mm: introduce VM_BUG_ON_MM

Very similar to VM_BUG_ON_PAGE and VM_BUG_ON_VMA, dump struct_mm when the
bug is hit.

[akpm@linux-foundation.org: coding-style fixes]
[mhocko@suse.cz: fix build]
[mhocko@suse.cz: fix build some more]
[akpm@linux-foundation.org: do strange things to avoid doing strange things for the comma separators]
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Cc: Dave Jones <davej@redhat.com>
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 78 insertions, 0 deletions

diff --git a/mm/debug.c b/mm/debug.c
index 697df9050193..5a1b6194089c 100644
--- a/mm/debug.c
+++ b/mm/debug.c
@@ -1,3 +1,10 @@
+/*
+ * mm/debug.c
+ *
+ * mm/ specific debug routines.
+ *
+ */
+
 #include <linux/kernel.h>
 #include <linux/mm.h>
 #include <linux/ftrace_event.h>
@@ -159,4 +166,75 @@ void dump_vma(const struct vm_area_struct *vma)
 }
 EXPORT_SYMBOL(dump_vma);
 
+void dump_mm(const struct mm_struct *mm)
+{
+        printk(KERN_ALERT
+                "mm %p mmap %p seqnum %d task_size %lu\n"
+#ifdef CONFIG_MMU
+                "get_unmapped_area %p\n"
+#endif
+                "mmap_base %lu mmap_legacy_base %lu highest_vm_end %lu\n"
+                "pgd %p mm_users %d mm_count %d nr_ptes %lu map_count %d\n"
+                "hiwater_rss %lx hiwater_vm %lx total_vm %lx locked_vm %lx\n"
+                "pinned_vm %lx shared_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 %p flags %lx core_state %p\n"
+#ifdef CONFIG_AIO
+                "ioctx_table %p\n"
+#endif
+#ifdef CONFIG_MEMCG
+                "owner %p "
+#endif
+                "exe_file %p\n"
+#ifdef CONFIG_MMU_NOTIFIER
+                "mmu_notifier_mm %p\n"
+#endif
+#ifdef CONFIG_NUMA_BALANCING
+                "numa_next_scan %lu numa_scan_offset %lu numa_scan_seq %d\n"
+#endif
+#if defined(CONFIG_NUMA_BALANCING) || defined(CONFIG_COMPACTION)
+                "tlb_flush_pending %d\n"
+#endif
+                "%s",   /* This is here to hold the comma */
+
+                mm, mm->mmap, 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),
+                atomic_long_read((atomic_long_t *)&mm->nr_ptes),
+                mm->map_count,
+                mm->hiwater_rss, mm->hiwater_vm, mm->total_vm, mm->locked_vm,
+                mm->pinned_vm, mm->shared_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
+#if defined(CONFIG_NUMA_BALANCING) || defined(CONFIG_COMPACTION)
+                mm->tlb_flush_pending,
+#endif
+                ""              /* This is here to not have a comma! */
+                );
+
+                dump_flags(mm->def_flags, vmaflags_names,
+                                ARRAY_SIZE(vmaflags_names));
+}
+
 #endif          /* CONFIG_DEBUG_VM */