Messages in this thread Patch in this message | | | Date | Mon, 25 May 2009 02:00:12 +0200 | From | Oleg Nesterov <> | Subject | [RFC PATCH 6/X] ptrace: change __ptrace_link() to set ->pt_flags, rename to ptrace_link() |
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Every caller of __ptrace_link() must set ->pt_flags, move this code into this helper and rename it to ptrace_link().
Note that we do not pass PT_PTRACED, it is always set by ptrace_link().
include/linux/ptrace.h | 11 +++++------ kernel/ptrace.c | 25 +++++++++++-------------- 2 files changed, 16 insertions(+), 20 deletions(-)
--- PTRACE/include/linux/ptrace.h~6_PTRACE_LINK 2009-05-24 22:37:50.000000000 +0200 +++ PTRACE/include/linux/ptrace.h 2009-05-24 23:38:10.000000000 +0200 @@ -91,8 +91,8 @@ extern void ptrace_disable(struct task_s extern int ptrace_check_attach(struct task_struct *task, int kill); extern int ptrace_request(struct task_struct *child, long request, long addr, long data); extern void ptrace_notify(int exit_code); -extern void __ptrace_link(struct task_struct *child, - struct task_struct *new_parent); +extern void ptrace_link(struct task_struct *child, unsigned int flags, + struct task_struct *tracer); extern void __ptrace_unlink(struct task_struct *child); extern void exit_ptrace(struct task_struct *tracer); extern void ptrace_fork(struct task_struct *task, unsigned long clone_flags); @@ -165,10 +165,9 @@ static inline void ptrace_init_task(stru INIT_LIST_HEAD(&child->ptrace_entry); INIT_LIST_HEAD(&child->ptraced); child->parent = child->real_parent; - if (unlikely(child->ptrace_task) && task_ptrace(current)) { - child->ptrace_task->pt_flags = task_ptrace(current); - __ptrace_link(child, current->parent); - } + + if (unlikely(child->ptrace_task) && task_ptrace(current)) + ptrace_link(child, task_ptrace(current), current->parent); } /** --- PTRACE/kernel/ptrace.c~6_PTRACE_LINK 2009-05-24 23:09:13.000000000 +0200 +++ PTRACE/kernel/ptrace.c 2009-05-25 00:03:45.000000000 +0200 @@ -40,11 +40,14 @@ void ptrace_fork(struct task_struct *chi * * Must be called with the tasklist lock write-held. */ -void __ptrace_link(struct task_struct *child, struct task_struct *new_parent) +void ptrace_link(struct task_struct *child, unsigned int flags, + struct task_struct *tracer) { + child->ptrace_task->pt_flags = flags | PT_PTRACED; + BUG_ON(!list_empty(&child->ptrace_entry)); - list_add(&child->ptrace_entry, &new_parent->ptraced); - child->parent = new_parent; + list_add(&child->ptrace_entry, &tracer->ptraced); + child->parent = tracer; } /* @@ -193,7 +196,7 @@ int alloc_ptrace_task(struct task_struct int ptrace_attach(struct task_struct *task) { - int retval; + int retval, flags; audit_ptrace(task); @@ -227,11 +230,8 @@ int ptrace_attach(struct task_struct *ta if (task_ptrace(task)) goto unlock_tasklist; - task->ptrace_task->pt_flags = PT_PTRACED; - if (capable(CAP_SYS_PTRACE)) - task->ptrace_task->pt_flags |= PT_PTRACE_CAP; - - __ptrace_link(task, current); + flags = capable(CAP_SYS_PTRACE) ? PT_PTRACE_CAP : 0; + ptrace_link(task, flags, current); send_sig_info(SIGSTOP, SEND_SIG_FORCED, task); retval = 0; @@ -246,7 +246,6 @@ out: /** * ptrace_traceme -- helper for PTRACE_TRACEME * - * Performs checks and sets PT_PTRACED. * Should be used by all ptrace implementations for PTRACE_TRACEME. */ int ptrace_traceme(void) @@ -266,10 +265,8 @@ int ptrace_traceme(void) * exit_ptrace(). Otherwise we don't report the error but * pretend ->real_parent untraces us right after return. */ - if (!ret && !(current->real_parent->flags & PF_EXITING)) { - current->ptrace_task->pt_flags = PT_PTRACED; - __ptrace_link(current, current->real_parent); - } + if (!ret && !(current->real_parent->flags & PF_EXITING)) + ptrace_link(current, 0, current->real_parent); } write_unlock_irq(&tasklist_lock);
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