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Merge 67850b7bdc ("Merge tag 'ptrace_stop-cleanup-for-v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace") into android-mainline

Browse Source 
Steps on the way to 5.19-rc1

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I24c33bd2bd16545f814b1b6a615ae1f0d8faee94
This commit is contained in:
Greg Kroah-Hartman
2022-07-07 13:25:59 +02:00
parent eb6d937732 67850b7bdc
commit b7876c8b7d
20 changed files with 140 additions and 240 deletions
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4
arch/ia64/include/asm/ptrace.h
View File

@@ -139,10 +139,6 @@ static inline long regs_return_value(struct pt_regs *regs)
#define arch_ptrace_stop_needed() \
(!test_thread_flag(TIF_RESTORE_RSE))
extern void ptrace_attach_sync_user_rbs (struct task_struct *);
#define arch_ptrace_attach(child) \
ptrace_attach_sync_user_rbs(child)
#define arch_has_single_step() (1)
#define arch_has_block_step() (1)

57
arch/ia64/kernel/ptrace.c
View File

@@ -617,63 +617,6 @@ void ia64_sync_krbs(void)
unw_init_running(do_sync_rbs, ia64_sync_kernel_rbs);
}
/*
* After PTRACE_ATTACH, a thread's register backing store area in user
* space is assumed to contain correct data whenever the thread is
* stopped. arch_ptrace_stop takes care of this on tracing stops.
* But if the child was already stopped for job control when we attach
* to it, then it might not ever get into ptrace_stop by the time we
* want to examine the user memory containing the RBS.
*/
void
ptrace_attach_sync_user_rbs (struct task_struct *child)
{
int stopped = 0;
struct unw_frame_info info;
/*
* If the child is in TASK_STOPPED, we need to change that to
* TASK_TRACED momentarily while we operate on it. This ensures
* that the child won't be woken up and return to user mode while
* we are doing the sync. (It can only be woken up for SIGKILL.)
*/
read_lock(&tasklist_lock);
if (child->sighand) {
spin_lock_irq(&child->sighand->siglock);
if (READ_ONCE(child->__state) == TASK_STOPPED &&
!test_and_set_tsk_thread_flag(child, TIF_RESTORE_RSE)) {
set_notify_resume(child);
WRITE_ONCE(child->__state, TASK_TRACED);
stopped = 1;
}
spin_unlock_irq(&child->sighand->siglock);
}
read_unlock(&tasklist_lock);
if (!stopped)
return;
unw_init_from_blocked_task(&info, child);
do_sync_rbs(&info, ia64_sync_user_rbs);
/*
* Now move the child back into TASK_STOPPED if it should be in a
* job control stop, so that SIGCONT can be used to wake it up.
*/
read_lock(&tasklist_lock);
if (child->sighand) {
spin_lock_irq(&child->sighand->siglock);
if (READ_ONCE(child->__state) == TASK_TRACED &&
(child->signal->flags & SIGNAL_STOP_STOPPED)) {
WRITE_ONCE(child->__state, TASK_STOPPED);
}
spin_unlock_irq(&child->sighand->siglock);
}
read_unlock(&tasklist_lock);
}
/*
* Write f32-f127 back to task->thread.fph if it has been modified.
*/

2
arch/um/include/asm/thread_info.h
View File

@@ -60,6 +60,7 @@ static inline struct thread_info *current_thread_info(void)
#define TIF_RESTORE_SIGMASK 7
#define TIF_NOTIFY_RESUME 8
#define TIF_SECCOMP 9 /* secure computing */
#define TIF_SINGLESTEP 10 /* single stepping userspace */
#define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE)
#define _TIF_SIGPENDING (1 << TIF_SIGPENDING)
@@ -68,5 +69,6 @@ static inline struct thread_info *current_thread_info(void)
#define _TIF_MEMDIE (1 << TIF_MEMDIE)
#define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT)
#define _TIF_SECCOMP (1 << TIF_SECCOMP)
#define _TIF_SINGLESTEP (1 << TIF_SINGLESTEP)
#endif

2
arch/um/kernel/exec.c
View File

@@ -43,7 +43,7 @@ void start_thread(struct pt_regs *regs, unsigned long eip, unsigned long esp)
{
PT_REGS_IP(regs) = eip;
PT_REGS_SP(regs) = esp;
current->ptrace &= ~PT_DTRACE;
clear_thread_flag(TIF_SINGLESTEP);
#ifdef SUBARCH_EXECVE1
SUBARCH_EXECVE1(regs->regs);
#endif

2
arch/um/kernel/process.c
View File

@@ -336,7 +336,7 @@ int singlestepping(void * t)
{
struct task_struct *task = t ? t : current;
if (!(task->ptrace & PT_DTRACE))
if (!test_thread_flag(TIF_SINGLESTEP))
return 0;
if (task->thread.singlestep_syscall)

8
arch/um/kernel/ptrace.c
View File

@@ -11,7 +11,7 @@
void user_enable_single_step(struct task_struct *child)
{
child->ptrace |= PT_DTRACE;
set_tsk_thread_flag(child, TIF_SINGLESTEP);
child->thread.singlestep_syscall = 0;
#ifdef SUBARCH_SET_SINGLESTEPPING
@@ -21,7 +21,7 @@ void user_enable_single_step(struct task_struct *child)
void user_disable_single_step(struct task_struct *child)
{
child->ptrace &= ~PT_DTRACE;
clear_tsk_thread_flag(child, TIF_SINGLESTEP);
child->thread.singlestep_syscall = 0;
#ifdef SUBARCH_SET_SINGLESTEPPING
@@ -120,7 +120,7 @@ static void send_sigtrap(struct uml_pt_regs *regs, int error_code)
}
/*
* XXX Check PT_DTRACE vs TIF_SINGLESTEP for singlestepping check and
* XXX Check TIF_SINGLESTEP for singlestepping check and
* PT_PTRACED vs TIF_SYSCALL_TRACE for syscall tracing check
*/
int syscall_trace_enter(struct pt_regs *regs)
@@ -144,7 +144,7 @@ void syscall_trace_leave(struct pt_regs *regs)
audit_syscall_exit(regs);
/* Fake a debug trap */
if (ptraced & PT_DTRACE)
if (test_thread_flag(TIF_SINGLESTEP))
send_sigtrap(&regs->regs, 0);
if (!test_thread_flag(TIF_SYSCALL_TRACE))

4
arch/um/kernel/signal.c
View File

@@ -53,7 +53,7 @@ static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
unsigned long sp;
int err;
if ((current->ptrace & PT_DTRACE) && (current->ptrace & PT_PTRACED))
if (test_thread_flag(TIF_SINGLESTEP) && (current->ptrace & PT_PTRACED))
singlestep = 1;
/* Did we come from a system call? */
@@ -128,7 +128,7 @@ void do_signal(struct pt_regs *regs)
* on the host. The tracing thread will check this flag and
* PTRACE_SYSCALL if necessary.
*/
if (current->ptrace & PT_DTRACE)
if (test_thread_flag(TIF_SINGLESTEP))
current->thread.singlestep_syscall =
is_syscall(PT_REGS_IP(&current->thread.regs));

3
arch/x86/kernel/step.c
View File

@@ -180,8 +180,7 @@ void set_task_blockstep(struct task_struct *task, bool on)
*
* NOTE: this means that set/clear TIF_BLOCKSTEP is only safe if
* task is current or it can't be running, otherwise we can race
* with __switch_to_xtra(). We rely on ptrace_freeze_traced() but
* PTRACE_KILL is not safe.
* with __switch_to_xtra(). We rely on ptrace_freeze_traced().
*/
local_irq_disable();
debugctl = get_debugctlmsr();

4
arch/xtensa/kernel/ptrace.c
View File

@@ -224,12 +224,12 @@ const struct user_regset_view *task_user_regset_view(struct task_struct *task)
void user_enable_single_step(struct task_struct *child)
{
child->ptrace |= PT_SINGLESTEP;
set_tsk_thread_flag(child, TIF_SINGLESTEP);
}
void user_disable_single_step(struct task_struct *child)
{
child->ptrace &= ~PT_SINGLESTEP;
clear_tsk_thread_flag(child, TIF_SINGLESTEP);
}
/*

4
arch/xtensa/kernel/signal.c
View File

@@ -472,7 +472,7 @@ static void do_signal(struct pt_regs *regs)
/* Set up the stack frame */
ret = setup_frame(&ksig, sigmask_to_save(), regs);
signal_setup_done(ret, &ksig, 0);
if (current->ptrace & PT_SINGLESTEP)
if (test_thread_flag(TIF_SINGLESTEP))
task_pt_regs(current)->icountlevel = 1;
return;
@@ -498,7 +498,7 @@ static void do_signal(struct pt_regs *regs)
/* If there's no signal to deliver, we just restore the saved mask. */
restore_saved_sigmask();
if (current->ptrace & PT_SINGLESTEP)
if (test_thread_flag(TIF_SINGLESTEP))
task_pt_regs(current)->icountlevel = 1;
return;
}

4
drivers/tty/tty_jobctrl.c
View File

@@ -215,8 +215,8 @@ int tty_signal_session_leader(struct tty_struct *tty, int exit_session)
spin_unlock_irq(&p->sighand->siglock);
continue;
}
__group_send_sig_info(SIGHUP, SEND_SIG_PRIV, p);
__group_send_sig_info(SIGCONT, SEND_SIG_PRIV, p);
send_signal_locked(SIGHUP, SEND_SIG_PRIV, p, PIDTYPE_TGID);
send_signal_locked(SIGCONT, SEND_SIG_PRIV, p, PIDTYPE_TGID);
put_pid(p->signal->tty_old_pgrp); /* A noop */
spin_lock(&tty->ctrl.lock);
tty_pgrp = get_pid(tty->ctrl.pgrp);

7
include/linux/ptrace.h
View File

@@ -30,7 +30,6 @@ extern int ptrace_access_vm(struct task_struct *tsk, unsigned long addr,
#define PT_SEIZED 0x00010000 /* SEIZE used, enable new behavior */
#define PT_PTRACED 0x00000001
#define PT_DTRACE 0x00000002 /* delayed trace (used on um) */
#define PT_OPT_FLAG_SHIFT 3
/* PT_TRACE_* event enable flags */
@@ -47,12 +46,6 @@ extern int ptrace_access_vm(struct task_struct *tsk, unsigned long addr,
#define PT_EXITKILL (PTRACE_O_EXITKILL << PT_OPT_FLAG_SHIFT)
#define PT_SUSPEND_SECCOMP (PTRACE_O_SUSPEND_SECCOMP << PT_OPT_FLAG_SHIFT)
/* single stepping state bits (used on ARM and PA-RISC) */
#define PT_SINGLESTEP_BIT 31
#define PT_SINGLESTEP (1<<PT_SINGLESTEP_BIT)
#define PT_BLOCKSTEP_BIT 30
#define PT_BLOCKSTEP (1<<PT_BLOCKSTEP_BIT)
extern long arch_ptrace(struct task_struct *child, long request,
unsigned long addr, unsigned long data);
extern int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len);

10
include/linux/sched.h
View File

@@ -104,7 +104,7 @@ struct task_group;
/* Convenience macros for the sake of set_current_state: */
#define TASK_KILLABLE (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
#define TASK_STOPPED (TASK_WAKEKILL | __TASK_STOPPED)
#define TASK_TRACED (TASK_WAKEKILL | __TASK_TRACED)
#define TASK_TRACED __TASK_TRACED
#define TASK_IDLE (TASK_UNINTERRUPTIBLE | TASK_NOLOAD)
@@ -119,11 +119,9 @@ struct task_group;
#define task_is_running(task) (READ_ONCE((task)->__state) == TASK_RUNNING)
#define task_is_traced(task) ((READ_ONCE(task->__state) & __TASK_TRACED) != 0)
#define task_is_stopped(task) ((READ_ONCE(task->__state) & __TASK_STOPPED) != 0)
#define task_is_stopped_or_traced(task) ((READ_ONCE(task->__state) & (__TASK_STOPPED | __TASK_TRACED)) != 0)
#define task_is_traced(task) ((READ_ONCE(task->jobctl) & JOBCTL_TRACED) != 0)
#define task_is_stopped(task) ((READ_ONCE(task->jobctl) & JOBCTL_STOPPED) != 0)
#define task_is_stopped_or_traced(task) ((READ_ONCE(task->jobctl) & (JOBCTL_STOPPED | JOBCTL_TRACED)) != 0)
/*
* Special states are those that do not use the normal wait-loop pattern. See

8
include/linux/sched/jobctl.h
View File

@@ -19,6 +19,10 @@ struct task_struct;
#define JOBCTL_TRAPPING_BIT 21 /* switching to TRACED */
#define JOBCTL_LISTENING_BIT 22 /* ptracer is listening for events */
#define JOBCTL_TRAP_FREEZE_BIT 23 /* trap for cgroup freezer */
#define JOBCTL_PTRACE_FROZEN_BIT 24 /* frozen for ptrace */
#define JOBCTL_STOPPED_BIT 26 /* do_signal_stop() */
#define JOBCTL_TRACED_BIT 27 /* ptrace_stop() */
#define JOBCTL_STOP_DEQUEUED (1UL << JOBCTL_STOP_DEQUEUED_BIT)
#define JOBCTL_STOP_PENDING (1UL << JOBCTL_STOP_PENDING_BIT)
@@ -28,6 +32,10 @@ struct task_struct;
#define JOBCTL_TRAPPING (1UL << JOBCTL_TRAPPING_BIT)
#define JOBCTL_LISTENING (1UL << JOBCTL_LISTENING_BIT)
#define JOBCTL_TRAP_FREEZE (1UL << JOBCTL_TRAP_FREEZE_BIT)
#define JOBCTL_PTRACE_FROZEN (1UL << JOBCTL_PTRACE_FROZEN_BIT)
#define JOBCTL_STOPPED (1UL << JOBCTL_STOPPED_BIT)
#define JOBCTL_TRACED (1UL << JOBCTL_TRACED_BIT)
#define JOBCTL_TRAP_MASK (JOBCTL_TRAP_STOP | JOBCTL_TRAP_NOTIFY)
#define JOBCTL_PENDING_MASK (JOBCTL_STOP_PENDING | JOBCTL_TRAP_MASK)

20
include/linux/sched/signal.h
View File

@@ -294,8 +294,10 @@ static inline int kernel_dequeue_signal(void)
static inline void kernel_signal_stop(void)
{
spin_lock_irq(&current->sighand->siglock);
if (current->jobctl & JOBCTL_STOP_DEQUEUED)
if (current->jobctl & JOBCTL_STOP_DEQUEUED) {
current->jobctl |= JOBCTL_STOPPED;
set_special_state(TASK_STOPPED);
}
spin_unlock_irq(&current->sighand->siglock);
schedule();
@@ -444,13 +446,23 @@ extern void calculate_sigpending(void);
extern void signal_wake_up_state(struct task_struct *t, unsigned int state);
static inline void signal_wake_up(struct task_struct *t, bool resume)
static inline void signal_wake_up(struct task_struct *t, bool fatal)
{
signal_wake_up_state(t, resume ? TASK_WAKEKILL : 0);
unsigned int state = 0;
if (fatal && !(t->jobctl & JOBCTL_PTRACE_FROZEN)) {
t->jobctl &= ~(JOBCTL_STOPPED | JOBCTL_TRACED);
state = TASK_WAKEKILL | __TASK_TRACED;
}
signal_wake_up_state(t, state);
}
static inline void ptrace_signal_wake_up(struct task_struct *t, bool resume)
{
signal_wake_up_state(t, resume ? __TASK_TRACED : 0);
unsigned int state = 0;
if (resume) {
t->jobctl &= ~JOBCTL_TRACED;
state = __TASK_TRACED;
}
signal_wake_up_state(t, state);
}
void task_join_group_stop(struct task_struct *task);

3
include/linux/signal.h
View File

@@ -282,7 +282,8 @@ extern int do_send_sig_info(int sig, struct kernel_siginfo *info,
struct task_struct *p, enum pid_type type);
extern int group_send_sig_info(int sig, struct kernel_siginfo *info,
struct task_struct *p, enum pid_type type);
extern int __group_send_sig_info(int, struct kernel_siginfo *, struct task_struct *);
extern int send_signal_locked(int sig, struct kernel_siginfo *info,
struct task_struct *p, enum pid_type type);
extern int sigprocmask(int, sigset_t *, sigset_t *);
extern void set_current_blocked(sigset_t *);
extern void __set_current_blocked(const sigset_t *);

87
kernel/ptrace.c
View File

@@ -185,7 +185,12 @@ static bool looks_like_a_spurious_pid(struct task_struct *task)
return true;
}
/* Ensure that nothing can wake it up, even SIGKILL */
/*
* Ensure that nothing can wake it up, even SIGKILL
*
* A task is switched to this state while a ptrace operation is in progress;
* such that the ptrace operation is uninterruptible.
*/
static bool ptrace_freeze_traced(struct task_struct *task)
{
bool ret = false;
@@ -197,7 +202,7 @@ static bool ptrace_freeze_traced(struct task_struct *task)
spin_lock_irq(&task->sighand->siglock);
if (task_is_traced(task) && !looks_like_a_spurious_pid(task) &&
!__fatal_signal_pending(task)) {
WRITE_ONCE(task->__state, __TASK_TRACED);
task->jobctl |= JOBCTL_PTRACE_FROZEN;
ret = true;
}
spin_unlock_irq(&task->sighand->siglock);
@@ -207,23 +212,21 @@ static bool ptrace_freeze_traced(struct task_struct *task)
static void ptrace_unfreeze_traced(struct task_struct *task)
{
if (READ_ONCE(task->__state) != __TASK_TRACED)
return;
WARN_ON(!task->ptrace || task->parent != current);
unsigned long flags;
/*
* PTRACE_LISTEN can allow ptrace_trap_notify to wake us up remotely.
* Recheck state under the lock to close this race.
* The child may be awake and may have cleared
* JOBCTL_PTRACE_FROZEN (see ptrace_resume). The child will
* not set JOBCTL_PTRACE_FROZEN or enter __TASK_TRACED anew.
*/
spin_lock_irq(&task->sighand->siglock);
if (READ_ONCE(task->__state) == __TASK_TRACED) {
if (__fatal_signal_pending(task))
if (lock_task_sighand(task, &flags)) {
task->jobctl &= ~JOBCTL_PTRACE_FROZEN;
if (__fatal_signal_pending(task)) {
task->jobctl &= ~TASK_TRACED;
wake_up_state(task, __TASK_TRACED);
else
WRITE_ONCE(task->__state, TASK_TRACED);
}
unlock_task_sighand(task, &flags);
}
spin_unlock_irq(&task->sighand->siglock);
}
/**
@@ -256,7 +259,6 @@ static int ptrace_check_attach(struct task_struct *child, bool ignore_state)
*/
read_lock(&tasklist_lock);
if (child->ptrace && child->parent == current) {
WARN_ON(READ_ONCE(child->__state) == __TASK_TRACED);
/*
* child->sighand can't be NULL, release_task()
* does ptrace_unlink() before __exit_signal().
@@ -266,17 +268,9 @@ static int ptrace_check_attach(struct task_struct *child, bool ignore_state)
}
read_unlock(&tasklist_lock);
if (!ret && !ignore_state) {
if (!wait_task_inactive(child, __TASK_TRACED)) {
/*
* This can only happen if may_ptrace_stop() fails and
* ptrace_stop() changes ->state back to TASK_RUNNING,
* so we should not worry about leaking __TASK_TRACED.
*/
WARN_ON(READ_ONCE(child->__state) == __TASK_TRACED);
ret = -ESRCH;
}
}
if (!ret && !ignore_state &&
WARN_ON_ONCE(!wait_task_inactive(child, __TASK_TRACED)))
ret = -ESRCH;
return ret;
}
@@ -475,8 +469,10 @@ static int ptrace_attach(struct task_struct *task, long request,
* in and out of STOPPED are protected by siglock.
*/
if (task_is_stopped(task) &&
task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING))
task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING)) {
task->jobctl &= ~JOBCTL_STOPPED;
signal_wake_up_state(task, __TASK_STOPPED);
}
spin_unlock(&task->sighand->siglock);
@@ -846,8 +842,6 @@ static long ptrace_get_rseq_configuration(struct task_struct *task,
static int ptrace_resume(struct task_struct *child, long request,
unsigned long data)
{
bool need_siglock;
if (!valid_signal(data))
return -EIO;
@@ -883,18 +877,12 @@ static int ptrace_resume(struct task_struct *child, long request,
* Note that we need siglock even if ->exit_code == data and/or this
* status was not reported yet, the new status must not be cleared by
* wait_task_stopped() after resume.
*
* If data == 0 we do not care if wait_task_stopped() reports the old
* status and clears the code too; this can't race with the tracee, it
* takes siglock after resume.
*/
need_siglock = data && !thread_group_empty(current);
if (need_siglock)
spin_lock_irq(&child->sighand->siglock);
spin_lock_irq(&child->sighand->siglock);
child->exit_code = data;
child->jobctl &= ~JOBCTL_TRACED;
wake_up_state(child, __TASK_TRACED);
if (need_siglock)
spin_unlock_irq(&child->sighand->siglock);
spin_unlock_irq(&child->sighand->siglock);
return 0;
}
@@ -1230,9 +1218,8 @@ int ptrace_request(struct task_struct *child, long request,
return ptrace_resume(child, request, data);
case PTRACE_KILL:
if (child->exit_state) /* already dead */
return 0;
return ptrace_resume(child, request, SIGKILL);
send_sig_info(SIGKILL, SEND_SIG_NOINFO, child);
return 0;
#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
case PTRACE_GETREGSET:
@@ -1279,10 +1266,6 @@ int ptrace_request(struct task_struct *child, long request,
return ret;
}
#ifndef arch_ptrace_attach
#define arch_ptrace_attach(child) do { } while (0)
#endif
SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr,
unsigned long, data)
{
@@ -1291,8 +1274,6 @@ SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr,
if (request == PTRACE_TRACEME) {
ret = ptrace_traceme();
if (!ret)
arch_ptrace_attach(current);
goto out;
}
@@ -1304,12 +1285,6 @@ SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr,
if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) {
ret = ptrace_attach(child, request, addr, data);
/*
* Some architectures need to do book-keeping after
* a ptrace attach.
*/
if (!ret)
arch_ptrace_attach(child);
goto out_put_task_struct;
}
@@ -1449,12 +1424,6 @@ COMPAT_SYSCALL_DEFINE4(ptrace, compat_long_t, request, compat_long_t, pid,
if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) {
ret = ptrace_attach(child, request, addr, data);
/*
* Some architectures need to do book-keeping after
* a ptrace attach.
*/
if (!ret)
arch_ptrace_attach(child);
goto out_put_task_struct;
}

5
kernel/sched/core.c
View File

@@ -6430,10 +6430,7 @@ static void __sched notrace __schedule(unsigned int sched_mode)
/*
* We must load prev->state once (task_struct::state is volatile), such
* that:
*
* - we form a control dependency vs deactivate_task() below.
* - ptrace_{,un}freeze_traced() can change ->state underneath us.
* that we form a control dependency vs deactivate_task() below.
*/
prev_state = READ_ONCE(prev->__state);
if (!(sched_mode & SM_MASK_PREEMPT) && prev_state) {

140
kernel/signal.c
View File

@@ -762,7 +762,10 @@ still_pending:
*/
void signal_wake_up_state(struct task_struct *t, unsigned int state)
{
lockdep_assert_held(&t->sighand->siglock);
set_tsk_thread_flag(t, TIF_SIGPENDING);
/*
* TASK_WAKEKILL also means wake it up in the stopped/traced/killable
* case. We don't check t->state here because there is a race with it
@@ -884,7 +887,7 @@ static int check_kill_permission(int sig, struct kernel_siginfo *info,
static void ptrace_trap_notify(struct task_struct *t)
{
WARN_ON_ONCE(!(t->ptrace & PT_SEIZED));
assert_spin_locked(&t->sighand->siglock);
lockdep_assert_held(&t->sighand->siglock);
task_set_jobctl_pending(t, JOBCTL_TRAP_NOTIFY);
ptrace_signal_wake_up(t, t->jobctl & JOBCTL_LISTENING);
@@ -930,9 +933,10 @@ static bool prepare_signal(int sig, struct task_struct *p, bool force)
for_each_thread(p, t) {
flush_sigqueue_mask(&flush, &t->pending);
task_clear_jobctl_pending(t, JOBCTL_STOP_PENDING);
if (likely(!(t->ptrace & PT_SEIZED)))
if (likely(!(t->ptrace & PT_SEIZED))) {
t->jobctl &= ~JOBCTL_STOPPED;
wake_up_state(t, __TASK_STOPPED);
else
} else
ptrace_trap_notify(t);
}
@@ -1071,15 +1075,15 @@ static inline bool legacy_queue(struct sigpending *signals, int sig)
return (sig < SIGRTMIN) && sigismember(&signals->signal, sig);
}
static int __send_signal(int sig, struct kernel_siginfo *info, struct task_struct *t,
enum pid_type type, bool force)
static int __send_signal_locked(int sig, struct kernel_siginfo *info,
struct task_struct *t, enum pid_type type, bool force)
{
struct sigpending *pending;
struct sigqueue *q;
int override_rlimit;
int ret = 0, result;
assert_spin_locked(&t->sighand->siglock);
lockdep_assert_held(&t->sighand->siglock);
result = TRACE_SIGNAL_IGNORED;
if (!prepare_signal(sig, t, force))
@@ -1212,8 +1216,8 @@ static inline bool has_si_pid_and_uid(struct kernel_siginfo *info)
return ret;
}
static int send_signal(int sig, struct kernel_siginfo *info, struct task_struct *t,
enum pid_type type)
int send_signal_locked(int sig, struct kernel_siginfo *info,
struct task_struct *t, enum pid_type type)
{
/* Should SIGKILL or SIGSTOP be received by a pid namespace init? */
bool force = false;
@@ -1245,7 +1249,7 @@ static int send_signal(int sig, struct kernel_siginfo *info, struct task_struct
force = true;
}
}
return __send_signal(sig, info, t, type, force);
return __send_signal_locked(sig, info, t, type, force);
}
static void print_fatal_signal(int signr)
@@ -1281,12 +1285,6 @@ static int __init setup_print_fatal_signals(char *str)
__setup("print-fatal-signals=", setup_print_fatal_signals);
int
__group_send_sig_info(int sig, struct kernel_siginfo *info, struct task_struct *p)
{
return send_signal(sig, info, p, PIDTYPE_TGID);
}
int do_send_sig_info(int sig, struct kernel_siginfo *info, struct task_struct *p,
enum pid_type type)
{
@@ -1294,7 +1292,7 @@ int do_send_sig_info(int sig, struct kernel_siginfo *info, struct task_struct *p
int ret = -ESRCH;
if (lock_task_sighand(p, &flags)) {
ret = send_signal(sig, info, p, type);
ret = send_signal_locked(sig, info, p, type);
unlock_task_sighand(p, &flags);
}
@@ -1347,7 +1345,7 @@ force_sig_info_to_task(struct kernel_siginfo *info, struct task_struct *t,
if (action->sa.sa_handler == SIG_DFL &&
(!t->ptrace || (handler == HANDLER_EXIT)))
t->signal->flags &= ~SIGNAL_UNKILLABLE;
ret = send_signal(sig, info, t, PIDTYPE_PID);
ret = send_signal_locked(sig, info, t, PIDTYPE_PID);
spin_unlock_irqrestore(&t->sighand->siglock, flags);
return ret;
@@ -1567,7 +1565,7 @@ int kill_pid_usb_asyncio(int sig, int errno, sigval_t addr,
if (sig) {
if (lock_task_sighand(p, &flags)) {
ret = __send_signal(sig, &info, p, PIDTYPE_TGID, false);
ret = __send_signal_locked(sig, &info, p, PIDTYPE_TGID, false);
unlock_task_sighand(p, &flags);
} else
ret = -ESRCH;
@@ -2114,7 +2112,7 @@ bool do_notify_parent(struct task_struct *tsk, int sig)
* parent's namespaces.
*/
if (valid_signal(sig) && sig)
__send_signal(sig, &info, tsk->parent, PIDTYPE_TGID, false);
__send_signal_locked(sig, &info, tsk->parent, PIDTYPE_TGID, false);
__wake_up_parent(tsk, tsk->parent);
spin_unlock_irqrestore(&psig->siglock, flags);
@@ -2184,7 +2182,7 @@ static void do_notify_parent_cldstop(struct task_struct *tsk,
spin_lock_irqsave(&sighand->siglock, flags);
if (sighand->action[SIGCHLD-1].sa.sa_handler != SIG_IGN &&
!(sighand->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDSTOP))
__group_send_sig_info(SIGCHLD, &info, parent);
send_signal_locked(SIGCHLD, &info, parent, PIDTYPE_TGID);
/*
* Even if SIGCHLD is not generated, we must wake up wait4 calls.
*/
@@ -2204,13 +2202,12 @@ static void do_notify_parent_cldstop(struct task_struct *tsk,
* with. If the code did not stop because the tracer is gone,
* the stop signal remains unchanged unless clear_code.
*/
static int ptrace_stop(int exit_code, int why, int clear_code,
unsigned long message, kernel_siginfo_t *info)
static int ptrace_stop(int exit_code, int why, unsigned long message,
kernel_siginfo_t *info)
__releases(&current->sighand->siglock)
__acquires(&current->sighand->siglock)
{
bool gstop_done = false;
bool read_code = true;
if (arch_ptrace_stop_needed()) {
/*
@@ -2227,10 +2224,16 @@ static int ptrace_stop(int exit_code, int why, int clear_code,
}
/*
* schedule() will not sleep if there is a pending signal that
* can awaken the task.
* After this point ptrace_signal_wake_up or signal_wake_up
* will clear TASK_TRACED if ptrace_unlink happens or a fatal
* signal comes in. Handle previous ptrace_unlinks and fatal
* signals here to prevent ptrace_stop sleeping in schedule.
*/
if (!current->ptrace || __fatal_signal_pending(current))
return exit_code;
set_special_state(TASK_TRACED);
current->jobctl |= JOBCTL_TRACED;
/*
* We're committing to trapping. TRACED should be visible before
@@ -2276,54 +2279,33 @@ static int ptrace_stop(int exit_code, int why, int clear_code,
spin_unlock_irq(&current->sighand->siglock);
read_lock(&tasklist_lock);
if (likely(current->ptrace)) {
/*
* Notify parents of the stop.
*
* While ptraced, there are two parents - the ptracer and
* the real_parent of the group_leader. The ptracer should
* know about every stop while the real parent is only
* interested in the completion of group stop. The states
* for the two don't interact with each other. Notify
* separately unless they're gonna be duplicates.
*/
/*
* Notify parents of the stop.
*
* While ptraced, there are two parents - the ptracer and
* the real_parent of the group_leader. The ptracer should
* know about every stop while the real parent is only
* interested in the completion of group stop. The states
* for the two don't interact with each other. Notify
* separately unless they're gonna be duplicates.
*/
if (current->ptrace)
do_notify_parent_cldstop(current, true, why);
if (gstop_done && ptrace_reparented(current))
do_notify_parent_cldstop(current, false, why);
if (gstop_done && (!current->ptrace || ptrace_reparented(current)))
do_notify_parent_cldstop(current, false, why);
/*
* Don't want to allow preemption here, because
* sys_ptrace() needs this task to be inactive.
*
* XXX: implement read_unlock_no_resched().
*/
preempt_disable();
read_unlock(&tasklist_lock);
cgroup_enter_frozen();
preempt_enable_no_resched();
freezable_schedule();
cgroup_leave_frozen(true);
} else {
/*
* By the time we got the lock, our tracer went away.
* Don't drop the lock yet, another tracer may come.
*
* If @gstop_done, the ptracer went away between group stop
* completion and here. During detach, it would have set
* 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);
/* tasklist protects us from ptrace_freeze_traced() */
__set_current_state(TASK_RUNNING);
read_code = false;
if (clear_code)
exit_code = 0;
read_unlock(&tasklist_lock);
}
/*
* Don't want to allow preemption here, because
* sys_ptrace() needs this task to be inactive.
*
* XXX: implement read_unlock_no_resched().
*/
preempt_disable();
read_unlock(&tasklist_lock);
cgroup_enter_frozen();
preempt_enable_no_resched();
freezable_schedule();
cgroup_leave_frozen(true);
/*
* We are back. Now reacquire the siglock before touching
@@ -2331,14 +2313,13 @@ static int ptrace_stop(int exit_code, int why, int clear_code,
* any signal-sending on another CPU that wants to examine it.
*/
spin_lock_irq(&current->sighand->siglock);
if (read_code)
exit_code = current->exit_code;
exit_code = current->exit_code;
current->last_siginfo = NULL;
current->ptrace_message = 0;
current->exit_code = 0;
/* LISTENING can be set only during STOP traps, clear it */
current->jobctl &= ~JOBCTL_LISTENING;
current->jobctl &= ~(JOBCTL_LISTENING | JOBCTL_PTRACE_FROZEN);
/*
* Queued signals ignored us while we were stopped for tracing.
@@ -2360,7 +2341,7 @@ static int ptrace_do_notify(int signr, int exit_code, int why, unsigned long mes
info.si_uid = from_kuid_munged(current_user_ns(), current_uid());
/* Let the debugger run. */
return ptrace_stop(exit_code, why, 1, message, &info);
return ptrace_stop(exit_code, why, message, &info);
}
int ptrace_notify(int exit_code, unsigned long message)
@@ -2471,6 +2452,7 @@ static bool do_signal_stop(int signr)
if (task_participate_group_stop(current))
notify = CLD_STOPPED;
current->jobctl |= JOBCTL_STOPPED;
set_special_state(TASK_STOPPED);
spin_unlock_irq(&current->sighand->siglock);
@@ -2532,7 +2514,7 @@ static void do_jobctl_trap(void)
CLD_STOPPED, 0);
} else {
WARN_ON_ONCE(!signr);
ptrace_stop(signr, CLD_STOPPED, 0, 0, NULL);
ptrace_stop(signr, CLD_STOPPED, 0, NULL);
}
}
@@ -2585,7 +2567,7 @@ static int ptrace_signal(int signr, kernel_siginfo_t *info, enum pid_type type)
* comment in dequeue_signal().
*/
current->jobctl |= JOBCTL_STOP_DEQUEUED;
signr = ptrace_stop(signr, CLD_TRAPPED, 0, 0, info);
signr = ptrace_stop(signr, CLD_TRAPPED, 0, info);
/* We're back. Did the debugger cancel the sig? */
if (signr == 0)
@@ -2612,7 +2594,7 @@ static int ptrace_signal(int signr, kernel_siginfo_t *info, enum pid_type type)
/* If the (new) signal is now blocked, requeue it. */
if (sigismember(&current->blocked, signr) ||
fatal_signal_pending(current)) {
send_signal(signr, info, current, type);
send_signal_locked(signr, info, current, type);
signr = 0;
}
@@ -4807,7 +4789,7 @@ void kdb_send_sig(struct task_struct *t, int sig)
"the deadlock.\n");
return;
}
ret = send_signal(sig, SEND_SIG_PRIV, t, PIDTYPE_PID);
ret = send_signal_locked(sig, SEND_SIG_PRIV, t, PIDTYPE_PID);
spin_unlock(&t->sighand->siglock);
if (ret)
kdb_printf("Fail to deliver Signal %d to process %d.\n",

6
kernel/time/posix-cpu-timers.c
View File

@@ -870,7 +870,7 @@ static inline void check_dl_overrun(struct task_struct *tsk)
{
if (tsk->dl.dl_overrun) {
tsk->dl.dl_overrun = 0;
__group_send_sig_info(SIGXCPU, SEND_SIG_PRIV, tsk);
send_signal_locked(SIGXCPU, SEND_SIG_PRIV, tsk, PIDTYPE_TGID);
}
}
@@ -884,7 +884,7 @@ static bool check_rlimit(u64 time, u64 limit, int signo, bool rt, bool hard)
rt ? "RT" : "CPU", hard ? "hard" : "soft",
current->comm, task_pid_nr(current));
}
__group_send_sig_info(signo, SEND_SIG_PRIV, current);
send_signal_locked(signo, SEND_SIG_PRIV, current, PIDTYPE_TGID);
return true;
}
@@ -958,7 +958,7 @@ static void check_cpu_itimer(struct task_struct *tsk, struct cpu_itimer *it,
trace_itimer_expire(signo == SIGPROF ?
ITIMER_PROF : ITIMER_VIRTUAL,
task_tgid(tsk), cur_time);
__group_send_sig_info(signo, SEND_SIG_PRIV, tsk);
send_signal_locked(signo, SEND_SIG_PRIV, tsk, PIDTYPE_TGID);
}
if (it->expires && it->expires < *expires)