ptrace_write_dr7() looks unnecessarily overcomplicated. We can
factor out ptrace_modify_breakpoint() and do not do "continue"
twice, just we need to pass the proper "disabled" argument to
ptrace_modify_breakpoint().
Signed-off-by: Oleg Nesterov <o...@redhat.com>
---
arch/x86/kernel/ptrace.c | 40 +++++++++++++++-------------------------
1 files changed, 15 insertions(+), 25 deletions(-)
diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index 7a98b21..0649f16 100644
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -637,9 +637,7 @@ static int ptrace_write_dr7(struct task_struct *tsk,
unsigned long data)
struct thread_struct *thread = &(tsk->thread);
unsigned long old_dr7;
int i, orig_ret = 0, rc = 0;
- int enabled, second_pass = 0;
- unsigned len, type;
- struct perf_event *bp;
+ int second_pass = 0;
data &= ~DR_CONTROL_RESERVED;
old_dr7 = ptrace_get_dr7(thread->ptrace_bps);
@@ -649,30 +647,22 @@ restore:
* appropriate changes to each.
*/
for (i = 0; i < HBP_NUM; i++) {
- enabled = decode_dr7(data, i, &len, &type);
- bp = thread->ptrace_bps[i];
-
- if (!enabled) {
- if (bp) {
- /*
- * Don't unregister the breakpoints right-away,
- * unless all register_user_hw_breakpoint()
- * requests have succeeded. This prevents
- * any window of opportunity for debug
- * register grabbing by other users.
- */
- if (!second_pass)
- continue;
-
- rc = ptrace_modify_breakpoint(bp, len, type,
- tsk, 1);
- if (rc)
- break;
- }
- continue;
+ unsigned len, type;
+ bool disabled = !decode_dr7(data, i, &len, &type);
+ struct perf_event *bp = thread->ptrace_bps[i];
+
+ if (disabled) {
+ /*
+ * Don't unregister the breakpoints right-away, unless
+ * all register_user_hw_breakpoint() requests have
+ * succeeded. This prevents any window of opportunity
+ * for debug register grabbing by other users.
+ */
+ if (!bp || !second_pass)
+ continue;
}
- rc = ptrace_modify_breakpoint(bp, len, type, tsk, 0);
+ rc = ptrace_modify_breakpoint(bp, len, type, tsk, disabled);
if (rc)
break;
}
--
1.5.5.1
--
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