From 262049dee2cc639a802f255ceeb34f7528dea5b2 Mon Sep 17 00:00:00 2001
From: Dr-Noob <peibolms@gmail.com>
Date: Sun, 18 Feb 2024 18:22:35 +0000
Subject: [PATCH] [v1.05][X86] Fix bug where the number of cpus were not set if
 NULL was returned inside the loop. Ensure topo is not NULL in
 get_peak_performance. Fallback to UNKNOWN_DATA when we have no information
 about topology

---
 src/x86/cpuid.c | 36 ++++++++++++++++++++----------------
 1 file changed, 20 insertions(+), 16 deletions(-)

diff --git a/src/x86/cpuid.c b/src/x86/cpuid.c
index 1b00207..3507114 100644
--- a/src/x86/cpuid.c
+++ b/src/x86/cpuid.c
@@ -220,7 +220,7 @@ int64_t get_peak_performance(struct cpuInfo* cpu, bool accurate_pp) {
   #endif
 
     //First, check we have consistent data
-    if(freq == UNKNOWN_DATA || topo->logical_cores == UNKNOWN_DATA) {
+    if(freq == UNKNOWN_DATA || topo == NULL || topo->logical_cores == UNKNOWN_DATA) {
       return -1;
     }
 
@@ -453,7 +453,7 @@ struct cpuInfo* get_cpu_info(void) {
   cpu->cach = NULL;
   cpu->feat = NULL;
 
-  uint32_t modules = 1;
+  cpu->num_cpus = 1;
   uint32_t eax = 0;
   uint32_t ebx = 0;
   uint32_t ecx = 0;
@@ -509,12 +509,12 @@ struct cpuInfo* get_cpu_info(void) {
     cpu->hybrid_flag = (edx >> 15) & 0x1;
   }
 
-  if(cpu->hybrid_flag) modules = 2;
+  if(cpu->hybrid_flag) cpu->num_cpus = 2;
 
   struct cpuInfo* ptr = cpu;
-  for(uint32_t i=0; i < modules; i++) {
+  for(uint32_t i=0; i < cpu->num_cpus; i++) {
     int32_t first_core;
-    set_cpu_module(i, modules, &first_core);
+    set_cpu_module(i, cpu->num_cpus, &first_core);
 
     if(i > 0) {
       ptr->next_cpu = emalloc(sizeof(struct cpuInfo));
@@ -549,11 +549,11 @@ struct cpuInfo* get_cpu_info(void) {
       cpu->cpu_name = infer_cpu_name_from_uarch(cpu->arch);
     }
 
-    // If any field of the struct is NULL,
-    // return early, as next functions
-    // require non NULL fields in cach and topo
+    // If cach is NULL continue,
+    // as get_topology_info
+    // requires non-NULL cache
     ptr->cach = get_cache_info(ptr);
-    if(ptr->cach == NULL) return cpu;
+    if(ptr->cach == NULL) continue;
 
     if(cpu->hybrid_flag) {
       ptr->topo = get_topology_info(ptr, ptr->cach, i);
@@ -561,10 +561,12 @@ struct cpuInfo* get_cpu_info(void) {
     else {
       ptr->topo = get_topology_info(ptr, ptr->cach, -1);
     }
-    if(cpu->topo == NULL) return cpu;
+
+    // If topo is NULL, return early, as get_peak_performance
+    // requries non-NULL topology.
+    if(ptr->topo == NULL) return cpu;
   }
 
-  cpu->num_cpus = modules;
   cpu->peak_performance = get_peak_performance(cpu, accurate_pp());
 
   return cpu;
@@ -646,10 +648,12 @@ bool get_cache_topology_amd(struct cpuInfo* cpu, struct topology* topo) {
 
 #ifdef __linux__
 void get_topology_from_udev(struct topology* topo) {
-  // TODO: To be improved in the future
   topo->total_cores = get_ncores_from_cpuinfo();
-  topo->logical_cores = topo->total_cores;
-  topo->physical_cores = topo->total_cores;
+  // TODO: To be improved in the future
+  // Conservative setting as we only know the total
+  // number of cores.
+  topo->logical_cores = UNKNOWN_DATA;
+  topo->physical_cores = UNKNOWN_DATA;
   topo->smt_available = 1;
   topo->smt_supported = 1;
   topo->sockets = 1;
@@ -713,8 +717,8 @@ struct topology* get_topology_info(struct cpuInfo* cpu, struct cache* cach, int
       }
       else {
         printWarn("Can't read topology information from cpuid (needed level is 0x%.8X, max is 0x%.8X)", 0x00000001, cpu->maxLevels);
-        topo->physical_cores = 1;
-        topo->logical_cores = 1;
+        topo->physical_cores = UNKNOWN_DATA;
+        topo->logical_cores = UNKNOWN_DATA;
         topo->smt_available = 1;
         topo->smt_supported = 1;
       }