[PATCH v2 2/2] kernelbase: Improve initialization of NUMA information to handle pathological cases

[wasertech]

From: wasertech

---
 dlls/kernelbase/memory.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/dlls/kernelbase/memory.c b/dlls/kernelbase/memory.c
index aa83ce85b24..a76d00df111 100644
--- a/dlls/kernelbase/memory.c
+++ b/dlls/kernelbase/memory.c
@@ -1557,8 +1557,16 @@ static void initialize_numa_info(void)
     /* Fallback single node if requested or none discovered */
     if (numa_force_single || (max_node == 0 && !numa_nodes[0].valid))
     {
-        SYSTEM_INFO si; GetSystemInfo(&si);
-        numa_nodes[0].cpu_mask = (si.dwNumberOfProcessors >= (sizeof(ULONG_PTR)*8)) ? ~(ULONG_PTR)0 : ((1ULL << si.dwNumberOfProcessors) - 1);
+        SYSTEM_INFO si; unsigned int cpu_count;
+        memset(&si, 0, sizeof(si)); /* explicit init to silence static analyzers */
+        GetSystemInfo(&si);
+        cpu_count = si.dwNumberOfProcessors;
+        if (cpu_count >= sizeof(ULONG_PTR) * 8)
+            numa_nodes[0].cpu_mask = ~(ULONG_PTR)0;
+        else if (cpu_count)
+            numa_nodes[0].cpu_mask = (((ULONG_PTR)1 << cpu_count) - 1);
+        else /* pathological case: assume at least CPU0 */
+            numa_nodes[0].cpu_mask = 1;
         numa_nodes[0].valid = TRUE; max_node = 0;
         TRACE_(numa)("NUMA fallback single: mask=0x%llx procs=%u\n", (unsigned long long)numa_nodes[0].cpu_mask, (unsigned)popcount_ulongptr(numa_nodes[0].cpu_mask));
     }