linux/arch
Eric Dumazet aee636c480 bpf: do not use reciprocal divide
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>
2014-01-15 17:02:08 -08:00
..
alpha Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mattst88/alpha 2013-11-20 15:03:45 -08:00
arc ARC: Allow conditional multiple inclusion of uapi/asm/unistd.h 2013-12-19 19:44:12 +05:30
arm bpf: do not use reciprocal divide 2014-01-15 17:02:08 -08:00
arm64 - arm64 ptrace fix. 2013-12-20 13:50:08 -08:00
avr32 avr32: favr-32: clk_round_rate() can return a zero upon error 2013-12-10 08:46:38 +01:00
blackfin Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-11-19 10:40:00 -08:00
c6x Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-11-19 10:40:00 -08:00
cris Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-11-19 10:40:00 -08:00
frv Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-11-19 10:40:00 -08:00
hexagon Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-11-19 10:40:00 -08:00
ia64 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-11-20 14:25:39 -08:00
m32r Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-11-19 10:40:00 -08:00
m68k Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-11-19 10:40:00 -08:00
metag Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-11-19 10:40:00 -08:00
microblaze Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-11-19 10:40:00 -08:00
mips Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-11-19 10:40:00 -08:00
mn10300 Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-11-19 10:40:00 -08:00
openrisc OpenRISC updates for 3.13 2013-11-15 14:26:38 -08:00
parisc parisc: Ensure full cache coherency for kmap/kunmap 2014-01-08 23:02:57 +01:00
powerpc bpf: do not use reciprocal divide 2014-01-15 17:02:08 -08:00
s390 bpf: do not use reciprocal divide 2014-01-15 17:02:08 -08:00
score Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-11-19 10:40:00 -08:00
sh sh: add EXPORT_SYMBOL(min_low_pfn) and EXPORT_SYMBOL(max_low_pfn) to sh_ksyms_32.c 2014-01-02 14:40:30 -08:00
sparc bpf: do not use reciprocal divide 2014-01-15 17:02:08 -08:00
tile Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-11-19 10:40:00 -08:00
um um: Build always with -mcmodel=large on 64bit 2013-12-01 13:06:51 +01:00
unicore32 Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-11-19 10:40:00 -08:00
x86 bpf: do not use reciprocal divide 2014-01-15 17:02:08 -08:00
xtensa Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-11-19 10:40:00 -08:00
.gitignore
Kconfig kernel: remove CONFIG_USE_GENERIC_SMP_HELPERS 2013-11-15 09:32:22 +09:00