kvm_cpu_thread()'s panic path uses the kernel's exit_reason to index
kvm_exit_reasons[] without checking it against the array's size. The
table does not cover every exit reason KVM can return, so a reason past
its last entry reads out of bounds. KVM_EXIT_SYSTEM_EVENT and
KVM_EXIT_ARM_NISV are both past it.

Move the table behind kvm__exit_reason_str(), which checks the index
first. The array now has a single caller inside kvm.c, so make it
static const.

Signed-off-by: Fuad Tabba <fuad.tabba@linux.dev>
---
 builtin-run.c     |  2 +-
 include/kvm/kvm.h |  2 +-
 kvm.c             | 10 +++++++++-
 3 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/builtin-run.c b/builtin-run.c
index 81f255f..f36d3e2 100644
--- a/builtin-run.c
+++ b/builtin-run.c
@@ -298,7 +298,7 @@ static void *kvm_cpu_thread(void *arg)
 panic_kvm:
 	pr_err("KVM exit reason: %u (\"%s\")",
 		current_kvm_cpu->kvm_run->exit_reason,
-		kvm_exit_reasons[current_kvm_cpu->kvm_run->exit_reason]);
+		kvm__exit_reason_str(current_kvm_cpu->kvm_run->exit_reason));
 
 	if (current_kvm_cpu->kvm_run->exit_reason == KVM_EXIT_UNKNOWN) {
 		pr_err("KVM exit code: %llu",
diff --git a/include/kvm/kvm.h b/include/kvm/kvm.h
index a9376b6..8619070 100644
--- a/include/kvm/kvm.h
+++ b/include/kvm/kvm.h
@@ -255,7 +255,7 @@ int kvm__for_each_mem_bank(struct kvm *kvm, enum kvm_mem_type type,
  */
 void kvm__dump_mem(struct kvm *kvm, unsigned long addr, unsigned long size, int debug_fd);
 
-extern const char *kvm_exit_reasons[];
+const char *kvm__exit_reason_str(__u32 exit_reason);
 
 static inline bool host_ptr_in_ram(struct kvm *kvm, void *p)
 {
diff --git a/kvm.c b/kvm.c
index 96583f9..b416f6f 100644
--- a/kvm.c
+++ b/kvm.c
@@ -33,7 +33,7 @@
 
 #define DEFINE_KVM_EXIT_REASON(reason) [reason] = #reason
 
-const char *kvm_exit_reasons[] = {
+static const char * const kvm_exit_reasons[] = {
 	DEFINE_KVM_EXIT_REASON(KVM_EXIT_UNKNOWN),
 	DEFINE_KVM_EXIT_REASON(KVM_EXIT_EXCEPTION),
 	DEFINE_KVM_EXIT_REASON(KVM_EXIT_IO),
@@ -57,6 +57,14 @@ const char *kvm_exit_reasons[] = {
 #endif
 };
 
+const char *kvm__exit_reason_str(__u32 exit_reason)
+{
+	if (exit_reason >= ARRAY_SIZE(kvm_exit_reasons))
+		return "UNKNOWN";
+
+	return kvm_exit_reasons[exit_reason];
+}
+
 static int pause_event;
 static DEFINE_MUTEX(pause_lock);
 static struct kvm_cpu *pause_req_cpu;
-- 
2.39.5