linux.git/net/bpf, branch v5.15

bpf, test, cgroup: Use sk_{alloc,free} for test cases

2021-09-28T07:29:28+00:00

BPF test infra has some hacks in place which kzalloc() a socket and perform
minimum init via sock_net_set() and sock_init_data(). As a result, the sk's
skcd->cgroup is NULL since it didn't go through proper initialization as it
would have been the case from sk_alloc(). Rather than re-adding a NULL test
in sock_cgroup_ptr() just for this, use sk_{alloc,free}() pair for the test
socket. The latter also allows to get rid of the bpf_sk_storage_free() special
case.

Fixes: 8520e224f547 ("bpf, cgroups: Fix cgroup v2 fallback on v1/v2 mixed mode")
Fixes: b7a1848e8398 ("bpf: add BPF_PROG_TEST_RUN support for flow dissector")
Fixes: 2cb494a36c98 ("bpf: add tests for direct packet access from CGROUP_SKB")
Reported-by: syzbot+664b58e9a40fbb2cec71@syzkaller.appspotmail.com
Reported-by: syzbot+33f36d0754d4c5c0e102@syzkaller.appspotmail.com
Signed-off-by: Daniel Borkmann 
Signed-off-by: Alexei Starovoitov 
Tested-by: syzbot+664b58e9a40fbb2cec71@syzkaller.appspotmail.com
Tested-by: syzbot+33f36d0754d4c5c0e102@syzkaller.appspotmail.com
Link: https://lore.kernel.org/bpf/20210927123921.21535-2-daniel@iogearbox.net

bpf: Refactor BPF_PROG_RUN into a function

2021-08-16T22:45:07+00:00

Turn BPF_PROG_RUN into a proper always inlined function. No functional and
performance changes are intended, but it makes it much easier to understand
what's going on with how BPF programs are actually get executed. It's more
obvious what types and callbacks are expected. Also extra () around input
parameters can be dropped, as well as `__` variable prefixes intended to avoid
naming collisions, which makes the code simpler to read and write.

This refactoring also highlighted one extra issue. BPF_PROG_RUN is both
a macro and an enum value (BPF_PROG_RUN == BPF_PROG_TEST_RUN). Turning
BPF_PROG_RUN into a function causes naming conflict compilation error. So
rename BPF_PROG_RUN into lower-case bpf_prog_run(), similar to
bpf_prog_run_xdp(), bpf_prog_run_pin_on_cpu(), etc. All existing callers of
BPF_PROG_RUN, the macro, are switched to bpf_prog_run() explicitly.

Signed-off-by: Andrii Nakryiko 
Signed-off-by: Daniel Borkmann 
Acked-by: Yonghong Song 
Link: https://lore.kernel.org/bpf/20210815070609.987780-2-andrii@kernel.org

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2021-08-13T13:41:22+00:00

Conflicts:

drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.h
  9e26680733d5 ("bnxt_en: Update firmware call to retrieve TX PTP timestamp")
  9e518f25802c ("bnxt_en: 1PPS functions to configure TSIO pins")
  099fdeda659d ("bnxt_en: Event handler for PPS events")

kernel/bpf/helpers.c
include/linux/bpf-cgroup.h
  a2baf4e8bb0f ("bpf: Fix potentially incorrect results with bpf_get_local_storage()")
  c7603cfa04e7 ("bpf: Add ambient BPF runtime context stored in current")

drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c
  5957cc557dc5 ("net/mlx5: Set all field of mlx5_irq before inserting it to the xarray")
  2d0b41a37679 ("net/mlx5: Refcount mlx5_irq with integer")

MAINTAINERS
  7b637cd52f02 ("MAINTAINERS: fix Microchip CAN BUS Analyzer Tool entry typo")
  7d901a1e878a ("net: phy: add Maxlinear GPY115/21x/24x driver")

Signed-off-by: Jakub Kicinski

bpf: Add missing bpf_read_[un]lock_trace() for syscall program

2021-08-10T08:10:49+00:00

Commit 79a7f8bdb159d ("bpf: Introduce bpf_sys_bpf() helper and program type.")
added support for syscall program, which is a sleepable program.

But the program run missed bpf_read_lock_trace()/bpf_read_unlock_trace(),
which is needed to ensure proper rcu callback invocations. This patch adds
bpf_read_[un]lock_trace() properly.

Fixes: 79a7f8bdb159d ("bpf: Introduce bpf_sys_bpf() helper and program type.")
Signed-off-by: Yonghong Song 
Signed-off-by: Daniel Borkmann 
Acked-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/20210809235151.1663680-1-yhs@fb.com

bpf: Fix bpf_prog_test_run_xdp logic after incorrect merge resolution

2021-08-04T21:55:00+00:00

During recent net into net-next merge ([0]) a piece of old logic ([1]) got
reintroduced accidentally while resolving merge conflict between bpf's [2]
and bpf-next's [3]. This check was removed in bpf-next tree to allow extra
ctx_in parameter passed for XDP test runs. Reinstating the check breaks
bpf_prog_test_run_xdp logic and causes a corresponding xdp_context_test_run
selftest failure. Fix by removing the check and allow ctx_in for XDP test
runs.

  [0] 5af84df962dd ("Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net")
  [1] 947e8b595b82 ("bpf: explicitly prohibit ctx_{in, out} in non-skb BPF_PROG_TEST_RUN")
  [2] 5e21bb4e8125 ("bpf, test: fix NULL pointer dereference on invalid expected_attach_type")
  [3] 47316f4a3053 ("bpf: Support input xdp_md context in BPF_PROG_TEST_RUN")

Fixes: 5af84df962dd ("Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net")
Signed-off-by: Andrii Nakryiko 
Signed-off-by: Daniel Borkmann 
Acked-by: Daniel Borkmann

Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

2021-07-31T18:23:26+00:00

Andrii Nakryiko says:

====================
bpf-next 2021-07-30

We've added 64 non-merge commits during the last 15 day(s) which contain
a total of 83 files changed, 5027 insertions(+), 1808 deletions(-).

The main changes are:

1) BTF-guided binary data dumping libbpf API, from Alan.

2) Internal factoring out of libbpf CO-RE relocation logic, from Alexei.

3) Ambient BPF run context and cgroup storage cleanup, from Andrii.

4) Few small API additions for libbpf 1.0 effort, from Evgeniy and Hengqi.

5) bpf_program__attach_kprobe_opts() fixes in libbpf, from Jiri.

6) bpf_{get,set}sockopt() support in BPF iterators, from Martin.

7) BPF map pinning improvements in libbpf, from Martynas.

8) Improved module BTF support in libbpf and bpftool, from Quentin.

9) Bpftool cleanups and documentation improvements, from Quentin.

10) Libbpf improvements for supporting CO-RE on old kernels, from Shuyi.

11) Increased maximum cgroup storage size, from Stanislav.

12) Small fixes and improvements to BPF tests and samples, from various folks.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (64 commits)
  tools: bpftool: Complete metrics list in "bpftool prog profile" doc
  tools: bpftool: Document and add bash completion for -L, -B options
  selftests/bpf: Update bpftool's consistency script for checking options
  tools: bpftool: Update and synchronise option list in doc and help msg
  tools: bpftool: Complete and synchronise attach or map types
  selftests/bpf: Check consistency between bpftool source, doc, completion
  tools: bpftool: Slightly ease bash completion updates
  unix_bpf: Fix a potential deadlock in unix_dgram_bpf_recvmsg()
  libbpf: Add btf__load_vmlinux_btf/btf__load_module_btf
  tools: bpftool: Support dumping split BTF by id
  libbpf: Add split BTF support for btf__load_from_kernel_by_id()
  tools: Replace btf__get_from_id() with btf__load_from_kernel_by_id()
  tools: Free BTF objects at various locations
  libbpf: Rename btf__get_from_id() as btf__load_from_kernel_by_id()
  libbpf: Rename btf__load() as btf__load_into_kernel()
  libbpf: Return non-null error on failures in libbpf_find_prog_btf_id()
  bpf: Emit better log message if bpf_iter ctx arg btf_id == 0
  tools/resolve_btfids: Emit warnings and patch zero id for missing symbols
  bpf: Increase supported cgroup storage value size
  libbpf: Fix race when pinning maps in parallel
  ...
====================

Link: https://lore.kernel.org/r/20210730225606.1897330-1-andrii@kernel.org
Signed-off-by: Jakub Kicinski

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2021-07-23T15:13:06+00:00

Conflicts are simple overlapping changes.

Signed-off-by: David S. Miller

bpf: Add ambient BPF runtime context stored in current

2021-07-16T19:15:28+00:00

b910eaaaa4b8 ("bpf: Fix NULL pointer dereference in bpf_get_local_storage()
helper") fixed the problem with cgroup-local storage use in BPF by
pre-allocating per-CPU array of 8 cgroup storage pointers to accommodate
possible BPF program preemptions and nested executions.

While this seems to work good in practice, it introduces new and unnecessary
failure mode in which not all BPF programs might be executed if we fail to
find an unused slot for cgroup storage, however unlikely it is. It might also
not be so unlikely when/if we allow sleepable cgroup BPF programs in the
future.

Further, the way that cgroup storage is implemented as ambiently-available
property during entire BPF program execution is a convenient way to pass extra
information to BPF program and helpers without requiring user code to pass
around extra arguments explicitly. So it would be good to have a generic
solution that can allow implementing this without arbitrary restrictions.
Ideally, such solution would work for both preemptable and sleepable BPF
programs in exactly the same way.

This patch introduces such solution, bpf_run_ctx. It adds one pointer field
(bpf_ctx) to task_struct. This field is maintained by BPF_PROG_RUN family of
macros in such a way that it always stays valid throughout BPF program
execution. BPF program preemption is handled by remembering previous
current->bpf_ctx value locally while executing nested BPF program and
restoring old value after nested BPF program finishes. This is handled by two
helper functions, bpf_set_run_ctx() and bpf_reset_run_ctx(), which are
supposed to be used before and after BPF program runs, respectively.

Restoring old value of the pointer handles preemption, while bpf_run_ctx
pointer being a property of current task_struct naturally solves this problem
for sleepable BPF programs by "following" BPF program execution as it is
scheduled in and out of CPU. It would even allow CPU migration of BPF
programs, even though it's not currently allowed by BPF infra.

This patch cleans up cgroup local storage handling as a first application. The
design itself is generic, though, with bpf_run_ctx being an empty struct that
is supposed to be embedded into a specific struct for a given BPF program type
(bpf_cg_run_ctx in this case). Follow up patches are planned that will expand
this mechanism for other uses within tracing BPF programs.

To verify that this change doesn't revert the fix to the original cgroup
storage issue, I ran the same repro as in the original report ([0]) and didn't
get any problems. Replacing bpf_reset_run_ctx(old_run_ctx) with
bpf_reset_run_ctx(NULL) triggers the issue pretty quickly (so repro does work).

[0] https://lore.kernel.org/bpf/YEEvBUiJl2pJkxTd@krava/

Fixes: b910eaaaa4b8 ("bpf: Fix NULL pointer dereference in bpf_get_local_storage() helper")
Signed-off-by: Andrii Nakryiko
Signed-off-by: Daniel Borkmann
Acked-by: Yonghong Song
Link: https://lore.kernel.org/bpf/20210712230615.3525979-1-andrii@kernel.org

bpf, test: fix NULL pointer dereference on invalid expected_attach_type

2021-07-12T15:13:08+00:00

These two types of XDP progs (BPF_XDP_DEVMAP, BPF_XDP_CPUMAP) will not be
executed directly in the driver, therefore we should also not directly
run them from here. To run in these two situations, there must be further
preparations done, otherwise these may cause a kernel panic.

For more details, see also dev_xdp_attach().

  [   46.982479] BUG: kernel NULL pointer dereference, address: 0000000000000000
  [   46.984295] #PF: supervisor read access in kernel mode
  [   46.985777] #PF: error_code(0x0000) - not-present page
  [   46.987227] PGD 800000010dca4067 P4D 800000010dca4067 PUD 10dca6067 PMD 0
  [   46.989201] Oops: 0000 [#1] SMP PTI
  [   46.990304] CPU: 7 PID: 562 Comm: a.out Not tainted 5.13.0+ #44
  [   46.992001] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/24
  [   46.995113] RIP: 0010:___bpf_prog_run+0x17b/0x1710
  [   46.996586] Code: 49 03 14 cc e8 76 f6 fe ff e9 ad fe ff ff 0f b6 43 01 48 0f bf 4b 02 48 83 c3 08 89 c2 83 e0 0f c0 ea 04 02
  [   47.001562] RSP: 0018:ffffc900005afc58 EFLAGS: 00010246
  [   47.003115] RAX: 0000000000000000 RBX: ffffc9000023f068 RCX: 0000000000000000
  [   47.005163] RDX: 0000000000000000 RSI: 0000000000000079 RDI: ffffc900005afc98
  [   47.007135] RBP: 0000000000000000 R08: ffffc9000023f048 R09: c0000000ffffdfff
  [   47.009171] R10: 0000000000000001 R11: ffffc900005afb40 R12: ffffc900005afc98
  [   47.011172] R13: 0000000000000001 R14: 0000000000000001 R15: ffffffff825258a8
  [   47.013244] FS:  00007f04a5207580(0000) GS:ffff88842fdc0000(0000) knlGS:0000000000000000
  [   47.015705] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  [   47.017475] CR2: 0000000000000000 CR3: 0000000100182005 CR4: 0000000000770ee0
  [   47.019558] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  [   47.021595] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  [   47.023574] PKRU: 55555554
  [   47.024571] Call Trace:
  [   47.025424]  __bpf_prog_run32+0x32/0x50
  [   47.026296]  ? printk+0x53/0x6a
  [   47.027066]  ? ktime_get+0x39/0x90
  [   47.027895]  bpf_test_run.cold.28+0x23/0x123
  [   47.028866]  ? printk+0x53/0x6a
  [   47.029630]  bpf_prog_test_run_xdp+0x149/0x1d0
  [   47.030649]  __sys_bpf+0x1305/0x23d0
  [   47.031482]  __x64_sys_bpf+0x17/0x20
  [   47.032316]  do_syscall_64+0x3a/0x80
  [   47.033165]  entry_SYSCALL_64_after_hwframe+0x44/0xae
  [   47.034254] RIP: 0033:0x7f04a51364dd
  [   47.035133] Code: 00 c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 48
  [   47.038768] RSP: 002b:00007fff8f9fc518 EFLAGS: 00000213 ORIG_RAX: 0000000000000141
  [   47.040344] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f04a51364dd
  [   47.041749] RDX: 0000000000000048 RSI: 0000000020002a80 RDI: 000000000000000a
  [   47.043171] RBP: 00007fff8f9fc530 R08: 0000000002049300 R09: 0000000020000100
  [   47.044626] R10: 0000000000000004 R11: 0000000000000213 R12: 0000000000401070
  [   47.046088] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
  [   47.047579] Modules linked in:
  [   47.048318] CR2: 0000000000000000
  [   47.049120] ---[ end trace 7ad34443d5be719a ]---
  [   47.050273] RIP: 0010:___bpf_prog_run+0x17b/0x1710
  [   47.051343] Code: 49 03 14 cc e8 76 f6 fe ff e9 ad fe ff ff 0f b6 43 01 48 0f bf 4b 02 48 83 c3 08 89 c2 83 e0 0f c0 ea 04 02
  [   47.054943] RSP: 0018:ffffc900005afc58 EFLAGS: 00010246
  [   47.056068] RAX: 0000000000000000 RBX: ffffc9000023f068 RCX: 0000000000000000
  [   47.057522] RDX: 0000000000000000 RSI: 0000000000000079 RDI: ffffc900005afc98
  [   47.058961] RBP: 0000000000000000 R08: ffffc9000023f048 R09: c0000000ffffdfff
  [   47.060390] R10: 0000000000000001 R11: ffffc900005afb40 R12: ffffc900005afc98
  [   47.061803] R13: 0000000000000001 R14: 0000000000000001 R15: ffffffff825258a8
  [   47.063249] FS:  00007f04a5207580(0000) GS:ffff88842fdc0000(0000) knlGS:0000000000000000
  [   47.065070] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  [   47.066307] CR2: 0000000000000000 CR3: 0000000100182005 CR4: 0000000000770ee0
  [   47.067747] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  [   47.069217] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  [   47.070652] PKRU: 55555554
  [   47.071318] Kernel panic - not syncing: Fatal exception
  [   47.072854] Kernel Offset: disabled
  [   47.073683] ---[ end Kernel panic - not syncing: Fatal exception ]---

Fixes: 9216477449f3 ("bpf: cpumap: Add the possibility to attach an eBPF program to cpumap")
Fixes: fbee97feed9b ("bpf: Add support to attach bpf program to a devmap entry")
Reported-by: Abaci 
Signed-off-by: Xuan Zhuo 
Signed-off-by: Daniel Borkmann 
Reviewed-by: Dust Li 
Acked-by: Jesper Dangaard Brouer 
Acked-by: David Ahern 
Acked-by: Song Liu 
Link: https://lore.kernel.org/bpf/20210708080409.73525-1-xuanzhuo@linux.alibaba.com

bpf: Support specifying ingress via xdp_md context in BPF_PROG_TEST_RUN

2021-07-08T02:51:13+00:00

Support specifying the ingress_ifindex and rx_queue_index of xdp_md
contexts for BPF_PROG_TEST_RUN.

The intended use case is to allow testing XDP programs that make decisions
based on the ingress interface or RX queue.

If ingress_ifindex is specified, look up the device by the provided index
in the current namespace and use its xdp_rxq for the xdp_buff. If the
rx_queue_index is out of range, or is non-zero when the ingress_ifindex is
0, return -EINVAL.

Co-developed-by: Cody Haas 
Co-developed-by: Lisa Watanabe 
Signed-off-by: Cody Haas 
Signed-off-by: Lisa Watanabe 
Signed-off-by: Zvi Effron 
Signed-off-by: Alexei Starovoitov 
Acked-by: Yonghong Song 
Link: https://lore.kernel.org/bpf/20210707221657.3985075-4-zeffron@riotgames.com