aboutsummaryrefslogtreecommitdiffstats
path: root/target/linux/xburst/patches-3.3/0009-dev-mem-Add-kernel-config-option-to-omit-this-device.patch
diff options
context:
space:
mode:
Diffstat (limited to 'target/linux/xburst/patches-3.3/0009-dev-mem-Add-kernel-config-option-to-omit-this-device.patch')
-rw-r--r--target/linux/xburst/patches-3.3/0009-dev-mem-Add-kernel-config-option-to-omit-this-device.patch124
1 files changed, 124 insertions, 0 deletions
diff --git a/target/linux/xburst/patches-3.3/0009-dev-mem-Add-kernel-config-option-to-omit-this-device.patch b/target/linux/xburst/patches-3.3/0009-dev-mem-Add-kernel-config-option-to-omit-this-device.patch
new file mode 100644
index 0000000000..28388fba76
--- /dev/null
+++ b/target/linux/xburst/patches-3.3/0009-dev-mem-Add-kernel-config-option-to-omit-this-device.patch
@@ -0,0 +1,124 @@
+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(-)
+
+--- 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
+--- 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
+--- a/drivers/char/mem.c
++++ b/drivers/char/mem.c
+@@ -87,6 +87,8 @@ void __weak unxlate_dev_mem_ptr(unsigned
+ {
+ }
+
++#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 *fi
+ 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, s
+ 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 *fi
+ 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 *
+ 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 * inod
+ #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_
+ .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