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-rw-r--r--include/linux/ptrace.h1
-rw-r--r--kernel/ptrace.c29
2 files changed, 28 insertions, 2 deletions
diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h
index 67ad3f15232..ad754d1e0b1 100644
--- a/include/linux/ptrace.h
+++ b/include/linux/ptrace.h
@@ -48,6 +48,7 @@
#define PTRACE_SETREGSET 0x4205
#define PTRACE_SEIZE 0x4206
+#define PTRACE_INTERRUPT 0x4207
/* flags in @data for PTRACE_SEIZE */
#define PTRACE_SEIZE_DEVEL 0x80000000 /* temp flag for development */
diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index dcf9f974198..6852c0f4a91 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -658,10 +658,12 @@ static int ptrace_regset(struct task_struct *task, int req, unsigned int type,
int ptrace_request(struct task_struct *child, long request,
unsigned long addr, unsigned long data)
{
+ bool seized = child->ptrace & PT_SEIZED;
int ret = -EIO;
siginfo_t siginfo;
void __user *datavp = (void __user *) data;
unsigned long __user *datalp = datavp;
+ unsigned long flags;
switch (request) {
case PTRACE_PEEKTEXT:
@@ -694,6 +696,27 @@ int ptrace_request(struct task_struct *child, long request,
ret = ptrace_setsiginfo(child, &siginfo);
break;
+ case PTRACE_INTERRUPT:
+ /*
+ * Stop tracee without any side-effect on signal or job
+ * control. At least one trap is guaranteed to happen
+ * after this request. If @child is already trapped, the
+ * current trap is not disturbed and another trap will
+ * happen after the current trap is ended with PTRACE_CONT.
+ *
+ * The actual trap might not be PTRACE_EVENT_STOP trap but
+ * the pending condition is cleared regardless.
+ */
+ if (unlikely(!seized || !lock_task_sighand(child, &flags)))
+ break;
+
+ if (likely(task_set_jobctl_pending(child, JOBCTL_TRAP_STOP)))
+ signal_wake_up(child, 0);
+
+ unlock_task_sighand(child, &flags);
+ ret = 0;
+ break;
+
case PTRACE_DETACH: /* detach a process that was attached. */
ret = ptrace_detach(child, data);
break;
@@ -819,7 +842,8 @@ SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr,
goto out_put_task_struct;
}
- ret = ptrace_check_attach(child, request == PTRACE_KILL);
+ ret = ptrace_check_attach(child, request == PTRACE_KILL ||
+ request == PTRACE_INTERRUPT);
if (ret < 0)
goto out_put_task_struct;
@@ -961,7 +985,8 @@ asmlinkage long compat_sys_ptrace(compat_long_t request, compat_long_t pid,
goto out_put_task_struct;
}
- ret = ptrace_check_attach(child, request == PTRACE_KILL);
+ ret = ptrace_check_attach(child, request == PTRACE_KILL ||
+ request == PTRACE_INTERRUPT);
if (!ret)
ret = compat_arch_ptrace(child, request, addr, data);