android_kernel_samsung_msm8976/arch/arm/net
Eric Dumazet cd7361dc9f bpf: do not use reciprocal divide
[ Upstream commit aee636c4809fa54848ff07a899b326eb1f9987a2 ]

At first Jakub Zawadzki noticed that some divisions by reciprocal_divide
were not correct. (off by one in some cases)
http://www.wireshark.org/~darkjames/reciprocal-buggy.c

He could also show this with BPF:
http://www.wireshark.org/~darkjames/set-and-dump-filter-k-bug.c

The reciprocal divide in linux kernel is not generic enough,
lets remove its use in BPF, as it is not worth the pain with
current cpus.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Jakub Zawadzki <darkjames-ws@darkjames.pl>
Cc: Mircea Gherzan <mgherzan@gmail.com>
Cc: Daniel Borkmann <dxchgb@gmail.com>
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Cc: Matt Evans <matt@ozlabs.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-06 11:08:16 -08:00
..
Makefile
bpf_jit_32.c bpf: do not use reciprocal divide 2014-02-06 11:08:16 -08:00
bpf_jit_32.h ARM: net: bpf_jit_32: add XOR instruction for BPF JIT 2012-11-13 18:21:10 -05:00