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authorRobert Love <rlove@google.com>2008-04-29 16:44:10 -0400
committerArve Hjønnevåg <arve@android.com>2013-07-01 13:34:56 -0700
commitdf30b7c96af858ed2fca315e9cf10386630f1b9d (patch)
treecc680d2ce7442d002294b1b8650fe23f299e9e0d
parent4f948f64ab7180b482b159993c79fabd2d1a7172 (diff)
downloadlinaro-lsk-df30b7c96af858ed2fca315e9cf10386630f1b9d.tar.gz
Make /dev/mem configurable, as we don't want it.
Signed-off-by: Brian Swetland <swetland@google.com>
-rw-r--r--drivers/char/Kconfig13
-rw-r--r--drivers/char/mem.c17
2 files changed, 30 insertions, 0 deletions
diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig
index 3bb6fa3930b..ddbed25c7af 100644
--- a/drivers/char/Kconfig
+++ b/drivers/char/Kconfig
@@ -6,6 +6,19 @@ menu "Character devices"
source "drivers/tty/Kconfig"
+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
diff --git a/drivers/char/mem.c b/drivers/char/mem.c
index 1ccbe9482fa..38d3069b7f0 100644
--- a/drivers/char/mem.c
+++ b/drivers/char/mem.c
@@ -60,6 +60,7 @@ 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)
{
@@ -85,7 +86,9 @@ static inline int range_is_allowed(unsigned long pfn, unsigned long size)
return 1;
}
#endif
+#endif
+#ifdef CONFIG_DEVMEM
void __weak unxlate_dev_mem_ptr(unsigned long phys, void *addr)
{
}
@@ -212,6 +215,9 @@ 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 __weak phys_mem_access_prot_allowed(struct file *file,
unsigned long pfn, unsigned long size, pgprot_t *vma_prot)
@@ -333,6 +339,7 @@ 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)
@@ -727,6 +734,8 @@ 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,
@@ -760,10 +769,14 @@ 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 = {
@@ -851,7 +866,9 @@ 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