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-rw-r--r--include/linux/uaccess.h43
1 files changed, 31 insertions, 12 deletions
diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h
index 7bcadca22100..94b285411659 100644
--- a/include/linux/uaccess.h
+++ b/include/linux/uaccess.h
@@ -6,11 +6,27 @@
#include <linux/sched.h>
#include <linux/thread_info.h>
-#define uaccess_kernel() segment_eq(get_fs(), KERNEL_DS)
-
#include <asm/uaccess.h>
/*
+ * Force the uaccess routines to be wired up for actual userspace access,
+ * overriding any possible set_fs(KERNEL_DS) still lingering around. Undone
+ * using force_uaccess_end below.
+ */
+static inline mm_segment_t force_uaccess_begin(void)
+{
+ mm_segment_t fs = get_fs();
+
+ set_fs(USER_DS);
+ return fs;
+}
+
+static inline void force_uaccess_end(mm_segment_t oldfs)
+{
+ set_fs(oldfs);
+}
+
+/*
* Architectures should provide two primitives (raw_copy_{to,from}_user())
* and get rid of their private instances of copy_{to,from}_user() and
* __copy_{to,from}_user{,_inatomic}().
@@ -301,13 +317,14 @@ copy_struct_from_user(void *dst, size_t ksize, const void __user *src,
return 0;
}
-bool probe_kernel_read_allowed(const void *unsafe_src, size_t size);
+bool copy_from_kernel_nofault_allowed(const void *unsafe_src, size_t size);
-extern long probe_kernel_read(void *dst, const void *src, size_t size);
-extern long probe_user_read(void *dst, const void __user *src, size_t size);
+long copy_from_kernel_nofault(void *dst, const void *src, size_t size);
+long notrace copy_to_kernel_nofault(void *dst, const void *src, size_t size);
-extern long notrace probe_kernel_write(void *dst, const void *src, size_t size);
-extern long notrace probe_user_write(void __user *dst, const void *src, size_t size);
+long copy_from_user_nofault(void *dst, const void __user *src, size_t size);
+long notrace copy_to_user_nofault(void __user *dst, const void *src,
+ size_t size);
long strncpy_from_kernel_nofault(char *dst, const void *unsafe_addr,
long count);
@@ -317,14 +334,16 @@ long strncpy_from_user_nofault(char *dst, const void __user *unsafe_addr,
long strnlen_user_nofault(const void __user *unsafe_addr, long count);
/**
- * probe_kernel_address(): safely attempt to read from a location
- * @addr: address to read from
- * @retval: read into this variable
+ * get_kernel_nofault(): safely attempt to read from a location
+ * @val: read into this variable
+ * @ptr: address to read from
*
* Returns 0 on success, or -EFAULT.
*/
-#define probe_kernel_address(addr, retval) \
- probe_kernel_read(&retval, addr, sizeof(retval))
+#define get_kernel_nofault(val, ptr) ({ \
+ const typeof(val) *__gk_ptr = (ptr); \
+ copy_from_kernel_nofault(&(val), __gk_ptr, sizeof(val));\
+})
#ifndef user_access_begin
#define user_access_begin(ptr,len) access_ok(ptr, len)