linux_dsm_epyc7002/arch/s390/kernel/vdso.c
Paul Gortmaker 3994a52b54 s390: kernel: Audit and remove any unnecessary uses of module.h
Historically a lot of these existed because we did not have
a distinction between what was modular code and what was providing
support to modules via EXPORT_SYMBOL and friends.  That changed
when we forked out support for the latter into the export.h file.

This means we should be able to reduce the usage of module.h
in code that is obj-y Makefile or bool Kconfig.  The advantage
in doing so is that module.h itself sources about 15 other headers;
adding significantly to what we feed cpp, and it can obscure what
headers we are effectively using.

Since module.h was the source for init.h (for __init) and for
export.h (for EXPORT_SYMBOL) we consider each change instance
for the presence of either and replace as needed.  Build testing
revealed some implicit header usage that was fixed up accordingly.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-02-17 07:40:31 +01:00

313 lines
7.8 KiB
C

/*
* vdso setup for s390
*
* Copyright IBM Corp. 2008
* Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License (version 2 only)
* as published by the Free Software Foundation.
*/
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/stddef.h>
#include <linux/unistd.h>
#include <linux/slab.h>
#include <linux/user.h>
#include <linux/elf.h>
#include <linux/security.h>
#include <linux/bootmem.h>
#include <linux/compat.h>
#include <asm/asm-offsets.h>
#include <asm/pgtable.h>
#include <asm/processor.h>
#include <asm/mmu.h>
#include <asm/mmu_context.h>
#include <asm/sections.h>
#include <asm/vdso.h>
#include <asm/facility.h>
#ifdef CONFIG_COMPAT
extern char vdso32_start, vdso32_end;
static void *vdso32_kbase = &vdso32_start;
static unsigned int vdso32_pages;
static struct page **vdso32_pagelist;
#endif
extern char vdso64_start, vdso64_end;
static void *vdso64_kbase = &vdso64_start;
static unsigned int vdso64_pages;
static struct page **vdso64_pagelist;
/*
* Should the kernel map a VDSO page into processes and pass its
* address down to glibc upon exec()?
*/
unsigned int __read_mostly vdso_enabled = 1;
static int __init vdso_setup(char *s)
{
unsigned long val;
int rc;
rc = 0;
if (strncmp(s, "on", 3) == 0)
vdso_enabled = 1;
else if (strncmp(s, "off", 4) == 0)
vdso_enabled = 0;
else {
rc = kstrtoul(s, 0, &val);
vdso_enabled = rc ? 0 : !!val;
}
return !rc;
}
__setup("vdso=", vdso_setup);
/*
* The vdso data page
*/
static union {
struct vdso_data data;
u8 page[PAGE_SIZE];
} vdso_data_store __page_aligned_data;
struct vdso_data *vdso_data = &vdso_data_store.data;
/*
* Setup vdso data page.
*/
static void __init vdso_init_data(struct vdso_data *vd)
{
vd->ectg_available = test_facility(31);
}
/*
* Allocate/free per cpu vdso data.
*/
#define SEGMENT_ORDER 2
int vdso_alloc_per_cpu(struct lowcore *lowcore)
{
unsigned long segment_table, page_table, page_frame;
struct vdso_per_cpu_data *vd;
u32 *psal, *aste;
int i;
lowcore->vdso_per_cpu_data = __LC_PASTE;
if (!vdso_enabled)
return 0;
segment_table = __get_free_pages(GFP_KERNEL, SEGMENT_ORDER);
page_table = get_zeroed_page(GFP_KERNEL | GFP_DMA);
page_frame = get_zeroed_page(GFP_KERNEL);
if (!segment_table || !page_table || !page_frame)
goto out;
/* Initialize per-cpu vdso data page */
vd = (struct vdso_per_cpu_data *) page_frame;
vd->cpu_nr = lowcore->cpu_nr;
vd->node_id = cpu_to_node(vd->cpu_nr);
/* Set up access register mode page table */
clear_table((unsigned long *) segment_table, _SEGMENT_ENTRY_EMPTY,
PAGE_SIZE << SEGMENT_ORDER);
clear_table((unsigned long *) page_table, _PAGE_INVALID,
256*sizeof(unsigned long));
*(unsigned long *) segment_table = _SEGMENT_ENTRY + page_table;
*(unsigned long *) page_table = _PAGE_PROTECT + page_frame;
psal = (u32 *) (page_table + 256*sizeof(unsigned long));
aste = psal + 32;
for (i = 4; i < 32; i += 4)
psal[i] = 0x80000000;
lowcore->paste[4] = (u32)(addr_t) psal;
psal[0] = 0x02000000;
psal[2] = (u32)(addr_t) aste;
*(unsigned long *) (aste + 2) = segment_table +
_ASCE_TABLE_LENGTH + _ASCE_USER_BITS + _ASCE_TYPE_SEGMENT;
aste[4] = (u32)(addr_t) psal;
lowcore->vdso_per_cpu_data = page_frame;
return 0;
out:
free_page(page_frame);
free_page(page_table);
free_pages(segment_table, SEGMENT_ORDER);
return -ENOMEM;
}
void vdso_free_per_cpu(struct lowcore *lowcore)
{
unsigned long segment_table, page_table, page_frame;
u32 *psal, *aste;
if (!vdso_enabled)
return;
psal = (u32 *)(addr_t) lowcore->paste[4];
aste = (u32 *)(addr_t) psal[2];
segment_table = *(unsigned long *)(aste + 2) & PAGE_MASK;
page_table = *(unsigned long *) segment_table;
page_frame = *(unsigned long *) page_table;
free_page(page_frame);
free_page(page_table);
free_pages(segment_table, SEGMENT_ORDER);
}
static void vdso_init_cr5(void)
{
unsigned long cr5;
if (!vdso_enabled)
return;
cr5 = offsetof(struct lowcore, paste);
__ctl_load(cr5, 5, 5);
}
/*
* This is called from binfmt_elf, we create the special vma for the
* vDSO and insert it into the mm struct tree
*/
int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
{
struct mm_struct *mm = current->mm;
struct page **vdso_pagelist;
unsigned long vdso_pages;
unsigned long vdso_base;
int rc;
if (!vdso_enabled)
return 0;
/*
* Only map the vdso for dynamically linked elf binaries.
*/
if (!uses_interp)
return 0;
vdso_pagelist = vdso64_pagelist;
vdso_pages = vdso64_pages;
#ifdef CONFIG_COMPAT
if (is_compat_task()) {
vdso_pagelist = vdso32_pagelist;
vdso_pages = vdso32_pages;
}
#endif
/*
* vDSO has a problem and was disabled, just don't "enable" it for
* the process
*/
if (vdso_pages == 0)
return 0;
current->mm->context.vdso_base = 0;
/*
* pick a base address for the vDSO in process space. We try to put
* it at vdso_base which is the "natural" base for it, but we might
* fail and end up putting it elsewhere.
*/
if (down_write_killable(&mm->mmap_sem))
return -EINTR;
vdso_base = get_unmapped_area(NULL, 0, vdso_pages << PAGE_SHIFT, 0, 0);
if (IS_ERR_VALUE(vdso_base)) {
rc = vdso_base;
goto out_up;
}
/*
* Put vDSO base into mm struct. We need to do this before calling
* install_special_mapping or the perf counter mmap tracking code
* will fail to recognise it as a vDSO (since arch_vma_name fails).
*/
current->mm->context.vdso_base = vdso_base;
/*
* our vma flags don't have VM_WRITE so by default, the process
* isn't allowed to write those pages.
* gdb can break that with ptrace interface, and thus trigger COW
* on those pages but it's then your responsibility to never do that
* on the "data" page of the vDSO or you'll stop getting kernel
* updates and your nice userland gettimeofday will be totally dead.
* It's fine to use that for setting breakpoints in the vDSO code
* pages though.
*/
rc = install_special_mapping(mm, vdso_base, vdso_pages << PAGE_SHIFT,
VM_READ|VM_EXEC|
VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
vdso_pagelist);
if (rc)
current->mm->context.vdso_base = 0;
out_up:
up_write(&mm->mmap_sem);
return rc;
}
const char *arch_vma_name(struct vm_area_struct *vma)
{
if (vma->vm_mm && vma->vm_start == vma->vm_mm->context.vdso_base)
return "[vdso]";
return NULL;
}
static int __init vdso_init(void)
{
int i;
if (!vdso_enabled)
return 0;
vdso_init_data(vdso_data);
#ifdef CONFIG_COMPAT
/* Calculate the size of the 32 bit vDSO */
vdso32_pages = ((&vdso32_end - &vdso32_start
+ PAGE_SIZE - 1) >> PAGE_SHIFT) + 1;
/* Make sure pages are in the correct state */
vdso32_pagelist = kzalloc(sizeof(struct page *) * (vdso32_pages + 1),
GFP_KERNEL);
BUG_ON(vdso32_pagelist == NULL);
for (i = 0; i < vdso32_pages - 1; i++) {
struct page *pg = virt_to_page(vdso32_kbase + i*PAGE_SIZE);
ClearPageReserved(pg);
get_page(pg);
vdso32_pagelist[i] = pg;
}
vdso32_pagelist[vdso32_pages - 1] = virt_to_page(vdso_data);
vdso32_pagelist[vdso32_pages] = NULL;
#endif
/* Calculate the size of the 64 bit vDSO */
vdso64_pages = ((&vdso64_end - &vdso64_start
+ PAGE_SIZE - 1) >> PAGE_SHIFT) + 1;
/* Make sure pages are in the correct state */
vdso64_pagelist = kzalloc(sizeof(struct page *) * (vdso64_pages + 1),
GFP_KERNEL);
BUG_ON(vdso64_pagelist == NULL);
for (i = 0; i < vdso64_pages - 1; i++) {
struct page *pg = virt_to_page(vdso64_kbase + i*PAGE_SIZE);
ClearPageReserved(pg);
get_page(pg);
vdso64_pagelist[i] = pg;
}
vdso64_pagelist[vdso64_pages - 1] = virt_to_page(vdso_data);
vdso64_pagelist[vdso64_pages] = NULL;
if (vdso_alloc_per_cpu(&S390_lowcore))
BUG();
vdso_init_cr5();
get_page(virt_to_page(vdso_data));
return 0;
}
early_initcall(vdso_init);