linux-stable.git/lib/test_bpf.c, branch v4.13.2

net: introduce __skb_put_[zero, data, u8]

2017-06-20T17:30:14+00:00

follow Johannes Berg, semantic patch file as below,
@@
identifier p, p2;
expression len;
expression skb;
type t, t2;
@@
(
-p = __skb_put(skb, len);
+p = __skb_put_zero(skb, len);
|
-p = (t)__skb_put(skb, len);
+p = __skb_put_zero(skb, len);
)
... when != p
(
p2 = (t2)p;
-memset(p2, 0, len);
|
-memset(p, 0, len);
)

@@
identifier p;
expression len;
expression skb;
type t;
@@
(
-t p = __skb_put(skb, len);
+t p = __skb_put_zero(skb, len);
)
... when != p
(
-memset(p, 0, len);
)

@@
type t, t2;
identifier p, p2;
expression skb;
@@
t *p;
...
(
-p = __skb_put(skb, sizeof(t));
+p = __skb_put_zero(skb, sizeof(t));
|
-p = (t *)__skb_put(skb, sizeof(t));
+p = __skb_put_zero(skb, sizeof(t));
)
... when != p
(
p2 = (t2)p;
-memset(p2, 0, sizeof(*p));
|
-memset(p, 0, sizeof(*p));
)

@@
expression skb, len;
@@
-memset(__skb_put(skb, len), 0, len);
+__skb_put_zero(skb, len);

@@
expression skb, len, data;
@@
-memcpy(__skb_put(skb, len), data, len);
+__skb_put_data(skb, data, len);

@@
expression SKB, C, S;
typedef u8;
identifier fn = {__skb_put};
fresh identifier fn2 = fn ## "_u8";
@@
- *(u8 *)fn(SKB, S) = C;
+ fn2(SKB, C);

Signed-off-by: yuan linyu 
Signed-off-by: David S. Miller

test_bpf: Add test to make conditional jump cross a large number of insns.

2017-06-14T19:03:22+00:00

On MIPS, conditional branches can only span 32k instructions.  To
exceed this limit in the JIT with the BPF maximum of 4k insns, we need
to choose eBPF insns that expand to more than 8 machine instructions.
Use BPF_LD_ABS as it is quite complex.  This forces the JIT to invert
the sense of the branch to branch around a long jump to the end.

This (somewhat) verifies that the branch inversion logic and target
address calculation of the long jumps are done correctly.

Signed-off-by: David Daney 
Acked-by: Daniel Borkmann 
Signed-off-by: David S. Miller

bpf: fix stack_depth usage by test_bpf.ko

2017-05-31T23:29:48+00:00

test_bpf.ko doesn't call verifier before selecting interpreter or JITing,
hence the tests need to manually specify the amount of stack they consume.

Signed-off-by: Alexei Starovoitov 
Acked-by: Daniel Borkmann 
Signed-off-by: David S. Miller

test_bpf: Add a couple of tests for BPF_JSGE.

2017-05-25T18:37:56+00:00

Some JITs can optimize comparisons with zero.  Add a couple of
BPF_JSGE tests against immediate zero.

Signed-off-by: David Daney 
Acked-by: Daniel Borkmann 
Signed-off-by: David S. Miller

test_bpf: Use ULL suffix for 64-bit constants

2017-05-03T13:51:26+00:00

On 32-bit:

    lib/test_bpf.c:4772: warning: integer constant is too large for ‘unsigned long’ type
    lib/test_bpf.c:4772: warning: integer constant is too large for ‘unsigned long’ type
    lib/test_bpf.c:4773: warning: integer constant is too large for ‘unsigned long’ type
    lib/test_bpf.c:4773: warning: integer constant is too large for ‘unsigned long’ type
    lib/test_bpf.c:4787: warning: integer constant is too large for ‘unsigned long’ type
    lib/test_bpf.c:4787: warning: integer constant is too large for ‘unsigned long’ type
    lib/test_bpf.c:4801: warning: integer constant is too large for ‘unsigned long’ type
    lib/test_bpf.c:4801: warning: integer constant is too large for ‘unsigned long’ type
    lib/test_bpf.c:4802: warning: integer constant is too large for ‘unsigned long’ type
    lib/test_bpf.c:4802: warning: integer constant is too large for ‘unsigned long’ type

On 32-bit systems, "long" is only 32-bit.
Replace the "UL" suffix by "ULL" to fix this.

Fixes: 85f68fe898320575 ("bpf, arm64: implement jiting of BPF_XADD")
Signed-off-by: Geert Uytterhoeven 
Acked-by: Daniel Borkmann 
Signed-off-by: David S. Miller

bpf, arm64: fix jit branch offset related to ldimm64

2017-05-02T19:04:50+00:00

When the instruction right before the branch destination is
a 64 bit load immediate, we currently calculate the wrong
jump offset in the ctx->offset[] array as we only account
one instruction slot for the 64 bit load immediate although
it uses two BPF instructions. Fix it up by setting the offset
into the right slot after we incremented the index.

Before (ldimm64 test 1):

  [...]
  00000020:  52800007  mov w7, #0x0 // #0
  00000024:  d2800060  mov x0, #0x3 // #3
  00000028:  d2800041  mov x1, #0x2 // #2
  0000002c:  eb01001f  cmp x0, x1
  00000030:  54ffff82  b.cs 0x00000020
  00000034:  d29fffe7  mov x7, #0xffff // #65535
  00000038:  f2bfffe7  movk x7, #0xffff, lsl #16
  0000003c:  f2dfffe7  movk x7, #0xffff, lsl #32
  00000040:  f2ffffe7  movk x7, #0xffff, lsl #48
  00000044:  d29dddc7  mov x7, #0xeeee // #61166
  00000048:  f2bdddc7  movk x7, #0xeeee, lsl #16
  0000004c:  f2ddddc7  movk x7, #0xeeee, lsl #32
  00000050:  f2fdddc7  movk x7, #0xeeee, lsl #48
  [...]

After (ldimm64 test 1):

  [...]
  00000020:  52800007  mov w7, #0x0 // #0
  00000024:  d2800060  mov x0, #0x3 // #3
  00000028:  d2800041  mov x1, #0x2 // #2
  0000002c:  eb01001f  cmp x0, x1
  00000030:  540000a2  b.cs 0x00000044
  00000034:  d29fffe7  mov x7, #0xffff // #65535
  00000038:  f2bfffe7  movk x7, #0xffff, lsl #16
  0000003c:  f2dfffe7  movk x7, #0xffff, lsl #32
  00000040:  f2ffffe7  movk x7, #0xffff, lsl #48
  00000044:  d29dddc7  mov x7, #0xeeee // #61166
  00000048:  f2bdddc7  movk x7, #0xeeee, lsl #16
  0000004c:  f2ddddc7  movk x7, #0xeeee, lsl #32
  00000050:  f2fdddc7  movk x7, #0xeeee, lsl #48
  [...]

Also, add a couple of test cases to make sure JITs pass
this test. Tested on Cavium ThunderX ARMv8. The added
test cases all pass after the fix.

Fixes: 8eee539ddea0 ("arm64: bpf: fix out-of-bounds read in bpf2a64_offset()")
Reported-by: David S. Miller 
Signed-off-by: Daniel Borkmann 
Acked-by: Alexei Starovoitov 
Cc: Xi Wang 
Signed-off-by: David S. Miller

bpf, arm64: implement jiting of BPF_XADD

2017-05-02T19:04:50+00:00

This work adds BPF_XADD for BPF_W/BPF_DW to the arm64 JIT and therefore
completes JITing of all BPF instructions, meaning we can thus also remove
the 'notyet' label and do not need to fall back to the interpreter when
BPF_XADD is used in a program!

This now also brings arm64 JIT in line with x86_64, s390x, ppc64, sparc64,
where all current eBPF features are supported.

BPF_W example from test_bpf:

  .u.insns_int = {
    BPF_ALU32_IMM(BPF_MOV, R0, 0x12),
    BPF_ST_MEM(BPF_W, R10, -40, 0x10),
    BPF_STX_XADD(BPF_W, R10, R0, -40),
    BPF_LDX_MEM(BPF_W, R0, R10, -40),
    BPF_EXIT_INSN(),
  },

  [...]
  00000020:  52800247  mov w7, #0x12 // #18
  00000024:  928004eb  mov x11, #0xffffffffffffffd8 // #-40
  00000028:  d280020a  mov x10, #0x10 // #16
  0000002c:  b82b6b2a  str w10, [x25,x11]
  // start of xadd mapping:
  00000030:  928004ea  mov x10, #0xffffffffffffffd8 // #-40
  00000034:  8b19014a  add x10, x10, x25
  00000038:  f9800151  prfm pstl1strm, [x10]
  0000003c:  885f7d4b  ldxr w11, [x10]
  00000040:  0b07016b  add w11, w11, w7
  00000044:  880b7d4b  stxr w11, w11, [x10]
  00000048:  35ffffab  cbnz w11, 0x0000003c
  // end of xadd mapping:
  [...]

BPF_DW example from test_bpf:

  .u.insns_int = {
    BPF_ALU32_IMM(BPF_MOV, R0, 0x12),
    BPF_ST_MEM(BPF_DW, R10, -40, 0x10),
    BPF_STX_XADD(BPF_DW, R10, R0, -40),
    BPF_LDX_MEM(BPF_DW, R0, R10, -40),
    BPF_EXIT_INSN(),
  },

  [...]
  00000020:  52800247  mov w7,  #0x12 // #18
  00000024:  928004eb  mov x11, #0xffffffffffffffd8 // #-40
  00000028:  d280020a  mov x10, #0x10 // #16
  0000002c:  f82b6b2a  str x10, [x25,x11]
  // start of xadd mapping:
  00000030:  928004ea  mov x10, #0xffffffffffffffd8 // #-40
  00000034:  8b19014a  add x10, x10, x25
  00000038:  f9800151  prfm pstl1strm, [x10]
  0000003c:  c85f7d4b  ldxr x11, [x10]
  00000040:  8b07016b  add x11, x11, x7
  00000044:  c80b7d4b  stxr w11, x11, [x10]
  00000048:  35ffffab  cbnz w11, 0x0000003c
  // end of xadd mapping:
  [...]

Tested on Cavium ThunderX ARMv8, test suite results after the patch:

  No JIT:   [ 3751.855362] test_bpf: Summary: 311 PASSED, 0 FAILED, [0/303 JIT'ed]
  With JIT: [ 3573.759527] test_bpf: Summary: 311 PASSED, 0 FAILED, [303/303 JIT'ed]

Signed-off-by: Daniel Borkmann 
Acked-by: Alexei Starovoitov 
Signed-off-by: David S. Miller

bpf, test: fix ld_abs + vlan push/pop stress test

2016-10-20T18:39:06+00:00

After commit 636c2628086e ("net: skbuff: Remove errornous length
validation in skb_vlan_pop()") mentioned test case stopped working,
throwing a -12 (ENOMEM) return code. The issue however is not due to
636c2628086e, but rather due to a buggy test case that got uncovered
from the change in behaviour in 636c2628086e.

The data_size of that test case for the skb was set to 1. In the
bpf_fill_ld_abs_vlan_push_pop() handler bpf insns are generated that
loop with: reading skb data, pushing 68 tags, reading skb data,
popping 68 tags, reading skb data, etc, in order to force a skb
expansion and thus trigger that JITs recache skb->data. Problem is
that initial data_size is too small.

While before 636c2628086e, the test silently bailed out due to the
skb->len < VLAN_ETH_HLEN check with returning 0, and now throwing an
error from failing skb_ensure_writable(). Set at least minimum of
ETH_HLEN as an initial length so that on first push of data, equivalent
pop will succeed.

Fixes: 4d9c5c53ac99 ("test_bpf: add bpf_skb_vlan_push/pop() tests")
Signed-off-by: Daniel Borkmann 
Acked-by: Alexei Starovoitov 
Signed-off-by: David S. Miller

test_bpf: fix the dummy skb after dissector changes

2016-09-15T23:17:15+00:00

Commit d5709f7ab776 ("flow_dissector: For stripped vlan, get vlan
info from skb->vlan_tci") made flow dissector look at vlan_proto
when vlan is present.  Since test_bpf sets skb->vlan_tci to ~0
(including VLAN_TAG_PRESENT) we have to populate skb->vlan_proto.

Fixes false negative on test #24:
test_bpf: #24 LD_PAYLOAD_OFF jited:0 175 ret 0 != 42 FAIL (1 times)

Signed-off-by: Jakub Kicinski 
Reviewed-by: Dinan Gunawardena 
Acked-by: Daniel Borkmann 
Acked-by: Alexei Starovoitov 
Signed-off-by: David S. Miller

bpf: prepare bpf_int_jit_compile/bpf_prog_select_runtime apis

2016-05-16T17:49:32+00:00

Since the blinding is strictly only called from inside eBPF JITs,
we need to change signatures for bpf_int_jit_compile() and
bpf_prog_select_runtime() first in order to prepare that the
eBPF program we're dealing with can change underneath. Hence,
for call sites, we need to return the latest prog. No functional
change in this patch.

Signed-off-by: Daniel Borkmann 
Acked-by: Alexei Starovoitov 
Signed-off-by: David S. Miller