| 1 | |
| 2 | #include <linux/mm.h>
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| 3 | #include <linux/page-isolation.h>
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| 4 |
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| 5 | unsigned int _debug_guardpage_minorder;
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| 6 |
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| 7 | bool _debug_pagealloc_enabled_early __read_mostly
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| 8 | = IS_ENABLED(CONFIG_DEBUG_PAGEALLOC_ENABLE_DEFAULT);
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| 9 | EXPORT_SYMBOL(_debug_pagealloc_enabled_early);
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| 10 | DEFINE_STATIC_KEY_FALSE(_debug_pagealloc_enabled);
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| 11 | EXPORT_SYMBOL(_debug_pagealloc_enabled);
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| 12 |
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| 13 | DEFINE_STATIC_KEY_FALSE(_debug_guardpage_enabled);
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| 14 |
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| 15 | static int __init early_debug_pagealloc(char *buf)
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| 16 | {
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| 17 | return kstrtobool(buf, &_debug_pagealloc_enabled_early);
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| 18 | }
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| 19 | early_param("debug_pagealloc", early_debug_pagealloc);
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| 20 |
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| 21 | static int __init debug_guardpage_minorder_setup(char *buf)
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| 22 | {
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| 23 | unsigned int res;
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| 24 |
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| 25 | if (!buf || kstrtouint(buf, 10, &res) < 0 || res > MAX_PAGE_ORDER / 2) {
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| 26 | pr_err("Bad debug_guardpage_minorder value: %s\n", buf ?: "(missing)");
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| 27 | return 0;
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| 28 | }
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| 29 | _debug_guardpage_minorder = res;
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| 30 | pr_info("Setting debug_guardpage_minorder to %u\n", res);
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| 31 | return 0;
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| 32 | }
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| 33 | early_param("debug_guardpage_minorder", debug_guardpage_minorder_setup);
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| 34 |
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| 35 | bool __set_page_guard(struct zone *zone, struct page *page, unsigned int order)
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| 36 | {
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| 37 | if (order >= debug_guardpage_minorder())
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| 38 | return false;
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| 39 |
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| 40 | __SetPageGuard(page);
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| 41 | INIT_LIST_HEAD(&page->buddy_list);
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| 42 | set_page_private(page, order);
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| 43 |
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| 44 | return true;
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| 45 | }
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| 46 |
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| 47 | void __clear_page_guard(struct zone *zone, struct page *page, unsigned int order)
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| 48 | {
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| 49 | __ClearPageGuard(page);
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| 50 | set_page_private(page, 0);
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| 51 | }
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