60 lines
1.6 KiB
C
60 lines
1.6 KiB
C
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// SPDX-License-Identifier: GPL-2.0
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#include <linux/mm.h>
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#include <linux/page-isolation.h>
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unsigned int _debug_guardpage_minorder;
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bool _debug_pagealloc_enabled_early __read_mostly
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= IS_ENABLED(CONFIG_DEBUG_PAGEALLOC_ENABLE_DEFAULT);
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EXPORT_SYMBOL(_debug_pagealloc_enabled_early);
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DEFINE_STATIC_KEY_FALSE(_debug_pagealloc_enabled);
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EXPORT_SYMBOL(_debug_pagealloc_enabled);
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DEFINE_STATIC_KEY_FALSE(_debug_guardpage_enabled);
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static int __init early_debug_pagealloc(char *buf)
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{
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return kstrtobool(buf, &_debug_pagealloc_enabled_early);
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}
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early_param("debug_pagealloc", early_debug_pagealloc);
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static int __init debug_guardpage_minorder_setup(char *buf)
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{
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unsigned long res;
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if (kstrtoul(buf, 10, &res) < 0 || res > MAX_ORDER / 2) {
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pr_err("Bad debug_guardpage_minorder value\n");
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return 0;
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}
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_debug_guardpage_minorder = res;
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pr_info("Setting debug_guardpage_minorder to %lu\n", res);
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return 0;
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}
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early_param("debug_guardpage_minorder", debug_guardpage_minorder_setup);
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bool __set_page_guard(struct zone *zone, struct page *page, unsigned int order,
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int migratetype)
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{
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if (order >= debug_guardpage_minorder())
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return false;
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__SetPageGuard(page);
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INIT_LIST_HEAD(&page->buddy_list);
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set_page_private(page, order);
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/* Guard pages are not available for any usage */
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if (!is_migrate_isolate(migratetype))
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__mod_zone_freepage_state(zone, -(1 << order), migratetype);
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return true;
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}
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void __clear_page_guard(struct zone *zone, struct page *page, unsigned int order,
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int migratetype)
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{
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__ClearPageGuard(page);
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set_page_private(page, 0);
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if (!is_migrate_isolate(migratetype))
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__mod_zone_freepage_state(zone, (1 << order), migratetype);
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}
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