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Make /dev/mem configurable, as we don't want it.

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Signed-off-by: Brian Swetland <swetland@google.com>
This commit is contained in:
Robert Love
2008-04-29 16:44:10 -04:00
committed by Arve Hjønnevåg
parent 604ad7390d
commit 196f3dc567
2 changed files with 30 additions and 0 deletions
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13
drivers/char/Kconfig
View File

@@ -88,6 +88,19 @@ config VT_HW_CONSOLE_BINDING
information. For framebuffer console users, please refer to
<file:Documentation/fb/fbcon.txt>.
config DEVMEM
bool "Memory device driver"
default y
help
The memory driver provides two character devices, mem and kmem, which
provide access to the system's memory. The mem device is a view of
physical memory, and each byte in the device corresponds to the
matching physical address. The kmem device is the same as mem, but
the addresses correspond to the kernel's virtual address space rather
than physical memory. These devices are standard parts of a Linux
system and most users should say Y here. You might say N if very
security conscience or memory is tight.
config DEVKMEM
bool "/dev/kmem virtual device support"
default y

17
drivers/char/mem.c
View File

@@ -80,6 +80,7 @@ static inline int valid_mmap_phys_addr_range(unsigned long pfn, size_t size)
}
#endif
#if defined(CONFIG_DEVMEM) || defined(CONFIG_DEVKMEM)
#ifdef CONFIG_STRICT_DEVMEM
static inline int range_is_allowed(unsigned long pfn, unsigned long size)
{
@@ -105,7 +106,9 @@ static inline int range_is_allowed(unsigned long pfn, unsigned long size)
return 1;
}
#endif
#endif
#ifdef CONFIG_DEVMEM
void __attribute__((weak)) unxlate_dev_mem_ptr(unsigned long phys, void *addr)
{
}
@@ -254,6 +257,9 @@ static ssize_t write_mem(struct file * file, const char __user * buf,
*ppos += written;
return written;
}
#endif /* CONFIG_DEVMEM */
#if defined(CONFIG_DEVMEM) || defined(CONFIG_DEVKMEM)
int __attribute__((weak)) phys_mem_access_prot_allowed(struct file *file,
unsigned long pfn, unsigned long size, pgprot_t *vma_prot)
@@ -340,6 +346,7 @@ static int mmap_mem(struct file * file, struct vm_area_struct * vma)
}
return 0;
}
#endif /* CONFIG_DEVMEM */
#ifdef CONFIG_DEVKMEM
static int mmap_kmem(struct file * file, struct vm_area_struct * vma)
@@ -730,6 +737,8 @@ static loff_t null_lseek(struct file * file, loff_t offset, int orig)
return file->f_pos = 0;
}
#if defined(CONFIG_DEVMEM) || defined(CONFIG_DEVKMEM) || defined(CONFIG_DEVPORT)
/*
* 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,
@@ -761,10 +770,14 @@ static loff_t memory_lseek(struct file * file, loff_t offset, int orig)
return ret;
}
#endif
#if defined(CONFIG_DEVMEM) || defined(CONFIG_DEVKMEM) || defined(CONFIG_DEVPORT)
static int open_port(struct inode * inode, struct file * filp)
{
return capable(CAP_SYS_RAWIO) ? 0 : -EPERM;
}
#endif
#define zero_lseek null_lseek
#define full_lseek null_lseek
@@ -774,6 +787,7 @@ static int open_port(struct inode * inode, struct file * filp)
#define open_kmem open_mem
#define open_oldmem open_mem
#ifdef CONFIG_DEVMEM
static const struct file_operations mem_fops = {
.llseek = memory_lseek,
.read = read_mem,
@@ -782,6 +796,7 @@ static const struct file_operations mem_fops = {
.open = open_mem,
.get_unmapped_area = get_unmapped_area_mem,
};
#endif
#ifdef CONFIG_DEVKMEM
static const struct file_operations kmem_fops = {
@@ -870,7 +885,9 @@ static const struct memdev {
const struct file_operations *fops;
struct backing_dev_info *dev_info;
} devlist[] = {
#ifdef CONFIG_DEVMEM
[1] = { "mem", 0, &mem_fops, &directly_mappable_cdev_bdi },
#endif
#ifdef CONFIG_DEVKMEM
[2] = { "kmem", 0, &kmem_fops, &directly_mappable_cdev_bdi },
#endif