Commit graph

3460 commits

Author SHA1 Message Date
Jakub Kicinski 6e62702feb bpf-next-for-netdev
-----BEGIN PGP SIGNATURE-----
 
 iHUEABYIAB0WIQTFp0I1jqZrAX+hPRXbK58LschIgwUCZkGcZAAKCRDbK58LschI
 g6o6APwLsqhrM2w71VUN5ciCxu4H5VDtZp6wkdqtVbxxU4qNxQEApKgYgKt8ZLF3
 Kily5c7m+S4ZXhMX21rb8JhSAz0dfQk=
 =5Dk7
 -----END PGP SIGNATURE-----

Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Daniel Borkmann says:

====================
pull-request: bpf-next 2024-05-13

We've added 119 non-merge commits during the last 14 day(s) which contain
a total of 134 files changed, 9462 insertions(+), 4742 deletions(-).

The main changes are:

1) Add BPF JIT support for 32-bit ARCv2 processors, from Shahab Vahedi.

2) Add BPF range computation improvements to the verifier in particular
   around XOR and OR operators, refactoring of checks for range computation
   and relaxing MUL range computation so that src_reg can also be an unknown
   scalar, from Cupertino Miranda.

3) Add support to attach kprobe BPF programs through kprobe_multi link in
   a session mode, meaning, a BPF program is attached to both function entry
   and return, the entry program can decide if the return program gets
   executed and the entry program can share u64 cookie value with return
   program. Session mode is a common use-case for tetragon and bpftrace,
   from Jiri Olsa.

4) Fix a potential overflow in libbpf's ring__consume_n() and improve libbpf
   as well as BPF selftest's struct_ops handling, from Andrii Nakryiko.

5) Improvements to BPF selftests in context of BPF gcc backend,
   from Jose E. Marchesi & David Faust.

6) Migrate remaining BPF selftest tests from test_sock_addr.c to prog_test-
   -style in order to retire the old test, run it in BPF CI and additionally
   expand test coverage, from Jordan Rife.

7) Big batch for BPF selftest refactoring in order to remove duplicate code
   around common network helpers, from Geliang Tang.

8) Another batch of improvements to BPF selftests to retire obsolete
   bpf_tcp_helpers.h as everything is available vmlinux.h,
   from Martin KaFai Lau.

9) Fix BPF map tear-down to not walk the map twice on free when both timer
   and wq is used, from Benjamin Tissoires.

10) Fix BPF verifier assumptions about socket->sk that it can be non-NULL,
    from Alexei Starovoitov.

11) Change BTF build scripts to using --btf_features for pahole v1.26+,
    from Alan Maguire.

12) Small improvements to BPF reusing struct_size() and krealloc_array(),
    from Andy Shevchenko.

13) Fix s390 JIT to emit a barrier for BPF_FETCH instructions,
    from Ilya Leoshkevich.

14) Extend TCP ->cong_control() callback in order to feed in ack and
    flag parameters and allow write-access to tp->snd_cwnd_stamp
    from BPF program, from Miao Xu.

15) Add support for internal-only per-CPU instructions to inline
    bpf_get_smp_processor_id() helper call for arm64 and riscv64 BPF JITs,
    from Puranjay Mohan.

16) Follow-up to remove the redundant ethtool.h from tooling infrastructure,
    from Tushar Vyavahare.

17) Extend libbpf to support "module:<function>" syntax for tracing
    programs, from Viktor Malik.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (119 commits)
  bpf: make list_for_each_entry portable
  bpf: ignore expected GCC warning in test_global_func10.c
  bpf: disable strict aliasing in test_global_func9.c
  selftests/bpf: Free strdup memory in xdp_hw_metadata
  selftests/bpf: Fix a few tests for GCC related warnings.
  bpf: avoid gcc overflow warning in test_xdp_vlan.c
  tools: remove redundant ethtool.h from tooling infra
  selftests/bpf: Expand ATTACH_REJECT tests
  selftests/bpf: Expand getsockname and getpeername tests
  sefltests/bpf: Expand sockaddr hook deny tests
  selftests/bpf: Expand sockaddr program return value tests
  selftests/bpf: Retire test_sock_addr.(c|sh)
  selftests/bpf: Remove redundant sendmsg test cases
  selftests/bpf: Migrate ATTACH_REJECT test cases
  selftests/bpf: Migrate expected_attach_type tests
  selftests/bpf: Migrate wildcard destination rewrite test
  selftests/bpf: Migrate sendmsg6 v4 mapped address tests
  selftests/bpf: Migrate sendmsg deny test cases
  selftests/bpf: Migrate WILDCARD_IP test
  selftests/bpf: Handle SYSCALL_EPERM and SYSCALL_ENOTSUPP test cases
  ...
====================

Link: https://lore.kernel.org/r/20240513134114.17575-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-05-13 16:41:10 -07:00
Puranjay Mohan 2ddec2c80b riscv, bpf: inline bpf_get_smp_processor_id()
Inline the calls to bpf_get_smp_processor_id() in the riscv bpf jit.

RISCV saves the pointer to the CPU's task_struct in the TP (thread
pointer) register. This makes it trivial to get the CPU's processor id.
As thread_info is the first member of task_struct, we can read the
processor id from TP + offsetof(struct thread_info, cpu).

          RISCV64 JIT output for `call bpf_get_smp_processor_id`
	  ======================================================

                Before                           After
               --------                         -------

         auipc   t1,0x848c                  ld    a5,32(tp)
         jalr    604(t1)
         mv      a5,a0

Benchmark using [1] on Qemu.

./benchs/run_bench_trigger.sh glob-arr-inc arr-inc hash-inc

+---------------+------------------+------------------+--------------+
|      Name     |     Before       |       After      |   % change   |
|---------------+------------------+------------------+--------------|
| glob-arr-inc  | 1.077 ± 0.006M/s | 1.336 ± 0.010M/s |   + 24.04%   |
| arr-inc       | 1.078 ± 0.002M/s | 1.332 ± 0.015M/s |   + 23.56%   |
| hash-inc      | 0.494 ± 0.004M/s | 0.653 ± 0.001M/s |   + 32.18%   |
+---------------+------------------+------------------+--------------+

NOTE: This benchmark includes changes from this patch and the previous
      patch that implemented the per-cpu insn.

[1] https://github.com/anakryiko/linux/commit/8dec900975ef

Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Björn Töpel <bjorn@kernel.org>
Link: https://lore.kernel.org/r/20240502151854.9810-3-puranjay@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-05-12 16:54:34 -07:00
Haiyue Wang 75b0fbf15d bpf: Remove redundant page mask of vmf->address
As the comment described in "struct vm_fault":
	".address"      : 'Faulting virtual address - masked'
	".real_address" : 'Faulting virtual address - unmasked'

The link [1] said: "Whatever the routes, all architectures end up to the
invocation of handle_mm_fault() which, in turn, (likely) ends up calling
__handle_mm_fault() to carry out the actual work of allocating the page
tables."

  __handle_mm_fault() does address assignment:
	.address = address & PAGE_MASK,
	.real_address = address,

This is debug dump by running `./test_progs -a "*arena*"`:

[   69.767494] arena fault: vmf->address = 10000001d000, vmf->real_address = 10000001d008
[   69.767496] arena fault: vmf->address = 10000001c000, vmf->real_address = 10000001c008
[   69.767499] arena fault: vmf->address = 10000001b000, vmf->real_address = 10000001b008
[   69.767501] arena fault: vmf->address = 10000001a000, vmf->real_address = 10000001a008
[   69.767504] arena fault: vmf->address = 100000019000, vmf->real_address = 100000019008
[   69.769388] arena fault: vmf->address = 10000001e000, vmf->real_address = 10000001e1e8

So we can use the value of 'vmf->address' to do BPF arena kernel address
space cast directly.

[1] https://docs.kernel.org/mm/page_tables.html

Signed-off-by: Haiyue Wang <haiyue.wang@intel.com>
Link: https://lore.kernel.org/r/20240507063358.8048-1-haiyue.wang@intel.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-05-07 14:13:17 -07:00
Cupertino Miranda 41d047a871 bpf/verifier: relax MUL range computation check
MUL instruction required that src_reg would be a known value (i.e.
src_reg would be a const value). The condition in this case can be
relaxed, since the range computation algorithm used in current code
already supports a proper range computation for any valid range value on
its operands.

Signed-off-by: Cupertino Miranda <cupertino.miranda@oracle.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Acked-by: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc: Yonghong Song <yonghong.song@linux.dev>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: David Faust <david.faust@oracle.com>
Cc: Jose Marchesi <jose.marchesi@oracle.com>
Cc: Elena Zannoni <elena.zannoni@oracle.com>
Link: https://lore.kernel.org/r/20240506141849.185293-6-cupertino.miranda@oracle.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-05-06 17:09:12 -07:00
Cupertino Miranda 138cc42c05 bpf/verifier: improve XOR and OR range computation
Range for XOR and OR operators would not be attempted unless src_reg
would resolve to a single value, i.e. a known constant value.
This condition is unnecessary, and the following XOR/OR operator
handling could compute a possible better range.

Acked-by: Eduard Zingerman <eddyz87@gmail.com>

Signed-off-by: Cupertino Miranda <cupertino.miranda@oracle.com
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Cc: Yonghong Song <yonghong.song@linux.dev>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: David Faust <david.faust@oracle.com>
Cc: Jose Marchesi <jose.marchesi@oracle.com>
Cc: Elena Zannoni <elena.zannoni@oracle.com>
Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Link: https://lore.kernel.org/r/20240506141849.185293-4-cupertino.miranda@oracle.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-05-06 17:09:11 -07:00
Cupertino Miranda 0922c78f59 bpf/verifier: refactor checks for range computation
Split range computation checks in its own function, isolating pessimitic
range set for dst_reg and failing return to a single point.

Signed-off-by: Cupertino Miranda <cupertino.miranda@oracle.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Cc: Yonghong Song <yonghong.song@linux.dev>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: David Faust <david.faust@oracle.com>
Cc: Jose Marchesi <jose.marchesi@oracle.com>
Cc: Elena Zannoni <elena.zannoni@oracle.com>
Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com>

bpf/verifier: improve code after range computation recent changes.
Link: https://lore.kernel.org/r/20240506141849.185293-3-cupertino.miranda@oracle.com

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-05-06 17:09:11 -07:00
Cupertino Miranda d786957ebd bpf/verifier: replace calls to mark_reg_unknown.
In order to further simplify the code in adjust_scalar_min_max_vals all
the calls to mark_reg_unknown are replaced by __mark_reg_unknown.

static void mark_reg_unknown(struct bpf_verifier_env *env,
  			     struct bpf_reg_state *regs, u32 regno)
{
	if (WARN_ON(regno >= MAX_BPF_REG)) {
		... mark all regs not init ...
		return;
    }
	__mark_reg_unknown(env, regs + regno);
}

The 'regno >= MAX_BPF_REG' does not apply to
adjust_scalar_min_max_vals(), because it is only called from the
following stack:
  - check_alu_op
    - adjust_reg_min_max_vals
      - adjust_scalar_min_max_vals

The check_alu_op() does check_reg_arg() which verifies that both src and
dst register numbers are within bounds.

Signed-off-by: Cupertino Miranda <cupertino.miranda@oracle.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Cc: Yonghong Song <yonghong.song@linux.dev>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: David Faust <david.faust@oracle.com>
Cc: Jose Marchesi <jose.marchesi@oracle.com>
Cc: Elena Zannoni <elena.zannoni@oracle.com>
Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Link: https://lore.kernel.org/r/20240506141849.185293-2-cupertino.miranda@oracle.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-05-06 17:09:11 -07:00
Jakub Kicinski e958da0ddb Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR.

Conflicts:

include/linux/filter.h
kernel/bpf/core.c
  66e13b615a ("bpf: verifier: prevent userspace memory access")
  d503a04f8b ("bpf: Add support for certain atomics in bpf_arena to x86 JIT")
https://lore.kernel.org/all/20240429114939.210328b0@canb.auug.org.au/

No adjacent changes.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-05-02 12:06:25 -07:00
Vadim Fedorenko ac2f438c2a bpf: crypto: fix build when CONFIG_CRYPTO=m
Crypto subsytem can be build as a module. In this case we still have to
build BPF crypto framework otherwise the build will fail.

Fixes: 3e1c6f3540 ("bpf: make common crypto API for TC/XDP programs")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202405011634.4JK40epY-lkp@intel.com/
Signed-off-by: Vadim Fedorenko <vadfed@meta.com>
Link: https://lore.kernel.org/r/20240501170130.1682309-1-vadfed@meta.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2024-05-01 13:32:26 -07:00
Jiri Olsa 5c919acef8 bpf: Add support for kprobe session cookie
Adding support for cookie within the session of kprobe multi
entry and return program.

The session cookie is u64 value and can be retrieved be new
kfunc bpf_session_cookie, which returns pointer to the cookie
value. The bpf program can use the pointer to store (on entry)
and load (on return) the value.

The cookie value is implemented via fprobe feature that allows
to share values between entry and return ftrace fprobe callbacks.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240430112830.1184228-4-jolsa@kernel.org
2024-04-30 09:45:53 -07:00
Jiri Olsa adf46d88ae bpf: Add support for kprobe session context
Adding struct bpf_session_run_ctx object to hold session related
data, which is atm is_return bool and data pointer coming in
following changes.

Placing bpf_session_run_ctx layer in between bpf_run_ctx and
bpf_kprobe_multi_run_ctx so the session data can be retrieved
regardless of if it's kprobe_multi or uprobe_multi link, which
support is coming in future. This way both kprobe_multi and
uprobe_multi can use same kfuncs to access the session data.

Adding bpf_session_is_return kfunc that returns true if the
bpf program is executed from the exit probe of the kprobe multi
link attached in wrapper mode. It returns false otherwise.

Adding new kprobe hook for kprobe program type.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240430112830.1184228-3-jolsa@kernel.org
2024-04-30 09:45:53 -07:00
Jiri Olsa 535a3692ba bpf: Add support for kprobe session attach
Adding support to attach bpf program for entry and return probe
of the same function. This is common use case which at the moment
requires to create two kprobe multi links.

Adding new BPF_TRACE_KPROBE_SESSION attach type that instructs
kernel to attach single link program to both entry and exit probe.

It's possible to control execution of the bpf program on return
probe simply by returning zero or non zero from the entry bpf
program execution to execute or not the bpf program on return
probe respectively.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240430112830.1184228-2-jolsa@kernel.org
2024-04-30 09:45:53 -07:00
Benjamin Tissoires a891711d01 bpf: Do not walk twice the hash map on free
If someone stores both a timer and a workqueue in a hash map, on free, we
would walk it twice.

Add a check in htab_free_malloced_timers_or_wq and free the timers and
workqueues if they are present.

Fixes: 246331e3f1 ("bpf: allow struct bpf_wq to be embedded in arraymaps and hashmaps")
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/bpf/20240430-bpf-next-v3-2-27afe7f3b17c@kernel.org
2024-04-30 16:28:46 +02:00
Benjamin Tissoires b98a5c68cc bpf: Do not walk twice the map on free
If someone stores both a timer and a workqueue in a map, on free
we would walk it twice.

Add a check in array_map_free_timers_wq and free the timers and
workqueues if they are present.

Fixes: 246331e3f1 ("bpf: allow struct bpf_wq to be embedded in arraymaps and hashmaps")
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/bpf/20240430-bpf-next-v3-1-27afe7f3b17c@kernel.org
2024-04-30 16:28:33 +02:00
Andy Shevchenko a3034872cd bpf: Switch to krealloc_array()
Let the krealloc_array() copy the original data and
check for a multiplication overflow.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/bpf/20240429120005.3539116-1-andriy.shevchenko@linux.intel.com
2024-04-29 16:13:14 -07:00
Andy Shevchenko cb01621b6d bpf: Use struct_size()
Use struct_size() instead of hand writing it.
This is less verbose and more robust.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/bpf/20240429121323.3818497-1-andriy.shevchenko@linux.intel.com
2024-04-29 16:12:03 -07:00
Alexei Starovoitov 0db63c0b86 bpf: Fix verifier assumptions about socket->sk
The verifier assumes that 'sk' field in 'struct socket' is valid
and non-NULL when 'socket' pointer itself is trusted and non-NULL.
That may not be the case when socket was just created and
passed to LSM socket_accept hook.
Fix this verifier assumption and adjust tests.

Reported-by: Liam Wisehart <liamwisehart@meta.com>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Fixes: 6fcd486b3a ("bpf: Refactor RCU enforcement in the verifier.")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/r/20240427002544.68803-1-alexei.starovoitov@gmail.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2024-04-29 14:16:41 -07:00
Jakub Kicinski 89de2db193 bpf-next-for-netdev
-----BEGIN PGP SIGNATURE-----
 
 iHUEABYIAB0WIQTFp0I1jqZrAX+hPRXbK58LschIgwUCZi9+AAAKCRDbK58LschI
 g0nEAP487m7L0nLVriC2oIOWsi29tklW3etm6DO7gmGRGIHgrgEAnMyV1xBj3bGj
 v6jJwDcybCym1hLx+1x1JCZ4eoAFswE=
 =xbna
 -----END PGP SIGNATURE-----

Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Daniel Borkmann says:

====================
pull-request: bpf-next 2024-04-29

We've added 147 non-merge commits during the last 32 day(s) which contain
a total of 158 files changed, 9400 insertions(+), 2213 deletions(-).

The main changes are:

1) Add an internal-only BPF per-CPU instruction for resolving per-CPU
   memory addresses and implement support in x86 BPF JIT. This allows
   inlining per-CPU array and hashmap lookups
   and the bpf_get_smp_processor_id() helper, from Andrii Nakryiko.

2) Add BPF link support for sk_msg and sk_skb programs, from Yonghong Song.

3) Optimize x86 BPF JIT's emit_mov_imm64, and add support for various
   atomics in bpf_arena which can be JITed as a single x86 instruction,
   from Alexei Starovoitov.

4) Add support for passing mark with bpf_fib_lookup helper,
   from Anton Protopopov.

5) Add a new bpf_wq API for deferring events and refactor sleepable
   bpf_timer code to keep common code where possible,
   from Benjamin Tissoires.

6) Fix BPF_PROG_TEST_RUN infra with regards to bpf_dummy_struct_ops programs
   to check when NULL is passed for non-NULLable parameters,
   from Eduard Zingerman.

7) Harden the BPF verifier's and/or/xor value tracking,
   from Harishankar Vishwanathan.

8) Introduce crypto kfuncs to make BPF programs able to utilize the kernel
   crypto subsystem, from Vadim Fedorenko.

9) Various improvements to the BPF instruction set standardization doc,
   from Dave Thaler.

10) Extend libbpf APIs to partially consume items from the BPF ringbuffer,
    from Andrea Righi.

11) Bigger batch of BPF selftests refactoring to use common network helpers
    and to drop duplicate code, from Geliang Tang.

12) Support bpf_tail_call_static() helper for BPF programs with GCC 13,
    from Jose E. Marchesi.

13) Add bpf_preempt_{disable,enable}() kfuncs in order to allow a BPF
    program to have code sections where preemption is disabled,
    from Kumar Kartikeya Dwivedi.

14) Allow invoking BPF kfuncs from BPF_PROG_TYPE_SYSCALL programs,
    from David Vernet.

15) Extend the BPF verifier to allow different input maps for a given
    bpf_for_each_map_elem() helper call in a BPF program, from Philo Lu.

16) Add support for PROBE_MEM32 and bpf_addr_space_cast instructions
    for riscv64 and arm64 JITs to enable BPF Arena, from Puranjay Mohan.

17) Shut up a false-positive KMSAN splat in interpreter mode by unpoison
    the stack memory, from Martin KaFai Lau.

18) Improve xsk selftest coverage with new tests on maximum and minimum
    hardware ring size configurations, from Tushar Vyavahare.

19) Various ReST man pages fixes as well as documentation and bash completion
    improvements for bpftool, from Rameez Rehman & Quentin Monnet.

20) Fix libbpf with regards to dumping subsequent char arrays,
    from Quentin Deslandes.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (147 commits)
  bpf, docs: Clarify PC use in instruction-set.rst
  bpf_helpers.h: Define bpf_tail_call_static when building with GCC
  bpf, docs: Add introduction for use in the ISA Internet Draft
  selftests/bpf: extend BPF_SOCK_OPS_RTT_CB test for srtt and mrtt_us
  bpf: add mrtt and srtt as BPF_SOCK_OPS_RTT_CB args
  selftests/bpf: dummy_st_ops should reject 0 for non-nullable params
  bpf: check bpf_dummy_struct_ops program params for test runs
  selftests/bpf: do not pass NULL for non-nullable params in dummy_st_ops
  selftests/bpf: adjust dummy_st_ops_success to detect additional error
  bpf: mark bpf_dummy_struct_ops.test_1 parameter as nullable
  selftests/bpf: Add ring_buffer__consume_n test.
  bpf: Add bpf_guard_preempt() convenience macro
  selftests: bpf: crypto: add benchmark for crypto functions
  selftests: bpf: crypto skcipher algo selftests
  bpf: crypto: add skcipher to bpf crypto
  bpf: make common crypto API for TC/XDP programs
  bpf: update the comment for BTF_FIELDS_MAX
  selftests/bpf: Fix wq test.
  selftests/bpf: Use make_sockaddr in test_sock_addr
  selftests/bpf: Use connect_to_addr in test_sock_addr
  ...
====================

Link: https://lore.kernel.org/r/20240429131657.19423-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-04-29 13:12:19 -07:00
Puranjay Mohan 66e13b615a bpf: verifier: prevent userspace memory access
With BPF_PROBE_MEM, BPF allows de-referencing an untrusted pointer. To
thwart invalid memory accesses, the JITs add an exception table entry
for all such accesses. But in case the src_reg + offset is a userspace
address, the BPF program might read that memory if the user has
mapped it.

Make the verifier add guard instructions around such memory accesses and
skip the load if the address falls into the userspace region.

The JITs need to implement bpf_arch_uaddress_limit() to define where
the userspace addresses end for that architecture or TASK_SIZE is taken
as default.

The implementation is as follows:

REG_AX =  SRC_REG
if(offset)
	REG_AX += offset;
REG_AX >>= 32;
if (REG_AX <= (uaddress_limit >> 32))
	DST_REG = 0;
else
	DST_REG = *(size *)(SRC_REG + offset);

Comparing just the upper 32 bits of the load address with the upper
32 bits of uaddress_limit implies that the values are being aligned down
to a 4GB boundary before comparison.

The above means that all loads with address <= uaddress_limit + 4GB are
skipped. This is acceptable because there is a large hole (much larger
than 4GB) between userspace and kernel space memory, therefore a
correctly functioning BPF program should not access this 4GB memory
above the userspace.

Let's analyze what this patch does to the following fentry program
dereferencing an untrusted pointer:

  SEC("fentry/tcp_v4_connect")
  int BPF_PROG(fentry_tcp_v4_connect, struct sock *sk)
  {
                *(volatile long *)sk;
                return 0;
  }

    BPF Program before              |           BPF Program after
    ------------------              |           -----------------

  0: (79) r1 = *(u64 *)(r1 +0)          0: (79) r1 = *(u64 *)(r1 +0)
  -----------------------------------------------------------------------
  1: (79) r1 = *(u64 *)(r1 +0) --\      1: (bf) r11 = r1
  ----------------------------\   \     2: (77) r11 >>= 32
  2: (b7) r0 = 0               \   \    3: (b5) if r11 <= 0x8000 goto pc+2
  3: (95) exit                  \   \-> 4: (79) r1 = *(u64 *)(r1 +0)
                                 \      5: (05) goto pc+1
                                  \     6: (b7) r1 = 0
                                   \--------------------------------------
                                        7: (b7) r0 = 0
                                        8: (95) exit

As you can see from above, in the best case (off=0), 5 extra instructions
are emitted.

Now, we analyze the same program after it has gone through the JITs of
ARM64 and RISC-V architectures. We follow the single load instruction
that has the untrusted pointer and see what instrumentation has been
added around it.

                                x86-64 JIT
                                ==========
     JIT's Instrumentation
          (upstream)
     ---------------------

   0:   nopl   0x0(%rax,%rax,1)
   5:   xchg   %ax,%ax
   7:   push   %rbp
   8:   mov    %rsp,%rbp
   b:   mov    0x0(%rdi),%rdi
  ---------------------------------
   f:   movabs $0x800000000000,%r11
  19:   cmp    %r11,%rdi
  1c:   jb     0x000000000000002a
  1e:   mov    %rdi,%r11
  21:   add    $0x0,%r11
  28:   jae    0x000000000000002e
  2a:   xor    %edi,%edi
  2c:   jmp    0x0000000000000032
  2e:   mov    0x0(%rdi),%rdi
  ---------------------------------
  32:   xor    %eax,%eax
  34:   leave
  35:   ret

The x86-64 JIT already emits some instructions to protect against user
memory access. This patch doesn't make any changes for the x86-64 JIT.

                                  ARM64 JIT
                                  =========

        No Intrumentation                       Verifier's Instrumentation
           (upstream)                                  (This patch)
        -----------------                       --------------------------

   0:   add     x9, x30, #0x0                0:   add     x9, x30, #0x0
   4:   nop                                  4:   nop
   8:   paciasp                              8:   paciasp
   c:   stp     x29, x30, [sp, #-16]!        c:   stp     x29, x30, [sp, #-16]!
  10:   mov     x29, sp                     10:   mov     x29, sp
  14:   stp     x19, x20, [sp, #-16]!       14:   stp     x19, x20, [sp, #-16]!
  18:   stp     x21, x22, [sp, #-16]!       18:   stp     x21, x22, [sp, #-16]!
  1c:   stp     x25, x26, [sp, #-16]!       1c:   stp     x25, x26, [sp, #-16]!
  20:   stp     x27, x28, [sp, #-16]!       20:   stp     x27, x28, [sp, #-16]!
  24:   mov     x25, sp                     24:   mov     x25, sp
  28:   mov     x26, #0x0                   28:   mov     x26, #0x0
  2c:   sub     x27, x25, #0x0              2c:   sub     x27, x25, #0x0
  30:   sub     sp, sp, #0x0                30:   sub     sp, sp, #0x0
  34:   ldr     x0, [x0]                    34:   ldr     x0, [x0]
--------------------------------------------------------------------------------
  38:   ldr     x0, [x0] ----------\        38:   add     x9, x0, #0x0
-----------------------------------\\       3c:   lsr     x9, x9, #32
  3c:   mov     x7, #0x0            \\      40:   cmp     x9, #0x10, lsl #12
  40:   mov     sp, sp               \\     44:   b.ls    0x0000000000000050
  44:   ldp     x27, x28, [sp], #16   \\--> 48:   ldr     x0, [x0]
  48:   ldp     x25, x26, [sp], #16    \    4c:   b       0x0000000000000054
  4c:   ldp     x21, x22, [sp], #16     \   50:   mov     x0, #0x0
  50:   ldp     x19, x20, [sp], #16      \---------------------------------------
  54:   ldp     x29, x30, [sp], #16         54:   mov     x7, #0x0
  58:   add     x0, x7, #0x0                58:   mov     sp, sp
  5c:   autiasp                             5c:   ldp     x27, x28, [sp], #16
  60:   ret                                 60:   ldp     x25, x26, [sp], #16
  64:   nop                                 64:   ldp     x21, x22, [sp], #16
  68:   ldr     x10, 0x0000000000000070     68:   ldp     x19, x20, [sp], #16
  6c:   br      x10                         6c:   ldp     x29, x30, [sp], #16
                                            70:   add     x0, x7, #0x0
                                            74:   autiasp
                                            78:   ret
                                            7c:   nop
                                            80:   ldr     x10, 0x0000000000000088
                                            84:   br      x10

There are 6 extra instructions added in ARM64 in the best case. This will
become 7 in the worst case (off != 0).

                           RISC-V JIT (RISCV_ISA_C Disabled)
                           ==========

        No Intrumentation           Verifier's Instrumentation
           (upstream)                      (This patch)
        -----------------           --------------------------

   0:   nop                            0:   nop
   4:   nop                            4:   nop
   8:   li      a6, 33                 8:   li      a6, 33
   c:   addi    sp, sp, -16            c:   addi    sp, sp, -16
  10:   sd      s0, 8(sp)             10:   sd      s0, 8(sp)
  14:   addi    s0, sp, 16            14:   addi    s0, sp, 16
  18:   ld      a0, 0(a0)             18:   ld      a0, 0(a0)
---------------------------------------------------------------
  1c:   ld      a0, 0(a0) --\         1c:   mv      t0, a0
--------------------------\  \        20:   srli    t0, t0, 32
  20:   li      a5, 0      \  \       24:   lui     t1, 4096
  24:   ld      s0, 8(sp)   \  \      28:   sext.w  t1, t1
  28:   addi    sp, sp, 16   \  \     2c:   bgeu    t1, t0, 12
  2c:   sext.w  a0, a5        \  \--> 30:   ld      a0, 0(a0)
  30:   ret                    \      34:   j       8
                                \     38:   li      a0, 0
                                 \------------------------------
                                      3c:   li      a5, 0
                                      40:   ld      s0, 8(sp)
                                      44:   addi    sp, sp, 16
                                      48:   sext.w  a0, a5
                                      4c:   ret

There are 7 extra instructions added in RISC-V.

Fixes: 8008342853 ("bpf, arm64: Add BPF exception tables")
Reported-by: Breno Leitao <leitao@debian.org>
Suggested-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Puranjay Mohan <puranjay12@gmail.com>
Link: https://lore.kernel.org/r/20240424100210.11982-2-puranjay@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-26 09:45:18 -07:00
Vadim Fedorenko 3e1c6f3540 bpf: make common crypto API for TC/XDP programs
Add crypto API support to BPF to be able to decrypt or encrypt packets
in TC/XDP BPF programs. Special care should be taken for initialization
part of crypto algo because crypto alloc) doesn't work with preemtion
disabled, it can be run only in sleepable BPF program. Also async crypto
is not supported because of the very same issue - TC/XDP BPF programs
are not sleepable.

Signed-off-by: Vadim Fedorenko <vadfed@meta.com>
Link: https://lore.kernel.org/r/20240422225024.2847039-2-vadfed@meta.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2024-04-24 16:01:10 -07:00
Kumar Kartikeya Dwivedi fc7566ad0a bpf: Introduce bpf_preempt_[disable,enable] kfuncs
Introduce two new BPF kfuncs, bpf_preempt_disable and
bpf_preempt_enable. These kfuncs allow disabling preemption in BPF
programs. Nesting is allowed, since the intended use cases includes
building native BPF spin locks without kernel helper involvement. Apart
from that, this can be used to per-CPU data structures for cases where
programs (or userspace) may preempt one or the other. Currently, while
per-CPU access is stable, whether it will be consistent is not
guaranteed, as only migration is disabled for BPF programs.

Global functions are disallowed from being called, but support for them
will be added as a follow up not just preempt kfuncs, but rcu_read_lock
kfuncs as well. Static subprog calls are permitted. Sleepable helpers
and kfuncs are disallowed in non-preemptible regions.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20240424031315.2757363-2-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-24 09:47:49 -07:00
Alexei Starovoitov dc92febf7b bpf: Don't check for recursion in bpf_wq_work.
__bpf_prog_enter_sleepable_recur does recursion check which is not applicable
to wq callback. The callback function is part of bpf program and bpf prog might
be running on the same cpu. So recursion check would incorrectly prevent
callback from running. The code can call __bpf_prog_enter_sleepable(), but
run_ctx would be fake, hence use explicit rcu_read_lock_trace();
migrate_disable(); to address this problem. Another reason to open code is
__bpf_prog_enter* are not available in !JIT configs.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202404241719.IIGdpAku-lkp@intel.com/
Closes: https://lore.kernel.org/oe-kbuild-all/202404241811.FFV4Bku3-lkp@intel.com/
Fixes: eb48f6cd41 ("bpf: wq: add bpf_wq_init")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-24 09:06:50 -07:00
Benjamin Tissoires 8e83da9732 bpf: add bpf_wq_start
again, copy/paste from bpf_timer_start().

Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
Link: https://lore.kernel.org/r/20240420-bpf_wq-v2-15-6c986a5a741f@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-23 19:46:57 -07:00
Benjamin Tissoires 81f1d7a583 bpf: wq: add bpf_wq_set_callback_impl
To support sleepable async callbacks, we need to tell push_async_cb()
whether the cb is sleepable or not.

The verifier now detects that we are in bpf_wq_set_callback_impl and
can allow a sleepable callback to happen.

Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
Link: https://lore.kernel.org/r/20240420-bpf_wq-v2-13-6c986a5a741f@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-23 19:46:57 -07:00
Benjamin Tissoires eb48f6cd41 bpf: wq: add bpf_wq_init
We need to teach the verifier about the second argument which is declared
as void * but which is of type KF_ARG_PTR_TO_MAP. We could have dropped
this extra case if we declared the second argument as struct bpf_map *,
but that means users will have to do extra casting to have their program
compile.

We also need to duplicate the timer code for the checking if the map
argument is matching the provided workqueue.

Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
Link: https://lore.kernel.org/r/20240420-bpf_wq-v2-11-6c986a5a741f@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-23 19:46:57 -07:00
Benjamin Tissoires 246331e3f1 bpf: allow struct bpf_wq to be embedded in arraymaps and hashmaps
Currently bpf_wq_cancel_and_free() is just a placeholder as there is
no memory allocation for bpf_wq just yet.

Again, duplication of the bpf_timer approach

Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
Link: https://lore.kernel.org/r/20240420-bpf_wq-v2-9-6c986a5a741f@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-23 18:31:25 -07:00
Benjamin Tissoires d940c9b94d bpf: add support for KF_ARG_PTR_TO_WORKQUEUE
Introduce support for KF_ARG_PTR_TO_WORKQUEUE. The kfuncs will use bpf_wq
as argument and that will be recognized as workqueue argument by verifier.
bpf_wq_kern casting can happen inside kfunc, but using bpf_wq in
argument makes life easier for users who work with non-kern type in BPF
progs.

Duplicate process_timer_func into process_wq_func.
meta argument is only needed to ensure bpf_wq_init's workqueue and map
arguments are coming from the same map (map_uid logic is necessary for
correct inner-map handling), so also amend check_kfunc_args() to
match what helpers functions check is doing.

Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
Link: https://lore.kernel.org/r/20240420-bpf_wq-v2-8-6c986a5a741f@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-23 18:31:25 -07:00
Benjamin Tissoires ad2c03e691 bpf: verifier: bail out if the argument is not a map
When a kfunc is declared with a KF_ARG_PTR_TO_MAP, we should have
reg->map_ptr set to a non NULL value, otherwise, that means that the
underlying type is not a map.

Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
Link: https://lore.kernel.org/r/20240420-bpf_wq-v2-7-6c986a5a741f@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-23 18:31:24 -07:00
Benjamin Tissoires d56b63cf0c bpf: add support for bpf_wq user type
Mostly a copy/paste from the bpf_timer API, without the initialization
and free, as they will be done in a separate patch.

Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
Link: https://lore.kernel.org/r/20240420-bpf_wq-v2-5-6c986a5a741f@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-23 18:31:24 -07:00
Benjamin Tissoires fc22d9495f bpf: replace bpf_timer_cancel_and_free with a generic helper
Same reason than most bpf_timer* functions, we need almost the same for
workqueues.
So extract the generic part out of it so bpf_wq_cancel_and_free can reuse
it.

Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
Link: https://lore.kernel.org/r/20240420-bpf_wq-v2-4-6c986a5a741f@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-23 18:31:24 -07:00
Benjamin Tissoires 073f11b026 bpf: replace bpf_timer_set_callback with a generic helper
In the same way we have a generic __bpf_async_init(), we also need
to share code between timer and workqueue for the set_callback call.

We just add an unused flags parameter, as it will be used for workqueues.

Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
Link: https://lore.kernel.org/r/20240420-bpf_wq-v2-3-6c986a5a741f@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-23 18:31:24 -07:00
Benjamin Tissoires 56b4a177ae bpf: replace bpf_timer_init with a generic helper
No code change except for the new flags argument being stored in the
local data struct.

Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
Link: https://lore.kernel.org/r/20240420-bpf_wq-v2-2-6c986a5a741f@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-23 18:31:24 -07:00
Benjamin Tissoires be2749beff bpf: make timer data struct more generic
To be able to add workqueues and reuse most of the timer code, we need
to make bpf_hrtimer more generic.

There is no code change except that the new struct gets a new u64 flags
attribute. We are still below 2 cache lines, so this shouldn't impact
the current running codes.

The ordering is also changed. Everything related to async callback
is now on top of bpf_hrtimer.

Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
Link: https://lore.kernel.org/r/20240420-bpf_wq-v2-1-6c986a5a741f@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-23 18:31:24 -07:00
Rafael Passos a7de265cb2 bpf: Fix typos in comments
Found the following typos in comments, and fixed them:

s/unpriviledged/unprivileged/
s/reponsible/responsible/
s/possiblities/possibilities/
s/Divison/Division/
s/precsion/precision/
s/havea/have a/
s/reponsible/responsible/
s/responsibile/responsible/
s/tigher/tighter/
s/respecitve/respective/

Signed-off-by: Rafael Passos <rafael@rcpassos.me>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/6af7deb4-bb24-49e8-b3f1-8dd410597337@smtp-relay.sendinblue.com
2024-04-22 17:48:08 +02:00
Rafael Passos e1a7545981 bpf: Fix typo in function save_aux_ptr_type
I found this typo in the save_aux_ptr_type function.
s/allow_trust_missmatch/allow_trust_mismatch/
I did not find this anywhere else in the codebase.

Signed-off-by: Rafael Passos <rafael@rcpassos.me>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/fbe1d636-8172-4698-9a5a-5a3444b55322@smtp-relay.sendinblue.com
2024-04-22 17:12:05 +02:00
Harishankar Vishwanathan 1f586614f3 bpf: Harden and/or/xor value tracking in verifier
This patch addresses a latent unsoundness issue in the
scalar(32)_min_max_and/or/xor functions. While it is not a bugfix,
it ensures that the functions produce sound outputs for all inputs.

The issue occurs in these functions when setting signed bounds. The
following example illustrates the issue for scalar_min_max_and(),
but it applies to the other functions.

In scalar_min_max_and() the following clause is executed when ANDing
positive numbers:

  /* ANDing two positives gives a positive, so safe to
   * cast result into s64.
   */
  dst_reg->smin_value = dst_reg->umin_value;
  dst_reg->smax_value = dst_reg->umax_value;

However, if umin_value and umax_value of dst_reg cross the sign boundary
(i.e., if (s64)dst_reg->umin_value > (s64)dst_reg->umax_value), then we
will end up with smin_value > smax_value, which is unsound.

Previous works [1, 2] have discovered and reported this issue. Our tool
Agni [2, 3] consideres it a false positive. This is because, during the
verification of the abstract operator scalar_min_max_and(), Agni restricts
its inputs to those passing through reg_bounds_sync(). This mimics
real-world verifier behavior, as reg_bounds_sync() is invariably executed
at the tail of every abstract operator. Therefore, such behavior is
unlikely in an actual verifier execution.

However, it is still unsound for an abstract operator to set signed bounds
such that smin_value > smax_value. This patch fixes it, making the abstract
operator sound for all (well-formed) inputs.

It is worth noting that while the previous code updated the signed bounds
(using the output unsigned bounds) only when the *input signed* bounds
were positive, the new code updates them whenever the *output unsigned*
bounds do not cross the sign boundary.

An alternative approach to fix this latent unsoundness would be to
unconditionally set the signed bounds to unbounded [S64_MIN, S64_MAX], and
let reg_bounds_sync() refine the signed bounds using the unsigned bounds
and the tnum. We found that our approach produces more precise (tighter)
bounds.

For example, consider these inputs to BPF_AND:

  /* dst_reg */
  var_off.value: 8608032320201083347
  var_off.mask: 615339716653692460
  smin_value: 8070450532247928832
  smax_value: 8070450532247928832
  umin_value: 13206380674380886586
  umax_value: 13206380674380886586
  s32_min_value: -2110561598
  s32_max_value: -133438816
  u32_min_value: 4135055354
  u32_max_value: 4135055354

  /* src_reg */
  var_off.value: 8584102546103074815
  var_off.mask: 9862641527606476800
  smin_value: 2920655011908158522
  smax_value: 7495731535348625717
  umin_value: 7001104867969363969
  umax_value: 8584102543730304042
  s32_min_value: -2097116671
  s32_max_value: 71704632
  u32_min_value: 1047457619
  u32_max_value: 4268683090

After going through tnum_and() -> scalar32_min_max_and() ->
scalar_min_max_and() -> reg_bounds_sync(), our patch produces the following
bounds for s32:

  s32_min_value: -1263875629
  s32_max_value: -159911942

Whereas, setting the signed bounds to unbounded in scalar_min_max_and()
produces:

  s32_min_value: -1263875629
  s32_max_value: -1

As observed, our patch produces a tighter s32 bound. We also confirmed
using Agni and SMT verification that our patch always produces signed
bounds that are equal to or more precise than setting the signed bounds to
unbounded in scalar_min_max_and().

  [1] https://sanjit-bhat.github.io/assets/pdf/ebpf-verifier-range-analysis22.pdf
  [2] https://link.springer.com/chapter/10.1007/978-3-031-37709-9_12
  [3] https://github.com/bpfverif/agni

Co-developed-by: Matan Shachnai <m.shachnai@rutgers.edu>
Signed-off-by: Matan Shachnai <m.shachnai@rutgers.edu>
Co-developed-by: Srinivas Narayana <srinivas.narayana@rutgers.edu>
Signed-off-by: Srinivas Narayana <srinivas.narayana@rutgers.edu>
Co-developed-by: Santosh Nagarakatte <santosh.nagarakatte@rutgers.edu>
Signed-off-by: Santosh Nagarakatte <santosh.nagarakatte@rutgers.edu>
Signed-off-by: Harishankar Vishwanathan <harishankar.vishwanathan@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20240402212039.51815-1-harishankar.vishwanathan@gmail.com
Link: https://lore.kernel.org/bpf/20240416115303.331688-1-harishankar.vishwanathan@gmail.com
2024-04-16 17:55:27 +02:00
Ard Biesheuvel fc5eb4a84e btf: Avoid weak external references
If the BTF code is enabled in the build configuration, the start/stop
BTF markers are guaranteed to exist. Only when CONFIG_DEBUG_INFO_BTF=n,
the references in btf_parse_vmlinux() will remain unsatisfied, relying
on the weak linkage of the external references to avoid breaking the
build.

Avoid GOT based relocations to these markers in the final executable by
dropping the weak attribute and instead, make btf_parse_vmlinux() return
ERR_PTR(-ENOENT) directly if CONFIG_DEBUG_INFO_BTF is not enabled to
begin with.  The compiler will drop any subsequent references to
__start_BTF and __stop_BTF in that case, allowing the link to succeed.

Note that Clang will notice that taking the address of __start_BTF can
no longer yield NULL, so testing for that condition becomes unnecessary.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20240415162041.2491523-8-ardb+git@google.com
2024-04-16 16:35:13 +02:00
Anton Protopopov 37eacb9f6e bpf: Fix a verifier verbose message
Long ago a map file descriptor in a pseudo ldimm64 instruction could
only be present as an immediate value insn[0].imm, and thus this value
was used in a verbose verifier message printed when the file descriptor
wasn't valid. Since addition of BPF_PSEUDO_MAP_IDX_VALUE/BPF_PSEUDO_MAP_IDX
the insn[0].imm field can also contain an index pointing to the file
descriptor in the attr.fd_array array. However, if the file descriptor
is invalid, the verifier still prints the verbose message containing
value of insn[0].imm. Patch the verifier message to always print the
actual file descriptor value.

Fixes: 387544bfa2 ("bpf: Introduce fd_idx")
Signed-off-by: Anton Protopopov <aspsk@isovalent.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20240412141100.3562942-1-aspsk@isovalent.com
2024-04-12 18:37:20 +02:00
Yonghong Song 699c23f02c bpf: Add bpf_link support for sk_msg and sk_skb progs
Add bpf_link support for sk_msg and sk_skb programs. We have an
internal request to support bpf_link for sk_msg programs so user
space can have a uniform handling with bpf_link based libbpf
APIs. Using bpf_link based libbpf API also has a benefit which
makes system robust by decoupling prog life cycle and
attachment life cycle.

Reviewed-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240410043527.3737160-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-10 19:52:25 -07:00
Alexei Starovoitov d503a04f8b bpf: Add support for certain atomics in bpf_arena to x86 JIT
Support atomics in bpf_arena that can be JITed as a single x86 instruction.
Instructions that are JITed as loops are not supported at the moment,
since they require more complex extable and loop logic.

JITs can choose to do smarter things with bpf_jit_supports_insn().
Like arm64 may decide to support all bpf atomics instructions
when emit_lse_atomic is available and none in ll_sc mode.

bpf_jit_supports_percpu_insn(), bpf_jit_supports_ptr_xchg() and
other such callbacks can be replaced with bpf_jit_supports_insn()
in the future.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20240405231134.17274-1-alexei.starovoitov@gmail.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2024-04-09 10:24:26 -07:00
David Vernet a8e03b6bbb bpf: Allow invoking kfuncs from BPF_PROG_TYPE_SYSCALL progs
Currently, a set of core BPF kfuncs (e.g. bpf_task_*, bpf_cgroup_*,
bpf_cpumask_*, etc) cannot be invoked from BPF_PROG_TYPE_SYSCALL
programs. The whitelist approach taken for enabling kfuncs makes sense:
it not safe to call these kfuncs from every program type. For example,
it may not be safe to call bpf_task_acquire() in an fentry to
free_task().

BPF_PROG_TYPE_SYSCALL, on the other hand, is a perfectly safe program
type from which to invoke these kfuncs, as it's a very controlled
environment, and we should never be able to run into any of the typical
problems such as recursive invoations, acquiring references on freeing
kptrs, etc. Being able to invoke these kfuncs would be useful, as
BPF_PROG_TYPE_SYSCALL can be invoked with BPF_PROG_RUN, and would
therefore enable user space programs to synchronously call into BPF to
manipulate these kptrs.

This patch therefore enables invoking the aforementioned core kfuncs
from BPF_PROG_TYPE_SYSCALL progs.

Signed-off-by: David Vernet <void@manifault.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/bpf/20240405143041.632519-2-void@manifault.com
2024-04-05 10:56:09 -07:00
Philo Lu 9d482da9e1 bpf: allow invoking bpf_for_each_map_elem with different maps
Taking different maps within a single bpf_for_each_map_elem call is not
allowed before, because from the second map,
bpf_insn_aux_data->map_ptr_state will be marked as *poison*. In fact
both map_ptr and state are needed to support this use case: map_ptr is
used by set_map_elem_callback_state() while poison state is needed to
determine whether to use direct call.

Signed-off-by: Philo Lu <lulie@linux.alibaba.com>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240405025536.18113-3-lulie@linux.alibaba.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-05 10:31:17 -07:00
Philo Lu 0a525621b7 bpf: store both map ptr and state in bpf_insn_aux_data
Currently, bpf_insn_aux_data->map_ptr_state is used to store either
map_ptr or its poison state (i.e., BPF_MAP_PTR_POISON). Thus
BPF_MAP_PTR_POISON must be checked before reading map_ptr. In certain
cases, we may need valid map_ptr even in case of poison state.
This will be explained in next patch with bpf_for_each_map_elem()
helper.

This patch changes map_ptr_state into a new struct including both map
pointer and its state (poison/unpriv). It's in the same union with
struct bpf_loop_inline_state, so there is no extra memory overhead.
Besides, macros BPF_MAP_PTR_UNPRIV/BPF_MAP_PTR_POISON/BPF_MAP_PTR are no
longer needed.

This patch does not change any existing functionality.

Signed-off-by: Philo Lu <lulie@linux.alibaba.com>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240405025536.18113-2-lulie@linux.alibaba.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-05 10:31:17 -07:00
Arnd Bergmann 58babe2718 bpf: fix perf_snapshot_branch_stack link failure
The newly added code to handle bpf_get_branch_snapshot fails to link when
CONFIG_PERF_EVENTS is disabled:

aarch64-linux-ld: kernel/bpf/verifier.o: in function `do_misc_fixups':
verifier.c:(.text+0x1090c): undefined reference to `__SCK__perf_snapshot_branch_stack'

Add a build-time check for that Kconfig symbol around the code to
remove the link time dependency.

Fixes: 314a53623c ("bpf: inline bpf_get_branch_snapshot() helper")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20240405142637.577046-1-arnd@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-05 08:39:15 -07:00
Andrii Nakryiko 1f2a74b41e bpf: prevent r10 register from being marked as precise
r10 is a special register that is not under BPF program's control and is
always effectively precise. The rest of precision logic assumes that
only r0-r9 SCALAR registers are marked as precise, so prevent r10 from
being marked precise.

This can happen due to signed cast instruction allowing to do something
like `r0 = (s8)r10;`, which later, if r0 needs to be precise, would lead
to an attempt to mark r10 as precise.

Prevent this with an extra check during instruction backtracking.

Fixes: 8100928c88 ("bpf: Support new sign-extension mov insns")
Reported-by: syzbot+148110ee7cf72f39f33e@syzkaller.appspotmail.com
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240404214536.3551295-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-04 18:31:08 -07:00
Jakub Kicinski cf1ca1f66d Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR.

Conflicts:

net/ipv4/ip_gre.c
  17af420545 ("erspan: make sure erspan_base_hdr is present in skb->head")
  5832c4a77d ("ip_tunnel: convert __be16 tunnel flags to bitmaps")
https://lore.kernel.org/all/20240402103253.3b54a1cf@canb.auug.org.au/

Adjacent changes:

net/ipv6/ip6_fib.c
  d21d40605b ("ipv6: Fix infinite recursion in fib6_dump_done().")
  5fc68320c1 ("ipv6: remove RTNL protection from inet6_dump_fib()")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-04-04 18:01:07 -07:00
Linus Torvalds c88b9b4cde Including fixes from netfilter, bluetooth and bpf.
Fairly usual collection of driver and core fixes. The large selftest
 accompanying one of the fixes is also becoming a common occurrence.
 
 Current release - regressions:
 
  - ipv6: fix infinite recursion in fib6_dump_done()
 
  - net/rds: fix possible null-deref in newly added error path
 
 Current release - new code bugs:
 
  - net: do not consume a full cacheline for system_page_pool
 
  - bpf: fix bpf_arena-related file descriptor leaks in the verifier
 
  - drv: ice: fix freeing uninitialized pointers, fixing misuse of
    the newfangled __free() auto-cleanup
 
 Previous releases - regressions:
 
  - x86/bpf: fixes the BPF JIT with retbleed=stuff
 
  - xen-netfront: add missing skb_mark_for_recycle, fix page pool
    accounting leaks, revealed by recently added explicit warning
 
  - tcp: fix bind() regression for v6-only wildcard and v4-mapped-v6
    non-wildcard addresses
 
  - Bluetooth:
    - replace "hci_qca: Set BDA quirk bit if fwnode exists in DT"
      with better workarounds to un-break some buggy Qualcomm devices
    - set conn encrypted before conn establishes, fix re-connecting
      to some headsets which use slightly unusual sequence of msgs
 
  - mptcp:
    - prevent BPF accessing lowat from a subflow socket
    - don't account accept() of non-MPC client as fallback to TCP
 
  - drv: mana: fix Rx DMA datasize and skb_over_panic
 
  - drv: i40e: fix VF MAC filter removal
 
 Previous releases - always broken:
 
  - gro: various fixes related to UDP tunnels - netns crossing problems,
    incorrect checksum conversions, and incorrect packet transformations
    which may lead to panics
 
  - bpf: support deferring bpf_link dealloc to after RCU grace period
 
  - nf_tables:
    - release batch on table validation from abort path
    - release mutex after nft_gc_seq_end from abort path
    - flush pending destroy work before exit_net release
 
  - drv: r8169: skip DASH fw status checks when DASH is disabled
 
 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCAAdFiEE6jPA+I1ugmIBA4hXMUZtbf5SIrsFAmYO91wACgkQMUZtbf5S
 IrvHBQ/+PH/hobI+o3aLqwtdVlyxhmA31bVQ0I3aTIZV7c3ideMBcfgYa8TiZM2g
 pLiBiWoJXCN0h33wgUmlUee+sBvpoPCdPjGD/g99OJyKWjVt2D7ObnSwxMfjHUoq
 dtcN2JupqHP0SHz6wPPCmnWtTLxSGUsDdKjmkHQcCRhQIGTYFkYyHcOmPgNbBjaB
 6jvmH1kE9WQTFD8QcOMaZmXQ5omoafpxxQLsgundtOWxPWHL7XNvk0B5k/ESDRG1
 ujbxwtNnOESzpxZMQ6OyZlsnN/1tWfnEvLJFYVwf9BMrOlahJT/f5b/EJ9/Xy4dC
 zkAp7Tul3uAvNRKhBNhVBTWQbnIykmiNMp1VBFmiScQAy8hcnX+6d4LKTIHxbXZK
 V3AqcUS6YU2nyMdLRkhvq9f3uxD6hcY19gQdyqgCUPOtyUAs/JPv7lXQjCuuEqkq
 urEZkigUApnEqPIrIqANJ7nXUy3U0K8qU6evOZoGZ5OdiKeNKC3+tIr+g2f1ZUZq
 a7Dkat7JH9WQ7IG8Geody6Z30K9EpSqYMTKzB5wTfmuqw6cV8bl9OAW9UOSRK0GL
 pyG8GwpkpFPkNiZdu9Zt44Pno5xdLIa1+C3QZR0r5CJWYAzCbI80MppP5veF9Mw+
 v+2v8iBWuh9iv0AUj9KJOwG5QQ+EXLUuSlhtx/DFnmn2CJ9plXI=
 =6bQI
 -----END PGP SIGNATURE-----

Merge tag 'net-6.9-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Pull networking fixes from Jakub Kicinski:
 "Including fixes from netfilter, bluetooth and bpf.

  Fairly usual collection of driver and core fixes. The large selftest
  accompanying one of the fixes is also becoming a common occurrence.

  Current release - regressions:

   - ipv6: fix infinite recursion in fib6_dump_done()

   - net/rds: fix possible null-deref in newly added error path

  Current release - new code bugs:

   - net: do not consume a full cacheline for system_page_pool

   - bpf: fix bpf_arena-related file descriptor leaks in the verifier

   - drv: ice: fix freeing uninitialized pointers, fixing misuse of the
     newfangled __free() auto-cleanup

  Previous releases - regressions:

   - x86/bpf: fixes the BPF JIT with retbleed=stuff

   - xen-netfront: add missing skb_mark_for_recycle, fix page pool
     accounting leaks, revealed by recently added explicit warning

   - tcp: fix bind() regression for v6-only wildcard and v4-mapped-v6
     non-wildcard addresses

   - Bluetooth:
      - replace "hci_qca: Set BDA quirk bit if fwnode exists in DT" with
        better workarounds to un-break some buggy Qualcomm devices
      - set conn encrypted before conn establishes, fix re-connecting to
        some headsets which use slightly unusual sequence of msgs

   - mptcp:
      - prevent BPF accessing lowat from a subflow socket
      - don't account accept() of non-MPC client as fallback to TCP

   - drv: mana: fix Rx DMA datasize and skb_over_panic

   - drv: i40e: fix VF MAC filter removal

  Previous releases - always broken:

   - gro: various fixes related to UDP tunnels - netns crossing
     problems, incorrect checksum conversions, and incorrect packet
     transformations which may lead to panics

   - bpf: support deferring bpf_link dealloc to after RCU grace period

   - nf_tables:
      - release batch on table validation from abort path
      - release mutex after nft_gc_seq_end from abort path
      - flush pending destroy work before exit_net release

   - drv: r8169: skip DASH fw status checks when DASH is disabled"

* tag 'net-6.9-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (81 commits)
  netfilter: validate user input for expected length
  net/sched: act_skbmod: prevent kernel-infoleak
  net: usb: ax88179_178a: avoid the interface always configured as random address
  net: dsa: sja1105: Fix parameters order in sja1110_pcs_mdio_write_c45()
  net: ravb: Always update error counters
  net: ravb: Always process TX descriptor ring
  netfilter: nf_tables: discard table flag update with pending basechain deletion
  netfilter: nf_tables: Fix potential data-race in __nft_flowtable_type_get()
  netfilter: nf_tables: reject new basechain after table flag update
  netfilter: nf_tables: flush pending destroy work before exit_net release
  netfilter: nf_tables: release mutex after nft_gc_seq_end from abort path
  netfilter: nf_tables: release batch on table validation from abort path
  Revert "tg3: Remove residual error handling in tg3_suspend"
  tg3: Remove residual error handling in tg3_suspend
  net: mana: Fix Rx DMA datasize and skb_over_panic
  net/sched: fix lockdep splat in qdisc_tree_reduce_backlog()
  net: phy: micrel: lan8814: Fix when enabling/disabling 1-step timestamping
  net: stmmac: fix rx queue priority assignment
  net: txgbe: fix i2c dev name cannot match clkdev
  net: fec: Set mac_managed_pm during probe
  ...
2024-04-04 14:49:10 -07:00
Andrii Nakryiko 314a53623c bpf: inline bpf_get_branch_snapshot() helper
Inline bpf_get_branch_snapshot() helper using architecture-agnostic
inline BPF code which calls directly into underlying callback of
perf_snapshot_branch_stack static call. This callback is set early
during kernel initialization and is never updated or reset, so it's ok
to fetch actual implementation using static_call_query() and call
directly into it.

This change eliminates a full function call and saves one LBR entry
in PERF_SAMPLE_BRANCH_ANY LBR mode.

Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240404002640.1774210-3-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-04 13:08:01 -07:00
Alexei Starovoitov af682b767a bpf: Optimize emit_mov_imm64().
Turned out that bpf prog callback addresses, bpf prog addresses
used in bpf_trampoline, and in other cases the 64-bit address
can be represented as sign extended 32-bit value.

According to https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82339
"Skylake has 0.64c throughput for mov r64, imm64, vs. 0.25 for mov r32, imm32."
So use shorter encoding and faster instruction when possible.

Special care is needed in jit_subprogs(), since bpf_pseudo_func()
instruction cannot change its size during the last step of JIT.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/CAADnVQKFfpY-QZBrOU2CG8v2du8Lgyb7MNVmOZVK_yTyOdNbBA@mail.gmail.com
Link: https://lore.kernel.org/bpf/20240401233800.42737-1-alexei.starovoitov@gmail.com
2024-04-04 16:13:26 +02:00
Andrii Nakryiko 0b56e637f7 bpf: inline bpf_map_lookup_elem() helper for PERCPU_HASH map
Using new per-CPU BPF instruction, partially inline
bpf_map_lookup_elem() helper for per-CPU hashmap BPF map. Just like for
normal HASH map, we still generate a call into __htab_map_lookup_elem(),
but after that we resolve per-CPU element address using a new
instruction, saving on extra functions calls.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/r/20240402021307.1012571-5-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-03 10:29:56 -07:00