x86, bts: add fork and exit handling

Impact: introduce new ptrace facility

Add arch_ptrace_untrace() function that is called when the tracer
detaches (either voluntarily or when the tracing task dies);
ptrace_disable() is only called on a voluntary detach.

Add ptrace_fork() and arch_ptrace_fork(). They are called when a
traced task is forked.

Clear DS and BTS related fields on fork.

Release DS resources and reclaim memory in ptrace_untrace(). This
releases resources already when the tracing task dies. We used to do
that when the traced task dies.

Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Markus Metzger 2008-12-19 15:10:24 +01:00 committed by Ingo Molnar
parent 30cd324e97
commit bf53de907d
9 changed files with 119 additions and 30 deletions

View file

@ -94,6 +94,7 @@ 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. */
@ -313,6 +314,27 @@ static inline void user_enable_block_step(struct task_struct *task)
#define arch_ptrace_stop(code, info) do { } while (0)
#endif
#ifndef arch_ptrace_untrace
/*
* Do machine-specific work before untracing child.
*
* This is called for a normal detach as well as from ptrace_exit()
* when the tracing task dies.
*
* Called with write_lock(&tasklist_lock) held.
*/
#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);