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Martin KaFai Lau says:
====================
This series ensures the line_info (passed by the userspace during
bpf_prog_load) cannot have its line_info.insn_off pointing to a
zero bpf insn code. F.e. a broken userspace tool might
generate a line_info.insn_off that points to the second
8 bytes of a BPF_LD_IMM64.
The first patch is the kernel change.
The second patch is a new test case.
====================
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This patch adds a BPF_LD_IMM64 case to the line_info test
to ensure the kernel rejects linfo_info.insn_off pointing
to the 2nd 8 bytes of the BPF_LD_IMM64.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This patch rejects a line_info if the bpf insn code referred by
line_info.insn_off is 0. F.e. a broken userspace tool might generate
a line_info.insn_off that points to the second 8 bytes of a BPF_LD_IMM64.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This allows transparent cross-compilation with CROSS_COMPILE by
relying on 7ed1c1901f ("tools: fix cross-compile var clobbering").
Signed-off-by: Ivan Babrou <ivan@cloudflare.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Prior this commit, when the struct socket object was being released,
the UMEM did not have its reference count decreased. Instead, this was
done in the struct sock sk_destruct function.
There is no reason to keep the UMEM reference around when the socket
is being orphaned, so in this patch the xdp_put_mem is called in the
xsk_release function. This results in that the xsk_destruct function
can be removed!
Note that, it still holds that a struct xsk_sock reference might still
linger in the XSKMAP after the UMEM is released, e.g. if a user does
not clear the XSKMAP prior to closing the process. This sock will be
in a "released" zombie like state, until the XSKMAP is removed.
Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Current btf internal verbose logger logs fwd type as
[2] FWD A type_id=0
where A is the type name.
Commit 9d5f9f701b ("bpf: btf: fix struct/union/fwd types
with kind_flag") introduced kind_flag which can be used
to distinguish whether a forward type is a struct or
union.
Also, "type_id=0" does not carry any meaningful
information for fwd type as btf_type.type = 0 is simply
enforced during btf verification and is not used
anywhere else.
This commit changed the log to
[2] FWD A struct
if kind_flag = 0, or
[2] FWD A union
if kind_flag = 1.
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
John Fastabend says:
====================
This adds a size field to the sk_msg_md data structure used by SK_MSG
programs. Without this in the zerocopy case and in the copy case
where multiple iovs are in use its difficult to know how much data
can be pulled in. The normal method of reading data and data_end
only give the current contiguous buffer. BPF programs can attempt to
pull in extra data but have to guess if it exists. This can result
in multiple "guesses" its much better if we know upfront the size
of the sk_msg.
====================
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This adds tests to read the size field to test_verifier.
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Add the size field to sk_msg_md for tools.
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This adds metadata to sk_msg_md for BPF programs to read the sk_msg
size.
When the SK_MSG program is running under an application that is using
sendfile the data is not copied into sk_msg buffers by default. Rather
the BPF program uses sk_msg_pull_data to read the bytes in. This
avoids doing the costly memcopy instructions when they are not in
fact needed. However, if we don't know the size of the sk_msg we
have to guess if needed bytes are available by doing a pull request
which may fail. By including the size of the sk_msg BPF programs can
check the size before issuing sk_msg_pull_data requests.
Additionally, the same applies for sendmsg calls when the application
provides multiple iovs. Here the BPF program needs to pull in data
to update data pointers but its not clear where the data ends without
a size parameter. In many cases "guessing" is not easy to do
and results in multiple calls to pull and without bounded loops
everything gets fairly tricky.
Clean this up by including a u32 size field. Note, all writes into
sk_msg_md are rejected already from sk_msg_is_valid_access so nothing
additional is needed there.
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Verifier is supposed to support sharing stack slot allocated to ptr with
SCALAR_VALUE for privileged program. However this doesn't happen for some
cases.
The reason is verifier is not clearing slot_type STACK_SPILL for all bytes,
it only clears part of them, while verifier is using:
slot_type[0] == STACK_SPILL
as a convention to check one slot is ptr type.
So, the consequence of partial clearing slot_type is verifier could treat a
partially overridden ptr slot, which should now be a SCALAR_VALUE slot,
still as ptr slot, and rejects some valid programs.
Before this patch, test_xdp_noinline.o under bpf selftests, bpf_lxc.o and
bpf_netdev.o under Cilium bpf repo, when built with -mattr=+alu32 are
rejected due to this issue. After this patch, they all accepted.
There is no processed insn number change before and after this patch on
Cilium bpf programs.
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Reviewed-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Distributions build drivers as modules, including network and filesystem
drivers which export numerous tracepoints. This enables
bpf(BPF_RAW_TRACEPOINT_OPEN) to attach to those tracepoints.
Signed-off-by: Matt Mullins <mmullins@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Quentin Monnet says:
====================
This series focus on mounting (or not mounting) tracefs with bpftool.
First patch makes bpftool attempt to mount tracefs if tracefs is not
found when running "bpftool prog tracelog".
Second patch adds an option to bpftool to prevent it from attempting
to mount any file system (tracefs or bpffs), in case this behaviour
is undesirable for some users.
====================
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
In order to make life easier for users, bpftool automatically attempts
to mount the BPF virtual file system, if it is not mounted already,
before trying to pin objects in it. Similarly, it attempts to mount
tracefs if necessary before trying to dump the trace pipe to the
console.
While mounting file systems on-the-fly can improve user experience, some
administrators might prefer to avoid that. Let's add an option to block
these mount attempts. Note that it does not prevent automatic mounting
of tracefs by debugfs for the "bpftool prog tracelog" command.
Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
As a follow-up to commit 30da46b5dc ("tools: bpftool: add a command to
dump the trace pipe"), attempt to mount the tracefs virtual file system
if it is not detected on the system before trying to dump content of the
tracing pipe on an invocation of "bpftool prog tracelog".
Usually, tracefs in automatically mounted by debugfs when the user tries
to access it (e.g. "ls /sys/kernel/debug/tracing" mounts the tracefs).
So if we failed to find it, it is probably that debugfs is not here
either. Therefore, we just attempt a single mount, at a location that
does not involve debugfs: /sys/kernel/tracing.
Suggested-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Current btf func_info, line_info and jited_line are designed to be
extensible. The record sizes for {func,line}_info are passed to kernel,
and the record sizes for {func,line,jited_line}_info are returned to
userspace during bpf_prog_info query.
In bpf selftests test_btf.c, when testing whether kernel returns
a legitimate {func,line, jited_line)_info rec_size, the test only
compares to the minimum allowed size. If the returned rec_size is smaller
than the minimum allowed size, it is considered incorrect.
The minimum allowed size for these three info sizes are equal to
current value of sizeof(struct bpf_func_info), sizeof(struct bpf_line_info)
and sizeof(__u64).
The original thinking was that in the future when rec_size is increased
in kernel, the same test should run correctly. But this sacrificed
the precision of testing under the very kernel the test is shipped with,
and bpf selftest is typically run with the same repo kernel.
So this patch changed the testing of rec_size such that the
kernel returned value should be equal to the size defined by
tools uapi header bpf.h which syncs with kernel uapi header.
Martin discovered a bug in one of rec_size comparisons.
Instead of comparing to minimum func_info rec_size 8, it compares to 4.
This patch fixed that issue as well.
Fixes: 999d82cbc0 ("tools/bpf: enhance test_btf file testing to test func info")
Fixes: 05687352c6 ("bpf: Refactor and bug fix in test_func_type in test_btf.c")
Fixes: 4d6304c763 ("bpf: Add unit tests for bpf_line_info")
Suggested-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This patch fixes a memory leak in libbpf by freeing up line_info
member of struct bpf_program while unloading a program.
Fixes: 3d65014146 ("bpf: libbpf: Add btf_line_info support to libbpf")
Signed-off-by: Prashant Bhole <bhole_prashant_q7@lab.ntt.co.jp>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Yonghong Song says:
====================
Commit 69b693f0ae ("bpf: btf: Introduce BPF Type Format (BTF)")
introduced BTF, a debug info format for BTF.
The original design has a couple of issues though.
First, the bitfield size is only encoded in int type.
If the struct member bitfield type is enum, pahole ([1])
or llvm is forced to replace enum with int type. As a result, the original
type information gets lost.
Second, the original BTF design does not envision the possibility of
BTF=>header_file conversion ([2]), hence does not encode "struct" or
"union" info for a forward type. Such information is necessary to
convert BTF to a header file.
This patch set fixed the issue by introducing kind_flag, using one bit
in type->info. When kind_flag, the struct/union btf_member->offset
will encode both bitfield_size and bit_offset, covering both
int and enum base types. The kind_flag is also used to indicate whether
the forward type is a union (when set) or a struct.
Patch #1 refactors function btf_int_bits_seq_show() so Patch #2
can reuse part of the function.
Patch #2 implemented kind_flag support for struct/union/fwd types.
Patch #3 added kind_flag support for cgroup local storage map pretty print.
Patch #4 syncs kernel uapi btf.h to tools directory.
Patch #5 added unit tests for kind_flag.
Patch #6 added tests for kernel bpffs based pretty print with kind_flag.
Patch #7 refactors function btf_dumper_int_bits() so Patch #8
can reuse part of the function.
Patch #8 added bpftool support of pretty print with kind_flag set.
[1] https://git.kernel.org/pub/scm/devel/pahole/pahole.git/commit/?id=b18354f64cc215368c3bc0df4a7e5341c55c378c
[2] https://lwn.net/SubscriberLink/773198/fe3074838f5c3f26/
Change logs:
v2 -> v3:
. Relocated comments about bitfield_size/bit_offset interpretation
of the "offset" field right before the "offset" struct member.
. Added missing byte alignment checking for non-bitfield enum
member of a struct with kind_flag set.
. Added two test cases in unit tests for struct type, kind_flag set,
non-bitfield int/enum member, not-byte aligned bit offsets.
. Added comments to help understand there is no overflow for
total_bits_offset in bpftool function btf_dumper_int_bits().
. Added explanation of typedef type dumping fix in Patch #8 commit
message.
v1 -> v2:
. If kind_flag is set for a structure, ensure an int member,
whether it is a bitfield or not, is a regular int type.
. Added support so cgroup local storage map pretty print
works with kind_flag.
====================
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
The following example shows map pretty print with structures
which include bitfield members.
enum A { A1, A2, A3, A4, A5 };
typedef enum A ___A;
struct tmp_t {
char a1:4;
int a2:4;
int :4;
__u32 a3:4;
int b;
___A b1:4;
enum A b2:4;
};
struct bpf_map_def SEC("maps") tmpmap = {
.type = BPF_MAP_TYPE_ARRAY,
.key_size = sizeof(__u32),
.value_size = sizeof(struct tmp_t),
.max_entries = 1,
};
BPF_ANNOTATE_KV_PAIR(tmpmap, int, struct tmp_t);
and the following map update in the bpf program:
key = 0;
struct tmp_t t = {};
t.a1 = 2;
t.a2 = 4;
t.a3 = 6;
t.b = 7;
t.b1 = 8;
t.b2 = 10;
bpf_map_update_elem(&tmpmap, &key, &t, 0);
With this patch, I am able to print out the map values
correctly with this patch:
bpftool map dump id 187
[{
"key": 0,
"value": {
"a1": 0x2,
"a2": 0x4,
"a3": 0x6,
"b": 7,
"b1": 0x8,
"b2": 0xa
}
}
]
Previously, if a function prototype argument has a typedef
type, the prototype is not printed since
function __btf_dumper_type_only() bailed out with error
if the type is a typedef. This commit corrected this
behavior by printing out typedef properly.
The following example shows forward type and
typedef type can be properly printed in function prototype
with modified test_btf_haskv.c.
struct t;
union u;
__attribute__((noinline))
static int test_long_fname_1(struct dummy_tracepoint_args *arg,
struct t *p1, union u *p2,
__u32 unused)
...
int _dummy_tracepoint(struct dummy_tracepoint_args *arg) {
return test_long_fname_1(arg, 0, 0, 0);
}
$ bpftool p d xlated id 24
...
int test_long_fname_1(struct dummy_tracepoint_args * arg,
struct t * p1, union u * p2,
__u32 unused)
...
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
The core dump funcitonality in btf_dumper_int_bits() is
refactored into a separate function btf_dumper_bitfield()
which will be used by the next patch.
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
The new tests are added to test bpffs map pretty print in kernel with kind_flag
for structure type.
$ test_btf -p
......
BTF pretty print array(#1)......OK
BTF pretty print array(#2)......OK
PASS:8 SKIP:0 FAIL:0
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This patch added unit tests for different types handling
type->info.kind_flag. The following new tests are added:
$ test_btf
...
BTF raw test[82] (invalid int kind_flag): OK
BTF raw test[83] (invalid ptr kind_flag): OK
BTF raw test[84] (invalid array kind_flag): OK
BTF raw test[85] (invalid enum kind_flag): OK
BTF raw test[86] (valid fwd kind_flag): OK
BTF raw test[87] (invalid typedef kind_flag): OK
BTF raw test[88] (invalid volatile kind_flag): OK
BTF raw test[89] (invalid const kind_flag): OK
BTF raw test[90] (invalid restrict kind_flag): OK
BTF raw test[91] (invalid func kind_flag): OK
BTF raw test[92] (invalid func_proto kind_flag): OK
BTF raw test[93] (valid struct kind_flag, bitfield_size = 0): OK
BTF raw test[94] (valid struct kind_flag, int member, bitfield_size != 0): OK
BTF raw test[95] (valid union kind_flag, int member, bitfield_size != 0): OK
BTF raw test[96] (valid struct kind_flag, enum member, bitfield_size != 0): OK
BTF raw test[97] (valid union kind_flag, enum member, bitfield_size != 0): OK
BTF raw test[98] (valid struct kind_flag, typedef member, bitfield_size != 0): OK
BTF raw test[99] (valid union kind_flag, typedef member, bitfield_size != 0): OK
BTF raw test[100] (invalid struct type, bitfield_size greater than struct size): OK
BTF raw test[101] (invalid struct type, kind_flag bitfield base_type int not regular): OK
BTF raw test[102] (invalid struct type, kind_flag base_type int not regular): OK
BTF raw test[103] (invalid union type, bitfield_size greater than struct size): OK
...
PASS:122 SKIP:0 FAIL:0
The second parameter name of macro
BTF_INFO_ENC(kind, root, vlen)
in selftests test_btf.c is also renamed from "root" to "kind_flag".
Note that before this patch "root" is not used and always 0.
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Sync include/uapi/linux/btf.h to tools/include/uapi/linux/btf.h.
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Commit 970289fc0a83 ("bpf: add bpffs pretty print for cgroup
local storage maps") added bpffs pretty print for cgroup
local storage maps. The commit worked for struct without kind_flag
set.
This patch refactored and made pretty print also work
with kind_flag set for the struct.
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This patch fixed two issues with BTF. One is related to
struct/union bitfield encoding and the other is related to
forward type.
Issue #1 and solution:
======================
Current btf encoding of bitfield follows what pahole generates.
For each bitfield, pahole will duplicate the type chain and
put the bitfield size at the final int or enum type.
Since the BTF enum type cannot encode bit size,
pahole workarounds the issue by generating
an int type whenever the enum bit size is not 32.
For example,
-bash-4.4$ cat t.c
typedef int ___int;
enum A { A1, A2, A3 };
struct t {
int a[5];
___int b:4;
volatile enum A c:4;
} g;
-bash-4.4$ gcc -c -O2 -g t.c
The current kernel supports the following BTF encoding:
$ pahole -JV t.o
[1] TYPEDEF ___int type_id=2
[2] INT int size=4 bit_offset=0 nr_bits=32 encoding=SIGNED
[3] ENUM A size=4 vlen=3
A1 val=0
A2 val=1
A3 val=2
[4] STRUCT t size=24 vlen=3
a type_id=5 bits_offset=0
b type_id=9 bits_offset=160
c type_id=11 bits_offset=164
[5] ARRAY (anon) type_id=2 index_type_id=2 nr_elems=5
[6] INT sizetype size=8 bit_offset=0 nr_bits=64 encoding=(none)
[7] VOLATILE (anon) type_id=3
[8] INT int size=1 bit_offset=0 nr_bits=4 encoding=(none)
[9] TYPEDEF ___int type_id=8
[10] INT (anon) size=1 bit_offset=0 nr_bits=4 encoding=SIGNED
[11] VOLATILE (anon) type_id=10
Two issues are in the above:
. by changing enum type to int, we lost the original
type information and this will not be ideal later
when we try to convert BTF to a header file.
. the type duplication for bitfields will cause
BTF bloat. Duplicated types cannot be deduplicated
later if the bitfield size is different.
To fix this issue, this patch implemented a compatible
change for BTF struct type encoding:
. the bit 31 of struct_type->info, previously reserved,
now is used to indicate whether bitfield_size is
encoded in btf_member or not.
. if bit 31 of struct_type->info is set,
btf_member->offset will encode like:
bit 0 - 23: bit offset
bit 24 - 31: bitfield size
if bit 31 is not set, the old behavior is preserved:
bit 0 - 31: bit offset
So if the struct contains a bit field, the maximum bit offset
will be reduced to (2^24 - 1) instead of MAX_UINT. The maximum
bitfield size will be 256 which is enough for today as maximum
bitfield in compiler can be 128 where int128 type is supported.
This kernel patch intends to support the new BTF encoding:
$ pahole -JV t.o
[1] TYPEDEF ___int type_id=2
[2] INT int size=4 bit_offset=0 nr_bits=32 encoding=SIGNED
[3] ENUM A size=4 vlen=3
A1 val=0
A2 val=1
A3 val=2
[4] STRUCT t kind_flag=1 size=24 vlen=3
a type_id=5 bitfield_size=0 bits_offset=0
b type_id=1 bitfield_size=4 bits_offset=160
c type_id=7 bitfield_size=4 bits_offset=164
[5] ARRAY (anon) type_id=2 index_type_id=2 nr_elems=5
[6] INT sizetype size=8 bit_offset=0 nr_bits=64 encoding=(none)
[7] VOLATILE (anon) type_id=3
Issue #2 and solution:
======================
Current forward type in BTF does not specify whether the original
type is struct or union. This will not work for type pretty print
and BTF-to-header-file conversion as struct/union must be specified.
$ cat tt.c
struct t;
union u;
int foo(struct t *t, union u *u) { return 0; }
$ gcc -c -g -O2 tt.c
$ pahole -JV tt.o
[1] INT int size=4 bit_offset=0 nr_bits=32 encoding=SIGNED
[2] FWD t type_id=0
[3] PTR (anon) type_id=2
[4] FWD u type_id=0
[5] PTR (anon) type_id=4
To fix this issue, similar to issue #1, type->info bit 31
is used. If the bit is set, it is union type. Otherwise, it is
a struct type.
$ pahole -JV tt.o
[1] INT int size=4 bit_offset=0 nr_bits=32 encoding=SIGNED
[2] FWD t kind_flag=0 type_id=0
[3] PTR (anon) kind_flag=0 type_id=2
[4] FWD u kind_flag=1 type_id=0
[5] PTR (anon) kind_flag=0 type_id=4
Pahole/LLVM change:
===================
The new kind_flag functionality has been implemented in pahole
and llvm:
https://github.com/yonghong-song/pahole/tree/bitfieldhttps://github.com/yonghong-song/llvm/tree/bitfield
Note that pahole hasn't implemented func/func_proto kind
and .BTF.ext. So to print function signature with bpftool,
the llvm compiler should be used.
Fixes: 69b693f0ae ("bpf: btf: Introduce BPF Type Format (BTF)")
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Refactor function btf_int_bits_seq_show() by creating
function btf_bitfield_seq_show() which has no dependence
on btf and btf_type. The function btf_bitfield_seq_show()
will be in later patch to directly dump bitfield member values.
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Existing libraries and tracing frameworks work around this kernel
version check by automatically deriving the kernel version from
uname(3) or similar such that the user does not need to do it
manually; these workarounds also make the version check useless
at the same time.
Moreover, most other BPF tracing types enabling bpf_probe_read()-like
functionality have /not/ adapted this check, and in general these
days it is well understood anyway that all the tracing programs are
not stable with regards to future kernels as kernel internal data
structures are subject to change from release to release.
Back at last netconf we discussed [0] and agreed to remove this
check from bpf_prog_load() and instead document it here in the uapi
header that there is no such guarantee for stable API for these
programs.
[0] http://vger.kernel.org/netconf2018_files/DanielBorkmann_netconf2018.pdf
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Quentin Monnet says:
====================
This series contains several minor fixes for bpftool source and
documentation.
The first patches focus on documentation: addition of an option in the page
for "bpftool prog", clean up and update of the same page, and addition of
an example of prog array map manipulation in "bpftool map" page.
The last two fix warnings susceptible to appear when libbfd is not present
(patch 4), or with additional warning flags passed to the compiler (last
patch).
====================
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Help compiler check arguments for several utility functions used to
print items to the console by adding the "printf" attribute when
declaring those functions.
Also, declare as "static" two functions that are only used in prog.c.
All of them discovered by compiling bpftool with
-Wmissing-format-attribute -Wmissing-declarations.
Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
The following warning appears when compiling bpftool without BFD
support:
main.h:198:23: warning: 'struct bpf_prog_linfo' declared inside
parameter list will not be visible outside of this definition or
declaration
const struct bpf_prog_linfo *prog_linfo,
Fix it by declaring struct bpf_prog_linfo even in the case BFD is not
supported.
Fixes: b053b439b7 ("bpf: libbpf: bpftool: Print bpf_line_info during prog dump")
Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Add an example in map documentation to show how to use bpftool in order
to update the references to programs hold by prog array maps.
Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Bring various fixes to the manual page for "bpftool prog" set of
commands:
- Fix typos ("dum" -> "dump")
- Harmonise indentation and format for command output
- Update date format for program load time
- Add instruction numbers on program dumps
- Fix JSON format for the example program listing
Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
The --mapcompat|-m option has been documented on the main bpftool.rst
page, and on the interactive help. As this option is useful for loading
programs with maps with the "bpftool prog load" command, it should also
appear in the related bpftool-prog.rst documentation page. Let's add it.
Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Alexei Starovoitov says:
====================
v1->v2:
With optimization suggested by Jakub patch 4 safety check became
cheap enough.
Several improvements to verifier state logic.
Patch 1 - trivial optimization
Patch 3 - significant optimization for stack state equivalence
Patch 4 - safety check for liveness and prep for future state merging
====================
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Introduce REG_LIVE_DONE to check the liveness propagation
and prepare the states for merging.
See algorithm description in clean_live_states().
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
"if (old->allocated_stack > cur->allocated_stack)" check is too conservative.
In some cases explored stack could have allocated more space,
but that stack space was not live.
The test case improves from 19 to 15 processed insns
and improvement on real programs is significant as well:
before after
bpf_lb-DLB_L3.o 1940 1831
bpf_lb-DLB_L4.o 3089 3029
bpf_lb-DUNKNOWN.o 1065 1064
bpf_lxc-DDROP_ALL.o 28052 26309
bpf_lxc-DUNKNOWN.o 35487 33517
bpf_netdev.o 10864 9713
bpf_overlay.o 6643 6184
bpf_lcx_jit.o 38437 37335
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Edward Cree <ecree@solarflare.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Teach test_verifier to parse verifier output for insn processed
and compare with expected number.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Edward Cree <ecree@solarflare.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Don't check the same stack liveness condition 8 times.
once is enough.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Edward Cree <ecree@solarflare.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Martin Lau says:
====================
This patch set provides bpf_line_info during the verifier's verbose
log. Please see individual patch for details.
====================
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This patch adds bpf_line_info during the verifier's verbose.
It can give error context for debug purpose.
~~~~~~~~~~
Here is the verbose log for backedge:
while (a) {
a += bpf_get_smp_processor_id();
bpf_trace_printk(fmt, sizeof(fmt), a);
}
~> bpftool prog load ./test_loop.o /sys/fs/bpf/test_loop type tracepoint
13: while (a) {
3: a += bpf_get_smp_processor_id();
back-edge from insn 13 to 3
~~~~~~~~~~
Here is the verbose log for invalid pkt access:
Modification to test_xdp_noinline.c:
data = (void *)(long)xdp->data;
data_end = (void *)(long)xdp->data_end;
/*
if (data + 4 > data_end)
return XDP_DROP;
*/
*(u32 *)data = dst->dst;
~> bpftool prog load ./test_xdp_noinline.o /sys/fs/bpf/test_xdp_noinline type xdp
; data = (void *)(long)xdp->data;
224: (79) r2 = *(u64 *)(r10 -112)
225: (61) r2 = *(u32 *)(r2 +0)
; *(u32 *)data = dst->dst;
226: (63) *(u32 *)(r2 +0) = r1
invalid access to packet, off=0 size=4, R2(id=0,off=0,r=0)
R2 offset is outside of the packet
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The current btf_name_by_offset() is returning "(anon)" type name for
the offset == 0 case and "(invalid-name-offset)" for the out-of-bound
offset case.
It fits well for the internal BTF verbose log purpose which
is focusing on type. For example,
offset == 0 => "(anon)" => anonymous type/name.
Returning non-NULL for the bad offset case is needed
during the BTF verification process because the BTF verifier may
complain about another field first before discovering the name_off
is invalid.
However, it may not be ideal for the newer use case which does not
necessary mean type name. For example, when logging line_info
in the BPF verifier in the next patch, it is better to log an
empty src line instead of logging "(anon)".
The existing bpf_name_by_offset() is renamed to __bpf_name_by_offset()
and static to btf.c.
A new bpf_name_by_offset() is added for generic context usage. It
returns "\0" for name_off == 0 (note that btf->strings[0] is "\0")
and NULL for invalid offset. It allows the caller to decide
what is the best output in its context.
The new btf_name_by_offset() is overlapped with btf_name_offset_valid().
Hence, btf_name_offset_valid() is removed from btf.h to keep the btf.h API
minimal. The existing btf_name_offset_valid() usage in btf.c could also be
replaced later.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Semantic of netns_id argument of bpf_sk_lookup_tcp and bpf_sk_lookup_udp
was changed (fixed) in f71c6143c2. Corresponding changes have to be
applied to all call sites in selftests. The patch fixes corresponding
call sites in test_sock_addr test: pass BPF_F_CURRENT_NETNS instead of 0
in netns_id argument.
Fixes: f71c6143c2 ("bpf: Support sk lookup in netns with id 0")
Reported-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Andrey Ignatov <rdna@fb.com>
Acked-by: Joe Stringer <joe@wand.net.nz>
Tested-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This logic is not needed anymore since we got rid of the verifier
rewrite that was using prog->aux address in f6069b9aa9 ("bpf:
fix redirect to map under tail calls").
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Sync bpf.h for nr_prog_tags and prog_tags.
Signed-off-by: Song Liu <songliubraving@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Changes v2 -> v3:
1. remove check for bpf_dump_raw_ok().
Changes v1 -> v2:
1. Fix error path as Martin suggested.
This patch adds nr_prog_tags and prog_tags to bpf_prog_info. This is a
reliable way for user space to get tags of all sub programs. Before this
patch, user space need to find sub program tags via kallsyms.
This feature will be used in BPF introspection, where user space queries
information about BPF programs via sys_bpf.
Signed-off-by: Song Liu <songliubraving@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Martin KaFai Lau says:
====================
This patch set removes the bpf_dump_raw_ok() guard for the func_info
and line_info during bpf_prog_get_info_by_fd().
====================
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
kernel can provide the func_info and line_info even
it fails the btf_dump_raw_ok() test because they don't contain
kernel address. This patch removes the corresponding '== 0'
test.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
The func_info and line_info have the bpf insn offset but
they do not contain kernel address. They will still be useful
for the userspace tool to annotate the xlated insn.
This patch removes the bpf_dump_raw_ok() guard for the
func_info and line_info during bpf_prog_get_info_by_fd().
The guard stays for jited_line_info which contains the kernel
address.
Although this bpf_dump_raw_ok() guard behavior has started since
the earlier func_info patch series, I marked the Fixes tag to the
latest line_info patch series which contains both func_info and
line_info and this patch is fixing for both of them.
Fixes: c454a46b5e ("bpf: Add bpf_line_info support")
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Jakub Kicinski says:
====================
We are changing/clarifying the license on bpftool to GPLv2-only +
BSD-2-Clause for all files. Current license mix is incompatible
with libbfd (which is GPLv3-only) and therefore Debian maintainers
are apprehensive about packaging bpftool.
Acks include authors of code which has been copied into bpftool (e.g.
JSON writer from iproute2, code from tools/bpf, code from BPF samples
and selftests, etc.)
Thanks again to all the authors who acked the change!
====================
Acked-by: Roman Gushchin <guro@fb.com>
Acked-by: YueHaibing <yuehaibing@huawei.com>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Stanislav Fomichev <sdf@google.com>
Acked-by: Sean Young <sean@mess.org>
Acked-by: Jiri Benc <jbenc@redhat.com>
Acked-by: David Calavera <david.calavera@gmail.com>
Acked-by: Andrey Ignatov <rdna@fb.com>
Acked-by: Joe Stringer <joe@wand.net.nz>
Acked-by: David Ahern <dsahern@gmail.com>
Acked-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Acked-by: Petar Penkov <ppenkov@stanford.edu>
Acked-by: Sandipan Das <sandipan@linux.ibm.com>
Acked-by: Prashant Bhole <bhole_prashant_q7@lab.ntt.co.jp>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Taeung Song <treeze.taeung@gmail.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
CC: okash.khawaja@gmail.com
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Currently bpftool contains a mix of GPL-only and GPL or BSD2
licensed files. Make sure all files are dual licensed under
GPLv2 and BSD-2-Clause.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Roman Gushchin <guro@fb.com>
Acked-by: YueHaibing <yuehaibing@huawei.com>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Stanislav Fomichev <sdf@google.com>
Acked-by: Sean Young <sean@mess.org>
Acked-by: Jiri Benc <jbenc@redhat.com>
Acked-by: David Calavera <david.calavera@gmail.com>
Acked-by: Andrey Ignatov <rdna@fb.com>
Acked-by: Joe Stringer <joe@wand.net.nz>
Acked-by: David Ahern <dsahern@gmail.com>
Acked-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Acked-by: Petar Penkov <ppenkov@stanford.edu>
Acked-by: Sandipan Das <sandipan@linux.ibm.com>
Acked-by: Prashant Bhole <bhole_prashant_q7@lab.ntt.co.jp>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Taeung Song <treeze.taeung@gmail.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
CC: okash.khawaja@gmail.com
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
