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* [PATCH 00/14] ARM BPF jit compiler improvements
@ 2018-07-11  9:30 ` Russell King - ARM Linux
  0 siblings, 0 replies; 40+ messages in thread
From: Russell King - ARM Linux @ 2018-07-11  9:30 UTC (permalink / raw)
  To: netdev, linux-arm-kernel; +Cc: Daniel Borkmann

Hi,

This series improves the ARM BPF JIT compiler by:
- enumerating the stack layout rather than using constants that happen
  to be multiples of four
- rejig the BPF "register" accesses to use negative numbers instead of
  positive, which could be confused with register numbers in the bpf2a32
  array.
- since we maintain the ARM FP register as a pointer to the top of our
  scratch space (or, with frame pointers enabled, a valid ARM frame
  pointer register), we can access our scratch space using FP, which is
  constant across all BPF programs, including tail-called programs.
- use immediate forms of ARM instructions where possible, rather than
  first loading the immediate into an ARM register.
- use load-with-shift instruction rather than seperate shift instruction
  followed by load
- avoid reloading index and array in the tail-call code
- use double-word load/store instructions where available

Version 2:
- Fix ARMv5 test pointed out by Olof
- Fix build error found by 0-day (adding an additional patch)

 arch/arm/net/bpf_jit_32.c | 982 ++++++++++++++++++++++++----------------------
 arch/arm/net/bpf_jit_32.h |  42 +-
 2 files changed, 543 insertions(+), 481 deletions(-)

-- 
RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
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^ permalink raw reply	[flat|nested] 40+ messages in thread

end of thread, other threads:[~2018-07-13 13:39 UTC | newest]

Thread overview: 40+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-07-11  9:30 [PATCH 00/14] ARM BPF jit compiler improvements Russell King - ARM Linux
2018-07-11  9:30 ` Russell King - ARM Linux
2018-07-11  9:31 ` [PATCH net-next v2 01/14] ARM: net: bpf: enumerate the JIT scratch stack layout Russell King
2018-07-11  9:31   ` Russell King
2018-07-11  9:31 ` [PATCH net-next v2 02/14] ARM: net: bpf: provide load/store ops with negative immediates Russell King
2018-07-11  9:31   ` Russell King
2018-07-11  9:31 ` [PATCH net-next v2 03/14] ARM: net: bpf: use negative numbers for stacked registers Russell King
2018-07-11  9:31   ` Russell King
2018-07-11  9:31 ` [PATCH net-next v2 04/14] ARM: net: bpf: remove is_on_stack() and sstk/dstk Russell King
2018-07-11  9:31   ` Russell King
2018-07-11  9:31 ` [PATCH net-next v2 05/14] ARM: net: bpf: provide accessor functions for BPF registers Russell King
2018-07-11  9:31   ` Russell King
2018-07-11  9:31 ` [PATCH net-next v2 06/14] ARM: net: bpf: 64-bit " Russell King
2018-07-11  9:31   ` Russell King
2018-07-11  9:32 ` [PATCH net-next v2 07/14] ARM: net: bpf: access eBPF scratch space using ARM FP register Russell King
2018-07-11  9:32   ` Russell King
2018-07-11  9:32 ` [PATCH net-next v2 08/14] ARM: net: bpf: imm12 constant conversion Russell King
2018-07-11  9:32   ` Russell King
2018-07-11  9:32 ` [PATCH net-next v2 09/14] ARM: net: bpf: use immediate forms of instructions where possible Russell King
2018-07-11  9:32   ` Russell King
2018-07-11  9:32 ` [PATCH net-next v2 10/14] ARM: net: bpf: use ldr instructions with shifted rm register Russell King
2018-07-11  9:32   ` Russell King
2018-07-11  9:32 ` [PATCH net-next v2 11/14] ARM: net: bpf: avoid reloading 'index' Russell King
2018-07-11  9:32   ` Russell King
2018-07-11  9:32 ` [PATCH net-next v2 12/14] ARM: net: bpf: avoid reloading 'array' Russell King
2018-07-11  9:32   ` Russell King
2018-07-11  9:32 ` [PATCH net-next v2 13/14] ARM: net: bpf: always use odd/even register pair Russell King
2018-07-11  9:32   ` Russell King
2018-07-11  9:32 ` [PATCH net-next v2 14/14] ARM: net: bpf: use double-word load/stores where available Russell King
2018-07-11  9:32   ` Russell King
2018-07-12 19:02 ` [PATCH 00/14] ARM BPF jit compiler improvements Daniel Borkmann
2018-07-12 19:02   ` Daniel Borkmann
2018-07-12 21:02   ` Russell King - ARM Linux
2018-07-12 21:02     ` Russell King - ARM Linux
2018-07-12 21:12     ` Daniel Borkmann
2018-07-12 21:12       ` Daniel Borkmann
2018-07-12 21:35       ` Russell King - ARM Linux
2018-07-12 21:35         ` Russell King - ARM Linux
2018-07-13 13:24         ` Daniel Borkmann
2018-07-13 13:24           ` Daniel Borkmann

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