proc/smaps: show amount of hwpoison pages

Add the line "HWPoinson: <size> kB" into /proc/pid/smaps if
CONFIG_MEMORY_FAILURE=y and some HWPoison pages were found.  This may be
useful for searching applications which use a broken memory.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index ddd55c781d114ccd8e9d660335f5e632e842d7d3..11e6ff9dce9beb903420cdc45d659113bf982836 100644 (file)
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -394,6 +394,7 @@ struct mem_size_stats {
        unsigned long anonymous_thp;
        unsigned long swap;
        unsigned long nonlinear;
+       unsigned long hwpoison;
        u64 pss;
 };
 
@@ -416,6 +417,8 @@ static void smaps_pte_entry(pte_t ptent, unsigned long addr,
                        mss->swap += ptent_size;
                else if (is_migration_entry(swpent))
                        page = migration_entry_to_page(swpent);
+               else if (is_hwpoison_entry(swpent))
+                       mss->hwpoison += ptent_size;
        } else if (pte_file(ptent)) {
                if (pte_to_pgoff(ptent) != pgoff)
                        mss->nonlinear += ptent_size;
@@ -430,6 +433,9 @@ static void smaps_pte_entry(pte_t ptent, unsigned long addr,
        if (page->index != pgoff)
                mss->nonlinear += ptent_size;
 
+       if (PageHWPoison(page))
+               mss->hwpoison += ptent_size;
+
        mss->resident += ptent_size;
        /* Accumulate the size in pages that have been accessed. */
        if (pte_young(ptent) || PageReferenced(page))
@@ -535,6 +541,10 @@ static int show_smap(struct seq_file *m, void *v, int is_pid)
                seq_printf(m, "Nonlinear:      %8lu kB\n",
                                mss.nonlinear >> 10);
 
+       if (IS_ENABLED(CONFIG_MEMORY_FAILURE) && mss.hwpoison)
+               seq_printf(m, "HWPoison:       %8lu kB\n",
+                               mss.hwpoison >> 10);
+
        if (m->count < m->size)  /* vma is copied successfully */
                m->version = (vma != get_gate_vma(task->mm))
                        ? vma->vm_start : 0;