mm: introduce dump_vma

Introduce a helper to dump information about a VMA, this also makes
dump_page_flags more generic and re-uses that so the output looks very
similar to dump_page:

[   61.903437] vma ffff88070f88be00 start 00007fff25970000 end 00007fff25992000
[   61.903437] next ffff88070facd600 prev ffff88070face400 mm ffff88070fade000
[   61.903437] prot 8000000000000025 anon_vma ffff88070fa1e200 vm_ops           (null)
[   61.903437] pgoff 7ffffffdd file           (null) private_data           (null)
[   61.909129] flags: 0x100173(read|write|mayread|maywrite|mayexec|growsdown|account)

[akpm@linux-foundation.org: make dump_vma() require CONFIG_DEBUG_VM]
[swarren@nvidia.com: fix dump_vma() compilation]
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Michel Lespinasse <walken@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 73 insertions, 9 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index f07588b11d59..3a950144f80b 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -6626,27 +6626,26 @@ static const struct trace_print_flags pageflag_names[] = {
 #endif
 };
 
-static void dump_page_flags(unsigned long flags)
+static void dump_flags(unsigned long flags,
+                        const struct trace_print_flags *names, int count)
 {
         const char *delim = "";
         unsigned long mask;
         int i;
 
-        BUILD_BUG_ON(ARRAY_SIZE(pageflag_names) != __NR_PAGEFLAGS);
-
-        printk(KERN_ALERT "page flags: %#lx(", flags);
+        printk(KERN_ALERT "flags: %#lx(", flags);
 
         /* remove zone id */
         flags &= (1UL << NR_PAGEFLAGS) - 1;
 
-        for (i = 0; i < ARRAY_SIZE(pageflag_names) && flags; i++) {
+        for (i = 0; i < count && flags; i++) {
 
-                mask = pageflag_names[i].mask;
+                mask = names[i].mask;
                 if ((flags & mask) != mask)
                         continue;
 
                 flags &= ~mask;
-                printk("%s%s", delim, pageflag_names[i].name);
+                printk("%s%s", delim, names[i].name);
                 delim = "|";
         }
 
@@ -6664,12 +6663,14 @@ void dump_page_badflags(struct page *page, const char *reason,
                "page:%p count:%d mapcount:%d mapping:%p index:%#lx\n",
                 page, atomic_read(&page->_count), page_mapcount(page),
                 page->mapping, page->index);
-        dump_page_flags(page->flags);
+        BUILD_BUG_ON(ARRAY_SIZE(pageflag_names) != __NR_PAGEFLAGS);
+        dump_flags(page->flags, pageflag_names, ARRAY_SIZE(pageflag_names));
         if (reason)
                 pr_alert("page dumped because: %s\n", reason);
         if (page->flags & badflags) {
                 pr_alert("bad because of flags:\n");
-                dump_page_flags(page->flags & badflags);
+                dump_flags(page->flags & badflags,
+                                pageflag_names, ARRAY_SIZE(pageflag_names));
         }
         mem_cgroup_print_bad_page(page);
 }
@@ -6679,3 +6680,66 @@ void dump_page(struct page *page, const char *reason)
         dump_page_badflags(page, reason, 0);
 }
 EXPORT_SYMBOL(dump_page);
+
+#ifdef CONFIG_DEBUG_VM
+
+static const struct trace_print_flags vmaflags_names[] = {
+        {VM_READ,                       "read"          },
+        {VM_WRITE,                      "write"         },
+        {VM_EXEC,                       "exec"          },
+        {VM_SHARED,                     "shared"        },
+        {VM_MAYREAD,                    "mayread"       },
+        {VM_MAYWRITE,                   "maywrite"      },
+        {VM_MAYEXEC,                    "mayexec"       },
+        {VM_MAYSHARE,                   "mayshare"      },
+        {VM_GROWSDOWN,                  "growsdown"     },
+        {VM_PFNMAP,                     "pfnmap"        },
+        {VM_DENYWRITE,                  "denywrite"     },
+        {VM_LOCKED,                     "locked"        },
+        {VM_IO,                         "io"            },
+        {VM_SEQ_READ,                   "seqread"       },
+        {VM_RAND_READ,                  "randread"      },
+        {VM_DONTCOPY,                   "dontcopy"      },
+        {VM_DONTEXPAND,                 "dontexpand"    },
+        {VM_ACCOUNT,                    "account"       },
+        {VM_NORESERVE,                  "noreserve"     },
+        {VM_HUGETLB,                    "hugetlb"       },
+        {VM_NONLINEAR,                  "nonlinear"     },
+#if defined(CONFIG_X86)
+        {VM_PAT,                        "pat"           },
+#elif defined(CONFIG_PPC)
+        {VM_SAO,                        "sao"           },
+#elif defined(CONFIG_PARISC) || defined(CONFIG_METAG) || defined(CONFIG_IA64)
+        {VM_GROWSUP,                    "growsup"       },
+#elif !defined(CONFIG_MMU)
+        {VM_MAPPED_COPY,                "mappedcopy"    },
+#else
+        {VM_ARCH_1,                     "arch_1"        },
+#endif
+        {VM_DONTDUMP,                   "dontdump"      },
+#ifdef CONFIG_MEM_SOFT_DIRTY
+        {VM_SOFTDIRTY,                  "softdirty"     },
+#endif
+        {VM_MIXEDMAP,                   "mixedmap"      },
+        {VM_HUGEPAGE,                   "hugepage"      },
+        {VM_NOHUGEPAGE,                 "nohugepage"    },
+        {VM_MERGEABLE,                  "mergeable"     },
+};
+
+void dump_vma(const struct vm_area_struct *vma)
+{
+        printk(KERN_ALERT
+                "vma %p start %p end %p\n"
+                "next %p prev %p mm %p\n"
+                "prot %lx anon_vma %p vm_ops %p\n"
+                "pgoff %lx file %p private_data %p\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);
+        dump_flags(vma->vm_flags, vmaflags_names, ARRAY_SIZE(vmaflags_names));
+}
+EXPORT_SYMBOL(dump_vma);
+
+#endif          /* CONFIG_DEBUG_VM */