fd476720c9
Another memory error injection interface debugfs:hwpoison/corrupt-pfn also takes bogus refcount for hwpoison_filter(). It's justified because this does a coarse filter, expecting that memory_failure() redoes the check for sure. Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Signed-off-by: Oscar Salvador <osalvador@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Aristeu Rozanski <aris@ruivo.org> Cc: Dave Hansen <dave.hansen@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: Dmitry Yakunin <zeil@yandex-team.ru> Cc: Michal Hocko <mhocko@kernel.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Oscar Salvador <osalvador@suse.com> Cc: Qian Cai <cai@lca.pw> Cc: Tony Luck <tony.luck@intel.com> Link: https://lkml.kernel.org/r/20200922135650.1634-4-osalvador@suse.de Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
111 lines
2.6 KiB
C
111 lines
2.6 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/* Inject a hwpoison memory failure on a arbitrary pfn */
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#include <linux/module.h>
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#include <linux/debugfs.h>
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#include <linux/kernel.h>
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#include <linux/mm.h>
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#include <linux/swap.h>
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#include <linux/pagemap.h>
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#include <linux/hugetlb.h>
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#include "internal.h"
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static struct dentry *hwpoison_dir;
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static int hwpoison_inject(void *data, u64 val)
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{
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unsigned long pfn = val;
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struct page *p;
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struct page *hpage;
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int err;
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if (!capable(CAP_SYS_ADMIN))
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return -EPERM;
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if (!pfn_valid(pfn))
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return -ENXIO;
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p = pfn_to_page(pfn);
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hpage = compound_head(p);
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if (!hwpoison_filter_enable)
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goto inject;
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shake_page(hpage, 0);
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/*
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* This implies unable to support non-LRU pages.
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*/
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if (!PageLRU(hpage) && !PageHuge(p))
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return 0;
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/*
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* do a racy check to make sure PG_hwpoison will only be set for
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* the targeted owner (or on a free page).
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* memory_failure() will redo the check reliably inside page lock.
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*/
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err = hwpoison_filter(hpage);
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if (err)
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return 0;
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inject:
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pr_info("Injecting memory failure at pfn %#lx\n", pfn);
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return memory_failure(pfn, 0);
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}
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static int hwpoison_unpoison(void *data, u64 val)
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{
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if (!capable(CAP_SYS_ADMIN))
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return -EPERM;
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return unpoison_memory(val);
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}
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DEFINE_DEBUGFS_ATTRIBUTE(hwpoison_fops, NULL, hwpoison_inject, "%lli\n");
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DEFINE_DEBUGFS_ATTRIBUTE(unpoison_fops, NULL, hwpoison_unpoison, "%lli\n");
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static void pfn_inject_exit(void)
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{
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debugfs_remove_recursive(hwpoison_dir);
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}
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static int pfn_inject_init(void)
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{
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hwpoison_dir = debugfs_create_dir("hwpoison", NULL);
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/*
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* Note that the below poison/unpoison interfaces do not involve
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* hardware status change, hence do not require hardware support.
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* They are mainly for testing hwpoison in software level.
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*/
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debugfs_create_file("corrupt-pfn", 0200, hwpoison_dir, NULL,
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&hwpoison_fops);
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debugfs_create_file("unpoison-pfn", 0200, hwpoison_dir, NULL,
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&unpoison_fops);
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debugfs_create_u32("corrupt-filter-enable", 0600, hwpoison_dir,
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&hwpoison_filter_enable);
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debugfs_create_u32("corrupt-filter-dev-major", 0600, hwpoison_dir,
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&hwpoison_filter_dev_major);
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debugfs_create_u32("corrupt-filter-dev-minor", 0600, hwpoison_dir,
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&hwpoison_filter_dev_minor);
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debugfs_create_u64("corrupt-filter-flags-mask", 0600, hwpoison_dir,
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&hwpoison_filter_flags_mask);
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debugfs_create_u64("corrupt-filter-flags-value", 0600, hwpoison_dir,
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&hwpoison_filter_flags_value);
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#ifdef CONFIG_MEMCG
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debugfs_create_u64("corrupt-filter-memcg", 0600, hwpoison_dir,
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&hwpoison_filter_memcg);
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#endif
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return 0;
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}
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module_init(pfn_inject_init);
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module_exit(pfn_inject_exit);
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MODULE_LICENSE("GPL");
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