Re: [PATCH 1/9] mm: kmemleak: properly disable task stack scanning

[kernel test robot]

Hi George,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on vbabka-slab/for-next]
[also build test ERROR on linus/master v6.2-rc5 next-20230123]
[cannot apply to akpm-mm/mm-everything]
[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/George-Prekas/mm-kmemleak-properly-disable-task-stack-scanning/20230124-010911
base:   git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab.git for-next
patch link:    https://lore.kernel.org/r/20230123170419.7292-2-george%40enfabrica.net
patch subject: [PATCH 1/9] mm: kmemleak: properly disable task stack scanning
config: s390-defconfig (https://download.01.org/0day-ci/archive/20230124/202301240827.j2GJi7v5-lkp@xxxxxxxxx/config)
compiler: s390-linux-gcc (GCC) 12.1.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/intel-lab-lkp/linux/commit/f0d9df4305849ecea4402bc614cadb0dd357da77
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review George-Prekas/mm-kmemleak-properly-disable-task-stack-scanning/20230124-010911
        git checkout f0d9df4305849ecea4402bc614cadb0dd357da77
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=s390 olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=s390 SHELL=/bin/bash

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@xxxxxxxxx>

All errors (new ones prefixed by >>):

   kernel/fork.c: In function 'alloc_thread_stack_node':
>> kernel/fork.c:320:9: error: implicit declaration of function 'kmemleak_mark_stack'; did you mean 'kmemleak_no_scan'? [-Werror=implicit-function-declaration]
     320 |         kmemleak_mark_stack(stack);
         |         ^~~~~~~~~~~~~~~~~~~
         |         kmemleak_no_scan
   kernel/fork.c: At top level:
   kernel/fork.c:865:20: warning: no previous prototype for 'arch_task_cache_init' [-Wmissing-prototypes]
     865 | void __init __weak arch_task_cache_init(void) { }
         |                    ^~~~~~~~~~~~~~~~~~~~
   cc1: some warnings being treated as errors


vim +320 kernel/fork.c

   274	
   275	static int alloc_thread_stack_node(struct task_struct *tsk, int node)
   276	{
   277		struct vm_struct *vm;
   278		void *stack;
   279		int i;
   280	
   281		for (i = 0; i < NR_CACHED_STACKS; i++) {
   282			struct vm_struct *s;
   283	
   284			s = this_cpu_xchg(cached_stacks[i], NULL);
   285	
   286			if (!s)
   287				continue;
   288	
   289			/* Reset stack metadata. */
   290			kasan_unpoison_range(s->addr, THREAD_SIZE);
   291	
   292			stack = kasan_reset_tag(s->addr);
   293	
   294			/* Clear stale pointers from reused stack. */
   295			memset(stack, 0, THREAD_SIZE);
   296	
   297			if (memcg_charge_kernel_stack(s)) {
   298				vfree(s->addr);
   299				return -ENOMEM;
   300			}
   301	
   302			tsk->stack_vm_area = s;
   303			tsk->stack = stack;
   304			return 0;
   305		}
   306	
   307		/*
   308		 * Allocated stacks are cached and later reused by new threads,
   309		 * so memcg accounting is performed manually on assigning/releasing
   310		 * stacks to tasks. Drop __GFP_ACCOUNT.
   311		 */
   312		stack = __vmalloc_node_range(THREAD_SIZE, THREAD_ALIGN,
   313					     VMALLOC_START, VMALLOC_END,
   314					     THREADINFO_GFP & ~__GFP_ACCOUNT,
   315					     PAGE_KERNEL,
   316					     0, node, __builtin_return_address(0));
   317		if (!stack)
   318			return -ENOMEM;
   319	
 > 320		kmemleak_mark_stack(stack);
   321	
   322		vm = find_vm_area(stack);
   323		if (memcg_charge_kernel_stack(vm)) {
   324			vfree(stack);
   325			return -ENOMEM;
   326		}
   327		/*
   328		 * We can't call find_vm_area() in interrupt context, and
   329		 * free_thread_stack() can be called in interrupt context,
   330		 * so cache the vm_struct.
   331		 */
   332		tsk->stack_vm_area = vm;
   333		stack = kasan_reset_tag(stack);
   334		tsk->stack = stack;
   335		return 0;
   336	}
   337	

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