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authorTony Luck <tony.luck@intel.com>2005-10-28 15:27:48 -0700
committerTony Luck <tony.luck@intel.com>2005-10-28 15:27:48 -0700
commit9590204d31f8a5f47e890fbbdbcd37dd78f0581a (patch)
tree670235feba2ca1fffe0bd26ddecdf1c08f87618c /arch/ia64/kernel/ptrace.c
parent8496f2a4513edbc0c1d40496f1b0868dfed36eb0 (diff)
parent4ac0068f44f192f2de95a7bb36df3e19767a45fb (diff)
Pull optimize-ptrace-threads into release branch
Diffstat (limited to 'arch/ia64/kernel/ptrace.c')
-rw-r--r--arch/ia64/kernel/ptrace.c26
1 files changed, 10 insertions, 16 deletions
diff --git a/arch/ia64/kernel/ptrace.c b/arch/ia64/kernel/ptrace.c
index bbb8bc7c055..9a9c1bd01db 100644
--- a/arch/ia64/kernel/ptrace.c
+++ b/arch/ia64/kernel/ptrace.c
@@ -589,6 +589,7 @@ find_thread_for_addr (struct task_struct *child, unsigned long addr)
{
struct task_struct *g, *p;
struct mm_struct *mm;
+ struct list_head *this, *next;
int mm_users;
if (!(mm = get_task_mm(child)))
@@ -600,28 +601,21 @@ find_thread_for_addr (struct task_struct *child, unsigned long addr)
goto out; /* not multi-threaded */
/*
- * First, traverse the child's thread-list. Good for scalability with
- * NPTL-threads.
+ * 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).
*/
- p = child;
- do {
- if (thread_matches(p, addr)) {
- child = p;
- goto out;
- }
- if (mm_users-- <= 1)
- goto out;
- } while ((p = next_thread(p)) != child);
-
- do_each_thread(g, p) {
- if (child->mm != mm)
+ list_for_each_safe(this, next, &current->children) {
+ p = list_entry(this, struct task_struct, sibling);
+ if (p->mm != mm)
continue;
-
if (thread_matches(p, addr)) {
child = p;
goto out;
}
- } while_each_thread(g, p);
+ }
+
out:
mmput(mm);
return child;