mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-06 05:06:40 +07:00
69beeb1d34
Sparse output following warnings. mm/vmalloc.c:1436:6: warning: symbol 'vread' was not declared. Should it be static? mm/vmalloc.c:1474:6: warning: symbol 'vwrite' was not declared. Should it be static? However, it is used by /dev/kmem. fixed here. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1000 lines
21 KiB
C
1000 lines
21 KiB
C
/*
|
|
* linux/drivers/char/mem.c
|
|
*
|
|
* Copyright (C) 1991, 1992 Linus Torvalds
|
|
*
|
|
* Added devfs support.
|
|
* Jan-11-1998, C. Scott Ananian <cananian@alumni.princeton.edu>
|
|
* Shared /dev/zero mmaping support, Feb 2000, Kanoj Sarcar <kanoj@sgi.com>
|
|
*/
|
|
|
|
#include <linux/mm.h>
|
|
#include <linux/miscdevice.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/vmalloc.h>
|
|
#include <linux/mman.h>
|
|
#include <linux/random.h>
|
|
#include <linux/init.h>
|
|
#include <linux/raw.h>
|
|
#include <linux/tty.h>
|
|
#include <linux/capability.h>
|
|
#include <linux/ptrace.h>
|
|
#include <linux/device.h>
|
|
#include <linux/highmem.h>
|
|
#include <linux/crash_dump.h>
|
|
#include <linux/backing-dev.h>
|
|
#include <linux/bootmem.h>
|
|
#include <linux/splice.h>
|
|
#include <linux/pfn.h>
|
|
#include <linux/smp_lock.h>
|
|
|
|
#include <asm/uaccess.h>
|
|
#include <asm/io.h>
|
|
|
|
#ifdef CONFIG_IA64
|
|
# include <linux/efi.h>
|
|
#endif
|
|
|
|
/*
|
|
* Architectures vary in how they handle caching for addresses
|
|
* outside of main memory.
|
|
*
|
|
*/
|
|
static inline int uncached_access(struct file *file, unsigned long addr)
|
|
{
|
|
#if defined(CONFIG_IA64)
|
|
/*
|
|
* On ia64, we ignore O_SYNC because we cannot tolerate memory attribute aliases.
|
|
*/
|
|
return !(efi_mem_attributes(addr) & EFI_MEMORY_WB);
|
|
#elif defined(CONFIG_MIPS)
|
|
{
|
|
extern int __uncached_access(struct file *file,
|
|
unsigned long addr);
|
|
|
|
return __uncached_access(file, addr);
|
|
}
|
|
#else
|
|
/*
|
|
* Accessing memory above the top the kernel knows about or through a file pointer
|
|
* that was marked O_SYNC will be done non-cached.
|
|
*/
|
|
if (file->f_flags & O_SYNC)
|
|
return 1;
|
|
return addr >= __pa(high_memory);
|
|
#endif
|
|
}
|
|
|
|
#ifndef ARCH_HAS_VALID_PHYS_ADDR_RANGE
|
|
static inline int valid_phys_addr_range(unsigned long addr, size_t count)
|
|
{
|
|
if (addr + count > __pa(high_memory))
|
|
return 0;
|
|
|
|
return 1;
|
|
}
|
|
|
|
static inline int valid_mmap_phys_addr_range(unsigned long pfn, size_t size)
|
|
{
|
|
return 1;
|
|
}
|
|
#endif
|
|
|
|
#ifdef CONFIG_STRICT_DEVMEM
|
|
static inline int range_is_allowed(unsigned long pfn, unsigned long size)
|
|
{
|
|
u64 from = ((u64)pfn) << PAGE_SHIFT;
|
|
u64 to = from + size;
|
|
u64 cursor = from;
|
|
|
|
while (cursor < to) {
|
|
if (!devmem_is_allowed(pfn)) {
|
|
printk(KERN_INFO
|
|
"Program %s tried to access /dev/mem between %Lx->%Lx.\n",
|
|
current->comm, from, to);
|
|
return 0;
|
|
}
|
|
cursor += PAGE_SIZE;
|
|
pfn++;
|
|
}
|
|
return 1;
|
|
}
|
|
#else
|
|
static inline int range_is_allowed(unsigned long pfn, unsigned long size)
|
|
{
|
|
return 1;
|
|
}
|
|
#endif
|
|
|
|
void __attribute__((weak)) unxlate_dev_mem_ptr(unsigned long phys, void *addr)
|
|
{
|
|
}
|
|
|
|
/*
|
|
* This funcion reads the *physical* memory. The f_pos points directly to the
|
|
* memory location.
|
|
*/
|
|
static ssize_t read_mem(struct file * file, char __user * buf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
unsigned long p = *ppos;
|
|
ssize_t read, sz;
|
|
char *ptr;
|
|
|
|
if (!valid_phys_addr_range(p, count))
|
|
return -EFAULT;
|
|
read = 0;
|
|
#ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED
|
|
/* we don't have page 0 mapped on sparc and m68k.. */
|
|
if (p < PAGE_SIZE) {
|
|
sz = PAGE_SIZE - p;
|
|
if (sz > count)
|
|
sz = count;
|
|
if (sz > 0) {
|
|
if (clear_user(buf, sz))
|
|
return -EFAULT;
|
|
buf += sz;
|
|
p += sz;
|
|
count -= sz;
|
|
read += sz;
|
|
}
|
|
}
|
|
#endif
|
|
|
|
while (count > 0) {
|
|
/*
|
|
* Handle first page in case it's not aligned
|
|
*/
|
|
if (-p & (PAGE_SIZE - 1))
|
|
sz = -p & (PAGE_SIZE - 1);
|
|
else
|
|
sz = PAGE_SIZE;
|
|
|
|
sz = min_t(unsigned long, sz, count);
|
|
|
|
if (!range_is_allowed(p >> PAGE_SHIFT, count))
|
|
return -EPERM;
|
|
|
|
/*
|
|
* On ia64 if a page has been mapped somewhere as
|
|
* uncached, then it must also be accessed uncached
|
|
* by the kernel or data corruption may occur
|
|
*/
|
|
ptr = xlate_dev_mem_ptr(p);
|
|
if (!ptr)
|
|
return -EFAULT;
|
|
|
|
if (copy_to_user(buf, ptr, sz)) {
|
|
unxlate_dev_mem_ptr(p, ptr);
|
|
return -EFAULT;
|
|
}
|
|
|
|
unxlate_dev_mem_ptr(p, ptr);
|
|
|
|
buf += sz;
|
|
p += sz;
|
|
count -= sz;
|
|
read += sz;
|
|
}
|
|
|
|
*ppos += read;
|
|
return read;
|
|
}
|
|
|
|
static ssize_t write_mem(struct file * file, const char __user * buf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
unsigned long p = *ppos;
|
|
ssize_t written, sz;
|
|
unsigned long copied;
|
|
void *ptr;
|
|
|
|
if (!valid_phys_addr_range(p, count))
|
|
return -EFAULT;
|
|
|
|
written = 0;
|
|
|
|
#ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED
|
|
/* we don't have page 0 mapped on sparc and m68k.. */
|
|
if (p < PAGE_SIZE) {
|
|
unsigned long sz = PAGE_SIZE - p;
|
|
if (sz > count)
|
|
sz = count;
|
|
/* Hmm. Do something? */
|
|
buf += sz;
|
|
p += sz;
|
|
count -= sz;
|
|
written += sz;
|
|
}
|
|
#endif
|
|
|
|
while (count > 0) {
|
|
/*
|
|
* Handle first page in case it's not aligned
|
|
*/
|
|
if (-p & (PAGE_SIZE - 1))
|
|
sz = -p & (PAGE_SIZE - 1);
|
|
else
|
|
sz = PAGE_SIZE;
|
|
|
|
sz = min_t(unsigned long, sz, count);
|
|
|
|
if (!range_is_allowed(p >> PAGE_SHIFT, sz))
|
|
return -EPERM;
|
|
|
|
/*
|
|
* On ia64 if a page has been mapped somewhere as
|
|
* uncached, then it must also be accessed uncached
|
|
* by the kernel or data corruption may occur
|
|
*/
|
|
ptr = xlate_dev_mem_ptr(p);
|
|
if (!ptr) {
|
|
if (written)
|
|
break;
|
|
return -EFAULT;
|
|
}
|
|
|
|
copied = copy_from_user(ptr, buf, sz);
|
|
if (copied) {
|
|
written += sz - copied;
|
|
unxlate_dev_mem_ptr(p, ptr);
|
|
if (written)
|
|
break;
|
|
return -EFAULT;
|
|
}
|
|
|
|
unxlate_dev_mem_ptr(p, ptr);
|
|
|
|
buf += sz;
|
|
p += sz;
|
|
count -= sz;
|
|
written += sz;
|
|
}
|
|
|
|
*ppos += written;
|
|
return written;
|
|
}
|
|
|
|
int __attribute__((weak)) phys_mem_access_prot_allowed(struct file *file,
|
|
unsigned long pfn, unsigned long size, pgprot_t *vma_prot)
|
|
{
|
|
return 1;
|
|
}
|
|
|
|
#ifndef __HAVE_PHYS_MEM_ACCESS_PROT
|
|
static pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
|
|
unsigned long size, pgprot_t vma_prot)
|
|
{
|
|
#ifdef pgprot_noncached
|
|
unsigned long offset = pfn << PAGE_SHIFT;
|
|
|
|
if (uncached_access(file, offset))
|
|
return pgprot_noncached(vma_prot);
|
|
#endif
|
|
return vma_prot;
|
|
}
|
|
#endif
|
|
|
|
#ifndef CONFIG_MMU
|
|
static unsigned long get_unmapped_area_mem(struct file *file,
|
|
unsigned long addr,
|
|
unsigned long len,
|
|
unsigned long pgoff,
|
|
unsigned long flags)
|
|
{
|
|
if (!valid_mmap_phys_addr_range(pgoff, len))
|
|
return (unsigned long) -EINVAL;
|
|
return pgoff << PAGE_SHIFT;
|
|
}
|
|
|
|
/* can't do an in-place private mapping if there's no MMU */
|
|
static inline int private_mapping_ok(struct vm_area_struct *vma)
|
|
{
|
|
return vma->vm_flags & VM_MAYSHARE;
|
|
}
|
|
#else
|
|
#define get_unmapped_area_mem NULL
|
|
|
|
static inline int private_mapping_ok(struct vm_area_struct *vma)
|
|
{
|
|
return 1;
|
|
}
|
|
#endif
|
|
|
|
void __attribute__((weak))
|
|
map_devmem(unsigned long pfn, unsigned long len, pgprot_t prot)
|
|
{
|
|
/* nothing. architectures can override. */
|
|
}
|
|
|
|
void __attribute__((weak))
|
|
unmap_devmem(unsigned long pfn, unsigned long len, pgprot_t prot)
|
|
{
|
|
/* nothing. architectures can override. */
|
|
}
|
|
|
|
static void mmap_mem_open(struct vm_area_struct *vma)
|
|
{
|
|
map_devmem(vma->vm_pgoff, vma->vm_end - vma->vm_start,
|
|
vma->vm_page_prot);
|
|
}
|
|
|
|
static void mmap_mem_close(struct vm_area_struct *vma)
|
|
{
|
|
unmap_devmem(vma->vm_pgoff, vma->vm_end - vma->vm_start,
|
|
vma->vm_page_prot);
|
|
}
|
|
|
|
static struct vm_operations_struct mmap_mem_ops = {
|
|
.open = mmap_mem_open,
|
|
.close = mmap_mem_close,
|
|
#ifdef CONFIG_HAVE_IOREMAP_PROT
|
|
.access = generic_access_phys
|
|
#endif
|
|
};
|
|
|
|
static int mmap_mem(struct file * file, struct vm_area_struct * vma)
|
|
{
|
|
size_t size = vma->vm_end - vma->vm_start;
|
|
|
|
if (!valid_mmap_phys_addr_range(vma->vm_pgoff, size))
|
|
return -EINVAL;
|
|
|
|
if (!private_mapping_ok(vma))
|
|
return -ENOSYS;
|
|
|
|
if (!range_is_allowed(vma->vm_pgoff, size))
|
|
return -EPERM;
|
|
|
|
if (!phys_mem_access_prot_allowed(file, vma->vm_pgoff, size,
|
|
&vma->vm_page_prot))
|
|
return -EINVAL;
|
|
|
|
vma->vm_page_prot = phys_mem_access_prot(file, vma->vm_pgoff,
|
|
size,
|
|
vma->vm_page_prot);
|
|
|
|
vma->vm_ops = &mmap_mem_ops;
|
|
|
|
/* Remap-pfn-range will mark the range VM_IO and VM_RESERVED */
|
|
if (remap_pfn_range(vma,
|
|
vma->vm_start,
|
|
vma->vm_pgoff,
|
|
size,
|
|
vma->vm_page_prot)) {
|
|
unmap_devmem(vma->vm_pgoff, size, vma->vm_page_prot);
|
|
return -EAGAIN;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
#ifdef CONFIG_DEVKMEM
|
|
static int mmap_kmem(struct file * file, struct vm_area_struct * vma)
|
|
{
|
|
unsigned long pfn;
|
|
|
|
/* Turn a kernel-virtual address into a physical page frame */
|
|
pfn = __pa((u64)vma->vm_pgoff << PAGE_SHIFT) >> PAGE_SHIFT;
|
|
|
|
/*
|
|
* RED-PEN: on some architectures there is more mapped memory
|
|
* than available in mem_map which pfn_valid checks
|
|
* for. Perhaps should add a new macro here.
|
|
*
|
|
* RED-PEN: vmalloc is not supported right now.
|
|
*/
|
|
if (!pfn_valid(pfn))
|
|
return -EIO;
|
|
|
|
vma->vm_pgoff = pfn;
|
|
return mmap_mem(file, vma);
|
|
}
|
|
#endif
|
|
|
|
#ifdef CONFIG_CRASH_DUMP
|
|
/*
|
|
* Read memory corresponding to the old kernel.
|
|
*/
|
|
static ssize_t read_oldmem(struct file *file, char __user *buf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
unsigned long pfn, offset;
|
|
size_t read = 0, csize;
|
|
int rc = 0;
|
|
|
|
while (count) {
|
|
pfn = *ppos / PAGE_SIZE;
|
|
if (pfn > saved_max_pfn)
|
|
return read;
|
|
|
|
offset = (unsigned long)(*ppos % PAGE_SIZE);
|
|
if (count > PAGE_SIZE - offset)
|
|
csize = PAGE_SIZE - offset;
|
|
else
|
|
csize = count;
|
|
|
|
rc = copy_oldmem_page(pfn, buf, csize, offset, 1);
|
|
if (rc < 0)
|
|
return rc;
|
|
buf += csize;
|
|
*ppos += csize;
|
|
read += csize;
|
|
count -= csize;
|
|
}
|
|
return read;
|
|
}
|
|
#endif
|
|
|
|
#ifdef CONFIG_DEVKMEM
|
|
/*
|
|
* This function reads the *virtual* memory as seen by the kernel.
|
|
*/
|
|
static ssize_t read_kmem(struct file *file, char __user *buf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
unsigned long p = *ppos;
|
|
ssize_t low_count, read, sz;
|
|
char * kbuf; /* k-addr because vread() takes vmlist_lock rwlock */
|
|
|
|
read = 0;
|
|
if (p < (unsigned long) high_memory) {
|
|
low_count = count;
|
|
if (count > (unsigned long) high_memory - p)
|
|
low_count = (unsigned long) high_memory - p;
|
|
|
|
#ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED
|
|
/* we don't have page 0 mapped on sparc and m68k.. */
|
|
if (p < PAGE_SIZE && low_count > 0) {
|
|
size_t tmp = PAGE_SIZE - p;
|
|
if (tmp > low_count) tmp = low_count;
|
|
if (clear_user(buf, tmp))
|
|
return -EFAULT;
|
|
buf += tmp;
|
|
p += tmp;
|
|
read += tmp;
|
|
low_count -= tmp;
|
|
count -= tmp;
|
|
}
|
|
#endif
|
|
while (low_count > 0) {
|
|
/*
|
|
* Handle first page in case it's not aligned
|
|
*/
|
|
if (-p & (PAGE_SIZE - 1))
|
|
sz = -p & (PAGE_SIZE - 1);
|
|
else
|
|
sz = PAGE_SIZE;
|
|
|
|
sz = min_t(unsigned long, sz, low_count);
|
|
|
|
/*
|
|
* On ia64 if a page has been mapped somewhere as
|
|
* uncached, then it must also be accessed uncached
|
|
* by the kernel or data corruption may occur
|
|
*/
|
|
kbuf = xlate_dev_kmem_ptr((char *)p);
|
|
|
|
if (copy_to_user(buf, kbuf, sz))
|
|
return -EFAULT;
|
|
buf += sz;
|
|
p += sz;
|
|
read += sz;
|
|
low_count -= sz;
|
|
count -= sz;
|
|
}
|
|
}
|
|
|
|
if (count > 0) {
|
|
kbuf = (char *)__get_free_page(GFP_KERNEL);
|
|
if (!kbuf)
|
|
return -ENOMEM;
|
|
while (count > 0) {
|
|
int len = count;
|
|
|
|
if (len > PAGE_SIZE)
|
|
len = PAGE_SIZE;
|
|
len = vread(kbuf, (char *)p, len);
|
|
if (!len)
|
|
break;
|
|
if (copy_to_user(buf, kbuf, len)) {
|
|
free_page((unsigned long)kbuf);
|
|
return -EFAULT;
|
|
}
|
|
count -= len;
|
|
buf += len;
|
|
read += len;
|
|
p += len;
|
|
}
|
|
free_page((unsigned long)kbuf);
|
|
}
|
|
*ppos = p;
|
|
return read;
|
|
}
|
|
|
|
|
|
static inline ssize_t
|
|
do_write_kmem(void *p, unsigned long realp, const char __user * buf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
ssize_t written, sz;
|
|
unsigned long copied;
|
|
|
|
written = 0;
|
|
#ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED
|
|
/* we don't have page 0 mapped on sparc and m68k.. */
|
|
if (realp < PAGE_SIZE) {
|
|
unsigned long sz = PAGE_SIZE - realp;
|
|
if (sz > count)
|
|
sz = count;
|
|
/* Hmm. Do something? */
|
|
buf += sz;
|
|
p += sz;
|
|
realp += sz;
|
|
count -= sz;
|
|
written += sz;
|
|
}
|
|
#endif
|
|
|
|
while (count > 0) {
|
|
char *ptr;
|
|
/*
|
|
* Handle first page in case it's not aligned
|
|
*/
|
|
if (-realp & (PAGE_SIZE - 1))
|
|
sz = -realp & (PAGE_SIZE - 1);
|
|
else
|
|
sz = PAGE_SIZE;
|
|
|
|
sz = min_t(unsigned long, sz, count);
|
|
|
|
/*
|
|
* On ia64 if a page has been mapped somewhere as
|
|
* uncached, then it must also be accessed uncached
|
|
* by the kernel or data corruption may occur
|
|
*/
|
|
ptr = xlate_dev_kmem_ptr(p);
|
|
|
|
copied = copy_from_user(ptr, buf, sz);
|
|
if (copied) {
|
|
written += sz - copied;
|
|
if (written)
|
|
break;
|
|
return -EFAULT;
|
|
}
|
|
buf += sz;
|
|
p += sz;
|
|
realp += sz;
|
|
count -= sz;
|
|
written += sz;
|
|
}
|
|
|
|
*ppos += written;
|
|
return written;
|
|
}
|
|
|
|
|
|
/*
|
|
* This function writes to the *virtual* memory as seen by the kernel.
|
|
*/
|
|
static ssize_t write_kmem(struct file * file, const char __user * buf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
unsigned long p = *ppos;
|
|
ssize_t wrote = 0;
|
|
ssize_t virtr = 0;
|
|
ssize_t written;
|
|
char * kbuf; /* k-addr because vwrite() takes vmlist_lock rwlock */
|
|
|
|
if (p < (unsigned long) high_memory) {
|
|
|
|
wrote = count;
|
|
if (count > (unsigned long) high_memory - p)
|
|
wrote = (unsigned long) high_memory - p;
|
|
|
|
written = do_write_kmem((void*)p, p, buf, wrote, ppos);
|
|
if (written != wrote)
|
|
return written;
|
|
wrote = written;
|
|
p += wrote;
|
|
buf += wrote;
|
|
count -= wrote;
|
|
}
|
|
|
|
if (count > 0) {
|
|
kbuf = (char *)__get_free_page(GFP_KERNEL);
|
|
if (!kbuf)
|
|
return wrote ? wrote : -ENOMEM;
|
|
while (count > 0) {
|
|
int len = count;
|
|
|
|
if (len > PAGE_SIZE)
|
|
len = PAGE_SIZE;
|
|
if (len) {
|
|
written = copy_from_user(kbuf, buf, len);
|
|
if (written) {
|
|
if (wrote + virtr)
|
|
break;
|
|
free_page((unsigned long)kbuf);
|
|
return -EFAULT;
|
|
}
|
|
}
|
|
len = vwrite(kbuf, (char *)p, len);
|
|
count -= len;
|
|
buf += len;
|
|
virtr += len;
|
|
p += len;
|
|
}
|
|
free_page((unsigned long)kbuf);
|
|
}
|
|
|
|
*ppos = p;
|
|
return virtr + wrote;
|
|
}
|
|
#endif
|
|
|
|
#ifdef CONFIG_DEVPORT
|
|
static ssize_t read_port(struct file * file, char __user * buf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
unsigned long i = *ppos;
|
|
char __user *tmp = buf;
|
|
|
|
if (!access_ok(VERIFY_WRITE, buf, count))
|
|
return -EFAULT;
|
|
while (count-- > 0 && i < 65536) {
|
|
if (__put_user(inb(i),tmp) < 0)
|
|
return -EFAULT;
|
|
i++;
|
|
tmp++;
|
|
}
|
|
*ppos = i;
|
|
return tmp-buf;
|
|
}
|
|
|
|
static ssize_t write_port(struct file * file, const char __user * buf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
unsigned long i = *ppos;
|
|
const char __user * tmp = buf;
|
|
|
|
if (!access_ok(VERIFY_READ,buf,count))
|
|
return -EFAULT;
|
|
while (count-- > 0 && i < 65536) {
|
|
char c;
|
|
if (__get_user(c, tmp)) {
|
|
if (tmp > buf)
|
|
break;
|
|
return -EFAULT;
|
|
}
|
|
outb(c,i);
|
|
i++;
|
|
tmp++;
|
|
}
|
|
*ppos = i;
|
|
return tmp-buf;
|
|
}
|
|
#endif
|
|
|
|
static ssize_t read_null(struct file * file, char __user * buf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static ssize_t write_null(struct file * file, const char __user * buf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
return count;
|
|
}
|
|
|
|
static int pipe_to_null(struct pipe_inode_info *info, struct pipe_buffer *buf,
|
|
struct splice_desc *sd)
|
|
{
|
|
return sd->len;
|
|
}
|
|
|
|
static ssize_t splice_write_null(struct pipe_inode_info *pipe,struct file *out,
|
|
loff_t *ppos, size_t len, unsigned int flags)
|
|
{
|
|
return splice_from_pipe(pipe, out, ppos, len, flags, pipe_to_null);
|
|
}
|
|
|
|
static ssize_t read_zero(struct file * file, char __user * buf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
size_t written;
|
|
|
|
if (!count)
|
|
return 0;
|
|
|
|
if (!access_ok(VERIFY_WRITE, buf, count))
|
|
return -EFAULT;
|
|
|
|
written = 0;
|
|
while (count) {
|
|
unsigned long unwritten;
|
|
size_t chunk = count;
|
|
|
|
if (chunk > PAGE_SIZE)
|
|
chunk = PAGE_SIZE; /* Just for latency reasons */
|
|
unwritten = clear_user(buf, chunk);
|
|
written += chunk - unwritten;
|
|
if (unwritten)
|
|
break;
|
|
buf += chunk;
|
|
count -= chunk;
|
|
cond_resched();
|
|
}
|
|
return written ? written : -EFAULT;
|
|
}
|
|
|
|
static int mmap_zero(struct file * file, struct vm_area_struct * vma)
|
|
{
|
|
#ifndef CONFIG_MMU
|
|
return -ENOSYS;
|
|
#endif
|
|
if (vma->vm_flags & VM_SHARED)
|
|
return shmem_zero_setup(vma);
|
|
return 0;
|
|
}
|
|
|
|
static ssize_t write_full(struct file * file, const char __user * buf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
return -ENOSPC;
|
|
}
|
|
|
|
/*
|
|
* Special lseek() function for /dev/null and /dev/zero. Most notably, you
|
|
* can fopen() both devices with "a" now. This was previously impossible.
|
|
* -- SRB.
|
|
*/
|
|
|
|
static loff_t null_lseek(struct file * file, loff_t offset, int orig)
|
|
{
|
|
return file->f_pos = 0;
|
|
}
|
|
|
|
/*
|
|
* The memory devices use the full 32/64 bits of the offset, and so we cannot
|
|
* check against negative addresses: they are ok. The return value is weird,
|
|
* though, in that case (0).
|
|
*
|
|
* also note that seeking relative to the "end of file" isn't supported:
|
|
* it has no meaning, so it returns -EINVAL.
|
|
*/
|
|
static loff_t memory_lseek(struct file * file, loff_t offset, int orig)
|
|
{
|
|
loff_t ret;
|
|
|
|
mutex_lock(&file->f_path.dentry->d_inode->i_mutex);
|
|
switch (orig) {
|
|
case 0:
|
|
file->f_pos = offset;
|
|
ret = file->f_pos;
|
|
force_successful_syscall_return();
|
|
break;
|
|
case 1:
|
|
file->f_pos += offset;
|
|
ret = file->f_pos;
|
|
force_successful_syscall_return();
|
|
break;
|
|
default:
|
|
ret = -EINVAL;
|
|
}
|
|
mutex_unlock(&file->f_path.dentry->d_inode->i_mutex);
|
|
return ret;
|
|
}
|
|
|
|
static int open_port(struct inode * inode, struct file * filp)
|
|
{
|
|
return capable(CAP_SYS_RAWIO) ? 0 : -EPERM;
|
|
}
|
|
|
|
#define zero_lseek null_lseek
|
|
#define full_lseek null_lseek
|
|
#define write_zero write_null
|
|
#define read_full read_zero
|
|
#define open_mem open_port
|
|
#define open_kmem open_mem
|
|
#define open_oldmem open_mem
|
|
|
|
static const struct file_operations mem_fops = {
|
|
.llseek = memory_lseek,
|
|
.read = read_mem,
|
|
.write = write_mem,
|
|
.mmap = mmap_mem,
|
|
.open = open_mem,
|
|
.get_unmapped_area = get_unmapped_area_mem,
|
|
};
|
|
|
|
#ifdef CONFIG_DEVKMEM
|
|
static const struct file_operations kmem_fops = {
|
|
.llseek = memory_lseek,
|
|
.read = read_kmem,
|
|
.write = write_kmem,
|
|
.mmap = mmap_kmem,
|
|
.open = open_kmem,
|
|
.get_unmapped_area = get_unmapped_area_mem,
|
|
};
|
|
#endif
|
|
|
|
static const struct file_operations null_fops = {
|
|
.llseek = null_lseek,
|
|
.read = read_null,
|
|
.write = write_null,
|
|
.splice_write = splice_write_null,
|
|
};
|
|
|
|
#ifdef CONFIG_DEVPORT
|
|
static const struct file_operations port_fops = {
|
|
.llseek = memory_lseek,
|
|
.read = read_port,
|
|
.write = write_port,
|
|
.open = open_port,
|
|
};
|
|
#endif
|
|
|
|
static const struct file_operations zero_fops = {
|
|
.llseek = zero_lseek,
|
|
.read = read_zero,
|
|
.write = write_zero,
|
|
.mmap = mmap_zero,
|
|
};
|
|
|
|
/*
|
|
* capabilities for /dev/zero
|
|
* - permits private mappings, "copies" are taken of the source of zeros
|
|
*/
|
|
static struct backing_dev_info zero_bdi = {
|
|
.capabilities = BDI_CAP_MAP_COPY,
|
|
};
|
|
|
|
static const struct file_operations full_fops = {
|
|
.llseek = full_lseek,
|
|
.read = read_full,
|
|
.write = write_full,
|
|
};
|
|
|
|
#ifdef CONFIG_CRASH_DUMP
|
|
static const struct file_operations oldmem_fops = {
|
|
.read = read_oldmem,
|
|
.open = open_oldmem,
|
|
};
|
|
#endif
|
|
|
|
static ssize_t kmsg_write(struct file * file, const char __user * buf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
char *tmp;
|
|
ssize_t ret;
|
|
|
|
tmp = kmalloc(count + 1, GFP_KERNEL);
|
|
if (tmp == NULL)
|
|
return -ENOMEM;
|
|
ret = -EFAULT;
|
|
if (!copy_from_user(tmp, buf, count)) {
|
|
tmp[count] = 0;
|
|
ret = printk("%s", tmp);
|
|
if (ret > count)
|
|
/* printk can add a prefix */
|
|
ret = count;
|
|
}
|
|
kfree(tmp);
|
|
return ret;
|
|
}
|
|
|
|
static const struct file_operations kmsg_fops = {
|
|
.write = kmsg_write,
|
|
};
|
|
|
|
static int memory_open(struct inode * inode, struct file * filp)
|
|
{
|
|
int ret = 0;
|
|
|
|
lock_kernel();
|
|
switch (iminor(inode)) {
|
|
case 1:
|
|
filp->f_op = &mem_fops;
|
|
filp->f_mapping->backing_dev_info =
|
|
&directly_mappable_cdev_bdi;
|
|
break;
|
|
#ifdef CONFIG_DEVKMEM
|
|
case 2:
|
|
filp->f_op = &kmem_fops;
|
|
filp->f_mapping->backing_dev_info =
|
|
&directly_mappable_cdev_bdi;
|
|
break;
|
|
#endif
|
|
case 3:
|
|
filp->f_op = &null_fops;
|
|
break;
|
|
#ifdef CONFIG_DEVPORT
|
|
case 4:
|
|
filp->f_op = &port_fops;
|
|
break;
|
|
#endif
|
|
case 5:
|
|
filp->f_mapping->backing_dev_info = &zero_bdi;
|
|
filp->f_op = &zero_fops;
|
|
break;
|
|
case 7:
|
|
filp->f_op = &full_fops;
|
|
break;
|
|
case 8:
|
|
filp->f_op = &random_fops;
|
|
break;
|
|
case 9:
|
|
filp->f_op = &urandom_fops;
|
|
break;
|
|
case 11:
|
|
filp->f_op = &kmsg_fops;
|
|
break;
|
|
#ifdef CONFIG_CRASH_DUMP
|
|
case 12:
|
|
filp->f_op = &oldmem_fops;
|
|
break;
|
|
#endif
|
|
default:
|
|
unlock_kernel();
|
|
return -ENXIO;
|
|
}
|
|
if (filp->f_op && filp->f_op->open)
|
|
ret = filp->f_op->open(inode,filp);
|
|
unlock_kernel();
|
|
return ret;
|
|
}
|
|
|
|
static const struct file_operations memory_fops = {
|
|
.open = memory_open, /* just a selector for the real open */
|
|
};
|
|
|
|
static const struct {
|
|
unsigned int minor;
|
|
char *name;
|
|
umode_t mode;
|
|
const struct file_operations *fops;
|
|
} devlist[] = { /* list of minor devices */
|
|
{1, "mem", S_IRUSR | S_IWUSR | S_IRGRP, &mem_fops},
|
|
#ifdef CONFIG_DEVKMEM
|
|
{2, "kmem", S_IRUSR | S_IWUSR | S_IRGRP, &kmem_fops},
|
|
#endif
|
|
{3, "null", S_IRUGO | S_IWUGO, &null_fops},
|
|
#ifdef CONFIG_DEVPORT
|
|
{4, "port", S_IRUSR | S_IWUSR | S_IRGRP, &port_fops},
|
|
#endif
|
|
{5, "zero", S_IRUGO | S_IWUGO, &zero_fops},
|
|
{7, "full", S_IRUGO | S_IWUGO, &full_fops},
|
|
{8, "random", S_IRUGO | S_IWUSR, &random_fops},
|
|
{9, "urandom", S_IRUGO | S_IWUSR, &urandom_fops},
|
|
{11,"kmsg", S_IRUGO | S_IWUSR, &kmsg_fops},
|
|
#ifdef CONFIG_CRASH_DUMP
|
|
{12,"oldmem", S_IRUSR | S_IWUSR | S_IRGRP, &oldmem_fops},
|
|
#endif
|
|
};
|
|
|
|
static struct class *mem_class;
|
|
|
|
static int __init chr_dev_init(void)
|
|
{
|
|
int i;
|
|
int err;
|
|
|
|
err = bdi_init(&zero_bdi);
|
|
if (err)
|
|
return err;
|
|
|
|
if (register_chrdev(MEM_MAJOR,"mem",&memory_fops))
|
|
printk("unable to get major %d for memory devs\n", MEM_MAJOR);
|
|
|
|
mem_class = class_create(THIS_MODULE, "mem");
|
|
for (i = 0; i < ARRAY_SIZE(devlist); i++)
|
|
device_create(mem_class, NULL,
|
|
MKDEV(MEM_MAJOR, devlist[i].minor), NULL,
|
|
devlist[i].name);
|
|
|
|
return 0;
|
|
}
|
|
|
|
fs_initcall(chr_dev_init);
|