighand->siglock);
read_lock(&tasklist_lock);
@@ -1779,7 +1846,7 @@
* separately unless they're gonna be duplicates.
*/
do_notify_parent_cldstop(current, true, why);
- if (gstop_done && !real_parent_is_ptracer(current))
+ if (gstop_done && ptrace_reparented(current))
do_notify_parent_cldstop(current, false, why);
/*
@@ -1799,9 +1866,9 @@
*
* If @gstop_done, the ptracer went away between group stop
* completion and here. During detach, it would have set
- * GROUP_STOP_PENDING on us and we'll re-enter TASK_STOPPED
- * in do_signal_stop() on return, so notifying the real
- * parent of the group stop completion is enough.
+ * JOBCTL_STOP_PENDING on us and we'll re-enter
+ * TASK_STOPPED in do_signal_stop() on return, so notifying
+ * the real parent of the group stop completion is enough.
*/
if (gstop_done)
do_notify_parent_cldstop(current, false, why);
@@ -1827,6 +1894,9 @@
spin_lock_irq(¤t->sighand->siglock);
current->last_siginfo = NULL;
+ /* LISTENING can be set only during STOP traps, clear it */
+ current->jobctl &= ~JOBCTL_LISTENING;
+
/*
* Queued signals ignored us while we were stopped for tracing.
* So check for any that we should take before resuming user mode.
@@ -1835,44 +1905,66 @@
recalc_sigpending_tsk(current);
}
-void ptrace_notify(int exit_code)
+static void ptrace_do_notify(int signr, int exit_code, int why)
{
siginfo_t info;
- BUG_ON((exit_code & (0x7f | ~0xffff)) != SIGTRAP);
-
memset(&info, 0, sizeof info);
- info.si_signo = SIGTRAP;
+ info.si_signo = signr;
info.si_code = exit_code;
info.si_pid = task_pid_vnr(current);
info.si_uid = current_uid();
/* Let the debugger run. */
+ ptrace_stop(exit_code, why, 1, &info);
+}
+
+void ptrace_notify(int exit_code)
+{
+ BUG_ON((exit_code & (0x7f | ~0xffff)) != SIGTRAP);
+
spin_lock_irq(¤t->sighand->siglock);
- ptrace_stop(exit_code, CLD_TRAPPED, 1, &info);
+ ptrace_do_notify(SIGTRAP, exit_code, CLD_TRAPPED);
spin_unlock_irq(¤t->sighand->siglock);
}
-/*
- * This performs the stopping for SIGSTOP and other stop signals.
- * We have to stop all threads in the thread group.
- * Returns non-zero if we've actually stopped and released the siglock.
- * Returns zero if we didn't stop and still hold the siglock.
+/**
+ * do_signal_stop - handle group stop for SIGSTOP and other stop signals
+ * @signr: signr causing group stop if initiating
+ *
+ * If %JOBCTL_STOP_PENDING is not set yet, initiate group stop with @signr
+ * and participate in it. If already set, participate in the existing
+ * group stop. If participated in a group stop (and thus slept), %true is
+ * returned with siglock released.
+ *
+ * If ptraced, this function doesn't handle stop itself. Instead,
+ * %JOBCTL_TRAP_STOP is scheduled and %false is returned with siglock
+ * untouched. The caller must ensure that INTERRUPT trap handling takes
+ * places afterwards.
+ *
+ * CONTEXT:
+ * Must be called with @current->sighand->siglock held, which is released
+ * on %true return.
+ *
+ * RETURNS:
+ * %false if group stop is already cancelled or ptrace trap is scheduled.
+ * %true if participated in group stop.
*/
-static int do_signal_stop(int signr)
+static bool do_signal_stop(int signr)
+ __releases(¤t->sighand->siglock)
{
struct signal_struct *sig = current->signal;
- if (!(current->group_stop & GROUP_STOP_PENDING)) {
- unsigned int gstop = GROUP_STOP_PENDING | GROUP_STOP_CONSUME;
+ if (!(current->jobctl & JOBCTL_STOP_PENDING)) {
+ unsigned int gstop = JOBCTL_STOP_PENDING | JOBCTL_STOP_CONSUME;
struct task_struct *t;
- /* signr will be recorded in task->group_stop for retries */
- WARN_ON_ONCE(signr & ~GROUP_STOP_SIGMASK);
+ /* signr will be recorded in task->jobctl for retries */
+ WARN_ON_ONCE(signr & ~JOBCTL_STOP_SIGMASK);
- if (!likely(current->group_stop & GROUP_STOP_DEQUEUED) ||
+ if (!likely(current->jobctl & JOBCTL_STOP_DEQUEUED) ||
unlikely(signal_group_exit(sig)))
- return 0;
+ return false;
/*
* There is no group stop already in progress. We must
* initiate one now.
@@ -1895,28 +1987,32 @@
if (!(sig->flags & SIGNAL_STOP_STOPPED))
sig->group_exit_code = signr;
else
- WARN_ON_ONCE(!task_ptrace(current));
+ WARN_ON_ONCE(!current->ptrace);
- current->group_stop &= ~GROUP_STOP_SIGMASK;
- current->group_stop |= signr | gstop;
- sig->group_stop_count = 1;
+ sig->group_stop_count = 0;
+
+ if (task_set_jobctl_pending(current, signr | gstop))
+ sig->group_stop_count++;
+
for (t = next_thread(current); t != current;
t = next_thread(t)) {
- t->group_stop &= ~GROUP_STOP_SIGMASK;
/*
* Setting state to TASK_STOPPED for a group
* stop is always done with the siglock held,
* so this check has no races.
*/
- if (!(t->flags & PF_EXITING) && !task_is_stopped(t)) {
- t->group_stop |= signr | gstop;
+ if (!task_is_stopped(t) &&
+ task_set_jobctl_pending(t, signr | gstop)) {
sig->group_stop_count++;
- signal_wake_up(t, 0);
+ if (likely(!(t->ptrace & PT_SEIZED)))
+ signal_wake_up(t, 0);
+ else
+ ptrace_trap_notify(t);
}
}
}
-retry:
- if (likely(!task_ptrace(current))) {
+
+ if (likely(!current->ptrace)) {
int notify = 0;
/*
@@ -1947,43 +2043,65 @@
/* Now we don't run again until woken by SIGCONT or SIGKILL */
schedule();
-
- spin_lock_irq(¤t->sighand->siglock);
+ return true;
} else {
- ptrace_stop(current->group_stop & GROUP_STOP_SIGMASK,
- CLD_STOPPED, 0, NULL);
+ /*
+ * While ptraced, group stop is handled by STOP trap.
+ * Schedule it and let the caller deal with it.
+ */
+ task_set_jobctl_pending(current, JOBCTL_TRAP_STOP);
+ return false;
+ }
+}
+
+/**
+ * do_jobctl_trap - take care of ptrace jobctl traps
+ *
+ * When PT_SEIZED, it's used for both group stop and explicit
+ * SEIZE/INTERRUPT traps. Both generate PTRACE_EVENT_STOP trap with
+ * accompanying siginfo. If stopped, lower eight bits of exit_code contain
+ * the stop signal; otherwise, %SIGTRAP.
+ *
+ * When !PT_SEIZED, it's used only for group stop trap with stop signal
+ * number as exit_code and no siginfo.
+ *
+ * CONTEXT:
+ * Must be called with @current->sighand->siglock held, which may be
+ * released and re-acquired before returning with intervening sleep.
+ */
+static void do_jobctl_trap(void)
+{
+ struct signal_struct *signal = current->signal;
+ int signr = current->jobctl & JOBCTL_STOP_SIGMASK;
+
+ if (current->ptrace & PT_SEIZED) {
+ if (!signal->group_stop_count &&
+ !(signal->flags & SIGNAL_STOP_STOPPED))
+ signr = SIGTRAP;
+ WARN_ON_ONCE(!signr);
+ ptrace_do_notify(signr, signr | (PTRACE_EVENT_STOP << 8),
+ CLD_STOPPED);
+ } else {
+ WARN_ON_ONCE(!signr);
+ ptrace_stop(signr, CLD_STOPPED, 0, NULL);
current->exit_code = 0;
}
-
- /*
- * GROUP_STOP_PENDING could be set if another group stop has
- * started since being woken up or ptrace wants us to transit
- * between TASK_STOPPED and TRACED. Retry group stop.
- */
- if (current->group_stop & GROUP_STOP_PENDING) {
- WARN_ON_ONCE(!(current->group_stop & GROUP_STOP_SIGMASK));
- goto retry;
- }
-
- /* PTRACE_ATTACH might have raced with task killing, clear trapping */
- task_clear_group_stop_trapping(current);
-
- spin_unlock_irq(¤t->sighand->siglock);
-
- tracehook_finish_jctl();
-
- return 1;
}
static int ptrace_signal(int signr, siginfo_t *info,
struct pt_regs *regs, void *cookie)
{
- if (!task_ptrace(current))
- return signr;
-
ptrace_signal_deliver(regs, cookie);
-
- /* Let the debugger run. */
+ /*
+ * We do not check sig_kernel_stop(signr) but set this marker
+ * unconditionally because we do not know whether debugger will
+ * change signr. This flag has no meaning unless we are going
+ * to stop after return from ptrace_stop(). In this case it will
+ * be checked in do_signal_stop(), we should only stop if it was
+ * not cleared by SIGCONT while we were sleeping. See also the
+ * comment in dequeue_signal().
+ */
+ current->jobctl |= JOBCTL_STOP_DEQUEUED;
ptrace_stop(signr, CLD_TRAPPED, 0, info);
/* We're back. Did the debugger cancel the sig? */
@@ -2039,7 +2157,6 @@
* the CLD_ si_code into SIGNAL_CLD_MASK bits.
*/
if (unlikely(signal->flags & SIGNAL_CLD_MASK)) {
- struct task_struct *leader;
int why;
if (signal->flags & SIGNAL_CLD_CONTINUED)
@@ -2060,13 +2177,11 @@
* a duplicate.
*/
read_lock(&tasklist_lock);
-
do_notify_parent_cldstop(current, false, why);
- leader = current->group_leader;
- if (task_ptrace(leader) && !real_parent_is_ptracer(leader))
- do_notify_parent_cldstop(leader, true, why);
-
+ if (ptrace_reparented(current->group_leader))
+ do_notify_parent_cldstop(current->group_leader,
+ true, why);
read_unlock(&tasklist_lock);
goto relock;
@@ -2074,37 +2189,31 @@
for (;;) {
struct k_sigaction *ka;
- /*
- * Tracing can induce an artificial signal and choose sigaction.
- * The return value in @signr determines the default action,
- * but @info->si_signo is the signal number we will report.
- */
- signr = tracehook_get_signal(current, regs, info, return_ka);
- if (unlikely(signr < 0))
+
+ if (unlikely(current->jobctl & JOBCTL_STOP_PENDING) &&
+ do_signal_stop(0))
goto relock;
- if (unlikely(signr != 0))
- ka = return_ka;
- else {
- if (unlikely(current->group_stop &
- GROUP_STOP_PENDING) && do_signal_stop(0))
- goto relock;
- signr = dequeue_signal(current, ¤t->blocked,
- info);
-
- if (!signr)
- break; /* will return 0 */
-
- if (signr != SIGKILL) {
- signr = ptrace_signal(signr, info,
- regs, cookie);
- if (!signr)
- continue;
- }
-
- ka = &sighand->action[signr-1];
+ if (unlikely(current->jobctl & JOBCTL_TRAP_MASK)) {
+ do_jobctl_trap();
+ spin_unlock_irq(&sighand->siglock);
+ goto relock;
}
+ signr = dequeue_signal(current, ¤t->blocked, info);
+
+ if (!signr)
+ break; /* will return 0 */
+
+ if (unlikely(current->ptrace) && signr != SIGKILL) {
+ signr = ptrace_signal(signr, info,
+ regs, cookie);
+ if (!signr)
+ continue;
+ }
+
+ ka = &sighand->action[signr-1];
+
/* Trace actually delivered signals. */
trace_signal_deliver(signr, info, ka);
@@ -2260,7 +2369,7 @@
signotset(&unblocked);
retarget_shared_pending(tsk, &unblocked);
- if (unlikely(tsk->group_stop & GROUP_STOP_PENDING) &&
+ if (unlikely(tsk->jobctl & JOBCTL_STOP_PENDING) &&
task_participate_group_stop(tsk))
group_stop = CLD_STOPPED;
out:
diff --git a/mm/nommu.c b/mm/nommu.c
index 9edc897..5c5c2d4 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -22,7 +22,6 @@
#include <linux/pagemap.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
-#include <linux/tracehook.h>
#include <linux/blkdev.h>
#include <linux/backing-dev.h>
#include <linux/mount.h>
@@ -1087,7 +1086,7 @@
* it's being traced - otherwise breakpoints set in it may interfere
* with another untraced process
*/
- if ((flags & MAP_PRIVATE) && tracehook_expect_breakpoints(current))
+ if ((flags & MAP_PRIVATE) && current->ptrace)
vm_flags &= ~VM_MAYSHARE;
return vm_flags;
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index e4b0991..b0be989 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -339,8 +339,7 @@
* then wait for it to finish before killing
* some other task unnecessarily.
*/
- if (!(task_ptrace(p->group_leader) &
- PT_TRACE_EXIT))
+ if (!(p->group_leader->ptrace & PT_TRACE_EXIT))
return ERR_PTR(-1UL);
}
}
diff --git a/security/apparmor/domain.c b/security/apparmor/domain.c
index c825c6e..7312bf9 100644
--- a/security/apparmor/domain.c
+++ b/security/apparmor/domain.c
@@ -67,7 +67,7 @@
int error = 0;
rcu_read_lock();
- tracer = tracehook_tracer_task(task);
+ tracer = ptrace_parent(task);
if (tracer) {
/* released below */
cred = get_task_cred(tracer);
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 20219ef..4225155 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -2053,7 +2053,7 @@
u32 ptsid = 0;
rcu_read_lock();
- tracer = tracehook_tracer_task(current);
+ tracer = ptrace_parent(current);
if (likely(tracer != NULL)) {
sec = __task_cred(tracer)->security;
ptsid = sec->sid;
@@ -5319,7 +5319,7 @@
Otherwise, leave SID unchanged and fail. */
ptsid = 0;
task_lock(p);
- tracer = tracehook_tracer_task(p);
+ tracer = ptrace_parent(p);
if (tracer)
ptsid = task_sid(tracer);
task_unlock(p);
