summaryrefslogtreecommitdiffstats
path: root/drivers/char/mem.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/char/mem.c')
-rw-r--r--drivers/char/mem.c76
1 files changed, 55 insertions, 21 deletions
diff --git a/drivers/char/mem.c b/drivers/char/mem.c
index 1fa9fa157c1..6511012cbdc 100644
--- a/drivers/char/mem.c
+++ b/drivers/char/mem.c
@@ -8,7 +8,6 @@
* Shared /dev/zero mmaping support, Feb 2000, Kanoj Sarcar <kanoj@sgi.com>
*/
-#include <linux/config.h>
#include <linux/mm.h>
#include <linux/miscdevice.h>
#include <linux/slab.h>
@@ -20,7 +19,6 @@
#include <linux/tty.h>
#include <linux/capability.h>
#include <linux/smp_lock.h>
-#include <linux/devfs_fs_kernel.h>
#include <linux/ptrace.h>
#include <linux/device.h>
#include <linux/highmem.h>
@@ -97,7 +95,7 @@ static inline int valid_phys_addr_range(unsigned long addr, size_t count)
return 1;
}
-static inline int valid_mmap_phys_addr_range(unsigned long addr, size_t size)
+static inline int valid_mmap_phys_addr_range(unsigned long pfn, size_t size)
{
return 1;
}
@@ -240,13 +238,42 @@ static pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
}
#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;
+}
+
+/* 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
+
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 << PAGE_SHIFT, size))
+ if (!valid_mmap_phys_addr_range(vma->vm_pgoff, size))
return -EINVAL;
+ if (!private_mapping_ok(vma))
+ return -ENOSYS;
+
vma->vm_page_prot = phys_mem_access_prot(file, vma->vm_pgoff,
size,
vma->vm_page_prot);
@@ -524,7 +551,7 @@ static ssize_t write_kmem(struct file * file, const char __user * buf,
return virtr + wrote;
}
-#if defined(CONFIG_ISA) || !defined(__mc68000__)
+#if (defined(CONFIG_ISA) || defined(CONFIG_PCI)) && !defined(__mc68000__)
static ssize_t read_port(struct file * file, char __user * buf,
size_t count, loff_t *ppos)
{
@@ -778,31 +805,33 @@ static int open_port(struct inode * inode, struct file * filp)
#define open_kmem open_mem
#define open_oldmem open_mem
-static struct file_operations mem_fops = {
+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,
};
-static struct file_operations kmem_fops = {
+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,
};
-static struct file_operations null_fops = {
+static const struct file_operations null_fops = {
.llseek = null_lseek,
.read = read_null,
.write = write_null,
.splice_write = splice_write_null,
};
-#if defined(CONFIG_ISA) || !defined(__mc68000__)
-static struct file_operations port_fops = {
+#if (defined(CONFIG_ISA) || defined(CONFIG_PCI)) && !defined(__mc68000__)
+static const struct file_operations port_fops = {
.llseek = memory_lseek,
.read = read_port,
.write = write_port,
@@ -810,25 +839,29 @@ static struct file_operations port_fops = {
};
#endif
-static struct file_operations zero_fops = {
+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 struct file_operations full_fops = {
+static const struct file_operations full_fops = {
.llseek = full_lseek,
.read = read_full,
.write = write_full,
};
#ifdef CONFIG_CRASH_DUMP
-static struct file_operations oldmem_fops = {
+static const struct file_operations oldmem_fops = {
.read = read_oldmem,
.open = open_oldmem,
};
@@ -855,7 +888,7 @@ static ssize_t kmsg_write(struct file * file, const char __user * buf,
return ret;
}
-static struct file_operations kmsg_fops = {
+static const struct file_operations kmsg_fops = {
.write = kmsg_write,
};
@@ -864,14 +897,18 @@ static int memory_open(struct inode * inode, struct file * filp)
switch (iminor(inode)) {
case 1:
filp->f_op = &mem_fops;
+ filp->f_mapping->backing_dev_info =
+ &directly_mappable_cdev_bdi;
break;
case 2:
filp->f_op = &kmem_fops;
+ filp->f_mapping->backing_dev_info =
+ &directly_mappable_cdev_bdi;
break;
case 3:
filp->f_op = &null_fops;
break;
-#if defined(CONFIG_ISA) || !defined(__mc68000__)
+#if (defined(CONFIG_ISA) || defined(CONFIG_PCI)) && !defined(__mc68000__)
case 4:
filp->f_op = &port_fops;
break;
@@ -905,7 +942,7 @@ static int memory_open(struct inode * inode, struct file * filp)
return 0;
}
-static struct file_operations memory_fops = {
+static const struct file_operations memory_fops = {
.open = memory_open, /* just a selector for the real open */
};
@@ -918,7 +955,7 @@ static const struct {
{1, "mem", S_IRUSR | S_IWUSR | S_IRGRP, &mem_fops},
{2, "kmem", S_IRUSR | S_IWUSR | S_IRGRP, &kmem_fops},
{3, "null", S_IRUGO | S_IWUGO, &null_fops},
-#if defined(CONFIG_ISA) || !defined(__mc68000__)
+#if (defined(CONFIG_ISA) || defined(CONFIG_PCI)) && !defined(__mc68000__)
{4, "port", S_IRUSR | S_IWUSR | S_IRGRP, &port_fops},
#endif
{5, "zero", S_IRUGO | S_IWUGO, &zero_fops},
@@ -941,13 +978,10 @@ static int __init chr_dev_init(void)
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++) {
+ for (i = 0; i < ARRAY_SIZE(devlist); i++)
class_device_create(mem_class, NULL,
MKDEV(MEM_MAJOR, devlist[i].minor),
NULL, devlist[i].name);
- devfs_mk_cdev(MKDEV(MEM_MAJOR, devlist[i].minor),
- S_IFCHR | devlist[i].mode, devlist[i].name);
- }
return 0;
}
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-03-31 06:32:25 +0000