lib: Add generic binary search function to the kernel.

There a large number hand-coded binary searches in the kernel (run
"git grep search | grep binary" to find many of them).  Since in my
experience, hand-coding binary searches can be error-prone, it seems
worth cleaning this up by providing a generic binary search function.

This generic binary search implementation comes from Ksplice.  It has
the same basic API as the C library bsearch() function.  Ksplice uses
it in half a dozen places with 4 different comparison functions, and I
think our code is substantially cleaner because of this.

Signed-off-by: Tim Abbott <tabbott@ksplice.com>
Extra-bikeshedding-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Extra-bikeshedding-by: André Goddard Rosa <andre.goddard@gmail.com>
Extra-bikeshedding-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Alessio Igor Bogani <abogani@kernel.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

1 files changed, 2 insertions, 1 deletions

diff --git a/lib/Makefile b/lib/Makefile
index ef0f28571156..4b49a249064b 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -21,7 +21,8 @@ lib-y	+= kobject.o kref.o klist.o
 
 obj-y += bcd.o div64.o sort.o parser.o halfmd4.o debug_locks.o random32.o \
 	 bust_spinlocks.o hexdump.o kasprintf.o bitmap.o scatterlist.o \
-	 string_helpers.o gcd.o lcm.o list_sort.o uuid.o flex_array.o
+	 string_helpers.o gcd.o lcm.o list_sort.o uuid.o flex_array.o \
+	 bsearch.o
 obj-y += kstrtox.o
 obj-$(CONFIG_TEST_KSTRTOX) += test-kstrtox.o