Commit graph

186 commits

Author SHA1 Message Date
David S. Miller
fcffe2edbd Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:

====================
pull-request: bpf-next 2017-12-28

The following pull-request contains BPF updates for your *net-next* tree.

The main changes are:

1) Fix incorrect state pruning related to recognition of zero initialized
   stack slots, where stacksafe exploration would mistakenly return a
   positive pruning verdict too early ignoring other slots, from Gianluca.

2) Various BPF to BPF calls related follow-up fixes. Fix an off-by-one
   in maximum call depth check, and rework maximum stack depth tracking
   logic to fix a bypass of the total stack size check reported by Jann.
   Also fix a bug in arm64 JIT where prog->jited_len was uninitialized.
   Addition of various test cases to BPF selftests, from Alexei.

3) Addition of a BPF selftest to test_verifier that is related to BPF to
   BPF calls which demonstrates a late caller stack size increase and
   thus out of bounds access. Fixed above in 2). Test case from Jann.

4) Addition of correlating BPF helper calls, BPF to BPF calls as well
   as BPF maps to bpftool xlated dump in order to allow for better
   BPF program introspection and debugging, from Daniel.

5) Fixing several bugs in BPF to BPF calls kallsyms handling in order
   to get it actually to work for subprogs, from Daniel.

6) Extending sparc64 JIT support for BPF to BPF calls and fix a couple
   of build errors for libbpf on sparc64, from David.

7) Allow narrower context access for BPF dev cgroup typed programs in
   order to adapt to LLVM code generation. Also adjust memlock rlimit
   in the test_dev_cgroup BPF selftest, from Yonghong.

8) Add netdevsim Kconfig entry to BPF selftests since test_offload.py
   relies on netdevsim device being available, from Jakub.

9) Reduce scope of xdp_do_generic_redirect_map() to being static,
   from Xiongwei.

10) Minor cleanups and spelling fixes in BPF verifier, from Colin.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-27 20:40:32 -05:00
Alexei Starovoitov
aada9ce644 bpf: fix max call depth check
fix off by one error in max call depth check
and add a test

Fixes: f4d7e40a5b ("bpf: introduce function calls (verification)")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-12-27 18:36:23 +01:00
Alexei Starovoitov
6b86c4217c selftests/bpf: additional stack depth tests
to test inner logic of stack depth tracking

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-12-27 18:36:23 +01:00
Jann Horn
6b80ad2992 bpf: selftest for late caller stack size increase
This checks that it is not possible to bypass the total stack size check in
update_stack_depth() by calling a function that uses a large amount of
stack memory *before* using a large amount of stack memory in the caller.

Currently, the first added testcase causes a rejection as expected, but
the second testcase is (AFAICS incorrectly) accepted:

[...]
#483/p calls: stack overflow using two frames (post-call access) FAIL
Unexpected success to load!
0: (85) call pc+2
caller:
 R10=fp0,call_-1
callee:
 frame1: R1=ctx(id=0,off=0,imm=0) R10=fp0,call_0
3: (72) *(u8 *)(r10 -300) = 0
4: (b7) r0 = 0
5: (95) exit
returning from callee:
 frame1: R0_w=inv0 R1=ctx(id=0,off=0,imm=0) R10=fp0,call_0
to caller at 1:
 R0_w=inv0 R10=fp0,call_-1

from 5 to 1: R0=inv0 R10=fp0,call_-1
1: (72) *(u8 *)(r10 -300) = 0
2: (95) exit
processed 6 insns, stack depth 300+300
[...]
Summary: 704 PASSED, 1 FAILED

AFAICS the JIT-generated code for the second testcase shows that this
really causes the stack pointer to be decremented by 300+300:

first function:
00000000  55                push rbp
00000001  4889E5            mov rbp,rsp
00000004  4881EC58010000    sub rsp,0x158
0000000B  4883ED28          sub rbp,byte +0x28
[...]
00000025  E89AB3AFE5        call 0xffffffffe5afb3c4
0000002A  C685D4FEFFFF00    mov byte [rbp-0x12c],0x0
[...]
00000041  4883C528          add rbp,byte +0x28
00000045  C9                leave
00000046  C3                ret

second function:
00000000  55                push rbp
00000001  4889E5            mov rbp,rsp
00000004  4881EC58010000    sub rsp,0x158
0000000B  4883ED28          sub rbp,byte +0x28
[...]
00000025  C685D4FEFFFF00    mov byte [rbp-0x12c],0x0
[...]
0000003E  4883C528          add rbp,byte +0x28
00000042  C9                leave
00000043  C3                ret

Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-12-27 18:35:07 +01:00
Gianluca Borello
fd05e57bb3 bpf: fix stacksafe exploration when comparing states
Commit cc2b14d510 ("bpf: teach verifier to recognize zero initialized
stack") introduced a very relaxed check when comparing stacks of different
states, effectively returning a positive result in many cases where it
shouldn't.

This can create problems in cases such as this following C pseudocode:

long var;
long *x = bpf_map_lookup(...);
if (!x)
        return;

if (*x != 0xbeef)
        var = 0;
else
        var = 1;

/* This is the key part, calling a helper causes an explored state
 * to be saved with the information that "var" is on the stack as
 * STACK_ZERO, since the helper is first met by the verifier after
 * the "var = 0" assignment. This state will however be wrongly used
 * also for the "var = 1" case, so the verifier assumes "var" is always
 * 0 and will replace the NULL assignment with nops, because the
 * search pruning prevents it from exploring the faulty branch.
 */
bpf_ktime_get_ns();

if (var)
        *(long *)0 = 0xbeef;

Fix the issue by making sure that the stack is fully explored before
returning a positive comparison result.

Also attach a couple tests that highlight the bad behavior. In the first
test, without this fix instructions 16 and 17 are replaced with nops
instead of being rejected by the verifier.

The second test, instead, allows a program to make a potentially illegal
read from the stack.

Fixes: cc2b14d510 ("bpf: teach verifier to recognize zero initialized stack")
Signed-off-by: Gianluca Borello <g.borello@gmail.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2017-12-23 11:04:58 -08:00
David S. Miller
fba961ab29 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Lots of overlapping changes.  Also on the net-next side
the XDP state management is handled more in the generic
layers so undo the 'net' nfp fix which isn't applicable
in net-next.

Include a necessary change by Jakub Kicinski, with log message:

====================
cls_bpf no longer takes care of offload tracking.  Make sure
netdevsim performs necessary checks.  This fixes a warning
caused by TC trying to remove a filter it has not added.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-22 11:16:31 -05:00
Yonghong Song
c475ffad58 tools/bpf: adjust rlimit RLIMIT_MEMLOCK for test_dev_cgroup
The default rlimit RLIMIT_MEMLOCK is 64KB. In certain cases,
e.g. in a test machine mimicking our production system, this test may
fail due to unable to charge the required memory for prog load:

  $ ./test_dev_cgroup
  libbpf: load bpf program failed: Operation not permitted
  libbpf: failed to load program 'cgroup/dev'
  libbpf: failed to load object './dev_cgroup.o'
  Failed to load DEV_CGROUP program
  ...

Changing the default rlimit RLIMIT_MEMLOCK to unlimited
makes the test pass.

This patch also fixed a problem where when bpf_prog_load fails,
cleanup_cgroup_environment() should not be called since
setup_cgroup_environment() has not been invoked. Otherwise,
the following confusing message will appear:
  ...
  (/home/yhs/local/linux/tools/testing/selftests/bpf/cgroup_helpers.c:95:
   errno: No such file or directory) Opening Cgroup Procs: /mnt/cgroup.procs
  ...

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2017-12-20 19:15:54 -08:00
Alexei Starovoitov
82abbf8d2f bpf: do not allow root to mangle valid pointers
Do not allow root to convert valid pointers into unknown scalars.
In particular disallow:
 ptr &= reg
 ptr <<= reg
 ptr += ptr
and explicitly allow:
 ptr -= ptr
since pkt_end - pkt == length

1.
This minimizes amount of address leaks root can do.
In the future may need to further tighten the leaks with kptr_restrict.

2.
If program has such pointer math it's likely a user mistake and
when verifier complains about it right away instead of many instructions
later on invalid memory access it's easier for users to fix their progs.

3.
when register holding a pointer cannot change to scalar it allows JITs to
optimize better. Like 32-bit archs could use single register for pointers
instead of a pair required to hold 64-bit scalars.

4.
reduces architecture dependent behavior. Since code:
r1 = r10;
r1 &= 0xff;
if (r1 ...)
will behave differently arm64 vs x64 and offloaded vs native.

A significant chunk of ptr mangling was allowed by
commit f1174f77b5 ("bpf/verifier: rework value tracking")
yet some of it was allowed even earlier.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-12-21 02:26:29 +01:00
Jann Horn
2255f8d520 selftests/bpf: add tests for recent bugfixes
These tests should cover the following cases:

 - MOV with both zero-extended and sign-extended immediates
 - implicit truncation of register contents via ALU32/MOV32
 - implicit 32-bit truncation of ALU32 output
 - oversized register source operand for ALU32 shift
 - right-shift of a number that could be positive or negative
 - map access where adding the operation size to the offset causes signed
   32-bit overflow
 - direct stack access at a ~4GiB offset

Also remove the F_LOAD_WITH_STRICT_ALIGNMENT flag from a bunch of tests
that should fail independent of what flags userspace passes.

Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-12-21 02:15:41 +01:00
David Miller
19c832ed9b bpf: Fix tools and testing build.
I'm getting various build failures on sparc64.  The key is
usually that the userland tools get built 32-bit.

1) clock_gettime() is in librt, so that must be added to the link
   libraries.

2) "sizeof(x)" must be printed with "%Z" printf prefix.

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-12-20 00:15:05 +01:00
Jakub Kicinski
4ca998fe46 selftests/bpf: add netdevsim to config
BPF offload tests (test_offload.py) will require netdevsim
to be built, add it to config.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-12-19 01:35:12 +01:00
David S. Miller
59436c9ee1 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:

====================
pull-request: bpf-next 2017-12-18

The following pull-request contains BPF updates for your *net-next* tree.

The main changes are:

1) Allow arbitrary function calls from one BPF function to another BPF function.
   As of today when writing BPF programs, __always_inline had to be used in
   the BPF C programs for all functions, unnecessarily causing LLVM to inflate
   code size. Handle this more naturally with support for BPF to BPF calls
   such that this __always_inline restriction can be overcome. As a result,
   it allows for better optimized code and finally enables to introduce core
   BPF libraries in the future that can be reused out of different projects.
   x86 and arm64 JIT support was added as well, from Alexei.

2) Add infrastructure for tagging functions as error injectable and allow for
   BPF to return arbitrary error values when BPF is attached via kprobes on
   those. This way of injecting errors generically eases testing and debugging
   without having to recompile or restart the kernel. Tags for opting-in for
   this facility are added with BPF_ALLOW_ERROR_INJECTION(), from Josef.

3) For BPF offload via nfp JIT, add support for bpf_xdp_adjust_head() helper
   call for XDP programs. First part of this work adds handling of BPF
   capabilities included in the firmware, and the later patches add support
   to the nfp verifier part and JIT as well as some small optimizations,
   from Jakub.

4) The bpftool now also gets support for basic cgroup BPF operations such
   as attaching, detaching and listing current BPF programs. As a requirement
   for the attach part, bpftool can now also load object files through
   'bpftool prog load'. This reuses libbpf which we have in the kernel tree
   as well. bpftool-cgroup man page is added along with it, from Roman.

5) Back then commit e87c6bc385 ("bpf: permit multiple bpf attachments for
   a single perf event") added support for attaching multiple BPF programs
   to a single perf event. Given they are configured through perf's ioctl()
   interface, the interface has been extended with a PERF_EVENT_IOC_QUERY_BPF
   command in this work in order to return an array of one or multiple BPF
   prog ids that are currently attached, from Yonghong.

6) Various minor fixes and cleanups to the bpftool's Makefile as well
   as a new 'uninstall' and 'doc-uninstall' target for removing bpftool
   itself or prior installed documentation related to it, from Quentin.

7) Add CONFIG_CGROUP_BPF=y to the BPF kernel selftest config file which is
   required for the test_dev_cgroup test case to run, from Naresh.

8) Fix reporting of XDP prog_flags for nfp driver, from Jakub.

9) Fix libbpf's exit code from the Makefile when libelf was not found in
   the system, also from Jakub.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-18 10:51:06 -05:00
Daniel Borkmann
28ab173e96 selftests/bpf: additional bpf_call tests
Add some additional checks for few more corner cases.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-12-17 20:34:36 +01:00
Alexei Starovoitov
b0b04fc49e selftests/bpf: add xdp noinline test
add large semi-artificial XDP test with 18 functions to stress test
bpf call verification logic

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-12-17 20:34:36 +01:00
Alexei Starovoitov
3bc35c63cb selftests/bpf: add bpf_call test
strip always_inline from test_l4lb.c and compile it with -fno-inline
to let verifier go through 11 function with various function arguments
and return values

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-12-17 20:34:36 +01:00
Alexei Starovoitov
d98588cef0 selftests/bpf: add tests for stack_zero tracking
adjust two tests, since verifier got smarter
and add new one to test stack_zero logic

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-12-17 20:34:35 +01:00
Alexei Starovoitov
a7ff3eca95 selftests/bpf: add verifier tests for bpf_call
Add extensive set of tests for bpf_call verification logic:

calls: basic sanity
calls: using r0 returned by callee
calls: callee is using r1
calls: callee using args1
calls: callee using wrong args2
calls: callee using two args
calls: callee changing pkt pointers
calls: two calls with args
calls: two calls with bad jump
calls: recursive call. test1
calls: recursive call. test2
calls: unreachable code
calls: invalid call
calls: jumping across function bodies. test1
calls: jumping across function bodies. test2
calls: call without exit
calls: call into middle of ld_imm64
calls: call into middle of other call
calls: two calls with bad fallthrough
calls: two calls with stack read
calls: two calls with stack write
calls: spill into caller stack frame
calls: two calls with stack write and void return
calls: ambiguous return value
calls: two calls that return map_value
calls: two calls that return map_value with bool condition
calls: two calls that return map_value with incorrect bool check
calls: two calls that receive map_value via arg=ptr_stack_of_caller. test1
calls: two calls that receive map_value via arg=ptr_stack_of_caller. test2
calls: two jumps that receive map_value via arg=ptr_stack_of_jumper. test3
calls: two calls that receive map_value_ptr_or_null via arg. test1
calls: two calls that receive map_value_ptr_or_null via arg. test2
calls: pkt_ptr spill into caller stack

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-12-17 20:34:35 +01:00
David S. Miller
c30abd5e40 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Three sets of overlapping changes, two in the packet scheduler
and one in the meson-gxl PHY driver.

Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-16 22:11:55 -05:00
Daniel Borkmann
87ab819430 bpf: add test case for ld_abs and helper changing pkt data
Add a test that i) uses LD_ABS, ii) zeroing R6 before call, iii) calls
a helper that triggers reload of cached skb data, iv) uses LD_ABS again.
It's added for test_bpf in order to do runtime testing after JITing as
well as test_verifier to test that the sequence is allowed.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2017-12-15 09:19:36 -08:00
Daniel Borkmann
720f228e8d bpf: fix broken BPF selftest build
At least on x86_64, the kernel's BPF selftests seemed to have stopped
to build due to 618e165b2a ("selftests/bpf: sync kernel headers and
introduce arch support in Makefile"):

  [...]
  In file included from test_verifier.c:29:0:
  ../../../include/uapi/linux/bpf_perf_event.h:11:32:
     fatal error: asm/bpf_perf_event.h: No such file or directory
   #include <asm/bpf_perf_event.h>
                                ^
  compilation terminated.
  [...]

While pulling in tools/arch/*/include/uapi/asm/bpf_perf_event.h seems
to work fine, there's no automated fall-back logic right now that would
do the same out of tools/include/uapi/asm-generic/bpf_perf_event.h. The
usual convention today is to add a include/[uapi/]asm/ equivalent that
would pull in the correct arch header or generic one as fall-back, all
ifdef'ed based on compiler target definition. It's similarly done also
in other cases such as tools/include/asm/barrier.h, thus adapt the same
here.

Fixes: 618e165b2a ("selftests/bpf: sync kernel headers and introduce arch support in Makefile")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2017-12-12 09:51:12 -08:00
Josef Bacik
965de87e54 samples/bpf: add a test for bpf_override_return
This adds a basic test for bpf_override_return to verify it works.  We
override the main function for mounting a btrfs fs so it'll return
-ENOMEM and then make sure that trying to mount a btrfs fs will fail.

Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2017-12-12 09:02:40 -08:00
Yonghong Song
d279f1f8c6 bpf/tracing: add a bpf test for new ioctl query interface
Added a subtest in test_progs. The tracepoint is
sched/sched_switch. Multiple bpf programs are attached to
this tracepoint and the query interface is exercised.

Signed-off-by: Yonghong Song <yhs@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2017-12-12 08:46:40 -08:00
Naresh Kamboju
63060c3916 selftests: bpf: Adding config fragment CONFIG_CGROUP_BPF=y
CONFIG_CGROUP_BPF=y is required for test_dev_cgroup test case.

Signed-off-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-12-12 02:32:45 +01:00
David S. Miller
51e18a453f Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflict was two parallel additions of include files to sch_generic.c,
no biggie.

Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-09 22:09:55 -05:00
David S. Miller
7cda4cee13 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Small overlapping change conflict ('net' changed a line,
'net-next' added a line right afterwards) in flexcan.c

Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-05 10:44:19 -05:00
Hendrik Brueckner
618e165b2a selftests/bpf: sync kernel headers and introduce arch support in Makefile
Synchronize the uapi kernel header files which solves the broken
uapi export of pt_regs.  Because of arch-specific uapi headers,
extended the include path in the Makefile.

With this change, the test_verifier program compiles and runs successfully
on s390.

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Reviewed-and-tested-by: Thomas Richter <tmricht@linux.vnet.ibm.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-12-05 15:02:41 +01:00
Jakub Kicinski
417ec26477 selftests/bpf: add offload test based on netdevsim
Add a test of BPF offload control path interfaces based on
just-added netdevsim driver.  Perform various checks of both
the stack and the expected driver behaviour.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-12-03 00:27:58 +01:00
Alexei Starovoitov
6a28b446b7 selftests/bpf: adjust test_align expected output
since verifier started to print liveness state of the registers
adjust expected output of test_align.
Now this test checks for both proper alignment handling by verifier
and correctness of liveness marks.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-12-01 11:25:10 +01:00
Yonghong Song
2b27941956 tools/bpf: adjust rlimit RLIMIT_MEMLOCK for test_verifier_log
The default rlimit RLIMIT_MEMLOCK is 64KB. In certain cases,
e.g. in a test machine mimicking our production system, this test may
fail due to unable to charge the required memory for prog load:
  # ./test_verifier_log
  Test log_level 0...
  ERROR: Program load returned: ret:-1/errno:1, expected ret:-1/errno:22

Changing the default rlimit RLIMIT_MEMLOCK to unlimited makes
the test always pass.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-11-30 19:55:18 +01:00
Gianluca Borello
db1ac4964f bpf: introduce ARG_PTR_TO_MEM_OR_NULL
With the current ARG_PTR_TO_MEM/ARG_PTR_TO_UNINIT_MEM semantics, an helper
argument can be NULL when the next argument type is ARG_CONST_SIZE_OR_ZERO
and the verifier can prove the value of this next argument is 0. However,
most helpers are just interested in handling <!NULL, 0>, so forcing them to
deal with <NULL, 0> makes the implementation of those helpers more
complicated for no apparent benefits, requiring them to explicitly handle
those corner cases with checks that bpf programs could start relying upon,
preventing the possibility of removing them later.

Solve this by making ARG_PTR_TO_MEM/ARG_PTR_TO_UNINIT_MEM never accept NULL
even when ARG_CONST_SIZE_OR_ZERO is set, and introduce a new argument type
ARG_PTR_TO_MEM_OR_NULL to explicitly deal with the NULL case.

Currently, the only helper that needs this is bpf_csum_diff_proto(), so
change arg1 and arg3 to this new type as well.

Also add a new battery of tests that explicitly test the
!ARG_PTR_TO_MEM_OR_NULL combination: all the current ones testing the
various <NULL, 0> variations are focused on bpf_csum_diff, so cover also
other helpers.

Signed-off-by: Gianluca Borello <g.borello@gmail.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-11-22 21:40:54 +01:00
Yonghong Song
f1a8b8e3d9 bpf: change bpf_probe_write_user to bpf_trace_printk in test_verifier
There are four tests in test_verifier using bpf_probe_write_user
helper. These four tests will emit the following kernel messages
  [   12.974753] test_verifier[220] is installing a program with bpf_probe_write_user
                                    helper that may corrupt user memory!
  [   12.979285] test_verifier[220] is installing a program with bpf_probe_write_user
                                    helper that may corrupt user memory!
  ......

This may confuse certain users. This patch replaces bpf_probe_write_user
with bpf_trace_printk. The test_verifier already uses bpf_trace_printk
earlier in the test and a trace_printk warning message has been printed.
So this patch does not emit any more kernel messages.

Fixes: b6ff639112 ("bpf: fix and add test cases for ARG_CONST_SIZE_OR_ZERO semantics change")
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-11-21 21:23:05 +01:00
Yonghong Song
b6ff639112 bpf: fix and add test cases for ARG_CONST_SIZE_OR_ZERO semantics change
Fix a few test cases to allow non-NULL map/packet/stack pointer
with size = 0. Change a few tests using bpf_probe_read to use
bpf_probe_write_user so ARG_CONST_SIZE arg can still be properly
tested. One existing test case already covers size = 0 with non-NULL
packet pointer, so add additional tests so all cases of
size = 0 and 0 <= size <= legal_upper_bound with non-NULL
map/packet/stack pointer are covered.

Signed-off-by: Yonghong Song <yhs@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-14 16:20:03 +09:00
David S. Miller
f3edacbd69 bpf: Revert bpf_overrid_function() helper changes.
NACK'd by x86 maintainer.

Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-11 18:24:55 +09:00
Josef Bacik
eafb3401fa samples/bpf: add a test for bpf_override_return
This adds a basic test for bpf_override_return to verify it works.  We
override the main function for mounting a btrfs fs so it'll return
-ENOMEM and then make sure that trying to mount a btrfs fs will fail.

Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-11 12:18:06 +09:00
Roman Gushchin
37f1ba0909 selftests/bpf: add a test for device cgroup controller
Add a test for device cgroup controller.

The test loads a simple bpf program which logs all
device access attempts using trace_printk() and forbids
all operations except operations with /dev/zero and
/dev/urandom.

Then the test creates and joins a test cgroup, and attaches
the bpf program to it.

Then it tries to perform some simple device operations
and checks the result:

  create /dev/null (should fail)
  create /dev/zero (should pass)
  copy data from /dev/urandom to /dev/zero (should pass)
  copy data from /dev/urandom to /dev/full (should fail)
  copy data from /dev/random to /dev/zero (should fail)

Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-05 23:26:51 +09:00
Roman Gushchin
9d1f159419 bpf: move cgroup_helpers from samples/bpf/ to tools/testing/selftesting/bpf/
The purpose of this move is to use these files in bpf tests.

Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-05 23:26:51 +09:00
David S. Miller
2a171788ba Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Files removed in 'net-next' had their license header updated
in 'net'.  We take the remove from 'net-next'.

Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-04 09:26:51 +09:00
Greg Kroah-Hartman
b24413180f License cleanup: add SPDX GPL-2.0 license identifier to files with no license
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02 11:10:55 +01:00
Daniel Borkmann
634eab11bd bpf: add test cases to bpf selftests to cover all meta tests
Lets also add test cases to cover all possible data_meta access tests
for good/bad access cases so we keep tracking them.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-02 17:01:39 +09:00
Daniel Borkmann
b06723da82 bpf: minor cleanups after merge
Two minor cleanups after Dave's recent merge in f8ddadc4db
("Merge git://git.kernel.org...") of net into net-next in
order to get the code in line with what was done originally
in the net tree: i) use max() instead of max_t() since both
ranges are u16, ii) don't split the direct access test cases
in the middle with bpf_exit test cases from 390ee7e29f
("bpf: enforce return code for cgroup-bpf programs").

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-02 17:01:38 +09:00
Alexei Starovoitov
81ba4e1ac4 selftests/bpf: remove useless bpf_trace_printk
sockmap test is using two programs that use bpf_trace_printk()
which prints into trace_pipe, but nothing is reading it.
Remove it.

Fixes: 6f6d33f3b3 ("bpf: selftests add sockmap tests")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-01 12:06:46 +09:00
Alexei Starovoitov
e27afb84b4 selftests/bpf: fix broken build of test_maps
fix multiple build errors and warnings

1.
test_maps.c: In function ‘test_map_rdonly’:
test_maps.c:1051:30: error: ‘BPF_F_RDONLY’ undeclared (first use in this function)
        MAP_SIZE, map_flags | BPF_F_RDONLY);

2.
test_maps.c:1048:6: warning: unused variable ‘i’ [-Wunused-variable]
  int i, fd, key = 0, value = 0;

3.
test_maps.c:1087:2: error: called object is not a function or function pointer
  assert(bpf_map_lookup_elem(fd, &key, &value) == -1 && errno == EPERM);

4.
./bpf_helpers.h:72:11: error: use of undeclared identifier 'BPF_FUNC_getsockopt'
        (void *) BPF_FUNC_getsockopt;

Fixes: e043325b30 ("bpf: Add tests for eBPF file mode")
Fixes: 6e71b04a82 ("bpf: Add file mode configuration into bpf maps")
Fixes: cd86d1fd21 ("bpf: Adding helper function bpf_getsockops")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-23 01:06:31 +01:00
David S. Miller
f8ddadc4db Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
There were quite a few overlapping sets of changes here.

Daniel's bug fix for off-by-ones in the new BPF branch instructions,
along with the added allowances for "data_end > ptr + x" forms
collided with the metadata additions.

Along with those three changes came veritifer test cases, which in
their final form I tried to group together properly.  If I had just
trimmed GIT's conflict tags as-is, this would have split up the
meta tests unnecessarily.

In the socketmap code, a set of preemption disabling changes
overlapped with the rename of bpf_compute_data_end() to
bpf_compute_data_pointers().

Changes were made to the mv88e6060.c driver set addr method
which got removed in net-next.

The hyperv transport socket layer had a locking change in 'net'
which overlapped with a change of socket state macro usage
in 'net-next'.

Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-22 13:39:14 +01:00
Lawrence Brakmo
cd86d1fd21 bpf: Adding helper function bpf_getsockops
Adding support for helper function bpf_getsockops to socket_ops BPF
programs. This patch only supports TCP_CONGESTION.

Signed-off-by: Vlad Vysotsky <vlad@cs.ucla.edu>
Acked-by: Lawrence Brakmo <brakmo@fb.com>
Acked-by: Alexei Starovoitov <ast@fb.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-22 03:12:05 +01:00
Daniel Borkmann
b37242c773 bpf: add test cases to bpf selftests to cover all access tests
Lets add test cases to cover really all possible direct packet
access tests for good/bad access cases so we keep tracking them.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-22 00:56:09 +01:00
Chenbo Feng
e043325b30 bpf: Add tests for eBPF file mode
Two related tests are added into bpf selftest to test read only map and
write only map. The tests verified the read only and write only flags
are working on hash maps.

Signed-off-by: Chenbo Feng <fengc@google.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-20 13:32:59 +01:00
John Fastabend
f7e9cb1ecb bpf: remove mark access for SK_SKB program types
The skb->mark field is a union with reserved_tailroom which is used
in the TCP code paths from stream memory allocation. Allowing SK_SKB
programs to set this field creates a conflict with future code
optimizations, such as "gifting" the skb to the egress path instead
of creating a new skb and doing a memcpy.

Because we do not have a released version of SK_SKB yet lets just
remove it for now. A more appropriate scratch pad to use at the
socket layer is dev_scratch, but lets add that in future kernels
when needed.

Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-20 13:01:29 +01:00
John Fastabend
34f79502bb bpf: avoid preempt enable/disable in sockmap using tcp_skb_cb region
SK_SKB BPF programs are run from the socket/tcp context but early in
the stack before much of the TCP metadata is needed in tcp_skb_cb. So
we can use some unused fields to place BPF metadata needed for SK_SKB
programs when implementing the redirect function.

This allows us to drop the preempt disable logic. It does however
require an API change so sk_redirect_map() has been updated to
additionally provide ctx_ptr to skb. Note, we do however continue to
disable/enable preemption around actual BPF program running to account
for map updates.

Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-20 13:01:29 +01:00
John Fastabend
435bf0d3f9 bpf: enforce TCP only support for sockmap
Only TCP sockets have been tested and at the moment the state change
callback only handles TCP sockets. This adds a check to ensure that
sockets actually being added are TCP sockets.

For net-next we can consider UDP support.

Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-20 13:01:29 +01:00
Jakub Kicinski
28e33f9d78 bpf: disallow arithmetic operations on context pointer
Commit f1174f77b5 ("bpf/verifier: rework value tracking")
removed the crafty selection of which pointer types are
allowed to be modified.  This is OK for most pointer types
since adjust_ptr_min_max_vals() will catch operations on
immutable pointers.  One exception is PTR_TO_CTX which is
now allowed to be offseted freely.

The intent of aforementioned commit was to allow context
access via modified registers.  The offset passed to
->is_valid_access() verifier callback has been adjusted
by the value of the variable offset.

What is missing, however, is taking the variable offset
into account when the context register is used.  Or in terms
of the code adding the offset to the value passed to the
->convert_ctx_access() callback.  This leads to the following
eBPF user code:

     r1 += 68
     r0 = *(u32 *)(r1 + 8)
     exit

being translated to this in kernel space:

   0: (07) r1 += 68
   1: (61) r0 = *(u32 *)(r1 +180)
   2: (95) exit

Offset 8 is corresponding to 180 in the kernel, but offset
76 is valid too.  Verifier will "accept" access to offset
68+8=76 but then "convert" access to offset 8 as 180.
Effective access to offset 248 is beyond the kernel context.
(This is a __sk_buff example on a debug-heavy kernel -
packet mark is 8 -> 180, 76 would be data.)

Dereferencing the modified context pointer is not as easy
as dereferencing other types, because we have to translate
the access to reading a field in kernel structures which is
usually at a different offset and often of a different size.
To allow modifying the pointer we would have to make sure
that given eBPF instruction will always access the same
field or the fields accessed are "compatible" in terms of
offset and size...

Disallow dereferencing modified context pointers and add
to selftests the test case described here.

Fixes: f1174f77b5 ("bpf/verifier: rework value tracking")
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-18 13:21:13 +01:00