cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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ksm.h (2539B)

      1/* SPDX-License-Identifier: GPL-2.0 */
      2#ifndef __LINUX_KSM_H
      3#define __LINUX_KSM_H
      4/*
      5 * Memory merging support.
      6 *
      7 * This code enables dynamic sharing of identical pages found in different
      8 * memory areas, even if they are not shared by fork().
      9 */
     10
     11#include <linux/bitops.h>
     12#include <linux/mm.h>
     13#include <linux/pagemap.h>
     14#include <linux/rmap.h>
     15#include <linux/sched.h>
     16#include <linux/sched/coredump.h>
     17
     18struct stable_node;
     19struct mem_cgroup;
     20
     21#ifdef CONFIG_KSM
     22int ksm_madvise(struct vm_area_struct *vma, unsigned long start,
     23		unsigned long end, int advice, unsigned long *vm_flags);
     24int __ksm_enter(struct mm_struct *mm);
     25void __ksm_exit(struct mm_struct *mm);
     26
     27static inline int ksm_fork(struct mm_struct *mm, struct mm_struct *oldmm)
     28{
     29	if (test_bit(MMF_VM_MERGEABLE, &oldmm->flags))
     30		return __ksm_enter(mm);
     31	return 0;
     32}
     33
     34static inline void ksm_exit(struct mm_struct *mm)
     35{
     36	if (test_bit(MMF_VM_MERGEABLE, &mm->flags))
     37		__ksm_exit(mm);
     38}
     39
     40/*
     41 * When do_swap_page() first faults in from swap what used to be a KSM page,
     42 * no problem, it will be assigned to this vma's anon_vma; but thereafter,
     43 * it might be faulted into a different anon_vma (or perhaps to a different
     44 * offset in the same anon_vma).  do_swap_page() cannot do all the locking
     45 * needed to reconstitute a cross-anon_vma KSM page: for now it has to make
     46 * a copy, and leave remerging the pages to a later pass of ksmd.
     47 *
     48 * We'd like to make this conditional on vma->vm_flags & VM_MERGEABLE,
     49 * but what if the vma was unmerged while the page was swapped out?
     50 */
     51struct page *ksm_might_need_to_copy(struct page *page,
     52			struct vm_area_struct *vma, unsigned long address);
     53
     54void rmap_walk_ksm(struct folio *folio, struct rmap_walk_control *rwc);
     55void folio_migrate_ksm(struct folio *newfolio, struct folio *folio);
     56
     57#else  /* !CONFIG_KSM */
     58
     59static inline int ksm_fork(struct mm_struct *mm, struct mm_struct *oldmm)
     60{
     61	return 0;
     62}
     63
     64static inline void ksm_exit(struct mm_struct *mm)
     65{
     66}
     67
     68#ifdef CONFIG_MMU
     69static inline int ksm_madvise(struct vm_area_struct *vma, unsigned long start,
     70		unsigned long end, int advice, unsigned long *vm_flags)
     71{
     72	return 0;
     73}
     74
     75static inline struct page *ksm_might_need_to_copy(struct page *page,
     76			struct vm_area_struct *vma, unsigned long address)
     77{
     78	return page;
     79}
     80
     81static inline void rmap_walk_ksm(struct folio *folio,
     82			struct rmap_walk_control *rwc)
     83{
     84}
     85
     86static inline void folio_migrate_ksm(struct folio *newfolio, struct folio *old)
     87{
     88}
     89#endif /* CONFIG_MMU */
     90#endif /* !CONFIG_KSM */
     91
     92#endif /* __LINUX_KSM_H */