lib: add generic strnlen_user() function
This adds a new generic optimized strnlen_user() function that uses the
<asm/word-at-a-time.h> infrastructure to portably do efficient string
handling.
In many ways, strnlen is much simpler than strncpy, and in particular we
can always pre-align the words we load from memory. That means that all
the worries about alignment etc are a non-issue, so this one can easily
be used on any architecture. You obviously do have to do the
appropriate word-at-a-time.h macros.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/lib/Makefile b/lib/Makefile
index b98df50..77937a7 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -126,6 +126,7 @@
obj-$(CONFIG_DDR) += jedec_ddr_data.o
obj-$(CONFIG_GENERIC_STRNCPY_FROM_USER) += strncpy_from_user.o
+obj-$(CONFIG_GENERIC_STRNLEN_USER) += strnlen_user.o
hostprogs-y := gen_crc32table
clean-files := crc32table.h