v4.19.13 snapshot.
diff --git a/mm/debug.c b/mm/debug.c
new file mode 100644
index 0000000..bd10aad
--- /dev/null
+++ b/mm/debug.c
@@ -0,0 +1,178 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * mm/debug.c
+ *
+ * mm/ specific debug routines.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/trace_events.h>
+#include <linux/memcontrol.h>
+#include <trace/events/mmflags.h>
+#include <linux/migrate.h>
+#include <linux/page_owner.h>
+
+#include "internal.h"
+
+char *migrate_reason_names[MR_TYPES] = {
+ "compaction",
+ "memory_failure",
+ "memory_hotplug",
+ "syscall_or_cpuset",
+ "mempolicy_mbind",
+ "numa_misplaced",
+ "cma",
+};
+
+const struct trace_print_flags pageflag_names[] = {
+ __def_pageflag_names,
+ {0, NULL}
+};
+
+const struct trace_print_flags gfpflag_names[] = {
+ __def_gfpflag_names,
+ {0, NULL}
+};
+
+const struct trace_print_flags vmaflag_names[] = {
+ __def_vmaflag_names,
+ {0, NULL}
+};
+
+void __dump_page(struct page *page, const char *reason)
+{
+ bool page_poisoned = PagePoisoned(page);
+ int mapcount;
+
+ /*
+ * If struct page is poisoned don't access Page*() functions as that
+ * leads to recursive loop. Page*() check for poisoned pages, and calls
+ * dump_page() when detected.
+ */
+ if (page_poisoned) {
+ pr_emerg("page:%px is uninitialized and poisoned", page);
+ goto hex_only;
+ }
+
+ /*
+ * Avoid VM_BUG_ON() in page_mapcount().
+ * page->_mapcount space in struct page is used by sl[aou]b pages to
+ * encode own info.
+ */
+ mapcount = PageSlab(page) ? 0 : page_mapcount(page);
+
+ pr_emerg("page:%px count:%d mapcount:%d mapping:%px index:%#lx",
+ page, page_ref_count(page), mapcount,
+ page->mapping, page_to_pgoff(page));
+ if (PageCompound(page))
+ pr_cont(" compound_mapcount: %d", compound_mapcount(page));
+ pr_cont("\n");
+ BUILD_BUG_ON(ARRAY_SIZE(pageflag_names) != __NR_PAGEFLAGS + 1);
+
+ pr_emerg("flags: %#lx(%pGp)\n", page->flags, &page->flags);
+
+hex_only:
+ print_hex_dump(KERN_ALERT, "raw: ", DUMP_PREFIX_NONE, 32,
+ sizeof(unsigned long), page,
+ sizeof(struct page), false);
+
+ if (reason)
+ pr_alert("page dumped because: %s\n", reason);
+
+#ifdef CONFIG_MEMCG
+ if (!page_poisoned && page->mem_cgroup)
+ pr_alert("page->mem_cgroup:%px\n", page->mem_cgroup);
+#endif
+}
+
+void dump_page(struct page *page, const char *reason)
+{
+ __dump_page(page, reason);
+ dump_page_owner(page);
+}
+EXPORT_SYMBOL(dump_page);
+
+#ifdef CONFIG_DEBUG_VM
+
+void dump_vma(const struct vm_area_struct *vma)
+{
+ pr_emerg("vma %px start %px end %px\n"
+ "next %px prev %px mm %px\n"
+ "prot %lx anon_vma %px vm_ops %px\n"
+ "pgoff %lx file %px private_data %px\n"
+ "flags: %#lx(%pGv)\n",
+ vma, (void *)vma->vm_start, (void *)vma->vm_end, vma->vm_next,
+ vma->vm_prev, vma->vm_mm,
+ (unsigned long)pgprot_val(vma->vm_page_prot),
+ vma->anon_vma, vma->vm_ops, vma->vm_pgoff,
+ vma->vm_file, vma->vm_private_data,
+ vma->vm_flags, &vma->vm_flags);
+}
+EXPORT_SYMBOL(dump_vma);
+
+void dump_mm(const struct mm_struct *mm)
+{
+ pr_emerg("mm %px mmap %px seqnum %llu task_size %lu\n"
+#ifdef CONFIG_MMU
+ "get_unmapped_area %px\n"
+#endif
+ "mmap_base %lu mmap_legacy_base %lu highest_vm_end %lu\n"
+ "pgd %px mm_users %d mm_count %d pgtables_bytes %lu map_count %d\n"
+ "hiwater_rss %lx hiwater_vm %lx total_vm %lx locked_vm %lx\n"
+ "pinned_vm %lx data_vm %lx exec_vm %lx stack_vm %lx\n"
+ "start_code %lx end_code %lx start_data %lx end_data %lx\n"
+ "start_brk %lx brk %lx start_stack %lx\n"
+ "arg_start %lx arg_end %lx env_start %lx env_end %lx\n"
+ "binfmt %px flags %lx core_state %px\n"
+#ifdef CONFIG_AIO
+ "ioctx_table %px\n"
+#endif
+#ifdef CONFIG_MEMCG
+ "owner %px "
+#endif
+ "exe_file %px\n"
+#ifdef CONFIG_MMU_NOTIFIER
+ "mmu_notifier_mm %px\n"
+#endif
+#ifdef CONFIG_NUMA_BALANCING
+ "numa_next_scan %lu numa_scan_offset %lu numa_scan_seq %d\n"
+#endif
+ "tlb_flush_pending %d\n"
+ "def_flags: %#lx(%pGv)\n",
+
+ mm, mm->mmap, (long long) mm->vmacache_seqnum, mm->task_size,
+#ifdef CONFIG_MMU
+ mm->get_unmapped_area,
+#endif
+ mm->mmap_base, mm->mmap_legacy_base, mm->highest_vm_end,
+ mm->pgd, atomic_read(&mm->mm_users),
+ atomic_read(&mm->mm_count),
+ mm_pgtables_bytes(mm),
+ mm->map_count,
+ mm->hiwater_rss, mm->hiwater_vm, mm->total_vm, mm->locked_vm,
+ mm->pinned_vm, mm->data_vm, mm->exec_vm, mm->stack_vm,
+ mm->start_code, mm->end_code, mm->start_data, mm->end_data,
+ mm->start_brk, mm->brk, mm->start_stack,
+ mm->arg_start, mm->arg_end, mm->env_start, mm->env_end,
+ mm->binfmt, mm->flags, mm->core_state,
+#ifdef CONFIG_AIO
+ mm->ioctx_table,
+#endif
+#ifdef CONFIG_MEMCG
+ mm->owner,
+#endif
+ mm->exe_file,
+#ifdef CONFIG_MMU_NOTIFIER
+ mm->mmu_notifier_mm,
+#endif
+#ifdef CONFIG_NUMA_BALANCING
+ mm->numa_next_scan, mm->numa_scan_offset, mm->numa_scan_seq,
+#endif
+ atomic_read(&mm->tlb_flush_pending),
+ mm->def_flags, &mm->def_flags
+ );
+}
+
+#endif /* CONFIG_DEBUG_VM */