Commit 6595d144 authored by Al Viro's avatar Al Viro Committed by Max Filippov

xtensa: fix {get,put}_user() for 64bit values

First of all, on short copies __copy_{to,from}_user() return the amount
of bytes left uncopied, *not* -EFAULT.  get_user() and put_user() are
expected to return -EFAULT on failure.

Another problem is get_user(v32, (__u64 __user *)p); that should
fetch 64bit value and the assign it to v32, truncating it in process.
Current code, OTOH, reads 8 bytes of data and stores them at the
address of v32, stomping on the 4 bytes that follow v32 itself.
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: default avatarMax Filippov <jcmvbkbc@gmail.com>
parent 4f5cafb5
...@@ -100,7 +100,7 @@ do { \ ...@@ -100,7 +100,7 @@ do { \
case 4: __put_user_asm(x, ptr, retval, 4, "s32i", __cb); break; \ case 4: __put_user_asm(x, ptr, retval, 4, "s32i", __cb); break; \
case 8: { \ case 8: { \
__typeof__(*ptr) __v64 = x; \ __typeof__(*ptr) __v64 = x; \
retval = __copy_to_user(ptr, &__v64, 8); \ retval = __copy_to_user(ptr, &__v64, 8) ? -EFAULT : 0; \
break; \ break; \
} \ } \
default: __put_user_bad(); \ default: __put_user_bad(); \
...@@ -198,7 +198,16 @@ do { \ ...@@ -198,7 +198,16 @@ do { \
case 1: __get_user_asm(x, ptr, retval, 1, "l8ui", __cb); break;\ case 1: __get_user_asm(x, ptr, retval, 1, "l8ui", __cb); break;\
case 2: __get_user_asm(x, ptr, retval, 2, "l16ui", __cb); break;\ case 2: __get_user_asm(x, ptr, retval, 2, "l16ui", __cb); break;\
case 4: __get_user_asm(x, ptr, retval, 4, "l32i", __cb); break;\ case 4: __get_user_asm(x, ptr, retval, 4, "l32i", __cb); break;\
case 8: retval = __copy_from_user(&x, ptr, 8); break; \ case 8: { \
u64 __x; \
if (unlikely(__copy_from_user(&__x, ptr, 8))) { \
retval = -EFAULT; \
(x) = 0; \
} else { \
(x) = *(__force __typeof__((ptr)))&__x; \
} \
break; \
} \
default: (x) = __get_user_bad(); \ default: (x) = __get_user_bad(); \
} \ } \
} while (0) } while (0)
......
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