s390/jump label: improve and fix sanity check

Fix the output of the jump label sanity check and also print the
code pattern that is supposed to be written to the jump label.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 8 insertions, 4 deletions

diff --git a/arch/s390/kernel/jump_label.c b/arch/s390/kernel/jump_label.c
index cb2d51e779df..830066f936c8 100644
--- a/arch/s390/kernel/jump_label.c
+++ b/arch/s390/kernel/jump_label.c
@@ -36,16 +36,20 @@ static void jump_label_make_branch(struct jump_entry *entry, struct insn *insn)
 	insn->offset = (entry->target - entry->code) >> 1;
 }
 
-static void jump_label_bug(struct jump_entry *entry, struct insn *insn)
+static void jump_label_bug(struct jump_entry *entry, struct insn *expected,
+			   struct insn *new)
 {
 	unsigned char *ipc = (unsigned char *)entry->code;
-	unsigned char *ipe = (unsigned char *)insn;
+	unsigned char *ipe = (unsigned char *)expected;
+	unsigned char *ipn = (unsigned char *)new;
 
 	pr_emerg("Jump label code mismatch at %pS [%p]\n", ipc, ipc);
 	pr_emerg("Found:    %02x %02x %02x %02x %02x %02x\n",
 		 ipc[0], ipc[1], ipc[2], ipc[3], ipc[4], ipc[5]);
 	pr_emerg("Expected: %02x %02x %02x %02x %02x %02x\n",
 		 ipe[0], ipe[1], ipe[2], ipe[3], ipe[4], ipe[5]);
+	pr_emerg("New:      %02x %02x %02x %02x %02x %02x\n",
+		 ipn[0], ipn[1], ipn[2], ipn[3], ipn[4], ipn[5]);
 	panic("Corrupted kernel text");
 }
 
@@ -69,10 +73,10 @@ static void __jump_label_transform(struct jump_entry *entry,
 	}
 	if (init) {
 		if (memcmp((void *)entry->code, &orignop, sizeof(orignop)))
-			jump_label_bug(entry, &old);
+			jump_label_bug(entry, &orignop, &new);
 	} else {
 		if (memcmp((void *)entry->code, &old, sizeof(old)))
-			jump_label_bug(entry, &old);
+			jump_label_bug(entry, &old, &new);
 	}
 	probe_kernel_write((void *)entry->code, &new, sizeof(new));
 }