lkml.org 
[lkml]   [2016]   [Sep]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 3/3] bpf powerpc: add support for bpf constant blinding
On 09/23/2016 10:35 PM, Naveen N. Rao wrote:
> In line with similar support for other architectures by Daniel Borkmann.
>
> 'MOD Default X' from test_bpf without constant blinding:
> 84 bytes emitted from JIT compiler (pass:3, flen:7)
> d0000000058a4688 + <x>:
> 0: nop
> 4: nop
> 8: std r27,-40(r1)
> c: std r28,-32(r1)
> 10: xor r8,r8,r8
> 14: xor r28,r28,r28
> 18: mr r27,r3
> 1c: li r8,66
> 20: cmpwi r28,0
> 24: bne 0x0000000000000030
> 28: li r8,0
> 2c: b 0x0000000000000044
> 30: divwu r9,r8,r28
> 34: mullw r9,r28,r9
> 38: subf r8,r9,r8
> 3c: rotlwi r8,r8,0
> 40: li r8,66
> 44: ld r27,-40(r1)
> 48: ld r28,-32(r1)
> 4c: mr r3,r8
> 50: blr
>
> ... and with constant blinding:
> 140 bytes emitted from JIT compiler (pass:3, flen:11)
> d00000000bd6ab24 + <x>:
> 0: nop
> 4: nop
> 8: std r27,-40(r1)
> c: std r28,-32(r1)
> 10: xor r8,r8,r8
> 14: xor r28,r28,r28
> 18: mr r27,r3
> 1c: lis r2,-22834
> 20: ori r2,r2,36083
> 24: rotlwi r2,r2,0
> 28: xori r2,r2,36017
> 2c: xoris r2,r2,42702
> 30: rotlwi r2,r2,0
> 34: mr r8,r2
> 38: rotlwi r8,r8,0
> 3c: cmpwi r28,0
> 40: bne 0x000000000000004c
> 44: li r8,0
> 48: b 0x000000000000007c
> 4c: divwu r9,r8,r28
> 50: mullw r9,r28,r9
> 54: subf r8,r9,r8
> 58: rotlwi r8,r8,0
> 5c: lis r2,-17137
> 60: ori r2,r2,39065
> 64: rotlwi r2,r2,0
> 68: xori r2,r2,39131
> 6c: xoris r2,r2,48399
> 70: rotlwi r2,r2,0
> 74: mr r8,r2
> 78: rotlwi r8,r8,0
> 7c: ld r27,-40(r1)
> 80: ld r28,-32(r1)
> 84: mr r3,r8
> 88: blr
>
> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>

Acked-by: Daniel Borkmann <daniel@iogearbox.net>

\
 
 \ /
  Last update: 2016-09-23 23:41    [W:0.069 / U:0.032 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site