From: Josh Poimboeuf <[email protected]>

Add an x86 implementation of unsafe_copy_from_user() similar to the
existing unsafe_copy_to_user().

Cc: Masami Hiramatsu <[email protected]>
Cc: Mathieu Desnoyers <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Andrii Nakryiko <[email protected]>
Cc: Indu Bhagat <[email protected]>
Cc: "Jose E. Marchesi" <[email protected]>
Cc: Beau Belgrave <[email protected]>
Cc: Jens Remus <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Florian Weimer <[email protected]>
Cc: Sam James <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: "Carlos O'Donell" <[email protected]>
Signed-off-by: Josh Poimboeuf <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>
Signed-off-by: Jens Remus <[email protected]>
---
 arch/x86/include/asm/uaccess.h | 39 +++++++++++++++++++++++++---------
 1 file changed, 29 insertions(+), 10 deletions(-)

diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h
index 367297b188c3..dfe143235967 100644
--- a/arch/x86/include/asm/uaccess.h
+++ b/arch/x86/include/asm/uaccess.h
@@ -598,7 +598,7 @@ _label:                                                     
                \
  * We want the unsafe accessors to always be inlined and use
  * the error labels - thus the macro games.
  */
-#define unsafe_copy_loop(dst, src, len, type, label)                           
\
+#define unsafe_copy_to_user_loop(dst, src, len, type, label)                   
\
        while (len >= sizeof(type)) {                                           
\
                unsafe_put_user(*(type *)(src),(type __user *)(dst),label);     
\
                dst += sizeof(type);                                            
\
@@ -606,15 +606,34 @@ _label:                                                   
                \
                len -= sizeof(type);                                            
\
        }
 
-#define unsafe_copy_to_user(_dst,_src,_len,label)                      \
-do {                                                                   \
-       char __user *__ucu_dst = (_dst);                                \
-       const char *__ucu_src = (_src);                                 \
-       size_t __ucu_len = (_len);                                      \
-       unsafe_copy_loop(__ucu_dst, __ucu_src, __ucu_len, u64, label);  \
-       unsafe_copy_loop(__ucu_dst, __ucu_src, __ucu_len, u32, label);  \
-       unsafe_copy_loop(__ucu_dst, __ucu_src, __ucu_len, u16, label);  \
-       unsafe_copy_loop(__ucu_dst, __ucu_src, __ucu_len, u8, label);   \
+#define unsafe_copy_to_user(_dst, _src, _len, label)                           
\
+do {                                                                           
\
+       void __user *__dst = (_dst);                                            
\
+       const void *__src = (_src);                                             
\
+       size_t __len = (_len);                                                  
\
+       unsafe_copy_to_user_loop(__dst, __src, __len, u64, label);              
\
+       unsafe_copy_to_user_loop(__dst, __src, __len, u32, label);              
\
+       unsafe_copy_to_user_loop(__dst, __src, __len, u16, label);              
\
+       unsafe_copy_to_user_loop(__dst, __src, __len, u8,  label);              
\
+} while (0)
+
+#define unsafe_copy_from_user_loop(dst, src, len, type, label)                 
\
+       while (len >= sizeof(type)) {                                           
\
+               unsafe_get_user(*(type *)(dst), (type __user *)(src), label);   
\
+               dst += sizeof(type);                                            
\
+               src += sizeof(type);                                            
\
+               len -= sizeof(type);                                            
\
+       }
+
+#define unsafe_copy_from_user(_dst, _src, _len, label)                         
\
+do {                                                                           
\
+       void *__dst = (_dst);                                                   
\
+       void __user *__src = (_src);                                            
\
+       size_t __len = (_len);                                                  
\
+       unsafe_copy_from_user_loop(__dst, __src, __len, u64, label);            
\
+       unsafe_copy_from_user_loop(__dst, __src, __len, u32, label);            
\
+       unsafe_copy_from_user_loop(__dst, __src, __len, u16, label);            
\
+       unsafe_copy_from_user_loop(__dst, __src, __len, u8,  label);            
\
 } while (0)
 
 #ifdef CONFIG_CC_HAS_ASM_GOTO_OUTPUT
-- 
2.48.1


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