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| author |   Al Viro <viro@zeniv.linux.org.uk> | 2017-03-20 21:56:06 -0400 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2017-03-28 18:22:11 -0400 |
| commit | d597580d373774b1bdab84b3d26ff0b55162b916 (patch) | |
| tree | ebbd7de012fcb731c40c67791e4e5e370844f70c /lib | |
| parent | asm-generic: zero in __get_user(), not __get_user_fn() (diff) | |
| download | linux-dev-d597580d373774b1bdab84b3d26ff0b55162b916.tar.xz linux-dev-d597580d373774b1bdab84b3d26ff0b55162b916.zip | |
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/Makefile | 2 | ||||
| -rw-r--r-- | lib/usercopy.c | 26 |
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 |