Fix: Disable IBT around indirect function calls
[lttng-modules.git] / src / wrapper / page_alloc.c
CommitLineData
b7cdc182 1/* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
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2 * wrapper/page_alloc.c
3 *
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4 * wrapper around get_pfnblock_flags_mask and Ubuntu
5 * get_pageblock_flags_mask. Using KALLSYMS to get their address when
6 * available, else we need to have a kernel that exports this function
7 * to GPL modules.
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8 *
9 * Copyright (C) 2015 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
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10 */
11
5a90857e 12#ifdef CONFIG_KALLSYMS
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13
14#include <linux/kallsyms.h>
15#include <linux/mm_types.h>
16#include <linux/module.h>
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17#include <wrapper/kallsyms.h>
18#include <wrapper/page_alloc.h>
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19
20static
21unsigned long (*get_pfnblock_flags_mask_sym)(struct page *page,
22 unsigned long pfn,
23 unsigned long end_bitidx,
24 unsigned long mask);
25
26unsigned long wrapper_get_pfnblock_flags_mask(struct page *page,
27 unsigned long pfn,
28 unsigned long end_bitidx,
29 unsigned long mask)
30{
31 WARN_ON_ONCE(!get_pfnblock_flags_mask_sym);
32 if (get_pfnblock_flags_mask_sym) {
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33 struct irq_ibt_state irq_ibt_state;
34 unsigned long ret;
35
36 irq_ibt_state = wrapper_irq_ibt_save();
37 ret = get_pfnblock_flags_mask_sym(page, pfn, end_bitidx, mask);
38 wrapper_irq_ibt_restore(irq_ibt_state);
39 return ret;
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40 } else {
41 return -ENOSYS;
42 }
43}
44EXPORT_SYMBOL_GPL(wrapper_get_pfnblock_flags_mask);
45
46int wrapper_get_pfnblock_flags_mask_init(void)
47{
48 get_pfnblock_flags_mask_sym =
49 (void *) kallsyms_lookup_funcptr("get_pfnblock_flags_mask");
50 if (!get_pfnblock_flags_mask_sym)
51 return -1;
52 return 0;
53}
1c999280 54EXPORT_SYMBOL_GPL(wrapper_get_pfnblock_flags_mask_init);
389d7070 55
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56/*
57 * Canary function to check for 'get_pfnblock_flags_mask()' at compile time.
58 *
59 * From 'include/linux/pageblock-flags.h':
60 *
61 * unsigned long get_pfnblock_flags_mask(struct page *page,
62 * unsigned long pfn,
63 * unsigned long end_bitidx,
64 * unsigned long mask);
65 */
66__attribute__((unused)) static
67unsigned long __canary__get_pfnblock_flags_mask(struct page *page,
68 unsigned long pfn,
69 unsigned long end_bitidx,
70 unsigned long mask)
71{
72 return get_pfnblock_flags_mask(page, pfn, end_bitidx, mask);
73}
74
0e14d6e7 75#else
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76
77#include <linux/pageblock-flags.h>
78
0e14d6e7 79#endif
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