Revision 9e3d6331789b113e4abc831ed3447fb67a105430 authored by Linus Torvalds on 28 May 2014, 15:06:50 UTC, committed by Linus Torvalds on 28 May 2014, 15:06:50 UTC
Pull two powerpc fixes from Ben Herrenschmidt: "Here's a pair of powerpc fixes for 3.15 which are also going to stable. One's a fix for building with newer binutils (the problem currently only affects the BookE kernels but the affected macro might come back into use on BookS platforms at any time). Unfortunately, the binutils maintainer did a backward incompatible change to a construct that we use so we have to add Makefile check. The other one is a fix for CPUs getting stuck in kexec when running single threaded. Since we routinely use kexec on power (including in our newer bootloaders), I deemed that important enough" * 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: powerpc, kexec: Fix "Processor X is stuck" issue during kexec from ST mode powerpc: Fix 64 bit builds with binutils 2.24
hwpoison-inject.c
/* Inject a hwpoison memory failure on a arbitrary pfn */
#include <linux/module.h>
#include <linux/debugfs.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/pagemap.h>
#include <linux/hugetlb.h>
#include "internal.h"
static struct dentry *hwpoison_dir;
static int hwpoison_inject(void *data, u64 val)
{
unsigned long pfn = val;
struct page *p;
struct page *hpage;
int err;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
if (!pfn_valid(pfn))
return -ENXIO;
p = pfn_to_page(pfn);
hpage = compound_head(p);
/*
* This implies unable to support free buddy pages.
*/
if (!get_page_unless_zero(hpage))
return 0;
if (!hwpoison_filter_enable)
goto inject;
if (!PageLRU(p) && !PageHuge(p))
shake_page(p, 0);
/*
* This implies unable to support non-LRU pages.
*/
if (!PageLRU(p) && !PageHuge(p))
return 0;
/*
* do a racy check with elevated page count, to make sure PG_hwpoison
* will only be set for the targeted owner (or on a free page).
* We temporarily take page lock for try_get_mem_cgroup_from_page().
* memory_failure() will redo the check reliably inside page lock.
*/
lock_page(hpage);
err = hwpoison_filter(hpage);
unlock_page(hpage);
if (err)
return 0;
inject:
pr_info("Injecting memory failure at pfn %#lx\n", pfn);
return memory_failure(pfn, 18, MF_COUNT_INCREASED);
}
static int hwpoison_unpoison(void *data, u64 val)
{
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
return unpoison_memory(val);
}
DEFINE_SIMPLE_ATTRIBUTE(hwpoison_fops, NULL, hwpoison_inject, "%lli\n");
DEFINE_SIMPLE_ATTRIBUTE(unpoison_fops, NULL, hwpoison_unpoison, "%lli\n");
static void pfn_inject_exit(void)
{
if (hwpoison_dir)
debugfs_remove_recursive(hwpoison_dir);
}
static int pfn_inject_init(void)
{
struct dentry *dentry;
hwpoison_dir = debugfs_create_dir("hwpoison", NULL);
if (hwpoison_dir == NULL)
return -ENOMEM;
/*
* Note that the below poison/unpoison interfaces do not involve
* hardware status change, hence do not require hardware support.
* They are mainly for testing hwpoison in software level.
*/
dentry = debugfs_create_file("corrupt-pfn", 0200, hwpoison_dir,
NULL, &hwpoison_fops);
if (!dentry)
goto fail;
dentry = debugfs_create_file("unpoison-pfn", 0200, hwpoison_dir,
NULL, &unpoison_fops);
if (!dentry)
goto fail;
dentry = debugfs_create_u32("corrupt-filter-enable", 0600,
hwpoison_dir, &hwpoison_filter_enable);
if (!dentry)
goto fail;
dentry = debugfs_create_u32("corrupt-filter-dev-major", 0600,
hwpoison_dir, &hwpoison_filter_dev_major);
if (!dentry)
goto fail;
dentry = debugfs_create_u32("corrupt-filter-dev-minor", 0600,
hwpoison_dir, &hwpoison_filter_dev_minor);
if (!dentry)
goto fail;
dentry = debugfs_create_u64("corrupt-filter-flags-mask", 0600,
hwpoison_dir, &hwpoison_filter_flags_mask);
if (!dentry)
goto fail;
dentry = debugfs_create_u64("corrupt-filter-flags-value", 0600,
hwpoison_dir, &hwpoison_filter_flags_value);
if (!dentry)
goto fail;
#ifdef CONFIG_MEMCG_SWAP
dentry = debugfs_create_u64("corrupt-filter-memcg", 0600,
hwpoison_dir, &hwpoison_filter_memcg);
if (!dentry)
goto fail;
#endif
return 0;
fail:
pfn_inject_exit();
return -ENOMEM;
}
module_init(pfn_inject_init);
module_exit(pfn_inject_exit);
MODULE_LICENSE("GPL");
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