Hi Ross, kernel test robot noticed the following build warnings: [auto build test WARNING on tip/x86/core] [also build test WARNING on herbert-cryptodev-2.6/master herbert-crypto-2.6/master linus/master v6.6 next-20231110] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch#_base_tree_information] url: https://github.com/intel-lab-lkp/linux/commits/Ross-Philipson/x86-boot-Place-kernel_info-at-a-fixed-offset/20231111-063453 base: tip/x86/core patch link: https://lore.kernel.org/r/20231110222751.219836-10-ross.philipson%40oracle.com patch subject: [PATCH v7 09/13] x86: Secure Launch SMP bringup support config: x86_64-rhel-8.3-rust (https://download.01.org/0day-ci/archive/20231111/202311111806.sbmcWUN1-lkp@xxxxxxxxx/config) compiler: clang version 16.0.4 (https://github.com/llvm/llvm-project.git ae42196bc493ffe877a7e3dff8be32035dea4d07) reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231111/202311111806.sbmcWUN1-lkp@xxxxxxxxx/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@xxxxxxxxx> | Closes: https://lore.kernel.org/oe-kbuild-all/202311111806.sbmcWUN1-lkp@xxxxxxxxx/ All warnings (new ones prefixed by >>): >> arch/x86/kernel/smpboot.c:1097:6: warning: variable 'ret' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized] if (slaunch_is_txt_launch()) ^~~~~~~~~~~~~~~~~~~~~~~ arch/x86/kernel/smpboot.c:1107:6: note: uninitialized use occurs here if (ret) ^~~ arch/x86/kernel/smpboot.c:1097:2: note: remove the 'if' if its condition is always false if (slaunch_is_txt_launch()) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/x86/kernel/smpboot.c:1046:9: note: initialize the variable 'ret' to silence this warning int ret; ^ = 0 1 warning generated. vim +1097 arch/x86/kernel/smpboot.c 1036 1037 /* 1038 * NOTE - on most systems this is a PHYSICAL apic ID, but on multiquad 1039 * (ie clustered apic addressing mode), this is a LOGICAL apic ID. 1040 * Returns zero if startup was successfully sent, else error code from 1041 * ->wakeup_secondary_cpu. 1042 */ 1043 static int do_boot_cpu(u32 apicid, int cpu, struct task_struct *idle) 1044 { 1045 unsigned long start_ip = real_mode_header->trampoline_start; 1046 int ret; 1047 1048 #ifdef CONFIG_X86_64 1049 /* If 64-bit wakeup method exists, use the 64-bit mode trampoline IP */ 1050 if (apic->wakeup_secondary_cpu_64) 1051 start_ip = real_mode_header->trampoline_start64; 1052 #endif 1053 idle->thread.sp = (unsigned long)task_pt_regs(idle); 1054 initial_code = (unsigned long)start_secondary; 1055 1056 if (IS_ENABLED(CONFIG_X86_32)) { 1057 early_gdt_descr.address = (unsigned long)get_cpu_gdt_rw(cpu); 1058 initial_stack = idle->thread.sp; 1059 } else if (!(smpboot_control & STARTUP_PARALLEL_MASK)) { 1060 smpboot_control = cpu; 1061 } 1062 1063 /* Enable the espfix hack for this CPU */ 1064 init_espfix_ap(cpu); 1065 1066 /* So we see what's up */ 1067 announce_cpu(cpu, apicid); 1068 1069 /* 1070 * This grunge runs the startup process for 1071 * the targeted processor. 1072 */ 1073 if (x86_platform.legacy.warm_reset) { 1074 1075 pr_debug("Setting warm reset code and vector.\n"); 1076 1077 smpboot_setup_warm_reset_vector(start_ip); 1078 /* 1079 * Be paranoid about clearing APIC errors. 1080 */ 1081 if (APIC_INTEGRATED(boot_cpu_apic_version)) { 1082 apic_write(APIC_ESR, 0); 1083 apic_read(APIC_ESR); 1084 } 1085 } 1086 1087 smp_mb(); 1088 1089 /* 1090 * Wake up a CPU in difference cases: 1091 * - Intel TXT DRTM launch uses its own method to wake the APs 1092 * - Use a method from the APIC driver if one defined, with wakeup 1093 * straight to 64-bit mode preferred over wakeup to RM. 1094 * Otherwise, 1095 * - Use an INIT boot APIC message 1096 */ > 1097 if (slaunch_is_txt_launch()) 1098 slaunch_wakeup_cpu_from_txt(cpu, apicid); 1099 else if (apic->wakeup_secondary_cpu_64) 1100 ret = apic->wakeup_secondary_cpu_64(apicid, start_ip); 1101 else if (apic->wakeup_secondary_cpu) 1102 ret = apic->wakeup_secondary_cpu(apicid, start_ip); 1103 else 1104 ret = wakeup_secondary_cpu_via_init(apicid, start_ip); 1105 1106 /* If the wakeup mechanism failed, cleanup the warm reset vector */ 1107 if (ret) 1108 arch_cpuhp_cleanup_kick_cpu(cpu); 1109 return ret; 1110 } 1111 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
