x86: some lock annotations for user copy paths, v2

 - introduce might_fault()
 - handle the atomic user copy paths correctly

[ mingo@elte.hu: move might_sleep() outside of in_atomic(). ]
Signed-off-by: Nick Piggin <npiggin@suse.de>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 3 insertions, 9 deletions

diff --git a/include/asm-x86/uaccess_64.h b/include/asm-x86/uaccess_64.h
index 40a7205fe576..13fd56fbc3ab 100644
--- a/include/asm-x86/uaccess_64.h
+++ b/include/asm-x86/uaccess_64.h
@@ -29,9 +29,7 @@ int __copy_from_user(void *dst, const void __user *src, unsigned size)
 {
         int ret = 0;
 
-        might_sleep();
-        if (current->mm)
-                might_lock_read(&current->mm->mmap_sem);
+        might_fault();
         if (!__builtin_constant_p(size))
                 return copy_user_generic(dst, (__force void *)src, size);
         switch (size) {
@@ -75,9 +73,7 @@ int __copy_to_user(void __user *dst, const void *src, unsigned size)
 {
         int ret = 0;
 
-        might_sleep();
-        if (current->mm)
-                might_lock_read(&current->mm->mmap_sem);
+        might_fault();
         if (!__builtin_constant_p(size))
                 return copy_user_generic((__force void *)dst, src, size);
         switch (size) {
@@ -121,9 +117,7 @@ int __copy_in_user(void __user *dst, const void __user *src, unsigned size)
 {
         int ret = 0;
 
-        might_sleep();
-        if (current->mm)
-                might_lock_read(&current->mm->mmap_sem);
+        might_fault();
         if (!__builtin_constant_p(size))
                 return copy_user_generic((__force void *)dst,
                                          (__force void *)src, size);