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-rw-r--r--include/linux/ptrace.h13
-rw-r--r--include/linux/sched.h3
-rw-r--r--kernel/exit.c2
-rw-r--r--kernel/ptrace.c17
4 files changed, 33 insertions, 2 deletions
diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h
index a1147e5dd24..9178d5cc0b0 100644
--- a/include/linux/ptrace.h
+++ b/include/linux/ptrace.h
@@ -189,6 +189,10 @@ static inline void ptrace_init_task(struct task_struct *child, bool ptrace)
child->ptrace = current->ptrace;
__ptrace_link(child, current->parent);
}
+
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
+ atomic_set(&child->ptrace_bp_refcnt, 1);
+#endif
}
/**
@@ -350,6 +354,13 @@ extern int task_current_syscall(struct task_struct *target, long *callno,
unsigned long args[6], unsigned int maxargs,
unsigned long *sp, unsigned long *pc);
-#endif
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
+extern int ptrace_get_breakpoints(struct task_struct *tsk);
+extern void ptrace_put_breakpoints(struct task_struct *tsk);
+#else
+static inline void ptrace_put_breakpoints(struct task_struct *tsk) { }
+#endif /* CONFIG_HAVE_HW_BREAKPOINT */
+
+#endif /* __KERNEL */
#endif
diff --git a/include/linux/sched.h b/include/linux/sched.h
index ed6c384ba6c..d2a5da917ed 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1531,6 +1531,9 @@ struct task_struct {
unsigned long memsw_bytes; /* uncharged mem+swap usage */
} memcg_batch;
#endif
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
+ atomic_t ptrace_bp_refcnt;
+#endif
};
/* Future-safe accessor for struct task_struct's cpus_allowed. */
diff --git a/kernel/exit.c b/kernel/exit.c
index f9a45ebcc7b..557a348f682 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -1015,7 +1015,7 @@ NORET_TYPE void do_exit(long code)
/*
* FIXME: do that only when needed, using sched_exit tracepoint
*/
- flush_ptrace_hw_breakpoint(tsk);
+ ptrace_put_breakpoints(tsk);
exit_notify(tsk, group_dead);
#ifdef CONFIG_NUMA
diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index e2302e40b36..254ad5b5251 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -22,6 +22,7 @@
#include <linux/syscalls.h>
#include <linux/uaccess.h>
#include <linux/regset.h>
+#include <linux/hw_breakpoint.h>
/*
@@ -876,3 +877,19 @@ asmlinkage long compat_sys_ptrace(compat_long_t request, compat_long_t pid,
return ret;
}
#endif /* CONFIG_COMPAT */
+
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
+int ptrace_get_breakpoints(struct task_struct *tsk)
+{
+ if (atomic_inc_not_zero(&tsk->ptrace_bp_refcnt))
+ return 0;
+
+ return -1;
+}
+
+void ptrace_put_breakpoints(struct task_struct *tsk)
+{
+ if (atomic_dec_and_test(&tsk->ptrace_bp_refcnt))
+ flush_ptrace_hw_breakpoint(tsk);
+}
+#endif /* CONFIG_HAVE_HW_BREAKPOINT */