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// SPDX-License-Identifier: GPL-2.0
/*
* vdso setup for s390
*
* Copyright IBM Corp. 2008
* Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
*/
#include <linux/binfmts.h>
#include <linux/compat.h>
#include <linux/elf.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/smp.h>
#include <vdso/datapage.h>
#include <asm/vdso.h>
extern char vdso64_start[], vdso64_end[];
static unsigned int vdso_pages;
static union {
struct vdso_data data[CS_BASES];
u8 page[PAGE_SIZE];
} vdso_data_store __page_aligned_data;
struct vdso_data *vdso_data = vdso_data_store.data;
unsigned int __read_mostly vdso_enabled = 1;
static int __init vdso_setup(char *str)
{
bool enabled;
if (!kstrtobool(str, &enabled))
vdso_enabled = enabled;
return 1;
}
__setup("vdso=", vdso_setup);
static vm_fault_t vvar_fault(const struct vm_special_mapping *sm,
struct vm_area_struct *vma, struct vm_fault *vmf)
{
if (vmf->pgoff == 0)
return vmf_insert_pfn(vma, vmf->address, virt_to_pfn(vdso_data));
return VM_FAULT_SIGBUS;
}
static int vdso_mremap(const struct vm_special_mapping *sm,
struct vm_area_struct *vma)
{
current->mm->context.vdso_base = vma->vm_start;
return 0;
}
static struct vm_special_mapping vvar_mapping = {
.name = "[vvar]",
.fault = vvar_fault,
};
static struct vm_special_mapping vdso_mapping = {
.name = "[vdso]",
.mremap = vdso_mremap,
};
int vdso_getcpu_init(void)
{
set_tod_programmable_field(smp_processor_id());
return 0;
}
early_initcall(vdso_getcpu_init); /* Must be called before SMP init */
int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
{
unsigned long addr, vdso_text_start, vdso_text_len, vdso_mapping_len;
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma;
int rc;
if (!vdso_enabled || is_compat_task())
return 0;
if (mmap_write_lock_killable(mm))
return -EINTR;
vdso_text_len = vdso_pages << PAGE_SHIFT;
vdso_mapping_len = vdso_text_len + PAGE_SIZE;
addr = get_unmapped_area(NULL, 0, vdso_mapping_len, 0, 0);
rc = addr;
if (IS_ERR_VALUE(addr))
goto out;
/* VM_MAYWRITE for COW so gdb can set breakpoints */
vdso_text_start = addr;
vma = _install_special_mapping(mm, addr, vdso_text_len,
VM_READ|VM_EXEC|
VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
&vdso_mapping);
rc = PTR_ERR(vma);
if (IS_ERR(vma))
goto out;
addr += vdso_text_len;
vma = _install_special_mapping(mm, addr, PAGE_SIZE,
VM_READ|VM_MAYREAD|VM_PFNMAP,
&vvar_mapping);
if (IS_ERR(vma)) {
do_munmap(mm, vdso_text_start, vdso_text_len, NULL);
rc = PTR_ERR(vma);
} else {
current->mm->context.vdso_base = vdso_text_start;
rc = 0;
}
out:
mmap_write_unlock(mm);
return rc;
}
static int __init vdso_init(void)
{
struct page **pages;
int i;
vdso_pages = (vdso64_end - vdso64_start) >> PAGE_SHIFT;
pages = kcalloc(vdso_pages + 1, sizeof(struct page *), GFP_KERNEL);
if (!pages) {
vdso_enabled = 0;
return -ENOMEM;
}
for (i = 0; i < vdso_pages; i++)
pages[i] = virt_to_page(vdso64_start + i * PAGE_SIZE);
pages[vdso_pages] = NULL;
vdso_mapping.pages = pages;
return 0;
}
arch_initcall(vdso_init);
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