mirror of https://github.com/hak5/openwrt.git
134 lines
4.1 KiB
Diff
134 lines
4.1 KiB
Diff
|
From 4003b9a2c05f4d0d37535c3dffbf4a7b47d5c36c Mon Sep 17 00:00:00 2001
|
||
|
|
From: Maarten ter Huurne <maarten@treewalker.org>
|
||
|
|
Date: Wed, 8 Sep 2010 02:31:19 +0200
|
||
|
|
Subject: [PATCH 09/21] /dev/mem: Add kernel config option to omit this
|
||
|
|
device.
|
||
|
|
|
||
|
|
Omitting this device prevents software from accessing the hardware directly, which can cause trouble if the kernel accesses the same hardware.
|
||
|
|
It also saves some space on embedded systems.
|
||
|
|
---
|
||
|
|
arch/x86/Kconfig.debug | 1 +
|
||
|
|
drivers/char/Kconfig | 10 ++++++++++
|
||
|
|
drivers/char/mem.c | 17 +++++++++++++++++
|
||
|
|
3 files changed, 28 insertions(+), 0 deletions(-)
|
||
|
|
|
||
|
|
diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug
|
||
|
|
index bf56e17..0c97d51 100644
|
||
|
|
--- a/arch/x86/Kconfig.debug
|
||
|
|
+++ b/arch/x86/Kconfig.debug
|
||
|
|
@@ -7,6 +7,7 @@ source "lib/Kconfig.debug"
|
||
|
|
|
||
|
|
config STRICT_DEVMEM
|
||
|
|
bool "Filter access to /dev/mem"
|
||
|
|
+ depends on DEVMEM
|
||
|
|
---help---
|
||
|
|
If this option is disabled, you allow userspace (root) access to all
|
||
|
|
of memory, including kernel and userspace memory. Accidental
|
||
|
|
diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig
|
||
|
|
index 4364303..a2e462e 100644
|
||
|
|
--- a/drivers/char/Kconfig
|
||
|
|
+++ b/drivers/char/Kconfig
|
||
|
|
@@ -6,6 +6,16 @@ menu "Character devices"
|
||
|
|
|
||
|
|
source "drivers/tty/Kconfig"
|
||
|
|
|
||
|
|
+config DEVMEM
|
||
|
|
+ bool "/dev/mem virtual device support"
|
||
|
|
+ default y
|
||
|
|
+ help
|
||
|
|
+ Say Y here if you want to support the /dev/mem device.
|
||
|
|
+ Some X server drivers access the video hardware using this device.
|
||
|
|
+ Accessing hardware directly from user space can be useful in some
|
||
|
|
+ cases, but it is not without risks.
|
||
|
|
+ When in doubt, say "N".
|
||
|
|
+
|
||
|
|
config DEVKMEM
|
||
|
|
bool "/dev/kmem virtual device support"
|
||
|
|
default y
|
||
|
|
diff --git a/drivers/char/mem.c b/drivers/char/mem.c
|
||
|
|
index 1451790..a6020ca 100644
|
||
|
|
--- a/drivers/char/mem.c
|
||
|
|
+++ b/drivers/char/mem.c
|
||
|
|
@@ -87,6 +87,8 @@ void __weak unxlate_dev_mem_ptr(unsigned long phys, void *addr)
|
||
|
|
{
|
||
|
|
}
|
||
|
|
|
||
|
|
+#ifdef CONFIG_DEVMEM
|
||
|
|
+
|
||
|
|
/*
|
||
|
|
* This funcion reads the *physical* memory. The f_pos points directly to the
|
||
|
|
* memory location.
|
||
|
|
@@ -210,6 +212,10 @@ static ssize_t write_mem(struct file *file, const char __user *buf,
|
||
|
|
return written;
|
||
|
|
}
|
||
|
|
|
||
|
|
+#endif
|
||
|
|
+
|
||
|
|
+#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)
|
||
|
|
{
|
||
|
|
@@ -331,6 +337,8 @@ static int mmap_mem(struct file *file, struct vm_area_struct *vma)
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
+#endif
|
||
|
|
+
|
||
|
|
#ifdef CONFIG_DEVKMEM
|
||
|
|
static int mmap_kmem(struct file *file, struct vm_area_struct *vma)
|
||
|
|
{
|
||
|
|
@@ -694,6 +702,7 @@ 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,
|
||
|
|
@@ -726,11 +735,15 @@ static loff_t memory_lseek(struct file *file, loff_t offset, int orig)
|
||
|
|
mutex_unlock(&file->f_path.dentry->d_inode->i_mutex);
|
||
|
|
return ret;
|
||
|
|
}
|
||
|
|
+#endif
|
||
|
|
|
||
|
|
+#if defined(CONFIG_DEVMEM) || defined(CONFIG_DEVKMEM) || \
|
||
|
|
+ defined(CONFIG_DEVPORT) || defined(CONFIG_CRASH_DUMP)
|
||
|
|
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
|
||
|
|
@@ -740,6 +753,7 @@ 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,
|
||
|
|
@@ -748,6 +762,7 @@ 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
|
||
|
|
--
|
||
|
|
1.7.5.4
|
||
|
|
|