[PATCH 1/7] ptrace: kill task_ptrace()

From: Tejun Heo
Date: Fri Jun 17 2011 - 10:54:01 EST


task_ptrace(task) simply dereferences task->ptrace and isn't even used
consistently only adding confusion. Kill it and directly access
->ptrace instead.

This doesn't introduce any behavior change.

Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>
---
include/linux/ptrace.h | 11 -----------
include/linux/tracehook.h | 16 ++++++++--------
kernel/exit.c | 8 ++++----
kernel/signal.c | 14 +++++++-------
mm/oom_kill.c | 3 +--
5 files changed, 20 insertions(+), 32 deletions(-)

diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h
index 4f224f1..3ff20b3 100644
--- a/include/linux/ptrace.h
+++ b/include/linux/ptrace.h
@@ -146,17 +146,6 @@ int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr,
unsigned long data);

/**
- * task_ptrace - return %PT_* flags that apply to a task
- * @task: pointer to &task_struct in question
- *
- * Returns the %PT_* flags that apply to @task.
- */
-static inline int task_ptrace(struct task_struct *task)
-{
- return task->ptrace;
-}
-
-/**
* 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
diff --git a/include/linux/tracehook.h b/include/linux/tracehook.h
index 15745cd..a3e8387 100644
--- a/include/linux/tracehook.h
+++ b/include/linux/tracehook.h
@@ -63,7 +63,7 @@ struct linux_binprm;
*/
static inline int tracehook_expect_breakpoints(struct task_struct *task)
{
- return (task_ptrace(task) & PT_PTRACED) != 0;
+ return (task->ptrace & PT_PTRACED) != 0;
}

/*
@@ -71,7 +71,7 @@ static inline int tracehook_expect_breakpoints(struct task_struct *task)
*/
static inline void ptrace_report_syscall(struct pt_regs *regs)
{
- int ptrace = task_ptrace(current);
+ int ptrace = current->ptrace;

if (!(ptrace & PT_PTRACED))
return;
@@ -155,7 +155,7 @@ static inline void tracehook_report_syscall_exit(struct pt_regs *regs, int step)
static inline int tracehook_unsafe_exec(struct task_struct *task)
{
int unsafe = 0;
- int ptrace = task_ptrace(task);
+ int ptrace = task->ptrace;
if (ptrace & PT_PTRACED) {
if (ptrace & PT_PTRACE_CAP)
unsafe |= LSM_UNSAFE_PTRACE_CAP;
@@ -178,7 +178,7 @@ static inline int tracehook_unsafe_exec(struct task_struct *task)
*/
static inline struct task_struct *tracehook_tracer_task(struct task_struct *tsk)
{
- if (task_ptrace(tsk) & PT_PTRACED)
+ if (tsk->ptrace & PT_PTRACED)
return rcu_dereference(tsk->parent);
return NULL;
}
@@ -202,7 +202,7 @@ static inline void tracehook_report_exec(struct linux_binfmt *fmt,
struct pt_regs *regs)
{
if (!ptrace_event(PT_TRACE_EXEC, PTRACE_EVENT_EXEC, 0) &&
- unlikely(task_ptrace(current) & PT_PTRACED))
+ unlikely(current->ptrace & PT_PTRACED))
send_sig(SIGTRAP, current, 0);
}

@@ -285,7 +285,7 @@ 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))) {
+ if (unlikely(child->ptrace)) {
/*
* It doesn't matter who attached/attaching to this
* task, the pending SIGSTOP is right in any case.
@@ -403,7 +403,7 @@ static inline void tracehook_signal_handler(int sig, siginfo_t *info,
static inline int tracehook_consider_ignored_signal(struct task_struct *task,
int sig)
{
- return (task_ptrace(task) & PT_PTRACED) != 0;
+ return (task->ptrace & PT_PTRACED) != 0;
}

/**
@@ -422,7 +422,7 @@ static inline int tracehook_consider_ignored_signal(struct task_struct *task,
static inline int tracehook_consider_fatal_signal(struct task_struct *task,
int sig)
{
- return (task_ptrace(task) & PT_PTRACED) != 0;
+ return (task->ptrace & PT_PTRACED) != 0;
}

#define DEATH_REAP -1
diff --git a/kernel/exit.c b/kernel/exit.c
index 289f59d..e5cc056 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -765,7 +765,7 @@ static void reparent_leader(struct task_struct *father, struct task_struct *p,
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)) {
@@ -795,7 +795,7 @@ static void forget_original_parent(struct task_struct *father)
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)
@@ -1565,7 +1565,7 @@ static int wait_consider_task(struct wait_opts *wo, int ptrace,
* 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;
@@ -1608,7 +1608,7 @@ static int wait_consider_task(struct wait_opts *wo, int ptrace,
* own children, it should create a separate process which
* takes the role of real parent.
*/
- if (likely(!ptrace) && task_ptrace(p) &&
+ if (likely(!ptrace) && p->ptrace &&
same_thread_group(p->parent, p->real_parent))
return 0;

diff --git a/kernel/signal.c b/kernel/signal.c
index 97e575a..0f33708 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1592,7 +1592,7 @@ int do_notify_parent(struct task_struct *tsk, int sig)
/* 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;
@@ -1631,7 +1631,7 @@ int do_notify_parent(struct task_struct *tsk, int sig)

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))) {
/*
@@ -1731,7 +1731,7 @@ static void do_notify_parent_cldstop(struct task_struct *tsk,

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?
@@ -1989,7 +1989,7 @@ static bool do_signal_stop(int signr)
if (!(sig->flags & SIGNAL_STOP_STOPPED))
sig->group_exit_code = signr;
else
- WARN_ON_ONCE(!task_ptrace(current));
+ WARN_ON_ONCE(!current->ptrace);

sig->group_stop_count = 0;

@@ -2014,7 +2014,7 @@ static bool do_signal_stop(int signr)
}
}

- if (likely(!task_ptrace(current))) {
+ if (likely(!current->ptrace)) {
int notify = 0;

/*
@@ -2093,7 +2093,7 @@ static void do_jobctl_trap(void)
static int ptrace_signal(int signr, siginfo_t *info,
struct pt_regs *regs, void *cookie)
{
- if (!task_ptrace(current))
+ if (!current->ptrace)
return signr;

ptrace_signal_deliver(regs, cookie);
@@ -2179,7 +2179,7 @@ relock:
do_notify_parent_cldstop(current, false, why);

leader = current->group_leader;
- if (task_ptrace(leader) && !real_parent_is_ptracer(leader))
+ if (leader->ptrace && !real_parent_is_ptracer(leader))
do_notify_parent_cldstop(leader, true, why);

read_unlock(&tasklist_lock);
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 @@ static struct task_struct *select_bad_process(unsigned int *ppoints,
* 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);
}
}
--
1.7.5.4

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