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authorAl Viro <viro@zeniv.linux.org.uk>2017-03-21 04:56:06 +0300
committerAl Viro <viro@zeniv.linux.org.uk>2017-03-29 01:22:11 +0300
commitd597580d373774b1bdab84b3d26ff0b55162b916 (patch)
treeebbd7de012fcb731c40c67791e4e5e370844f70c /lib
parentc1aad8dcc49382399f48541dc47b6e30b0ef1b62 (diff)
downloadlinux-d597580d373774b1bdab84b3d26ff0b55162b916.tar.xz
generic ...copy_..._user primitives
provide raw_copy_..._user() and select ARCH_HAS_RAW_COPY_USER to use those. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'lib')
-rw-r--r--lib/Makefile2
-rw-r--r--lib/usercopy.c26
2 files changed, 28 insertions, 0 deletions
diff --git a/lib/Makefile b/lib/Makefile
index 320ac46a8725..7d875c389172 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -242,3 +242,5 @@ UBSAN_SANITIZE_ubsan.o := n
obj-$(CONFIG_SBITMAP) += sbitmap.o
obj-$(CONFIG_PARMAN) += parman.o
+
+obj-$(CONFIG_ARCH_HAS_RAW_COPY_USER) += usercopy.o
diff --git a/lib/usercopy.c b/lib/usercopy.c
new file mode 100644
index 000000000000..1b6010a3beb8
--- /dev/null
+++ b/lib/usercopy.c
@@ -0,0 +1,26 @@
+#include <linux/uaccess.h>
+
+/* out-of-line parts */
+
+#ifndef INLINE_COPY_FROM_USER
+unsigned long _copy_from_user(void *to, const void __user *from, unsigned long n)
+{
+ unsigned long res = n;
+ if (likely(access_ok(VERIFY_READ, from, n)))
+ res = raw_copy_from_user(to, from, n);
+ if (unlikely(res))
+ memset(to + (n - res), 0, res);
+ return res;
+}
+EXPORT_SYMBOL(_copy_from_user);
+#endif
+
+#ifndef INLINE_COPY_TO_USER
+unsigned long _copy_to_user(void *to, const void __user *from, unsigned long n)
+{
+ if (likely(access_ok(VERIFY_WRITE, to, n)))
+ n = raw_copy_to_user(to, from, n);
+ return n;
+}
+EXPORT_SYMBOL(_copy_to_user);
+#endif