[kbuild-all] [sashal-stable:pending-5.15 390/807] arch/x86/kernel/process.c:953:2: error: implicit declaration of function 'stack_trace_save_tsk'

tree: https://git.kernel.org/pub/scm/linux/kernel/git/sashal/linux-stable.git pending-5.15 head: d67a6e7b954de93239657201bf85d3a6156e9ad3 commit: 3d79226ba332066e0af90c26da1636e508a09cfc [390/807] x86: Fix get_wchan() to support the ORC unwinder config: i386-tinyconfig (attached as .config) compiler: gcc-9 (Debian 9.3.0-22) 9.3.0 reproduce (this is a W=1 build): # https://git.kernel.org/pub/scm/linux/kernel/git/sashal/linux-stable.git/c... git remote add sashal-stable https://git.kernel.org/pub/scm/linux/kernel/git/sashal/linux-stable.git git fetch --no-tags sashal-stable pending-5.15 git checkout 3d79226ba332066e0af90c26da1636e508a09cfc # save the attached .config to linux build tree make W=1 ARCH=i386 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; Note: the sashal-stable/pending-5.15 HEAD d67a6e7b954de93239657201bf85d3a6156e9ad3 builds fine. It only hurts bisectability. All errors (new ones prefixed by >>): arch/x86/kernel/process.c:871:13: warning: no previous prototype for 'arch_post_acpi_subsys_init' [-Wmissing-prototypes] 871 | void __init arch_post_acpi_subsys_init(void) | ^~~~~~~~~~~~~~~~~~~~~~~~~~ arch/x86/kernel/process.c: In function 'get_wchan': 953 | stack_trace_save_tsk(p, &entry, 1, 0); | ^~~~~~~~~~~~~~~~~~~~ cc1: some warnings being treated as errors vim +/stack_trace_save_tsk +953 arch/x86/kernel/process.c 939 940 /* 941 * Called from fs/proc with a reference on @p to find the function 942 * which called into schedule(). This needs to be done carefully 943 * because the task might wake up and we might look at a stack 944 * changing under us. 945 */ 946 unsigned long get_wchan(struct task_struct *p) 947 { 948 unsigned long entry = 0; 949 950 if (p == current || task_is_running(p)) 951 return 0; 952 954 return entry; 955 } 956 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org