From 662912d8961ec73e1cbc2b4f0903627c242cf9d6 Mon Sep 17 00:00:00 2001
From: Arthur Hanson Rasmusson <arthur@vgpu.io>
Date: Wed, 30 Sep 2026 08:08:32 -0400
Subject: guest-diag: cdt2 payload scan only touches anon/device mappings
 (avoid SIGBUS on truncated file maps)

---
 tools/test/cuda_drv_test2.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/tools/test/cuda_drv_test2.c b/tools/test/cuda_drv_test2.c
index cfe21d8..d4f848a 100644
--- a/tools/test/cuda_drv_test2.c
+++ b/tools/test/cuda_drv_test2.c
@@ -87,6 +87,13 @@ static void scan_self_for_payload(const char *tag)
                    perms, off, path);
         if (perms[0] != 'r' || b <= a || b - a > (512ULL << 20))
             continue;
+        /*
+         * Only scan anonymous and device mappings: reading a truncated
+         * file-backed mapping past EOF raises SIGBUS and killed the client
+         * silently before cuMemcpyDtoH.
+         */
+        if (path[0] && path[0] != '[' && strncmp(path, "/dev/", 5))
+            continue;
         {
             volatile unsigned long long *p;
             for (p = (volatile unsigned long long *)a;
-- 
cgit v1.2.3