android_kernel_oneplus_msm8998/arch
Daniel Borkmann d0da2877d4 bpf, s390: fix jit branch offset related to ldimm64
[ Upstream commit b0a0c2566f28e71e5e32121992ac8060cec75510 ]

While testing some other work that required JIT modifications, I
run into test_bpf causing a hang when JIT enabled on s390. The
problematic test case was the one from ddc665a4bb4b (bpf, arm64:
fix jit branch offset related to ldimm64), and turns out that we
do have a similar issue on s390 as well. In bpf_jit_prog() we
update next instruction address after returning from bpf_jit_insn()
with an insn_count. bpf_jit_insn() returns either -1 in case of
error (e.g. unsupported insn), 1 or 2. The latter is only the
case for ldimm64 due to spanning 2 insns, however, next address
is only set to i + 1 not taking actual insn_count into account,
thus fix is to use insn_count instead of 1. bpf_jit_enable in
mode 2 provides also disasm on s390:

Before fix:

  000003ff800349b6: a7f40003   brc     15,3ff800349bc                 ; target
  000003ff800349ba: 0000               unknown
  000003ff800349bc: e3b0f0700024       stg     %r11,112(%r15)
  000003ff800349c2: e3e0f0880024       stg     %r14,136(%r15)
  000003ff800349c8: 0db0               basr    %r11,%r0
  000003ff800349ca: c0ef00000000       llilf   %r14,0
  000003ff800349d0: e320b0360004       lg      %r2,54(%r11)
  000003ff800349d6: e330b03e0004       lg      %r3,62(%r11)
  000003ff800349dc: ec23ffeda065       clgrj   %r2,%r3,10,3ff800349b6 ; jmp
  000003ff800349e2: e3e0b0460004       lg      %r14,70(%r11)
  000003ff800349e8: e3e0b04e0004       lg      %r14,78(%r11)
  000003ff800349ee: b904002e   lgr     %r2,%r14
  000003ff800349f2: e3b0f0700004       lg      %r11,112(%r15)
  000003ff800349f8: e3e0f0880004       lg      %r14,136(%r15)
  000003ff800349fe: 07fe               bcr     15,%r14

After fix:

  000003ff80ef3db4: a7f40003   brc     15,3ff80ef3dba
  000003ff80ef3db8: 0000               unknown
  000003ff80ef3dba: e3b0f0700024       stg     %r11,112(%r15)
  000003ff80ef3dc0: e3e0f0880024       stg     %r14,136(%r15)
  000003ff80ef3dc6: 0db0               basr    %r11,%r0
  000003ff80ef3dc8: c0ef00000000       llilf   %r14,0
  000003ff80ef3dce: e320b0360004       lg      %r2,54(%r11)
  000003ff80ef3dd4: e330b03e0004       lg      %r3,62(%r11)
  000003ff80ef3dda: ec230006a065       clgrj   %r2,%r3,10,3ff80ef3de6 ; jmp
  000003ff80ef3de0: e3e0b0460004       lg      %r14,70(%r11)
  000003ff80ef3de6: e3e0b04e0004       lg      %r14,78(%r11)          ; target
  000003ff80ef3dec: b904002e   lgr     %r2,%r14
  000003ff80ef3df0: e3b0f0700004       lg      %r11,112(%r15)
  000003ff80ef3df6: e3e0f0880004       lg      %r14,136(%r15)
  000003ff80ef3dfc: 07fe               bcr     15,%r14

test_bpf.ko suite runs fine after the fix.

Fixes: 0546231057 ("s390/bpf: Add s390x eBPF JIT compiler backend")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-12 19:29:08 -07:00
..
alpha osf_wait4(): fix infoleak 2017-05-25 14:30:17 +02:00
arc mm: larger stack guard gap, between vmas 2017-06-26 07:13:11 +02:00
arm ARM: 8632/1: ftrace: fix syscall name matching 2017-08-11 09:08:58 -07:00
arm64 arm64: mm: fix show_pte KERN_CONT fallout 2017-08-06 19:19:46 -07:00
avr32 avr32: off by one in at32_init_pio() 2016-10-07 15:23:45 +02:00
blackfin net: smc91x: fix SMC accesses 2016-09-30 10:18:37 +02:00
c6x c6x/ptrace: Remove useless PTRACE_SETREGSET implementation 2017-03-31 09:49:53 +02:00
cris cris: Only build flash rescue image if CONFIG_ETRAX_AXISFLASHMAP is selected 2017-01-12 11:22:48 +01:00
frv mm: larger stack guard gap, between vmas 2017-06-26 07:13:11 +02:00
h8300 h8300/ptrace: Fix incorrect register transfer count 2017-03-31 09:49:53 +02:00
hexagon hexagon: fix strncpy_from_user() error return 2016-09-24 10:07:44 +02:00
ia64 ia64: copy_from_user() should zero the destination on access_ok() failure 2016-09-24 10:07:46 +02:00
m32r m32r: fix __get_user() 2016-09-24 10:07:43 +02:00
m68k m68k: Fix ndelay() macro 2016-12-15 08:49:23 -08:00
metag metag/uaccess: Check access_ok in strncpy_from_user 2017-05-25 14:30:16 +02:00
microblaze microblaze: fix copy_from_user() 2016-09-24 10:07:43 +02:00
mips MIPS: Fix a typo: s/preset/present/ in r2-to-r6 emulation error message 2017-07-27 15:06:08 -07:00
mn10300 mn10300: copy_from_user() should zero on access_ok() failure... 2016-09-24 10:07:45 +02:00
nios2 nios2: reserve boot memory for device tree 2017-04-12 12:38:34 +02:00
openrisc openrisc: Add _text symbol to fix ksym build error 2017-08-06 19:19:45 -07:00
parisc parisc/mm: Ensure IRQs are off in switch_mm() 2017-07-21 07:44:56 +02:00
powerpc Revert "powerpc/numa: Fix percpu allocations to be NUMA aware" 2017-08-06 19:19:40 -07:00
s390 bpf, s390: fix jit branch offset related to ldimm64 2017-08-12 19:29:08 -07:00
score score: fix copy_from_user() and friends 2016-09-24 10:07:44 +02:00
sh mm: larger stack guard gap, between vmas 2017-06-26 07:13:11 +02:00
sparc sparc64: Measure receiver forward progress to avoid send mondo timeout 2017-08-11 09:08:56 -07:00
tile mm: larger stack guard gap, between vmas 2017-06-26 07:13:11 +02:00
um um: Don't discard .text.exit section 2016-09-07 08:32:38 +02:00
unicore32 pwm: Changes for v4.4-rc1 2015-11-11 09:16:10 -08:00
x86 x86/boot: Add missing declaration of string functions 2017-08-11 09:08:57 -07:00
xtensa mm: larger stack guard gap, between vmas 2017-06-26 07:13:11 +02:00
.gitignore
Kconfig kexec: split kexec_load syscall from kexec core code 2015-09-10 13:29:01 -07:00