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-rw-r--r--arch/x86/kernel/unwind_orc.c48
1 files changed, 47 insertions, 1 deletions
diff --git a/arch/x86/kernel/unwind_orc.c b/arch/x86/kernel/unwind_orc.c
index be86a865087a..1f9188f5357c 100644
--- a/arch/x86/kernel/unwind_orc.c
+++ b/arch/x86/kernel/unwind_orc.c
@@ -74,8 +74,50 @@ static struct orc_entry *orc_module_find(unsigned long ip)
}
#endif
+#ifdef CONFIG_DYNAMIC_FTRACE
+static struct orc_entry *orc_find(unsigned long ip);
+
+/*
+ * Ftrace dynamic trampolines do not have orc entries of their own.
+ * But they are copies of the ftrace entries that are static and
+ * defined in ftrace_*.S, which do have orc entries.
+ *
+ * If the undwinder comes across a ftrace trampoline, then find the
+ * ftrace function that was used to create it, and use that ftrace
+ * function's orc entrie, as the placement of the return code in
+ * the stack will be identical.
+ */
+static struct orc_entry *orc_ftrace_find(unsigned long ip)
+{
+ struct ftrace_ops *ops;
+ unsigned long caller;
+
+ ops = ftrace_ops_trampoline(ip);
+ if (!ops)
+ return NULL;
+
+ if (ops->flags & FTRACE_OPS_FL_SAVE_REGS)
+ caller = (unsigned long)ftrace_regs_call;
+ else
+ caller = (unsigned long)ftrace_call;
+
+ /* Prevent unlikely recursion */
+ if (ip == caller)
+ return NULL;
+
+ return orc_find(caller);
+}
+#else
+static struct orc_entry *orc_ftrace_find(unsigned long ip)
+{
+ return NULL;
+}
+#endif
+
static struct orc_entry *orc_find(unsigned long ip)
{
+ static struct orc_entry *orc;
+
if (!orc_init)
return NULL;
@@ -111,7 +153,11 @@ static struct orc_entry *orc_find(unsigned long ip)
__stop_orc_unwind_ip - __start_orc_unwind_ip, ip);
/* Module lookup: */
- return orc_module_find(ip);
+ orc = orc_module_find(ip);
+ if (orc)
+ return orc;
+
+ return orc_ftrace_find(ip);
}
static void orc_sort_swap(void *_a, void *_b, int size)