[IA64] remove find_thread_for_addr()

find_thread_for_addr() is no longer needed.  It was only used to find
the correct kernel RBS for a given memory address, but since the kernel
RBS is not needed any longer, this function can go away.

Signed-off-by: Petr Tesarik <ptesarik@suse.cz>
Signed-off-by: Tony Luck <tony.luck@intel.com>

1 files changed, 1 insertions, 55 deletions

diff --git a/arch/ia64/kernel/ptrace.c b/arch/ia64/kernel/ptrace.c
index 54b7ea551559..e82fe296c2c0 100644
--- a/arch/ia64/kernel/ptrace.c
+++ b/arch/ia64/kernel/ptrace.c
@@ -698,52 +698,6 @@ thread_matches (struct task_struct *thread, unsigned long addr)
 }
 
 /*
- * GDB apparently wants to be able to read the register-backing store
- * of any thread when attached to a given process.  If we are peeking
- * or poking an address that happens to reside in the kernel-backing
- * store of another thread, we need to attach to that thread, because
- * otherwise we end up accessing stale data.
- *
- * task_list_lock must be read-locked before calling this routine!
- */
-static struct task_struct *
-find_thread_for_addr (struct task_struct *child, unsigned long addr)
-{
-        struct task_struct *p;
-        struct mm_struct *mm;
-        struct list_head *this, *next;
-        int mm_users;
-
-        if (!(mm = get_task_mm(child)))
-                return child;
-
-        /* -1 because of our get_task_mm(): */
-        mm_users = atomic_read(&mm->mm_users) - 1;
-        if (mm_users <= 1)
-                goto out;               /* not multi-threaded */
-
-        /*
-         * Traverse the current process' children list.  Every task that
-         * one attaches to becomes a child.  And it is only attached children
-         * of the debugger that are of interest (ptrace_check_attach checks
-         * for this).
-         */
-        list_for_each_safe(this, next, &current->children) {
-                p = list_entry(this, struct task_struct, sibling);
-                if (p->tgid != child->tgid)
-                        continue;
-                if (thread_matches(p, addr)) {
-                        child = p;
-                        goto out;
-                }
-        }
-
-  out:
-        mmput(mm);
-        return child;
-}
-
-/*
  * Write f32-f127 back to task->thread.fph if it has been modified.
  */
 inline void
@@ -1520,7 +1474,6 @@ asmlinkage long
 sys_ptrace (long request, pid_t pid, unsigned long addr, unsigned long data)
 {
         struct pt_regs *pt;
-        unsigned long peek_or_poke;
         struct task_struct *child;
         struct switch_stack *sw;
         long ret;
@@ -1532,19 +1485,12 @@ sys_ptrace (long request, pid_t pid, unsigned long addr, unsigned long data)
                 goto out;
         }
 
-        peek_or_poke = (request == PTRACE_PEEKTEXT
-                        || request == PTRACE_PEEKDATA
-                        || request == PTRACE_POKETEXT
-                        || request == PTRACE_POKEDATA);
         ret = -ESRCH;
         read_lock(&tasklist_lock);
         {
                 child = find_task_by_pid(pid);
-                if (child) {
-                        if (peek_or_poke)
-                                child = find_thread_for_addr(child, addr);
+                if (child)
                         get_task_struct(child);
-                }
         }
         read_unlock(&tasklist_lock);
         if (!child)