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Diffstat (limited to 'arch/s390/kernel/jump_label.c')
-rw-r--r--arch/s390/kernel/jump_label.c19
1 files changed, 13 insertions, 6 deletions
diff --git a/arch/s390/kernel/jump_label.c b/arch/s390/kernel/jump_label.c
index 25aef40584f7..cb2d51e779df 100644
--- a/arch/s390/kernel/jump_label.c
+++ b/arch/s390/kernel/jump_label.c
@@ -49,6 +49,11 @@ static void jump_label_bug(struct jump_entry *entry, struct insn *insn)
panic("Corrupted kernel text");
}
+static struct insn orignop = {
+ .opcode = 0xc004,
+ .offset = JUMP_LABEL_NOP_OFFSET >> 1,
+};
+
static void __jump_label_transform(struct jump_entry *entry,
enum jump_label_type type,
int init)
@@ -59,14 +64,16 @@ static void __jump_label_transform(struct jump_entry *entry,
jump_label_make_nop(entry, &old);
jump_label_make_branch(entry, &new);
} else {
- if (init)
- jump_label_make_nop(entry, &old);
- else
- jump_label_make_branch(entry, &old);
+ jump_label_make_branch(entry, &old);
jump_label_make_nop(entry, &new);
}
- if (memcmp((void *)entry->code, &old, sizeof(old)))
- jump_label_bug(entry, &old);
+ if (init) {
+ if (memcmp((void *)entry->code, &orignop, sizeof(orignop)))
+ jump_label_bug(entry, &old);
+ } else {
+ if (memcmp((void *)entry->code, &old, sizeof(old)))
+ jump_label_bug(entry, &old);
+ }
probe_kernel_write((void *)entry->code, &new, sizeof(new));
}