vma.c | Explore in Territory

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright 2007 Andi Kleen, SUSE Labs.
 *
 * This contains most of the x86 vDSO kernel-side code.
 */
#include <linux/mm.h>
#include <linux/err.h>
#include <linux/sched.h>
#include <linux/sched/task_stack.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/random.h>
#include <linux/elf.h>
#include <linux/cpu.h>
#include <linux/ptrace.h>
#include <linux/time_namespace.h>

#include <asm/pvclock.h>
#include <asm/vgtod.h>
#include <asm/proto.h>
#include <asm/vdso.h>
#include <asm/vvar.h>
#include <asm/tlb.h>
#include <asm/page.h>
#include <asm/desc.h>
#include <asm/cpufeature.h>
#include <clocksource/hyperv_timer.h>

#undef _ASM_X86_VVAR_H
#define EMIT_VVAR …
#include <asm/vvar.h>

struct vdso_data *arch_get_vdso_data(void *vvar_page)
{ … }
#undef EMIT_VVAR

unsigned int vclocks_used __read_mostly;

#if defined(CONFIG_X86_64)
unsigned int __read_mostly vdso64_enabled = …;
#endif

int __init init_vdso_image(const struct vdso_image *image)
{ … }

static const struct vm_special_mapping vvar_mapping;
struct linux_binprm;

static vm_fault_t vdso_fault(const struct vm_special_mapping *sm,
		      struct vm_area_struct *vma, struct vm_fault *vmf)
{ … }

static void vdso_fix_landing(const struct vdso_image *image,
		struct vm_area_struct *new_vma)
{ … }

static int vdso_mremap(const struct vm_special_mapping *sm,
		struct vm_area_struct *new_vma)
{ … }

#ifdef CONFIG_TIME_NS
/*
 * The vvar page layout depends on whether a task belongs to the root or
 * non-root time namespace. Whenever a task changes its namespace, the VVAR
 * page tables are cleared and then they will re-faulted with a
 * corresponding layout.
 * See also the comment near timens_setup_vdso_data() for details.
 */
int vdso_join_timens(struct task_struct *task, struct time_namespace *ns)
{ … }
#endif

static vm_fault_t vvar_fault(const struct vm_special_mapping *sm,
		      struct vm_area_struct *vma, struct vm_fault *vmf)
{ … }

static const struct vm_special_mapping vdso_mapping = …;
static const struct vm_special_mapping vvar_mapping = …;

/*
 * Add vdso and vvar mappings to current process.
 * @image          - blob to map
 * @addr           - request a specific address (zero to map at free addr)
 */
static int map_vdso(const struct vdso_image *image, unsigned long addr)
{ … }

int map_vdso_once(const struct vdso_image *image, unsigned long addr)
{ … }

#if defined(CONFIG_X86_32) || defined(CONFIG_IA32_EMULATION)
static int load_vdso32(void)
{ … }
#endif

#ifdef CONFIG_X86_64
int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
{ … }

#ifdef CONFIG_COMPAT
int compat_arch_setup_additional_pages(struct linux_binprm *bprm,
				       int uses_interp, bool x32)
{ … }
#endif
#else
int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
{
	return load_vdso32();
}
#endif

bool arch_syscall_is_vdso_sigreturn(struct pt_regs *regs)
{ … }

#ifdef CONFIG_X86_64
static __init int vdso_setup(char *s)
{ … }
__setup(…);
#endif /* CONFIG_X86_64 */
linux/arch/x86/entry/vdso/vma.c
