[patch 15/18] x86, ptrace: remove duplicate functionality

From: markus . t . metzger
Date: Thu Apr 02 2009 - 11:02:38 EST


Some time ago, I added a ptrace_fork() function to initialize branch
tracing stuff when a new task is created.
There is already a ptrace_init_task() function for that.


Add an arch_ variant to ptrace_init_task() and remove the
ptrace_fork() version.


Signed-off-by: Markus Metzger <markus.t.metzger@xxxxxxxxx>
---
arch/x86/include/asm/ptrace.h | 11 6 + 5 - 0 !
arch/x86/kernel/ptrace.c | 17 2 + 15 - 0 !
include/linux/ptrace.h | 24 14 + 10 - 0 !
kernel/fork.c | 2 0 + 2 - 0 !
kernel/ptrace.c | 10 0 + 10 - 0 !
5 files changed, 22 insertions(+), 42 deletions(-)

Index: b/arch/x86/include/asm/ptrace.h
===================================================================
--- a/arch/x86/include/asm/ptrace.h
+++ b/arch/x86/include/asm/ptrace.h
@@ -235,12 +235,13 @@ extern int do_get_thread_area(struct tas
extern int do_set_thread_area(struct task_struct *p, int idx,
struct user_desc __user *info, int can_allocate);

-extern void x86_ptrace_untrace(struct task_struct *);
-extern void x86_ptrace_fork(struct task_struct *child,
- unsigned long clone_flags);
+#ifdef CONFIG_X86_PTRACE_BTS
+extern void ptrace_bts_untrace(struct task_struct *tsk);
+extern void ptrace_bts_init_task(struct task_struct *tsk);

-#define arch_ptrace_untrace(tsk) x86_ptrace_untrace(tsk)
-#define arch_ptrace_fork(child, flags) x86_ptrace_fork(child, flags)
+#define arch_ptrace_untrace(tsk) ptrace_bts_untrace(tsk)
+#define arch_ptrace_init_task(tsk) ptrace_bts_init_task(tsk)
+#endif /* CONFIG_X86_PTRACE_BTS */

#endif /* __KERNEL__ */

Index: b/include/linux/ptrace.h
===================================================================
--- a/include/linux/ptrace.h
+++ b/include/linux/ptrace.h
@@ -94,7 +94,6 @@ extern void ptrace_notify(int exit_code)
extern void __ptrace_link(struct task_struct *child,
struct task_struct *new_parent);
extern void __ptrace_unlink(struct task_struct *child);
-extern void ptrace_fork(struct task_struct *task, unsigned long clone_flags);
#define PTRACE_MODE_READ 1
#define PTRACE_MODE_ATTACH 2
/* Returns 0 on success, -errno on denial. */
@@ -154,6 +153,18 @@ static inline int ptrace_event(int mask,
return 1;
}

+#ifndef arch_ptrace_init_task
+/**
+ * arch_ptrace_init_task - initialize machine specific state for a new child
+ * @child: new child task
+ *
+ * This is called immediately after initializing the general ptrace state.
+ *
+ * Called with current's siglock and write_lock_irq(&tasklist_lock) held.
+ */
+#define arch_ptrace_init_task(child) do { } while (0)
+#endif
+
/**
* ptrace_init_task - initialize ptrace state for a new child
* @child: new child task
@@ -174,6 +185,8 @@ static inline void ptrace_init_task(stru
child->ptrace = current->ptrace;
ptrace_link(child, current->parent);
}
+
+ arch_ptrace_init_task(child);
}

/**
@@ -326,15 +339,6 @@ static inline void user_enable_block_ste
#define arch_ptrace_untrace(task) do { } while (0)
#endif

-#ifndef arch_ptrace_fork
-/*
- * Do machine-specific work to initialize a new task.
- *
- * This is called from copy_process().
- */
-#define arch_ptrace_fork(child, clone_flags) do { } while (0)
-#endif
-
extern int task_current_syscall(struct task_struct *target, long *callno,
unsigned long args[6], unsigned int maxargs,
unsigned long *sp, unsigned long *pc);
Index: b/kernel/fork.c
===================================================================
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1100,8 +1100,6 @@ static struct task_struct *copy_process(
#ifdef CONFIG_DEBUG_MUTEXES
p->blocked_on = NULL; /* not blocked yet */
#endif
- if (unlikely(current->ptrace))
- ptrace_fork(p, clone_flags);

/* Perform scheduler related setup. Assign this task to a CPU. */
sched_fork(p, clone_flags);
Index: b/kernel/ptrace.c
===================================================================
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -27,16 +27,6 @@


/*
- * Initialize a new task whose father had been ptraced.
- *
- * Called from copy_process().
- */
-void ptrace_fork(struct task_struct *child, unsigned long clone_flags)
-{
- arch_ptrace_fork(child, clone_flags);
-}
-
-/*
* ptrace a task: make the debugger its new parent and
* move it to the ptrace list.
*
Index: b/arch/x86/kernel/ptrace.c
===================================================================
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -885,7 +885,7 @@ static int ptrace_bts_size(struct task_s
return (trace->ds.top - trace->ds.begin) / trace->ds.size;
}

-static inline void ptrace_bts_fork(struct task_struct *tsk)
+void ptrace_bts_init_task(struct task_struct *tsk)
{
tsk->bts = NULL;
tsk->thread.bts_ovfl_signal = 0;
@@ -895,28 +895,15 @@ static inline void ptrace_bts_fork(struc
* Called from __ptrace_unlink() after the child has been moved back
* to its original parent.
*/
-static inline void ptrace_bts_untrace(struct task_struct *child)
+void ptrace_bts_untrace(struct task_struct *child)
{
if (unlikely(child->bts)) {
free_bts_context(child->bts);
child->bts = NULL;
}
}
-#else
-static inline void ptrace_bts_fork(struct task_struct *tsk) {}
-static inline void ptrace_bts_untrace(struct task_struct *child) {}
#endif /* CONFIG_X86_PTRACE_BTS */

-void x86_ptrace_fork(struct task_struct *child, unsigned long clone_flags)
-{
- ptrace_bts_fork(child);
-}
-
-void x86_ptrace_untrace(struct task_struct *child)
-{
- ptrace_bts_untrace(child);
-}
-
/*
* Called by kernel/ptrace.c when detaching..
*

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