[RFC][PATCH 1/7] objtool: is_fentry_call() crashes if call has no destination

[Peter Zijlstra]

From: Alexandre Chartre <alexandre.chartre@xxxxxxxxxx>

Fix is_fentry_call() so that it works if a call has no destination
set (call_dest). This needs to be done in order to support intra-
function calls.

Signed-off-by: Alexandre Chartre <alexandre.chartre@xxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Link: https://lkml.kernel.org/r/20200414103618.12657-2-alexandre.chartre@xxxxxxxxxx
---
 tools/objtool/check.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -1490,7 +1490,7 @@ static int decode_sections(struct objtoo
 
 static bool is_fentry_call(struct instruction *insn)
 {
-	if (insn->type == INSN_CALL &&
+	if (insn->type == INSN_CALL && insn->call_dest &&
 	    insn->call_dest->type == STT_NOTYPE &&
 	    !strcmp(insn->call_dest->name, "__fentry__"))
 		return true;