[tglx-devel:x86/topo-full 56/71] arch/x86/kernel/cpu/topology.c:150:31: warning: variable 'bsp_apicid' is uninitialized when used here

[tglx-devel:x86/topo-full 56/71] arch/x86/kernel/cpu/topology.c:150:31: warning: variable 'bsp_apicid' is uninitialized when used here

[kernel test robot]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/tglx/devel.git x86/topo-full
head:   db28d91b811f57395f2628ad23002acaef9e1ee1
commit: 3159457cc55b83cde16d0db14e765eabd4160b98 [56/71] x86/cpu: Detect real BSP on crash kernels
config: i386-buildonly-randconfig-003-20240118 (https://download.01.org/0day-ci/archive/20240118/202401180751.hErhvgvl-lkp@intel.com/config)
compiler: ClangBuiltLinux clang version 17.0.6 (https://github.com/llvm/llvm-project 6009708b4367171ccdbf4b5905cb6a803753fe18)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240118/202401180751.hErhvgvl-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202401180751.hErhvgvl-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> arch/x86/kernel/cpu/topology.c:150:31: warning: variable 'bsp_apicid' is uninitialized when used here [-Wuninitialized]
     150 |         topo_info.real_bsp_apic_id = bsp_apicid;
         |                                      ^~~~~~~~~~
   arch/x86/kernel/cpu/topology.c:123:16: note: initialize the variable 'bsp_apicid' to silence this warning
     123 |         u32 bsp_apicid;
         |                       ^
         |                        = 0
   arch/x86/kernel/cpu/topology.c:156:11: warning: unused variable 'dom' [-Wunused-variable]
     156 |         int cpu, dom;
         |                  ^~~
   2 warnings generated.


vim +/bsp_apicid +150 arch/x86/kernel/cpu/topology.c

   120	
   121	static __init bool check_for_real_bsp(u32 apic_id)
   122	{
   123		u32 bsp_apicid;
   124	
   125		/*
   126		 * There is no real good way to detect whether this a kdump()
   127		 * kernel, but except on the Voyager SMP monstrosity which is not
   128		 * longer supported, the real BSP APIC ID is the first one which is
   129		 * enumerated by firmware. That allows to detect whether the boot
   130		 * CPU is the real BSP. If it is not, then do not register the APIC
   131		 * because sending INIT to the real BSP would reset the whole
   132		 * system.
   133		 *
   134		 * The first APIC ID which is enumerated by firmware is detectable
   135		 * because the boot CPU APIC ID is registered before that without
   136		 * invoking this code.
   137		 */
   138		if (topo_info.real_bsp_apic_id != BAD_APICID)
   139			return false;
   140	
   141		if (apic_id == topo_info.boot_cpu_apic_id) {
   142			topo_info.real_bsp_apic_id = apic_id;
   143			return false;
   144		}
   145	
   146		pr_warn("Boot CPU APIC ID not the first enumerated APIC ID: %x > %x\n",
   147			topo_info.boot_cpu_apic_id, bsp_apicid);
   148		pr_warn("Crash kernel detected. Disabling real BSP to prevent machine INIT\n");
   149	
 > 150		topo_info.real_bsp_apic_id = bsp_apicid;
   151		return true;
   152	}
   153	

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