tools/testing/vma/shared.c

Source file repositories/reference/linux-study-clean/tools/testing/vma/shared.c

File Facts

System
Linux kernel
Corpus path
tools/testing/vma/shared.c
Extension
.c
Size
2808 bytes
Lines
132
Domain
Support Tooling And Documentation
Bucket
tools
Inferred role
Support Tooling And Documentation: implementation source
Status
source implementation candidate

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0-or-later

#include "shared.h"


bool fail_prealloc;
unsigned long mmap_min_addr = CONFIG_DEFAULT_MMAP_MIN_ADDR;
unsigned long dac_mmap_min_addr = CONFIG_DEFAULT_MMAP_MIN_ADDR;
unsigned long stack_guard_gap = 256UL<<PAGE_SHIFT;

const struct vm_operations_struct vma_dummy_vm_ops;
struct anon_vma dummy_anon_vma;
struct task_struct __current;

struct vm_area_struct *alloc_vma(struct mm_struct *mm,
		unsigned long start, unsigned long end,
		pgoff_t pgoff, vma_flags_t vma_flags)
{
	struct vm_area_struct *vma = vm_area_alloc(mm);

	if (vma == NULL)
		return NULL;

	vma->vm_start = start;
	vma->vm_end = end;
	vma->vm_pgoff = pgoff;
	vma->flags = vma_flags;
	vma_assert_detached(vma);

	return vma;
}

void detach_free_vma(struct vm_area_struct *vma)
{
	vma_mark_detached(vma);
	vm_area_free(vma);
}

struct vm_area_struct *alloc_and_link_vma(struct mm_struct *mm,
		unsigned long start, unsigned long end,
		pgoff_t pgoff, vma_flags_t vma_flags)
{
	struct vm_area_struct *vma = alloc_vma(mm, start, end, pgoff, vma_flags);

	if (vma == NULL)
		return NULL;

	if (attach_vma(mm, vma)) {
		detach_free_vma(vma);
		return NULL;
	}

	/*
	 * Reset this counter which we use to track whether writes have
	 * begun. Linking to the tree will have caused this to be incremented,
	 * which means we will get a false positive otherwise.
	 */
	vma->vm_lock_seq = UINT_MAX;

	return vma;
}

void reset_dummy_anon_vma(void)
{
	dummy_anon_vma.was_cloned = false;
	dummy_anon_vma.was_unlinked = false;
}

int cleanup_mm(struct mm_struct *mm, struct vma_iterator *vmi)
{
	struct vm_area_struct *vma;
	int count = 0;

	fail_prealloc = false;
	reset_dummy_anon_vma();

	vma_iter_set(vmi, 0);
	for_each_vma(*vmi, vma) {
		detach_free_vma(vma);
		count++;
	}

	mtree_destroy(&mm->mm_mt);
	mm->map_count = 0;
	return count;
}

bool vma_write_started(struct vm_area_struct *vma)
{
	int seq = vma->vm_lock_seq;

Annotation

Implementation Notes