2fcc6e202a
When calling debugfs functions, there is no need to ever check the return value. The function can work or not, but the code logic should never do something different based on this. Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: linux-mm@kvack.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
119 lines
2.8 KiB
C
119 lines
2.8 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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/*
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* This implies unable to support free buddy pages.
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*/
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if (!get_hwpoison_page(p))
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return 0;
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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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goto put_out;
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/*
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* do a racy check with elevated page count, to make sure PG_hwpoison
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* will only be set for 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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goto put_out;
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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, MF_COUNT_INCREASED);
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put_out:
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put_hwpoison_page(p);
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return 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_SIMPLE_ATTRIBUTE(hwpoison_fops, NULL, hwpoison_inject, "%lli\n");
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DEFINE_SIMPLE_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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