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0d4fad3e57
564 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Yonghong Song
|
0d4fad3e57 |
bpf: Add bpf_skc_to_udp6_sock() helper
The helper is used in tracing programs to cast a socket pointer to a udp6_sock pointer. The return value could be NULL if the casting is illegal. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Cc: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/bpf/20200623230815.3988481-1-yhs@fb.com |
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Yonghong Song
|
478cfbdf5f |
bpf: Add bpf_skc_to_{tcp, tcp_timewait, tcp_request}_sock() helpers
Three more helpers are added to cast a sock_common pointer to an tcp_sock, tcp_timewait_sock or a tcp_request_sock for tracing programs. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20200623230811.3988277-1-yhs@fb.com |
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Yonghong Song
|
af7ec13833 |
bpf: Add bpf_skc_to_tcp6_sock() helper
The helper is used in tracing programs to cast a socket pointer to a tcp6_sock pointer. The return value could be NULL if the casting is illegal. A new helper return type RET_PTR_TO_BTF_ID_OR_NULL is added so the verifier is able to deduce proper return types for the helper. Different from the previous BTF_ID based helpers, the bpf_skc_to_tcp6_sock() argument can be several possible btf_ids. More specifically, all possible socket data structures with sock_common appearing in the first in the memory layout. This patch only added socket types related to tcp and udp. All possible argument btf_id and return value btf_id for helper bpf_skc_to_tcp6_sock() are pre-calculcated and cached. In the future, it is even possible to precompute these btf_id's at kernel build time. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20200623230809.3988195-1-yhs@fb.com |
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Dmitry Yakunin
|
f9bcf96837 |
bpf: Add SO_KEEPALIVE and related options to bpf_setsockopt
This patch adds support of SO_KEEPALIVE flag and TCP related options to bpf_setsockopt() routine. This is helpful if we want to enable or tune TCP keepalive for applications which don't do it in the userspace code. v3: - update kernel-doc in uapi (Nikita Vetoshkin <nekto0n@yandex-team.ru>) v4: - update kernel-doc in tools too (Alexei Starovoitov) - add test to selftests (Alexei Starovoitov) Signed-off-by: Dmitry Yakunin <zeil@yandex-team.ru> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20200620153052.9439-3-zeil@yandex-team.ru |
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Alexei Starovoitov
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4e608675e7 | Merge up to bpf_probe_read_kernel_str() fix into bpf-next | ||
Andrii Nakryiko
|
bdb7b79b4c |
bpf: Switch most helper return values from 32-bit int to 64-bit long
Switch most of BPF helper definitions from returning int to long. These
definitions are coming from comments in BPF UAPI header and are used to
generate bpf_helper_defs.h (under libbpf) to be later included and used from
BPF programs.
In actual in-kernel implementation, all the helpers are defined as returning
u64, but due to some historical reasons, most of them are actually defined as
returning int in UAPI (usually, to return 0 on success, and negative value on
error).
This actually causes Clang to quite often generate sub-optimal code, because
compiler believes that return value is 32-bit, and in a lot of cases has to be
up-converted (usually with a pair of 32-bit bit shifts) to 64-bit values,
before they can be used further in BPF code.
Besides just "polluting" the code, these 32-bit shifts quite often cause
problems for cases in which return value matters. This is especially the case
for the family of bpf_probe_read_str() functions. There are few other similar
helpers (e.g., bpf_read_branch_records()), in which return value is used by
BPF program logic to record variable-length data and process it. For such
cases, BPF program logic carefully manages offsets within some array or map to
read variable-length data. For such uses, it's crucial for BPF verifier to
track possible range of register values to prove that all the accesses happen
within given memory bounds. Those extraneous zero-extending bit shifts,
inserted by Clang (and quite often interleaved with other code, which makes
the issues even more challenging and sometimes requires employing extra
per-variable compiler barriers), throws off verifier logic and makes it mark
registers as having unknown variable offset. We'll study this pattern a bit
later below.
Another common pattern is to check return of BPF helper for non-zero state to
detect error conditions and attempt alternative actions in such case. Even in
this simple and straightforward case, this 32-bit vs BPF's native 64-bit mode
quite often leads to sub-optimal and unnecessary extra code. We'll look at
this pattern as well.
Clang's BPF target supports two modes of code generation: ALU32, in which it
is capable of using lower 32-bit parts of registers, and no-ALU32, in which
only full 64-bit registers are being used. ALU32 mode somewhat mitigates the
above described problems, but not in all cases.
This patch switches all the cases in which BPF helpers return 0 or negative
error from returning int to returning long. It is shown below that such change
in definition leads to equivalent or better code. No-ALU32 mode benefits more,
but ALU32 mode doesn't degrade or still gets improved code generation.
Another class of cases switched from int to long are bpf_probe_read_str()-like
helpers, which encode successful case as non-negative values, while still
returning negative value for errors.
In all of such cases, correctness is preserved due to two's complement
encoding of negative values and the fact that all helpers return values with
32-bit absolute value. Two's complement ensures that for negative values
higher 32 bits are all ones and when truncated, leave valid negative 32-bit
value with the same value. Non-negative values have upper 32 bits set to zero
and similarly preserve value when high 32 bits are truncated. This means that
just casting to int/u32 is correct and efficient (and in ALU32 mode doesn't
require any extra shifts).
To minimize the chances of regressions, two code patterns were investigated,
as mentioned above. For both patterns, BPF assembly was analyzed in
ALU32/NO-ALU32 compiler modes, both with current 32-bit int return type and
new 64-bit long return type.
Case 1. Variable-length data reading and concatenation. This is quite
ubiquitous pattern in tracing/monitoring applications, reading data like
process's environment variables, file path, etc. In such case, many pieces of
string-like variable-length data are read into a single big buffer, and at the
end of the process, only a part of array containing actual data is sent to
user-space for further processing. This case is tested in test_varlen.c
selftest (in the next patch). Code flow is roughly as follows:
void *payload = &sample->payload;
u64 len;
len = bpf_probe_read_kernel_str(payload, MAX_SZ1, &source_data1);
if (len <= MAX_SZ1) {
payload += len;
sample->len1 = len;
}
len = bpf_probe_read_kernel_str(payload, MAX_SZ2, &source_data2);
if (len <= MAX_SZ2) {
payload += len;
sample->len2 = len;
}
/* and so on */
sample->total_len = payload - &sample->payload;
/* send over, e.g., perf buffer */
There could be two variations with slightly different code generated: when len
is 64-bit integer and when it is 32-bit integer. Both variations were analysed.
BPF assembly instructions between two successive invocations of
bpf_probe_read_kernel_str() were used to check code regressions. Results are
below, followed by short analysis. Left side is using helpers with int return
type, the right one is after the switch to long.
ALU32 + INT ALU32 + LONG
=========== ============
64-BIT (13 insns): 64-BIT (10 insns):
------------------------------------ ------------------------------------
17: call 115 17: call 115
18: if w0 > 256 goto +9 <LBB0_4> 18: if r0 > 256 goto +6 <LBB0_4>
19: w1 = w0 19: r1 = 0 ll
20: r1 <<= 32 21: *(u64 *)(r1 + 0) = r0
21: r1 s>>= 32 22: r6 = 0 ll
22: r2 = 0 ll 24: r6 += r0
24: *(u64 *)(r2 + 0) = r1 00000000000000c8 <LBB0_4>:
25: r6 = 0 ll 25: r1 = r6
27: r6 += r1 26: w2 = 256
00000000000000e0 <LBB0_4>: 27: r3 = 0 ll
28: r1 = r6 29: call 115
29: w2 = 256
30: r3 = 0 ll
32: call 115
32-BIT (11 insns): 32-BIT (12 insns):
------------------------------------ ------------------------------------
17: call 115 17: call 115
18: if w0 > 256 goto +7 <LBB1_4> 18: if w0 > 256 goto +8 <LBB1_4>
19: r1 = 0 ll 19: r1 = 0 ll
21: *(u32 *)(r1 + 0) = r0 21: *(u32 *)(r1 + 0) = r0
22: w1 = w0 22: r0 <<= 32
23: r6 = 0 ll 23: r0 >>= 32
25: r6 += r1 24: r6 = 0 ll
00000000000000d0 <LBB1_4>: 26: r6 += r0
26: r1 = r6 00000000000000d8 <LBB1_4>:
27: w2 = 256 27: r1 = r6
28: r3 = 0 ll 28: w2 = 256
30: call 115 29: r3 = 0 ll
31: call 115
In ALU32 mode, the variant using 64-bit length variable clearly wins and
avoids unnecessary zero-extension bit shifts. In practice, this is even more
important and good, because BPF code won't need to do extra checks to "prove"
that payload/len are within good bounds.
32-bit len is one instruction longer. Clang decided to do 64-to-32 casting
with two bit shifts, instead of equivalent `w1 = w0` assignment. The former
uses extra register. The latter might potentially lose some range information,
but not for 32-bit value. So in this case, verifier infers that r0 is [0, 256]
after check at 18:, and shifting 32 bits left/right keeps that range intact.
We should probably look into Clang's logic and see why it chooses bitshifts
over sub-register assignments for this.
NO-ALU32 + INT NO-ALU32 + LONG
============== ===============
64-BIT (14 insns): 64-BIT (10 insns):
------------------------------------ ------------------------------------
17: call 115 17: call 115
18: r0 <<= 32 18: if r0 > 256 goto +6 <LBB0_4>
19: r1 = r0 19: r1 = 0 ll
20: r1 >>= 32 21: *(u64 *)(r1 + 0) = r0
21: if r1 > 256 goto +7 <LBB0_4> 22: r6 = 0 ll
22: r0 s>>= 32 24: r6 += r0
23: r1 = 0 ll 00000000000000c8 <LBB0_4>:
25: *(u64 *)(r1 + 0) = r0 25: r1 = r6
26: r6 = 0 ll 26: r2 = 256
28: r6 += r0 27: r3 = 0 ll
00000000000000e8 <LBB0_4>: 29: call 115
29: r1 = r6
30: r2 = 256
31: r3 = 0 ll
33: call 115
32-BIT (13 insns): 32-BIT (13 insns):
------------------------------------ ------------------------------------
17: call 115 17: call 115
18: r1 = r0 18: r1 = r0
19: r1 <<= 32 19: r1 <<= 32
20: r1 >>= 32 20: r1 >>= 32
21: if r1 > 256 goto +6 <LBB1_4> 21: if r1 > 256 goto +6 <LBB1_4>
22: r2 = 0 ll 22: r2 = 0 ll
24: *(u32 *)(r2 + 0) = r0 24: *(u32 *)(r2 + 0) = r0
25: r6 = 0 ll 25: r6 = 0 ll
27: r6 += r1 27: r6 += r1
00000000000000e0 <LBB1_4>: 00000000000000e0 <LBB1_4>:
28: r1 = r6 28: r1 = r6
29: r2 = 256 29: r2 = 256
30: r3 = 0 ll 30: r3 = 0 ll
32: call 115 32: call 115
In NO-ALU32 mode, for the case of 64-bit len variable, Clang generates much
superior code, as expected, eliminating unnecessary bit shifts. For 32-bit
len, code is identical.
So overall, only ALU-32 32-bit len case is more-or-less equivalent and the
difference stems from internal Clang decision, rather than compiler lacking
enough information about types.
Case 2. Let's look at the simpler case of checking return result of BPF helper
for errors. The code is very simple:
long bla;
if (bpf_probe_read_kenerl(&bla, sizeof(bla), 0))
return 1;
else
return 0;
ALU32 + CHECK (9 insns) ALU32 + CHECK (9 insns)
==================================== ====================================
0: r1 = r10 0: r1 = r10
1: r1 += -8 1: r1 += -8
2: w2 = 8 2: w2 = 8
3: r3 = 0 3: r3 = 0
4: call 113 4: call 113
5: w1 = w0 5: r1 = r0
6: w0 = 1 6: w0 = 1
7: if w1 != 0 goto +1 <LBB2_2> 7: if r1 != 0 goto +1 <LBB2_2>
8: w0 = 0 8: w0 = 0
0000000000000048 <LBB2_2>: 0000000000000048 <LBB2_2>:
9: exit 9: exit
Almost identical code, the only difference is the use of full register
assignment (r1 = r0) vs half-registers (w1 = w0) in instruction #5. On 32-bit
architectures, new BPF assembly might be slightly less optimal, in theory. But
one can argue that's not a big issue, given that use of full registers is
still prevalent (e.g., for parameter passing).
NO-ALU32 + CHECK (11 insns) NO-ALU32 + CHECK (9 insns)
==================================== ====================================
0: r1 = r10 0: r1 = r10
1: r1 += -8 1: r1 += -8
2: r2 = 8 2: r2 = 8
3: r3 = 0 3: r3 = 0
4: call 113 4: call 113
5: r1 = r0 5: r1 = r0
6: r1 <<= 32 6: r0 = 1
7: r1 >>= 32 7: if r1 != 0 goto +1 <LBB2_2>
8: r0 = 1 8: r0 = 0
9: if r1 != 0 goto +1 <LBB2_2> 0000000000000048 <LBB2_2>:
10: r0 = 0 9: exit
0000000000000058 <LBB2_2>:
11: exit
NO-ALU32 is a clear improvement, getting rid of unnecessary zero-extension bit
shifts.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200623032224.4020118-1-andriin@fb.com
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Andrii Nakryiko
|
b0659d8a95 |
bpf: Fix definition of bpf_ringbuf_output() helper in UAPI comments
Fix definition of bpf_ringbuf_output() in UAPI header comments, which is used
to generate libbpf's bpf_helper_defs.h header. Return value is a number (error
code), not a pointer.
Fixes:
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Jesper Dangaard Brouer
|
042b1545fe |
bpf: Selftests and tools use struct bpf_devmap_val from uapi
Sync tools uapi bpf.h header file and update selftests that use struct bpf_devmap_val. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/159170951195.2102545.1833108712124273987.stgit@firesoul |
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Linus Torvalds
|
cb8e59cc87 |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next
Pull networking updates from David Miller:
1) Allow setting bluetooth L2CAP modes via socket option, from Luiz
Augusto von Dentz.
2) Add GSO partial support to igc, from Sasha Neftin.
3) Several cleanups and improvements to r8169 from Heiner Kallweit.
4) Add IF_OPER_TESTING link state and use it when ethtool triggers a
device self-test. From Andrew Lunn.
5) Start moving away from custom driver versions, use the globally
defined kernel version instead, from Leon Romanovsky.
6) Support GRO vis gro_cells in DSA layer, from Alexander Lobakin.
7) Allow hard IRQ deferral during NAPI, from Eric Dumazet.
8) Add sriov and vf support to hinic, from Luo bin.
9) Support Media Redundancy Protocol (MRP) in the bridging code, from
Horatiu Vultur.
10) Support netmap in the nft_nat code, from Pablo Neira Ayuso.
11) Allow UDPv6 encapsulation of ESP in the ipsec code, from Sabrina
Dubroca. Also add ipv6 support for espintcp.
12) Lots of ReST conversions of the networking documentation, from Mauro
Carvalho Chehab.
13) Support configuration of ethtool rxnfc flows in bcmgenet driver,
from Doug Berger.
14) Allow to dump cgroup id and filter by it in inet_diag code, from
Dmitry Yakunin.
15) Add infrastructure to export netlink attribute policies to
userspace, from Johannes Berg.
16) Several optimizations to sch_fq scheduler, from Eric Dumazet.
17) Fallback to the default qdisc if qdisc init fails because otherwise
a packet scheduler init failure will make a device inoperative. From
Jesper Dangaard Brouer.
18) Several RISCV bpf jit optimizations, from Luke Nelson.
19) Correct the return type of the ->ndo_start_xmit() method in several
drivers, it's netdev_tx_t but many drivers were using
'int'. From Yunjian Wang.
20) Add an ethtool interface for PHY master/slave config, from Oleksij
Rempel.
21) Add BPF iterators, from Yonghang Song.
22) Add cable test infrastructure, including ethool interfaces, from
Andrew Lunn. Marvell PHY driver is the first to support this
facility.
23) Remove zero-length arrays all over, from Gustavo A. R. Silva.
24) Calculate and maintain an explicit frame size in XDP, from Jesper
Dangaard Brouer.
25) Add CAP_BPF, from Alexei Starovoitov.
26) Support terse dumps in the packet scheduler, from Vlad Buslov.
27) Support XDP_TX bulking in dpaa2 driver, from Ioana Ciornei.
28) Add devm_register_netdev(), from Bartosz Golaszewski.
29) Minimize qdisc resets, from Cong Wang.
30) Get rid of kernel_getsockopt and kernel_setsockopt in order to
eliminate set_fs/get_fs calls. From Christoph Hellwig.
* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2517 commits)
selftests: net: ip_defrag: ignore EPERM
net_failover: fixed rollback in net_failover_open()
Revert "tipc: Fix potential tipc_aead refcnt leak in tipc_crypto_rcv"
Revert "tipc: Fix potential tipc_node refcnt leak in tipc_rcv"
vmxnet3: allow rx flow hash ops only when rss is enabled
hinic: add set_channels ethtool_ops support
selftests/bpf: Add a default $(CXX) value
tools/bpf: Don't use $(COMPILE.c)
bpf, selftests: Use bpf_probe_read_kernel
s390/bpf: Use bcr 0,%0 as tail call nop filler
s390/bpf: Maintain 8-byte stack alignment
selftests/bpf: Fix verifier test
selftests/bpf: Fix sample_cnt shared between two threads
bpf, selftests: Adapt cls_redirect to call csum_level helper
bpf: Add csum_level helper for fixing up csum levels
bpf: Fix up bpf_skb_adjust_room helper's skb csum setting
sfc: add missing annotation for efx_ef10_try_update_nic_stats_vf()
crypto/chtls: IPv6 support for inline TLS
Crypto/chcr: Fixes a coccinile check error
Crypto/chcr: Fixes compilations warnings
...
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Daniel Borkmann
|
7cdec54f97 |
bpf: Add csum_level helper for fixing up csum levels
Add a bpf_csum_level() helper which BPF programs can use in combination
with bpf_skb_adjust_room() when they pass in BPF_F_ADJ_ROOM_NO_CSUM_RESET
flag to the latter to avoid falling back to CHECKSUM_NONE.
The bpf_csum_level() allows to adjust CHECKSUM_UNNECESSARY skb->csum_levels
via BPF_CSUM_LEVEL_{INC,DEC} which calls __skb_{incr,decr}_checksum_unnecessary()
on the skb. The helper also allows a BPF_CSUM_LEVEL_RESET which sets the skb's
csum to CHECKSUM_NONE as well as a BPF_CSUM_LEVEL_QUERY to just return the
current level. Without this helper, there is no way to otherwise adjust the
skb->csum_level. I did not add an extra dummy flags as there is plenty of free
bitspace in level argument itself iff ever needed in future.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Acked-by: Lorenz Bauer <lmb@cloudflare.com>
Link: https://lore.kernel.org/bpf/279ae3717cb3d03c0ffeb511493c93c450a01e1a.1591108731.git.daniel@iogearbox.net
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Daniel Borkmann
|
836e66c218 |
bpf: Fix up bpf_skb_adjust_room helper's skb csum setting
Lorenz recently reported:
In our TC classifier cls_redirect [0], we use the following sequence of
helper calls to decapsulate a GUE (basically IP + UDP + custom header)
encapsulated packet:
bpf_skb_adjust_room(skb, -encap_len, BPF_ADJ_ROOM_MAC, BPF_F_ADJ_ROOM_FIXED_GSO)
bpf_redirect(skb->ifindex, BPF_F_INGRESS)
It seems like some checksums of the inner headers are not validated in
this case. For example, a TCP SYN packet with invalid TCP checksum is
still accepted by the network stack and elicits a SYN ACK. [...]
That is, we receive the following packet from the driver:
| ETH | IP | UDP | GUE | IP | TCP |
skb->ip_summed == CHECKSUM_UNNECESSARY
ip_summed is CHECKSUM_UNNECESSARY because our NICs do rx checksum offloading.
On this packet we run skb_adjust_room_mac(-encap_len), and get the following:
| ETH | IP | TCP |
skb->ip_summed == CHECKSUM_UNNECESSARY
Note that ip_summed is still CHECKSUM_UNNECESSARY. After bpf_redirect()'ing
into the ingress, we end up in tcp_v4_rcv(). There, skb_checksum_init() is
turned into a no-op due to CHECKSUM_UNNECESSARY.
The bpf_skb_adjust_room() helper is not aware of protocol specifics. Internally,
it handles the CHECKSUM_COMPLETE case via skb_postpull_rcsum(), but that does
not cover CHECKSUM_UNNECESSARY. In this case skb->csum_level of the original
skb prior to bpf_skb_adjust_room() call was 0, that is, covering UDP. Right now
there is no way to adjust the skb->csum_level. NICs that have checksum offload
disabled (CHECKSUM_NONE) or that support CHECKSUM_COMPLETE are not affected.
Use a safe default for CHECKSUM_UNNECESSARY by resetting to CHECKSUM_NONE and
add a flag to the helper called BPF_F_ADJ_ROOM_NO_CSUM_RESET that allows users
from opting out. Opting out is useful for the case where we don't remove/add
full protocol headers, or for the case where a user wants to adjust the csum
level manually e.g. through bpf_csum_level() helper that is added in subsequent
patch.
The bpf_skb_proto_{4_to_6,6_to_4}() for NAT64/46 translation from the BPF
bpf_skb_change_proto() helper uses bpf_skb_net_hdr_{push,pop}() pair internally
as well but doesn't change layers, only transitions between v4 to v6 and vice
versa, therefore no adoption is required there.
[0] https://lore.kernel.org/bpf/20200424185556.7358-1-lmb@cloudflare.com/
Fixes:
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Linus Torvalds
|
f359287765 |
Merge branch 'from-miklos' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs updates from Al Viro: "Assorted patches from Miklos. An interesting part here is /proc/mounts stuff..." The "/proc/mounts stuff" is using a cursor for keeeping the location data while traversing the mount listing. Also probably worth noting is the addition of faccessat2(), which takes an additional set of flags to specify how the lookup is done (AT_EACCESS, AT_SYMLINK_NOFOLLOW, AT_EMPTY_PATH). * 'from-miklos' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: vfs: add faccessat2 syscall vfs: don't parse "silent" option vfs: don't parse "posixacl" option vfs: don't parse forbidden flags statx: add mount_root statx: add mount ID statx: don't clear STATX_ATIME on SB_RDONLY uapi: deprecate STATX_ALL utimensat: AT_EMPTY_PATH support vfs: split out access_override_creds() proc/mounts: add cursor aio: fix async fsync creds vfs: allow unprivileged whiteout creation |
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|
Linus Torvalds
|
b23c4771ff |
A fair amount of stuff this time around, dominated by yet another massive
set from Mauro toward the completion of the RST conversion. I *really* hope we are getting close to the end of this. Meanwhile, those patches reach pretty far afield to update document references around the tree; there should be no actual code changes there. There will be, alas, more of the usual trivial merge conflicts. Beyond that we have more translations, improvements to the sphinx scripting, a number of additions to the sysctl documentation, and lots of fixes. -----BEGIN PGP SIGNATURE----- iQFDBAABCAAtFiEEIw+MvkEiF49krdp9F0NaE2wMflgFAl7VId8PHGNvcmJldEBs d24ubmV0AAoJEBdDWhNsDH5Yq/gH/iaDgirQZV6UZ2v9sfwQNYolNpf2sKAuOZjd bPFB7WJoMQbKwQEvYrAUL2+5zPOcLYuIfzyOfo1BV1py+EyKbACcKjI4AedxfJF7 +NchmOBhlEqmEhzx2U08HRc4/8J223WG17fJRVsV3p+opJySexSFeQucfOciX5NR RUCxweWWyg/FgyqjkyMMTtsePqZPmcT5dWTlVXISlbWzcv5NFhuJXnSrw8Sfzcmm SJMzqItv3O+CabnKQ8kMLV2PozXTMfjeWH47ZUK0Y8/8PP9+cvqwFzZ0UDQJ1Xaz oyW/TqmunaXhfMsMFeFGSwtfgwRHvXdxkQdtwNHvo1dV4dzTvDw= =fDC/ -----END PGP SIGNATURE----- Merge tag 'docs-5.8' of git://git.lwn.net/linux Pull documentation updates from Jonathan Corbet: "A fair amount of stuff this time around, dominated by yet another massive set from Mauro toward the completion of the RST conversion. I *really* hope we are getting close to the end of this. Meanwhile, those patches reach pretty far afield to update document references around the tree; there should be no actual code changes there. There will be, alas, more of the usual trivial merge conflicts. Beyond that we have more translations, improvements to the sphinx scripting, a number of additions to the sysctl documentation, and lots of fixes" * tag 'docs-5.8' of git://git.lwn.net/linux: (130 commits) Documentation: fixes to the maintainer-entry-profile template zswap: docs/vm: Fix typo accept_threshold_percent in zswap.rst tracing: Fix events.rst section numbering docs: acpi: fix old http link and improve document format docs: filesystems: add info about efivars content Documentation: LSM: Correct the basic LSM description mailmap: change email for Ricardo Ribalda docs: sysctl/kernel: document unaligned controls Documentation: admin-guide: update bug-hunting.rst docs: sysctl/kernel: document ngroups_max nvdimm: fixes to maintainter-entry-profile Documentation/features: Correct RISC-V kprobes support entry Documentation/features: Refresh the arch support status files Revert "docs: sysctl/kernel: document ngroups_max" docs: move locking-specific documents to locking/ docs: move digsig docs to the security book docs: move the kref doc into the core-api book docs: add IRQ documentation at the core-api book docs: debugging-via-ohci1394.txt: add it to the core-api book docs: fix references for ipmi.rst file ... |
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Jakub Sitnicki
|
7f045a49fe |
bpf: Add link-based BPF program attachment to network namespace
Extend bpf() syscall subcommands that operate on bpf_link, that is LINK_CREATE, LINK_UPDATE, OBJ_GET_INFO, to accept attach types tied to network namespaces (only flow dissector at the moment). Link-based and prog-based attachment can be used interchangeably, but only one can exist at a time. Attempts to attach a link when a prog is already attached directly, and the other way around, will be met with -EEXIST. Attempts to detach a program when link exists result in -EINVAL. Attachment of multiple links of same attach type to one netns is not supported with the intention to lift the restriction when a use-case presents itself. Because of that link create returns -E2BIG when trying to create another netns link, when one already exists. Link-based attachments to netns don't keep a netns alive by holding a ref to it. Instead links get auto-detached from netns when the latter is being destroyed, using a pernet pre_exit callback. When auto-detached, link lives in defunct state as long there are open FDs for it. -ENOLINK is returned if a user tries to update a defunct link. Because bpf_link to netns doesn't hold a ref to struct net, special care is taken when releasing, updating, or filling link info. The netns might be getting torn down when any of these link operations are in progress. That is why auto-detach and update/release/fill_info are synchronized by the same mutex. Also, link ops have to always check if auto-detach has not happened yet and if netns is still alive (refcnt > 0). Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200531082846.2117903-5-jakub@cloudflare.com |
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Alexei Starovoitov
|
df8fe57c07 |
tools/bpf: sync bpf.h
Sync bpf.h into tool/include/uapi/ Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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David Ahern
|
64b59025c1 |
xdp: Add xdp_txq_info to xdp_buff
Add xdp_txq_info as the Tx counterpart to xdp_rxq_info. At the moment only the device is added. Other fields (queue_index) can be added as use cases arise. >From a UAPI perspective, add egress_ifindex to xdp context for bpf programs to see the Tx device. Update the verifier to only allow accesses to egress_ifindex by XDP programs with BPF_XDP_DEVMAP expected attach type. Signed-off-by: David Ahern <dsahern@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://lore.kernel.org/bpf/20200529220716.75383-4-dsahern@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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David Ahern
|
fbee97feed |
bpf: Add support to attach bpf program to a devmap entry
Add BPF_XDP_DEVMAP attach type for use with programs associated with a DEVMAP entry. Allow DEVMAPs to associate a program with a device entry by adding a bpf_prog.fd to 'struct bpf_devmap_val'. Values read show the program id, so the fd and id are a union. bpf programs can get access to the struct via vmlinux.h. The program associated with the fd must have type XDP with expected attach type BPF_XDP_DEVMAP. When a program is associated with a device index, the program is run on an XDP_REDIRECT and before the buffer is added to the per-cpu queue. At this point rxq data is still valid; the next patch adds tx device information allowing the prorgam to see both ingress and egress device indices. XDP generic is skb based and XDP programs do not work with skb's. Block the use case by walking maps used by a program that is to be attached via xdpgeneric and fail if any of them are DEVMAP / DEVMAP_HASH with Block attach of BPF_XDP_DEVMAP programs to devices. Signed-off-by: David Ahern <dsahern@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://lore.kernel.org/bpf/20200529220716.75383-3-dsahern@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Andrii Nakryiko
|
457f44363a |
bpf: Implement BPF ring buffer and verifier support for it
This commit adds a new MPSC ring buffer implementation into BPF ecosystem,
which allows multiple CPUs to submit data to a single shared ring buffer. On
the consumption side, only single consumer is assumed.
Motivation
----------
There are two distinctive motivators for this work, which are not satisfied by
existing perf buffer, which prompted creation of a new ring buffer
implementation.
- more efficient memory utilization by sharing ring buffer across CPUs;
- preserving ordering of events that happen sequentially in time, even
across multiple CPUs (e.g., fork/exec/exit events for a task).
These two problems are independent, but perf buffer fails to satisfy both.
Both are a result of a choice to have per-CPU perf ring buffer. Both can be
also solved by having an MPSC implementation of ring buffer. The ordering
problem could technically be solved for perf buffer with some in-kernel
counting, but given the first one requires an MPSC buffer, the same solution
would solve the second problem automatically.
Semantics and APIs
------------------
Single ring buffer is presented to BPF programs as an instance of BPF map of
type BPF_MAP_TYPE_RINGBUF. Two other alternatives considered, but ultimately
rejected.
One way would be to, similar to BPF_MAP_TYPE_PERF_EVENT_ARRAY, make
BPF_MAP_TYPE_RINGBUF could represent an array of ring buffers, but not enforce
"same CPU only" rule. This would be more familiar interface compatible with
existing perf buffer use in BPF, but would fail if application needed more
advanced logic to lookup ring buffer by arbitrary key. HASH_OF_MAPS addresses
this with current approach. Additionally, given the performance of BPF
ringbuf, many use cases would just opt into a simple single ring buffer shared
among all CPUs, for which current approach would be an overkill.
Another approach could introduce a new concept, alongside BPF map, to
represent generic "container" object, which doesn't necessarily have key/value
interface with lookup/update/delete operations. This approach would add a lot
of extra infrastructure that has to be built for observability and verifier
support. It would also add another concept that BPF developers would have to
familiarize themselves with, new syntax in libbpf, etc. But then would really
provide no additional benefits over the approach of using a map.
BPF_MAP_TYPE_RINGBUF doesn't support lookup/update/delete operations, but so
doesn't few other map types (e.g., queue and stack; array doesn't support
delete, etc).
The approach chosen has an advantage of re-using existing BPF map
infrastructure (introspection APIs in kernel, libbpf support, etc), being
familiar concept (no need to teach users a new type of object in BPF program),
and utilizing existing tooling (bpftool). For common scenario of using
a single ring buffer for all CPUs, it's as simple and straightforward, as
would be with a dedicated "container" object. On the other hand, by being
a map, it can be combined with ARRAY_OF_MAPS and HASH_OF_MAPS map-in-maps to
implement a wide variety of topologies, from one ring buffer for each CPU
(e.g., as a replacement for perf buffer use cases), to a complicated
application hashing/sharding of ring buffers (e.g., having a small pool of
ring buffers with hashed task's tgid being a look up key to preserve order,
but reduce contention).
Key and value sizes are enforced to be zero. max_entries is used to specify
the size of ring buffer and has to be a power of 2 value.
There are a bunch of similarities between perf buffer
(BPF_MAP_TYPE_PERF_EVENT_ARRAY) and new BPF ring buffer semantics:
- variable-length records;
- if there is no more space left in ring buffer, reservation fails, no
blocking;
- memory-mappable data area for user-space applications for ease of
consumption and high performance;
- epoll notifications for new incoming data;
- but still the ability to do busy polling for new data to achieve the
lowest latency, if necessary.
BPF ringbuf provides two sets of APIs to BPF programs:
- bpf_ringbuf_output() allows to *copy* data from one place to a ring
buffer, similarly to bpf_perf_event_output();
- bpf_ringbuf_reserve()/bpf_ringbuf_commit()/bpf_ringbuf_discard() APIs
split the whole process into two steps. First, a fixed amount of space is
reserved. If successful, a pointer to a data inside ring buffer data area
is returned, which BPF programs can use similarly to a data inside
array/hash maps. Once ready, this piece of memory is either committed or
discarded. Discard is similar to commit, but makes consumer ignore the
record.
bpf_ringbuf_output() has disadvantage of incurring extra memory copy, because
record has to be prepared in some other place first. But it allows to submit
records of the length that's not known to verifier beforehand. It also closely
matches bpf_perf_event_output(), so will simplify migration significantly.
bpf_ringbuf_reserve() avoids the extra copy of memory by providing a memory
pointer directly to ring buffer memory. In a lot of cases records are larger
than BPF stack space allows, so many programs have use extra per-CPU array as
a temporary heap for preparing sample. bpf_ringbuf_reserve() avoid this needs
completely. But in exchange, it only allows a known constant size of memory to
be reserved, such that verifier can verify that BPF program can't access
memory outside its reserved record space. bpf_ringbuf_output(), while slightly
slower due to extra memory copy, covers some use cases that are not suitable
for bpf_ringbuf_reserve().
The difference between commit and discard is very small. Discard just marks
a record as discarded, and such records are supposed to be ignored by consumer
code. Discard is useful for some advanced use-cases, such as ensuring
all-or-nothing multi-record submission, or emulating temporary malloc()/free()
within single BPF program invocation.
Each reserved record is tracked by verifier through existing
reference-tracking logic, similar to socket ref-tracking. It is thus
impossible to reserve a record, but forget to submit (or discard) it.
bpf_ringbuf_query() helper allows to query various properties of ring buffer.
Currently 4 are supported:
- BPF_RB_AVAIL_DATA returns amount of unconsumed data in ring buffer;
- BPF_RB_RING_SIZE returns the size of ring buffer;
- BPF_RB_CONS_POS/BPF_RB_PROD_POS returns current logical possition of
consumer/producer, respectively.
Returned values are momentarily snapshots of ring buffer state and could be
off by the time helper returns, so this should be used only for
debugging/reporting reasons or for implementing various heuristics, that take
into account highly-changeable nature of some of those characteristics.
One such heuristic might involve more fine-grained control over poll/epoll
notifications about new data availability in ring buffer. Together with
BPF_RB_NO_WAKEUP/BPF_RB_FORCE_WAKEUP flags for output/commit/discard helpers,
it allows BPF program a high degree of control and, e.g., more efficient
batched notifications. Default self-balancing strategy, though, should be
adequate for most applications and will work reliable and efficiently already.
Design and implementation
-------------------------
This reserve/commit schema allows a natural way for multiple producers, either
on different CPUs or even on the same CPU/in the same BPF program, to reserve
independent records and work with them without blocking other producers. This
means that if BPF program was interruped by another BPF program sharing the
same ring buffer, they will both get a record reserved (provided there is
enough space left) and can work with it and submit it independently. This
applies to NMI context as well, except that due to using a spinlock during
reservation, in NMI context, bpf_ringbuf_reserve() might fail to get a lock,
in which case reservation will fail even if ring buffer is not full.
The ring buffer itself internally is implemented as a power-of-2 sized
circular buffer, with two logical and ever-increasing counters (which might
wrap around on 32-bit architectures, that's not a problem):
- consumer counter shows up to which logical position consumer consumed the
data;
- producer counter denotes amount of data reserved by all producers.
Each time a record is reserved, producer that "owns" the record will
successfully advance producer counter. At that point, data is still not yet
ready to be consumed, though. Each record has 8 byte header, which contains
the length of reserved record, as well as two extra bits: busy bit to denote
that record is still being worked on, and discard bit, which might be set at
commit time if record is discarded. In the latter case, consumer is supposed
to skip the record and move on to the next one. Record header also encodes
record's relative offset from the beginning of ring buffer data area (in
pages). This allows bpf_ringbuf_commit()/bpf_ringbuf_discard() to accept only
the pointer to the record itself, without requiring also the pointer to ring
buffer itself. Ring buffer memory location will be restored from record
metadata header. This significantly simplifies verifier, as well as improving
API usability.
Producer counter increments are serialized under spinlock, so there is
a strict ordering between reservations. Commits, on the other hand, are
completely lockless and independent. All records become available to consumer
in the order of reservations, but only after all previous records where
already committed. It is thus possible for slow producers to temporarily hold
off submitted records, that were reserved later.
Reservation/commit/consumer protocol is verified by litmus tests in
Documentation/litmus-test/bpf-rb.
One interesting implementation bit, that significantly simplifies (and thus
speeds up as well) implementation of both producers and consumers is how data
area is mapped twice contiguously back-to-back in the virtual memory. This
allows to not take any special measures for samples that have to wrap around
at the end of the circular buffer data area, because the next page after the
last data page would be first data page again, and thus the sample will still
appear completely contiguous in virtual memory. See comment and a simple ASCII
diagram showing this visually in bpf_ringbuf_area_alloc().
Another feature that distinguishes BPF ringbuf from perf ring buffer is
a self-pacing notifications of new data being availability.
bpf_ringbuf_commit() implementation will send a notification of new record
being available after commit only if consumer has already caught up right up
to the record being committed. If not, consumer still has to catch up and thus
will see new data anyways without needing an extra poll notification.
Benchmarks (see tools/testing/selftests/bpf/benchs/bench_ringbuf.c) show that
this allows to achieve a very high throughput without having to resort to
tricks like "notify only every Nth sample", which are necessary with perf
buffer. For extreme cases, when BPF program wants more manual control of
notifications, commit/discard/output helpers accept BPF_RB_NO_WAKEUP and
BPF_RB_FORCE_WAKEUP flags, which give full control over notifications of data
availability, but require extra caution and diligence in using this API.
Comparison to alternatives
--------------------------
Before considering implementing BPF ring buffer from scratch existing
alternatives in kernel were evaluated, but didn't seem to meet the needs. They
largely fell into few categores:
- per-CPU buffers (perf, ftrace, etc), which don't satisfy two motivations
outlined above (ordering and memory consumption);
- linked list-based implementations; while some were multi-producer designs,
consuming these from user-space would be very complicated and most
probably not performant; memory-mapping contiguous piece of memory is
simpler and more performant for user-space consumers;
- io_uring is SPSC, but also requires fixed-sized elements. Naively turning
SPSC queue into MPSC w/ lock would have subpar performance compared to
locked reserve + lockless commit, as with BPF ring buffer. Fixed sized
elements would be too limiting for BPF programs, given existing BPF
programs heavily rely on variable-sized perf buffer already;
- specialized implementations (like a new printk ring buffer, [0]) with lots
of printk-specific limitations and implications, that didn't seem to fit
well for intended use with BPF programs.
[0] https://lwn.net/Articles/779550/
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200529075424.3139988-2-andriin@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
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John Fastabend
|
13d70f5a5e |
bpf, sk_msg: Add get socket storage helpers
Add helpers to use local socket storage. Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/159033907577.12355.14740125020572756560.stgit@john-Precision-5820-Tower Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Alexei Starovoitov
|
fb53d3b637 |
tools/bpf: sync bpf.h
Sync tools/include/uapi/linux/bpf.h from include/uapi. Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Daniel Borkmann
|
1b66d25361 |
bpf: Add get{peer, sock}name attach types for sock_addr
As stated in
|
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Andrey Ignatov
|
f307fa2cb4 |
bpf: Introduce bpf_sk_{, ancestor_}cgroup_id helpers
With having ability to lookup sockets in cgroup skb programs it becomes
useful to access cgroup id of retrieved sockets so that policies can be
implemented based on origin cgroup of such socket.
For example, a container running in a cgroup can have cgroup skb ingress
program that can lookup peer socket that is sending packets to a process
inside the container and decide whether those packets should be allowed
or denied based on cgroup id of the peer.
More specifically such ingress program can implement intra-host policy
"allow incoming packets only from this same container and not from any
other container on same host" w/o relying on source IP addresses since
quite often it can be the case that containers share same IP address on
the host.
Introduce two new helpers for this use-case: bpf_sk_cgroup_id() and
bpf_sk_ancestor_cgroup_id().
These helpers are similar to existing bpf_skb_{,ancestor_}cgroup_id
helpers with the only difference that sk is used to get cgroup id
instead of skb, and share code with them.
See documentation in UAPI for more details.
Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/f5884981249ce911f63e9b57ecd5d7d19154ff39.1589486450.git.rdna@fb.com
|
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Andrey Ignatov
|
7aebfa1b38 |
bpf: Support narrow loads from bpf_sock_addr.user_port
bpf_sock_addr.user_port supports only 4-byte load and it leads to ugly code in BPF programs, like: volatile __u32 user_port = ctx->user_port; __u16 port = bpf_ntohs(user_port); Since otherwise clang may optimize the load to be 2-byte and it's rejected by verifier. Add support for 1- and 2-byte loads same way as it's supported for other fields in bpf_sock_addr like user_ip4, msg_src_ip4, etc. Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/c1e983f4c17573032601d0b2b1f9d1274f24bc16.1589420814.git.rdna@fb.com |
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Miklos Szeredi
|
581701b7ef |
uapi: deprecate STATX_ALL
Constants of the *_ALL type can be actively harmful due to the fact that developers will usually fail to consider the possible effects of future changes to the definition. Deprecate STATX_ALL in the uapi, while no damage has been done yet. We could keep something like this around in the kernel, but there's actually no point, since all filesystems should be explicitly checking flags that they support and not rely on the VFS masking unknown ones out: a flag could be known to the VFS, yet not known to the filesystem. Cc: David Howells <dhowells@redhat.com> Cc: linux-api@vger.kernel.org Cc: linux-man@vger.kernel.org Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> |
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Quentin Monnet
|
ff20460e94 |
tools, bpf: Synchronise BPF UAPI header with tools
Synchronise the bpf.h header under tools, to report the fixes recently brought to the documentation for the BPF helpers. Signed-off-by: Quentin Monnet <quentin@isovalent.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200511161536.29853-5-quentin@isovalent.com |
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Yonghong Song
|
492e639f0c |
bpf: Add bpf_seq_printf and bpf_seq_write helpers
Two helpers bpf_seq_printf and bpf_seq_write, are added for
writing data to the seq_file buffer.
bpf_seq_printf supports common format string flag/width/type
fields so at least I can get identical results for
netlink and ipv6_route targets.
For bpf_seq_printf and bpf_seq_write, return value -EOVERFLOW
specifically indicates a write failure due to overflow, which
means the object will be repeated in the next bpf invocation
if object collection stays the same. Note that if the object
collection is changed, depending how collection traversal is
done, even if the object still in the collection, it may not
be visited.
For bpf_seq_printf, format %s, %p{i,I}{4,6} needs to
read kernel memory. Reading kernel memory may fail in
the following two cases:
- invalid kernel address, or
- valid kernel address but requiring a major fault
If reading kernel memory failed, the %s string will be
an empty string and %p{i,I}{4,6} will be all 0.
Not returning error to bpf program is consistent with
what bpf_trace_printk() does for now.
bpf_seq_printf may return -EBUSY meaning that internal percpu
buffer for memory copy of strings or other pointees is
not available. Bpf program can return 1 to indicate it
wants the same object to be repeated. Right now, this should not
happen on no-RT kernels since migrate_disable(), which guards
bpf prog call, calls preempt_disable().
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200509175914.2476661-1-yhs@fb.com
|
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Yonghong Song
|
ac51d99bf8 |
bpf: Create anonymous bpf iterator
A new bpf command BPF_ITER_CREATE is added.
The anonymous bpf iterator is seq_file based.
The seq_file private data are referenced by targets.
The bpf_iter infrastructure allocated additional space
at seq_file->private before the space used by targets
to store some meta data, e.g.,
prog: prog to run
session_id: an unique id for each opened seq_file
seq_num: how many times bpf programs are queried in this session
done_stop: an internal state to decide whether bpf program
should be called in seq_ops->stop() or not
The seq_num will start from 0 for valid objects.
The bpf program may see the same seq_num more than once if
- seq_file buffer overflow happens and the same object
is retried by bpf_seq_read(), or
- the bpf program explicitly requests a retry of the
same object
Since module is not supported for bpf_iter, all target
registeration happens at __init time, so there is no
need to change bpf_iter_unreg_target() as it is used
mostly in error path of the init function at which time
no bpf iterators have been created yet.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200509175905.2475770-1-yhs@fb.com
|
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Yonghong Song
|
de4e05cac4 |
bpf: Support bpf tracing/iter programs for BPF_LINK_CREATE
Given a bpf program, the step to create an anonymous bpf iterator is:
- create a bpf_iter_link, which combines bpf program and the target.
In the future, there could be more information recorded in the link.
A link_fd will be returned to the user space.
- create an anonymous bpf iterator with the given link_fd.
The bpf_iter_link can be pinned to bpffs mount file system to
create a file based bpf iterator as well.
The benefit to use of bpf_iter_link:
- using bpf link simplifies design and implementation as bpf link
is used for other tracing bpf programs.
- for file based bpf iterator, bpf_iter_link provides a standard
way to replace underlying bpf programs.
- for both anonymous and free based iterators, bpf link query
capability can be leveraged.
The patch added support of tracing/iter programs for BPF_LINK_CREATE.
A new link type BPF_LINK_TYPE_ITER is added to facilitate link
querying. Currently, only prog_id is needed, so there is no
additional in-kernel show_fdinfo() and fill_link_info() hook
is needed for BPF_LINK_TYPE_ITER link.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200509175901.2475084-1-yhs@fb.com
|
||
|
Yonghong Song
|
15d83c4d7c |
bpf: Allow loading of a bpf_iter program
A bpf_iter program is a tracing program with attach type
BPF_TRACE_ITER. The load attribute
attach_btf_id
is used by the verifier against a particular kernel function,
which represents a target, e.g., __bpf_iter__bpf_map
for target bpf_map which is implemented later.
The program return value must be 0 or 1 for now.
0 : successful, except potential seq_file buffer overflow
which is handled by seq_file reader.
1 : request to restart the same object
In the future, other return values may be used for filtering or
teminating the iterator.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200509175900.2474947-1-yhs@fb.com
|
||
Stanislav Fomichev
|
8086fbaf49 |
bpf: Allow any port in bpf_bind helper
We want to have a tighter control on what ports we bind to in
the BPF_CGROUP_INET{4,6}_CONNECT hooks even if it means
connect() becomes slightly more expensive. The expensive part
comes from the fact that we now need to call inet_csk_get_port()
that verifies that the port is not used and allocates an entry
in the hash table for it.
Since we can't rely on "snum || !bind_address_no_port" to prevent
us from calling POST_BIND hook anymore, let's add another bind flag
to indicate that the call site is BPF program.
v5:
* fix wrong AF_INET (should be AF_INET6) in the bpf program for v6
v3:
* More bpf_bind documentation refinements (Martin KaFai Lau)
* Add UDP tests as well (Martin KaFai Lau)
* Don't start the thread, just do socket+bind+listen (Martin KaFai Lau)
v2:
* Update documentation (Andrey Ignatov)
* Pass BIND_FORCE_ADDRESS_NO_PORT conditionally (Andrey Ignatov)
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrey Ignatov <rdna@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20200508174611.228805-5-sdf@google.com
|
||
David S. Miller
|
115506fea4 |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Alexei Starovoitov says: ==================== pull-request: bpf-next 2020-05-01 (v2) The following pull-request contains BPF updates for your *net-next* tree. We've added 61 non-merge commits during the last 6 day(s) which contain a total of 153 files changed, 6739 insertions(+), 3367 deletions(-). The main changes are: 1) pulled work.sysctl from vfs tree with sysctl bpf changes. 2) bpf_link observability, from Andrii. 3) BTF-defined map in map, from Andrii. 4) asan fixes for selftests, from Andrii. 5) Allow bpf_map_lookup_elem for SOCKMAP and SOCKHASH, from Jakub. 6) production cloudflare classifier as a selftes, from Lorenz. 7) bpf_ktime_get_*_ns() helper improvements, from Maciej. 8) unprivileged bpftool feature probe, from Quentin. 9) BPF_ENABLE_STATS command, from Song. 10) enable bpf_[gs]etsockopt() helpers for sock_ops progs, from Stanislav. 11) enable a bunch of common helpers for cg-device, sysctl, sockopt progs, from Stanislav. ==================== Signed-off-by: David S. Miller <davem@davemloft.net> |
||
|
Stanislav Fomichev
|
beecf11bc2 |
bpf: Bpf_{g,s}etsockopt for struct bpf_sock_addr
Currently, bpf_getsockopt and bpf_setsockopt helpers operate on the
'struct bpf_sock_ops' context in BPF_PROG_TYPE_SOCK_OPS program.
Let's generalize them and make them available for 'struct bpf_sock_addr'.
That way, in the future, we can allow those helpers in more places.
As an example, let's expose those 'struct bpf_sock_addr' based helpers to
BPF_CGROUP_INET{4,6}_CONNECT hooks. That way we can override CC before the
connection is made.
v3:
* Expose custom helpers for bpf_sock_addr context instead of doing
generic bpf_sock argument (as suggested by Daniel). Even with
try_socket_lock that doesn't sleep we have a problem where context sk
is already locked and socket lock is non-nestable.
v2:
* s/BPF_PROG_TYPE_CGROUP_SOCKOPT/BPF_PROG_TYPE_SOCK_OPS/
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20200430233152.199403-1-sdf@google.com
|
||
Song Liu
|
d46edd671a |
bpf: Sharing bpf runtime stats with BPF_ENABLE_STATS
Currently, sysctl kernel.bpf_stats_enabled controls BPF runtime stats. Typical userspace tools use kernel.bpf_stats_enabled as follows: 1. Enable kernel.bpf_stats_enabled; 2. Check program run_time_ns; 3. Sleep for the monitoring period; 4. Check program run_time_ns again, calculate the difference; 5. Disable kernel.bpf_stats_enabled. The problem with this approach is that only one userspace tool can toggle this sysctl. If multiple tools toggle the sysctl at the same time, the measurement may be inaccurate. To fix this problem while keep backward compatibility, introduce a new bpf command BPF_ENABLE_STATS. On success, this command enables stats and returns a valid fd. BPF_ENABLE_STATS takes argument "type". Currently, only one type, BPF_STATS_RUN_TIME, is supported. We can extend the command to support other types of stats in the future. With BPF_ENABLE_STATS, user space tool would have the following flow: 1. Get a fd with BPF_ENABLE_STATS, and make sure it is valid; 2. Check program run_time_ns; 3. Sleep for the monitoring period; 4. Check program run_time_ns again, calculate the difference; 5. Close the fd. Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200430071506.1408910-2-songliubraving@fb.com |
||
|
Andrii Nakryiko
|
f2e10bff16 |
bpf: Add support for BPF_OBJ_GET_INFO_BY_FD for bpf_link
Add ability to fetch bpf_link details through BPF_OBJ_GET_INFO_BY_FD command. Also enhance show_fdinfo to potentially include bpf_link type-specific information (similarly to obj_info). Also introduce enum bpf_link_type stored in bpf_link itself and expose it in UAPI. bpf_link_tracing also now will store and return bpf_attach_type. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200429001614.1544-5-andriin@fb.com |
||
Horatiu Vultur
|
3e54442c93 |
net: bridge: Add port attribute IFLA_BRPORT_MRP_RING_OPEN
This patch adds a new port attribute, IFLA_BRPORT_MRP_RING_OPEN, which allows to notify the userspace when the port lost the continuite of MRP frames. This attribute is set by kernel whenever the SW or HW detects that the ring is being open or closed. Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com> Signed-off-by: David S. Miller <davem@davemloft.net> |
||
Maciej Żenczykowski
|
71d1921477 |
bpf: add bpf_ktime_get_boot_ns()
On a device like a cellphone which is constantly suspending and resuming CLOCK_MONOTONIC is not particularly useful for keeping track of or reacting to external network events. Instead you want to use CLOCK_BOOTTIME. Hence add bpf_ktime_get_boot_ns() as a mirror of bpf_ktime_get_ns() based around CLOCK_BOOTTIME instead of CLOCK_MONOTONIC. Signed-off-by: Maciej Żenczykowski <maze@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Linus Torvalds
|
ab51cac00e |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from David Miller:
1) Fix memory leak in netfilter flowtable, from Roi Dayan.
2) Ref-count leaks in netrom and tipc, from Xiyu Yang.
3) Fix warning when mptcp socket is never accepted before close, from
Florian Westphal.
4) Missed locking in ovs_ct_exit(), from Tonghao Zhang.
5) Fix large delays during PTP synchornization in cxgb4, from Rahul
Lakkireddy.
6) team_mode_get() can hang, from Taehee Yoo.
7) Need to use kvzalloc() when allocating fw tracer in mlx5 driver,
from Niklas Schnelle.
8) Fix handling of bpf XADD on BTF memory, from Jann Horn.
9) Fix BPF_STX/BPF_B encoding in x86 bpf jit, from Luke Nelson.
10) Missing queue memory release in iwlwifi pcie code, from Johannes
Berg.
11) Fix NULL deref in macvlan device event, from Taehee Yoo.
12) Initialize lan87xx phy correctly, from Yuiko Oshino.
13) Fix looping between VRF and XFRM lookups, from David Ahern.
14) etf packet scheduler assumes all sockets are full sockets, which is
not necessarily true. From Eric Dumazet.
15) Fix mptcp data_fin handling in RX path, from Paolo Abeni.
16) fib_select_default() needs to handle nexthop objects, from David
Ahern.
17) Use GFP_ATOMIC under spinlock in mac80211_hwsim, from Wei Yongjun.
18) vxlan and geneve use wrong nlattr array, from Sabrina Dubroca.
19) Correct rx/tx stats in bcmgenet driver, from Doug Berger.
20) BPF_LDX zero-extension is encoded improperly in x86_32 bpf jit, fix
from Luke Nelson.
* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (100 commits)
selftests/bpf: Fix a couple of broken test_btf cases
tools/runqslower: Ensure own vmlinux.h is picked up first
bpf: Make bpf_link_fops static
bpftool: Respect the -d option in struct_ops cmd
selftests/bpf: Add test for freplace program with expected_attach_type
bpf: Propagate expected_attach_type when verifying freplace programs
bpf: Fix leak in LINK_UPDATE and enforce empty old_prog_fd
bpf, x86_32: Fix logic error in BPF_LDX zero-extension
bpf, x86_32: Fix clobbering of dst for BPF_JSET
bpf, x86_32: Fix incorrect encoding in BPF_LDX zero-extension
bpf: Fix reStructuredText markup
net: systemport: suppress warnings on failed Rx SKB allocations
net: bcmgenet: suppress warnings on failed Rx SKB allocations
macsec: avoid to set wrong mtu
mac80211: sta_info: Add lockdep condition for RCU list usage
mac80211: populate debugfs only after cfg80211 init
net: bcmgenet: correct per TX/RX ring statistics
net: meth: remove spurious copyright text
net: phy: bcm84881: clear settings on link down
chcr: Fix CPU hard lockup
...
|
||
Jakub Wilk
|
a33d314794 |
bpf: Fix reStructuredText markup
The patch fixes: $ scripts/bpf_helpers_doc.py > bpf-helpers.rst $ rst2man bpf-helpers.rst > bpf-helpers.7 bpf-helpers.rst:1105: (WARNING/2) Inline strong start-string without end-string. Signed-off-by: Jakub Wilk <jwilk@jwilk.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Quentin Monnet <quentin@isovalent.com> Link: https://lore.kernel.org/bpf/20200422082324.2030-1-jwilk@jwilk.net |
||
Mauro Carvalho Chehab
|
3ecad8c2c1 |
docs: fix broken references for ReST files that moved around
Some broken references happened due to shifting files around and ReST renames. Those can't be auto-fixed by the script, so let's fix them manually. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Acked-by: Corentin Labbe <clabbe.montjoie@gmail.com> Link: https://lore.kernel.org/r/64773a12b4410aaf3e3be89e3ec7e34de2484eea.1586881715.git.mchehab+huawei@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net> |
||
Arnaldo Carvalho de Melo
|
54a58ebc66 |
tools headers UAPI: Sync drm/i915_drm.h with the kernel sources
To pick the change in:
|
||
|
Arnaldo Carvalho de Melo
|
0719bdf467 |
tools headers UAPI: Update tools's copy of drm.h headers
Picking the changes from:
|
||
|
Arnaldo Carvalho de Melo
|
b8fc22803e |
tools headers kvm: Sync linux/kvm.h with the kernel sources
To pick up the changes from: |
||
|
Arnaldo Carvalho de Melo
|
1abcb9d96d |
tools headers UAPI: Sync linux/fscrypt.h with the kernel sources
To pick the changes from:
|
||
|
Arnaldo Carvalho de Melo
|
3df4d4bf3c |
tools include UAPI: Sync linux/vhost.h with the kernel sources
To get the changes in:
|
||
|
Arnaldo Carvalho de Melo
|
f60b3878f4 |
tools headers UAPI: Sync linux/mman.h with the kernel
To get the changes in:
|
||
|
Arnaldo Carvalho de Melo
|
027fa8fb63 |
tools headers UAPI: Sync sched.h with the kernel
To get the changes in:
|
||
|
Linus Torvalds
|
c48b07226b |
perf updates all over the place:
core:
- Support for cgroup tracking in samples to allow cgroup based
analysis
tools:
- Support for cgroup analysis
- Commandline option and hotkey for perf top to change the sort order
- A set of fixes all over the place
- Various build system related improvements
- Updates of the X86 pmu event JSON data
- Documentation updates
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Merge tag 'perf-urgent-2020-04-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull more perf updates from Thomas Gleixner:
"Perf updates all over the place:
core:
- Support for cgroup tracking in samples to allow cgroup based
analysis
tools:
- Support for cgroup analysis
- Commandline option and hotkey for perf top to change the sort order
- A set of fixes all over the place
- Various build system related improvements
- Updates of the X86 pmu event JSON data
- Documentation updates"
* tag 'perf-urgent-2020-04-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (55 commits)
perf python: Fix clang detection to strip out options passed in $CC
perf tools: Support Python 3.8+ in Makefile
perf script: Fix invalid read of directory entry after closedir()
perf script report: Fix SEGFAULT when using DWARF mode
perf script: add -S/--symbols documentation
perf pmu-events x86: Use CPU_CLK_UNHALTED.THREAD in Kernel_Utilization metric
perf events parser: Add missing Intel CPU events to parser
perf script: Allow --symbol to accept hexadecimal addresses
perf report/top TUI: Fix title line formatting
perf top: Support hotkey to change sort order
perf top: Support --group-sort-idx to change the sort order
perf symbols: Fix arm64 gap between kernel start and module end
perf build-test: Honour JOBS to override detection of number of cores
perf script: Add --show-cgroup-events option
perf top: Add --all-cgroups option
perf record: Add --all-cgroups option
perf record: Support synthesizing cgroup events
perf report: Add 'cgroup' sort key
perf cgroup: Maintain cgroup hierarchy
perf tools: Basic support for CGROUP event
...
|
||
Namhyung Kim
|
03590fb409 |
tools headers UAPI: Update tools's copy of linux/perf_event.h
To get the changes in: |
||
|
Linus Torvalds
|
29d9f30d4c |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next
Pull networking updates from David Miller:
"Highlights:
1) Fix the iwlwifi regression, from Johannes Berg.
2) Support BSS coloring and 802.11 encapsulation offloading in
hardware, from John Crispin.
3) Fix some potential Spectre issues in qtnfmac, from Sergey
Matyukevich.
4) Add TTL decrement action to openvswitch, from Matteo Croce.
5) Allow paralleization through flow_action setup by not taking the
RTNL mutex, from Vlad Buslov.
6) A lot of zero-length array to flexible-array conversions, from
Gustavo A. R. Silva.
7) Align XDP statistics names across several drivers for consistency,
from Lorenzo Bianconi.
8) Add various pieces of infrastructure for offloading conntrack, and
make use of it in mlx5 driver, from Paul Blakey.
9) Allow using listening sockets in BPF sockmap, from Jakub Sitnicki.
10) Lots of parallelization improvements during configuration changes
in mlxsw driver, from Ido Schimmel.
11) Add support to devlink for generic packet traps, which report
packets dropped during ACL processing. And use them in mlxsw
driver. From Jiri Pirko.
12) Support bcmgenet on ACPI, from Jeremy Linton.
13) Make BPF compatible with RT, from Thomas Gleixnet, Alexei
Starovoitov, and your's truly.
14) Support XDP meta-data in virtio_net, from Yuya Kusakabe.
15) Fix sysfs permissions when network devices change namespaces, from
Christian Brauner.
16) Add a flags element to ethtool_ops so that drivers can more simply
indicate which coalescing parameters they actually support, and
therefore the generic layer can validate the user's ethtool
request. Use this in all drivers, from Jakub Kicinski.
17) Offload FIFO qdisc in mlxsw, from Petr Machata.
18) Support UDP sockets in sockmap, from Lorenz Bauer.
19) Fix stretch ACK bugs in several TCP congestion control modules,
from Pengcheng Yang.
20) Support virtual functiosn in octeontx2 driver, from Tomasz
Duszynski.
21) Add region operations for devlink and use it in ice driver to dump
NVM contents, from Jacob Keller.
22) Add support for hw offload of MACSEC, from Antoine Tenart.
23) Add support for BPF programs that can be attached to LSM hooks,
from KP Singh.
24) Support for multiple paths, path managers, and counters in MPTCP.
From Peter Krystad, Paolo Abeni, Florian Westphal, Davide Caratti,
and others.
25) More progress on adding the netlink interface to ethtool, from
Michal Kubecek"
* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2121 commits)
net: ipv6: rpl_iptunnel: Fix potential memory leak in rpl_do_srh_inline
cxgb4/chcr: nic-tls stats in ethtool
net: dsa: fix oops while probing Marvell DSA switches
net/bpfilter: remove superfluous testing message
net: macb: Fix handling of fixed-link node
net: dsa: ksz: Select KSZ protocol tag
netdevsim: dev: Fix memory leak in nsim_dev_take_snapshot_write
net: stmmac: add EHL 2.5Gbps PCI info and PCI ID
net: stmmac: add EHL PSE0 & PSE1 1Gbps PCI info and PCI ID
net: stmmac: create dwmac-intel.c to contain all Intel platform
net: dsa: bcm_sf2: Support specifying VLAN tag egress rule
net: dsa: bcm_sf2: Add support for matching VLAN TCI
net: dsa: bcm_sf2: Move writing of CFP_DATA(5) into slicing functions
net: dsa: bcm_sf2: Check earlier for FLOW_EXT and FLOW_MAC_EXT
net: dsa: bcm_sf2: Disable learning for ASP port
net: dsa: b53: Deny enslaving port 7 for 7278 into a bridge
net: dsa: b53: Prevent tagged VLAN on port 7 for 7278
net: dsa: b53: Restore VLAN entries upon (re)configuration
net: dsa: bcm_sf2: Fix overflow checks
hv_netvsc: Remove unnecessary round_up for recv_completion_cnt
...
|
||
|
David S. Miller
|
ed52f2c608 |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Signed-off-by: David S. Miller <davem@davemloft.net> |