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Author SHA1 Message Date
Linus Torvalds
91bd008d4e Probes updates for v6.11:
Uprobes:
 - x86/shstk: Make return uprobe work with shadow stack.
 - Add uretprobe syscall which speeds up the uretprobe 10-30% faster. This
   syscall is automatically used from user-space trampolines which are
   generated by the uretprobe. If this syscall is used by normal
   user program, it will cause SIGILL. Note that this is currently only
   implemented on x86_64.
   (This also has 2 fixes for adjusting the syscall number to avoid conflict
    with new *attrat syscalls.)
 - uprobes/perf: fix user stack traces in the presence of pending uretprobe.
   This corrects the uretprobe's trampoline address in the stacktrace with
   correct return address.
 - selftests/x86: Add a return uprobe with shadow stack test.
 - selftests/bpf: Add uretprobe syscall related tests.
   . test case for register integrity check.
   . test case with register changing case.
   . test case for uretprobe syscall without uprobes (expected to be failed).
   . test case for uretprobe with shadow stack.
 - selftests/bpf: add test validating uprobe/uretprobe stack traces
 - MAINTAINERS: Add uprobes entry. This does not specify the tree but to
   clarify who maintains and reviews the uprobes.
 
 Kprobes:
 - tracing/kprobes: Test case cleanups. Replace redundant WARN_ON_ONCE() +
   pr_warn() with WARN_ONCE() and remove unnecessary code from selftest.
 - tracing/kprobes: Add symbol counting check when module loads. This
   checks the uniqueness of the probed symbol on modules. The same check
   has already done for kernel symbols.
   (This also has a fix for build error with CONFIG_MODULES=n)
 
 Cleanup:
 - Add MODULE_DESCRIPTION() macros for fprobe and kprobe examples.
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Merge tag 'probes-v6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull probes updates from Masami Hiramatsu:
 "Uprobes:

   - x86/shstk: Make return uprobe work with shadow stack

   - Add uretprobe syscall which speeds up the uretprobe 10-30% faster.
     This syscall is automatically used from user-space trampolines
     which are generated by the uretprobe. If this syscall is used by
     normal user program, it will cause SIGILL. Note that this is
     currently only implemented on x86_64.

     (This also has two fixes for adjusting the syscall number to avoid
     conflict with new *attrat syscalls.)

   - uprobes/perf: fix user stack traces in the presence of pending
     uretprobe. This corrects the uretprobe's trampoline address in the
     stacktrace with correct return address

   - selftests/x86: Add a return uprobe with shadow stack test

   - selftests/bpf: Add uretprobe syscall related tests.
      - test case for register integrity check
      - test case with register changing case
      - test case for uretprobe syscall without uprobes (expected to fail)
      - test case for uretprobe with shadow stack

   - selftests/bpf: add test validating uprobe/uretprobe stack traces

   - MAINTAINERS: Add uprobes entry. This does not specify the tree but
     to clarify who maintains and reviews the uprobes

  Kprobes:

   - tracing/kprobes: Test case cleanups.

     Replace redundant WARN_ON_ONCE() + pr_warn() with WARN_ONCE() and
     remove unnecessary code from selftest

   - tracing/kprobes: Add symbol counting check when module loads.

     This checks the uniqueness of the probed symbol on modules. The
     same check has already done for kernel symbols

     (This also has a fix for build error with CONFIG_MODULES=n)

  Cleanup:

   - Add MODULE_DESCRIPTION() macros for fprobe and kprobe examples"

* tag 'probes-v6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  MAINTAINERS: Add uprobes entry
  selftests/bpf: Change uretprobe syscall number in uprobe_syscall test
  uprobe: Change uretprobe syscall scope and number
  tracing/kprobes: Fix build error when find_module() is not available
  tracing/kprobes: Add symbol counting check when module loads
  selftests/bpf: add test validating uprobe/uretprobe stack traces
  perf,uprobes: fix user stack traces in the presence of pending uretprobes
  tracing/kprobe: Remove cleanup code unrelated to selftest
  tracing/kprobe: Integrate test warnings into WARN_ONCE
  selftests/bpf: Add uretprobe shadow stack test
  selftests/bpf: Add uretprobe syscall call from user space test
  selftests/bpf: Add uretprobe syscall test for regs changes
  selftests/bpf: Add uretprobe syscall test for regs integrity
  selftests/x86: Add return uprobe shadow stack test
  uprobe: Add uretprobe syscall to speed up return probe
  uprobe: Wire up uretprobe system call
  x86/shstk: Make return uprobe work with shadow stack
  samples: kprobes: add missing MODULE_DESCRIPTION() macros
  fprobe: add missing MODULE_DESCRIPTION() macro
2024-07-18 12:19:20 -07:00
Pu Lehui
9474f72cd6 selftests/bpf: Add testcase where 7th argment is struct
Add testcase where 7th argument is struct for architectures with 8 argument
registers, and increase the complexity of the struct.

Signed-off-by: Pu Lehui <pulehui@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Björn Töpel <bjorn@rivosinc.com>
Acked-by: Björn Töpel <bjorn@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20240702121944.1091530-4-pulehui@huaweicloud.com
2024-07-02 16:02:02 +02:00
Alan Maguire
47a8cf0c5b selftests/bpf: Add kfunc_call test for simple dtor in bpf_testmod
add simple kfuncs to create/destroy a context type to bpf_testmod,
register them and add a kfunc_call test to use them.  This provides
test coverage for registration of dtor kfuncs from modules.

By transferring the context pointer to a map value as a __kptr
we also trigger the map-based dtor cleanup logic, improving test
coverage.

Suggested-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240620091733.1967885-7-alan.maguire@oracle.com
2024-06-21 14:46:29 -07:00
Vadim Fedorenko
2d45ab1eda selftests: bpf: add testmod kfunc for nullable params
Add special test to be sure that only __nullable BTF params can be
replaced by NULL. This patch adds fake kfuncs in bpf_testmod to
properly test different params.

Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Vadim Fedorenko <vadfed@meta.com>
Link: https://lore.kernel.org/r/20240613211817.1551967-6-vadfed@meta.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-06-13 16:33:04 -07:00
Jiri Olsa
f42a58ffb8 selftests/bpf: Add uretprobe syscall test for regs changes
Adding test that creates uprobe consumer on uretprobe which changes some
of the registers. Making sure the changed registers are propagated to the
user space when the ureptobe syscall trampoline is used on x86_64.

To be able to do this, adding support to bpf_testmod to create uprobe via
new attribute file:
  /sys/kernel/bpf_testmod_uprobe

This file is expecting file offset and creates related uprobe on current
process exe file and removes existing uprobe if offset is 0. The can be
only single uprobe at any time.

The uprobe has specific consumer that changes registers used in ureprobe
syscall trampoline and which are later checked in the test.

Link: https://lore.kernel.org/all/20240611112158.40795-7-jolsa@kernel.org/

Acked-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2024-06-12 08:44:28 +09:00
Kui-Feng Lee
73287fe228 bpf: pass bpf_struct_ops_link to callbacks in bpf_struct_ops.
Pass an additional pointer of bpf_struct_ops_link to callback function reg,
unreg, and update provided by subsystems defined in bpf_struct_ops. A
bpf_struct_ops_map can be registered for multiple links. Passing a pointer
of bpf_struct_ops_link helps subsystems to distinguish them.

This pointer will be used in the later patches to let the subsystem
initiate a detachment on a link that was registered to it previously.

Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com>
Link: https://lore.kernel.org/r/20240530065946.979330-2-thinker.li@gmail.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2024-05-30 15:34:13 -07:00
Jakub Kicinski
6e62702feb bpf-next-for-netdev
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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
Jordan Rife
bbb1cfdd02 selftests/bpf: Implement socket kfuncs for bpf_testmod
This patch adds a set of kfuncs to bpf_testmod that can be used to
manipulate a socket from kernel space.

Signed-off-by: Jordan Rife <jrife@google.com>
Link: https://lore.kernel.org/r/20240429214529.2644801-3-jrife@google.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2024-05-02 12:09:22 -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
Puranjay Mohan
7cd6750d9a selftests/bpf: Test PROBE_MEM of VSYSCALL_ADDR on x86-64
The vsyscall is a legacy API for fast execution of system calls. It maps
a page at address VSYSCALL_ADDR into the userspace program. This address
is in the top 10MB of the address space:

ffffffffff600000 - ffffffffff600fff |    4 kB | legacy vsyscall ABI

The last commit fixes the x86-64 BPF JIT to skip accessing addresses in
this memory region. Add this address to bpf_testmod_return_ptr() so we
can make sure that it is fixed.

After this change and without the previous commit, subprogs_extable
selftest will crash the kernel.

Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Link: https://lore.kernel.org/r/20240424100210.11982-4-puranjay@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-26 09:45:18 -07:00
Benjamin Tissoires
01b7b1c5f3 selftests/bpf: add checks for bpf_wq_set_callback()
We assign the callback and set everything up.
The actual tests of these callbacks will be done when bpf_wq_start() is
available.

Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
Link: https://lore.kernel.org/r/20240420-bpf_wq-v2-14-6c986a5a741f@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-23 19:46:57 -07:00
Eduard Zingerman
c1b93c07b3 selftests/bpf: Bad_struct_ops test
When loading struct_ops programs kernel requires BTF id of the
struct_ops type and member index for attachment point inside that
type. This makes impossible to use same BPF program in several
struct_ops maps that have different struct_ops type.
Check if libbpf rejects such BPF objects files.

Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240306104529.6453-7-eddyz87@gmail.com
2024-03-06 15:18:15 -08:00
Eduard Zingerman
5bab7a277c selftests/bpf: Test struct_ops map definition with type suffix
Extend struct_ops_module test case to check if it is possible to use
'___' suffixes for struct_ops type specification.

Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: David Vernet <void@manifault.com>
Link: https://lore.kernel.org/bpf/20240306104529.6453-5-eddyz87@gmail.com
2024-03-06 15:18:15 -08:00
Kui-Feng Lee
93bc28d859 selftests/bpf: Test struct_ops maps with a large number of struct_ops program.
Create and load a struct_ops map with a large number of struct_ops
programs to generate trampolines taking a size over multiple pages. The
map includes 40 programs. Their trampolines takes 6.6k+, more than 1.5
pages, on x86.

Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com>
Link: https://lore.kernel.org/r/20240224223418.526631-4-thinker.li@gmail.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2024-03-04 14:09:24 -08:00
Kui-Feng Lee
0623e73317 selftests/bpf: Test if shadow types work correctly.
Change the values of fields, including scalar types and function pointers,
and check if the struct_ops map works as expected.

The test changes the field "test_2" of "testmod_1" from the pointer to
test_2() to pointer to test_3() and the field "data" to 13. The function
test_2() and test_3() both compute a new value for "test_2_result", but in
different way. By checking the value of "test_2_result", it ensures the
struct_ops map works as expected with changes through shadow types.

Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240229064523.2091270-6-thinker.li@gmail.com
2024-02-29 14:23:53 -08:00
Kui-Feng Lee
00f239eccf selftests/bpf: Test PTR_MAYBE_NULL arguments of struct_ops operators.
Test if the verifier verifies nullable pointer arguments correctly for BPF
struct_ops programs.

"test_maybe_null" in struct bpf_testmod_ops is the operator defined for the
test cases here.

A BPF program should check a pointer for NULL beforehand to access the
value pointed by the nullable pointer arguments, or the verifier should
reject the programs. The test here includes two parts; the programs
checking pointers properly and the programs not checking pointers
beforehand. The test checks if the verifier accepts the programs checking
properly and rejects the programs not checking at all.

Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com>
Link: https://lore.kernel.org/r/20240209023750.1153905-5-thinker.li@gmail.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2024-02-13 15:16:44 -08:00
Kui-Feng Lee
169e650069 selftests/bpf: Suppress warning message of an unused variable.
"r" is used to receive the return value of test_2 in bpf_testmod.c, but it
is not actually used. So, we remove "r" and change the return type to
"void".

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202401300557.z5vzn8FM-lkp@intel.com/
Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240204061204.1864529-1-thinker.li@gmail.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2024-02-05 10:52:38 -08:00
Daniel Xu
6f3189f38a bpf: treewide: Annotate BPF kfuncs in BTF
This commit marks kfuncs as such inside the .BTF_ids section. The upshot
of these annotations is that we'll be able to automatically generate
kfunc prototypes for downstream users. The process is as follows:

1. In source, use BTF_KFUNCS_START/END macro pair to mark kfuncs
2. During build, pahole injects into BTF a "bpf_kfunc" BTF_DECL_TAG for
   each function inside BTF_KFUNCS sets
3. At runtime, vmlinux or module BTF is made available in sysfs
4. At runtime, bpftool (or similar) can look at provided BTF and
   generate appropriate prototypes for functions with "bpf_kfunc" tag

To ensure future kfunc are similarly tagged, we now also return error
inside kfunc registration for untagged kfuncs. For vmlinux kfuncs,
we also WARN(), as initcall machinery does not handle errors.

Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Acked-by: Benjamin Tissoires <bentiss@kernel.org>
Link: https://lore.kernel.org/r/e55150ceecbf0a5d961e608941165c0bee7bc943.1706491398.git.dxu@dxuuu.xyz
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-01-31 20:40:56 -08:00
Geliang Tang
f149d03f45 selftests/bpf: Drop return in bpf_testmod_exit
bpf_testmod_exit() does not need to have a return value (given the void),
so this patch drops this useless 'return' in it.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/5765b287ea088f0c820f2a834faf9b20fb2f8215.1706442113.git.tanggeliang@kylinos.cn
2024-01-29 16:41:29 +01:00
Kui-Feng Lee
0253e0590e selftests/bpf: test case for register_bpf_struct_ops().
Create a new struct_ops type called bpf_testmod_ops within the bpf_testmod
module. When a struct_ops object is registered, the bpf_testmod module will
invoke test_2 from the module.

Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com>
Link: https://lore.kernel.org/r/20240119225005.668602-15-thinker.li@gmail.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2024-01-23 17:12:52 -08:00
Artem Savkov
d177c1be06 selftests/bpf: Fix potential premature unload in bpf_testmod
It is possible for bpf_kfunc_call_test_release() to be called from
bpf_map_free_deferred() when bpf_testmod is already unloaded and
perf_test_stuct.cnt which it tries to decrease is no longer in memory.
This patch tries to fix the issue by waiting for all references to be
dropped in bpf_testmod_exit().

The issue can be triggered by running 'test_progs -t map_kptr' in 6.5,
but is obscured in 6.6 by d119357d07 ("rcu-tasks: Treat only
synchronous grace periods urgently").

Fixes: 65eb006d85 ("bpf: Move kernel test kfuncs to bpf_testmod")
Signed-off-by: Artem Savkov <asavkov@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/82f55c0e-0ec8-4fe1-8d8c-b1de07558ad9@linux.dev
Link: https://lore.kernel.org/bpf/20240110085737.8895-1-asavkov@redhat.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-01-23 14:40:23 -08:00
Dave Marchevsky
15fb6f2b6c bpf: Add __bpf_hook_{start,end} macros
Not all uses of __diag_ignore_all(...) in BPF-related code in order to
suppress warnings are wrapping kfunc definitions. Some "hook point"
definitions - small functions meant to be used as attach points for
fentry and similar BPF progs - need to suppress -Wmissing-declarations.

We could use __bpf_kfunc_{start,end}_defs added in the previous patch in
such cases, but this might be confusing to someone unfamiliar with BPF
internals. Instead, this patch adds __bpf_hook_{start,end} macros,
currently having the same effect as __bpf_kfunc_{start,end}_defs, then
uses them to suppress warnings for two hook points in the kernel itself
and some bpf_testmod hook points as well.

Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Cc: Yafang Shao <laoar.shao@gmail.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://lore.kernel.org/r/20231031215625.2343848-2-davemarchevsky@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-11-01 22:33:53 -07:00
Jiri Olsa
01e4ae474e selftests/bpf: Add test for missed counts of perf event link kprobe
Adding test that puts kprobe on bpf_fentry_test1 that calls
bpf_kfunc_common_test kfunc, which has also kprobe on.

The latter won't get triggered due to kprobe recursion check
and kprobe missed counter is incremented.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/bpf/20230920213145.1941596-8-jolsa@kernel.org
2023-09-25 16:37:44 -07:00
Yonghong Song
0c606571ae selftests/bpf: Test ldsx with more complex cases
The following ldsx cases are tested:
  - signed readonly map value
  - read/write map value
  - probed memory
  - not-narrowed ctx field access
  - narrowed ctx field access.

Without previous proper verifier/git handling, the test will fail.

If cpuv4 is not supported either by compiler or by jit,
the test will be skipped.

  # ./test_progs -t ldsx_insn
  #113/1   ldsx_insn/map_val and probed_memory:SKIP
  #113/2   ldsx_insn/ctx_member_sign_ext:SKIP
  #113/3   ldsx_insn/ctx_member_narrow_sign_ext:SKIP
  #113     ldsx_insn:SKIP
  Summary: 1/0 PASSED, 3 SKIPPED, 0 FAILED

Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20230728011336.3723434-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-07-27 18:54:17 -07:00
Menglong Dong
5e9cf77d81 selftests/bpf: add testcase for TRACING with 6+ arguments
Add fentry_many_args.c and fexit_many_args.c to test the fentry/fexit
with 7/11 arguments. As this feature is not supported by arm64 yet, we
disable these testcases for arm64 in DENYLIST.aarch64. We can combine
them with fentry_test.c/fexit_test.c when arm64 is supported too.

Correspondingly, add bpf_testmod_fentry_test7() and
bpf_testmod_fentry_test11() to bpf_testmod.c

Meanwhile, add bpf_modify_return_test2() to test_run.c to test the
MODIFY_RETURN with 7 arguments.

Add bpf_testmod_test_struct_arg_7/bpf_testmod_test_struct_arg_7 in
bpf_testmod.c to test the struct in the arguments.

And the testcases passed on x86_64:

./test_progs -t fexit
Summary: 5/14 PASSED, 0 SKIPPED, 0 FAILED

./test_progs -t fentry
Summary: 3/2 PASSED, 0 SKIPPED, 0 FAILED

./test_progs -t modify_return
Summary: 1/0 PASSED, 0 SKIPPED, 0 FAILED

./test_progs -t tracing_struct
Summary: 1/0 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Menglong Dong <imagedong@tencent.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20230713040738.1789742-4-imagedong@tencent.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-07-13 16:04:56 -07:00
Jiri Olsa
67faabbde3 selftests/bpf: Add missing prototypes for several test kfuncs
Adding missing prototypes for several kfuncs that are used by
test_verifier tests. We don't really need kfunc prototypes for
these tests, but adding them to silence 'make W=1' build and
to have all test kfuncs declarations in bpf_testmod_kfunc.h.

Also moving __diag_pop for -Wmissing-prototypes to cover also
bpf_testmod_test_write and bpf_testmod_test_read and adding
bpf_fentry_shadow_test in there as well. All of them need to
be exported, but there's no need for declarations.

Fixes: 65eb006d85 ("bpf: Move kernel test kfuncs to bpf_testmod")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Closes: https://lore.kernel.org/oe-kbuild-all/202306051319.EihCQZPs-lkp@intel.com
Link: https://lore.kernel.org/bpf/20230607224046.236510-1-jolsa@kernel.org
2023-06-08 13:26:12 +02:00
Jiri Olsa
65eb006d85 bpf: Move kernel test kfuncs to bpf_testmod
Moving kernel test kfuncs into bpf_testmod kernel module, and adding
necessary init calls and BTF IDs records.

We need to keep following structs in kernel:
  struct prog_test_ref_kfunc
  struct prog_test_member (embedded in prog_test_ref_kfunc)

The reason is because they need to be marked as rcu safe (check test
prog mark_ref_as_untrusted_or_null) and such objects are being required
to be defined only in kernel at the moment (see rcu_safe_kptr check
in kernel).

We need to keep also dtor functions for both objects in kernel:
  bpf_kfunc_call_test_release
  bpf_kfunc_call_memb_release

We also keep the copy of these struct in bpf_testmod_kfunc.h, because
other test functions use them. This is unfortunate, but this is just
temporary solution until we are able to these structs them to bpf_testmod
completely.

As suggested by David adding bpf_testmod.ko make dependency for
bpf programs, so they are rebuilt if we change the bpf_testmod.ko
module.

Also adding missing __bpf_kfunc to bpf_kfunc_call_test4 functions.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: David Vernet <void@manifault.com>
Link: https://lore.kernel.org/r/20230515133756.1658301-11-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-16 22:09:24 -07:00
Jiri Olsa
6e2b50fa81 selftests/bpf: Remove extern from kfuncs declarations
There's no need to keep the extern in kfuncs declarations.

Suggested-by: David Vernet <void@manifault.com>
Acked-by: David Vernet <void@manifault.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230515133756.1658301-10-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-16 22:09:23 -07:00
Jiri Olsa
8e9af82171 selftests/bpf: Move kfunc exports to bpf_testmod/bpf_testmod_kfunc.h
Move all kfunc exports into separate bpf_testmod_kfunc.h header file
and include it in tests that need it.

We will move all test kfuncs into bpf_testmod in following change,
so it's convenient to have declarations in single place.

The bpf_testmod_kfunc.h is included by both bpf_testmod and bpf
programs that use test kfuncs.

As suggested by David, the bpf_testmod_kfunc.h includes vmlinux.h
and bpf/bpf_helpers.h for bpf programs build, so the declarations
have proper __ksym attribute and we can resolve all the structs.

Note in kfunc_call_test_subprog.c we can no longer use the sk_state
define from bpf_tcp_helpers.h (because it clashed with vmlinux.h)
and we need to address __sk_common.skc_state field directly.

Acked-by: David Vernet <void@manifault.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230515133756.1658301-3-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-16 22:09:23 -07:00
Feng Zhou
5ff54dedf3 selftests/bpf: Add test to access integer type of variable array
Add prog test for accessing integer type of variable array in tracing
program.
In addition, hook load_balance function to access sd->span[0], only
to confirm whether the load is successful. Because there is no direct
way to trigger load_balance call.

Co-developed-by: Chengming Zhou <zhouchengming@bytedance.com>
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Signed-off-by: Feng Zhou <zhoufeng.zf@bytedance.com>
Link: https://lore.kernel.org/r/20230420032735.27760-3-zhoufeng.zf@bytedance.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-04-19 21:29:39 -07:00
Andrii Nakryiko
4099be372f selftests/bpf: Fix compiler warnings in bpf_testmod for kfuncs
Add -Wmissing-prototypes ignore in bpf_testmod.c, similarly to what we
do in kernel code proper.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/oe-kbuild-all/202304080951.l14IDv3n-lkp@intel.com/
Link: https://lore.kernel.org/bpf/20230412034647.3968143-1-andrii@kernel.org
2023-04-13 14:54:45 +02:00
Song Liu
2995f9a8d4 selftests/bpf: Keep the loop in bpf_testmod_loop_test
Some compilers (for example clang-15) optimize bpf_testmod_loop_test and
remove the loop:

gcc version
(gdb) disassemble bpf_testmod_loop_test
Dump of assembler code for function bpf_testmod_loop_test:
   0x0000000000000570 <+0>:     callq  0x575 <bpf_testmod_loop_test+5>
   0x0000000000000575 <+5>:     xor    %eax,%eax
   0x0000000000000577 <+7>:     test   %edi,%edi
   0x0000000000000579 <+9>:     jle    0x587 <bpf_testmod_loop_test+23>
   0x000000000000057b <+11>:    xor    %edx,%edx
   0x000000000000057d <+13>:    add    %edx,%eax
   0x000000000000057f <+15>:    add    $0x1,%edx
   0x0000000000000582 <+18>:    cmp    %edx,%edi
   0x0000000000000584 <+20>:    jne    0x57d <bpf_testmod_loop_test+13>
   0x0000000000000586 <+22>:    retq
   0x0000000000000587 <+23>:    retq

clang-15 version
(gdb) disassemble bpf_testmod_loop_test
Dump of assembler code for function bpf_testmod_loop_test:
   0x0000000000000450 <+0>:     nopl   0x0(%rax,%rax,1)
   0x0000000000000455 <+5>:     test   %edi,%edi
   0x0000000000000457 <+7>:     jle    0x46b <bpf_testmod_loop_test+27>
   0x0000000000000459 <+9>:     lea    -0x1(%rdi),%eax
   0x000000000000045c <+12>:    lea    -0x2(%rdi),%ecx
   0x000000000000045f <+15>:    imul   %rax,%rcx
   0x0000000000000463 <+19>:    shr    %rcx
   0x0000000000000466 <+22>:    lea    -0x1(%rdi,%rcx,1),%eax
   0x000000000000046a <+26>:    retq
   0x000000000000046b <+27>:    xor    %eax,%eax
   0x000000000000046d <+29>:    retq

Note: The jne instruction is removed in clang-15 version.

Force the compile to keep the loop by making sum volatile.

Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230412210423.900851-4-song@kernel.org
2023-04-13 14:32:05 +02:00
Viktor Malik
aa3d65de4b bpf/selftests: Test fentry attachment to shadowed functions
Adds a new test that tries to attach a program to fentry of two
functions of the same name, one located in vmlinux and the other in
bpf_testmod.

To avoid conflicts with existing tests, a new function
"bpf_fentry_shadow_test" was created both in vmlinux and in bpf_testmod.

The previous commit fixed a bug which caused this test to fail. The
verifier would always use the vmlinux function's address as the target
trampoline address, hence trying to create two trampolines for a single
address, which is forbidden.

The test (similarly to other fentry/fexit tests) is not working on arm64
at the moment.

Signed-off-by: Viktor Malik <vmalik@redhat.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/5fe2f364190b6f79b085066ed7c5989c5bc475fa.1678432753.git.vmalik@redhat.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-03-15 18:38:30 -07:00
Andrii Nakryiko
7e86a8c4ac selftests/bpf: implement and test custom testmod_seq iterator
Implement a trivial iterator returning same specified integer value
N times as part of bpf_testmod kernel module. Add selftests to validate
everything works end to end.

We also reuse these tests as "verification-only" tests to validate that
kernel prints the state of custom kernel module-defined iterator correctly:

  fp-16=iter_testmod_seq(ref_id=1,state=drained,depth=0)

"testmod_seq" part is an iterator type, and is coming from module's BTF
data dynamically at runtime.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230308184121.1165081-9-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-03-08 16:19:51 -08:00
David Vernet
400031e05a bpf: Add __bpf_kfunc tag to all kfuncs
Now that we have the __bpf_kfunc tag, we should use add it to all
existing kfuncs to ensure that they'll never be elided in LTO builds.

Signed-off-by: David Vernet <void@manifault.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/bpf/20230201173016.342758-4-void@manifault.com
2023-02-02 00:25:14 +01:00
Jiri Olsa
fee356ede9 selftests/bpf: Add bpf_testmod_fentry_* functions
Adding 3 bpf_testmod_fentry_* functions to have a way to test
kprobe multi link on kernel module. They follow bpf_fentry_test*
functions prototypes/code.

Adding equivalent functions to all bpf_fentry_test* does not
seems necessary at the moment, could be added later.

Acked-by: Song Liu <song@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20221025134148.3300700-7-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-10-25 10:14:51 -07:00
Yonghong Song
1642a3945e selftests/bpf: Add struct argument tests with fentry/fexit programs.
Add various struct argument tests with fentry/fexit programs.
Also add one test with a kernel func which does not have any
argument to test BPF_PROG2 macro in such situation.

Signed-off-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20220831152713.2080039-1-yhs@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-09-06 19:51:14 -07:00
Kumar Kartikeya Dwivedi
a4703e3184 bpf: Switch to new kfunc flags infrastructure
Instead of populating multiple sets to indicate some attribute and then
researching the same BTF ID in them, prepare a single unified BTF set
which indicates whether a kfunc is allowed to be called, and also its
attributes if any at the same time. Now, only one call is needed to
perform the lookup for both kfunc availability and its attributes.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20220721134245.2450-4-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-07-21 20:59:42 -07:00
Hao Luo
50c6b8a9ae selftests/bpf: Add a test for btf_type_tag "percpu"
Add test for percpu btf_type_tag. Similar to the "user" tag, we test
the following cases:

 1. __percpu struct field.
 2. __percpu as function parameter.
 3. per_cpu_ptr() accepts dynamically allocated __percpu memory.

Because the test for "user" and the test for "percpu" are very similar,
a little bit of refactoring has been done in btf_tag.c. Basically, both
tests share the same function for loading vmlinux and module btf.

Example output from log:

 > ./test_progs -v -t btf_tag

 libbpf: prog 'test_percpu1': BPF program load failed: Permission denied
 libbpf: prog 'test_percpu1': -- BEGIN PROG LOAD LOG --
 ...
 ; g = arg->a;
 1: (61) r1 = *(u32 *)(r1 +0)
 R1 is ptr_bpf_testmod_btf_type_tag_1 access percpu memory: off=0
 ...
 test_btf_type_tag_mod_percpu:PASS:btf_type_tag_percpu 0 nsec
 #26/6 btf_tag/btf_type_tag_percpu_mod1:OK

 libbpf: prog 'test_percpu2': BPF program load failed: Permission denied
 libbpf: prog 'test_percpu2': -- BEGIN PROG LOAD LOG --
 ...
 ; g = arg->p->a;
 2: (61) r1 = *(u32 *)(r1 +0)
 R1 is ptr_bpf_testmod_btf_type_tag_1 access percpu memory: off=0
 ...
 test_btf_type_tag_mod_percpu:PASS:btf_type_tag_percpu 0 nsec
 #26/7 btf_tag/btf_type_tag_percpu_mod2:OK

 libbpf: prog 'test_percpu_load': BPF program load failed: Permission denied
 libbpf: prog 'test_percpu_load': -- BEGIN PROG LOAD LOG --
 ...
 ; g = (__u64)cgrp->rstat_cpu->updated_children;
 2: (79) r1 = *(u64 *)(r1 +48)
 R1 is ptr_cgroup_rstat_cpu access percpu memory: off=48
 ...
 test_btf_type_tag_vmlinux_percpu:PASS:btf_type_tag_percpu_load 0 nsec
 #26/8 btf_tag/btf_type_tag_percpu_vmlinux_load:OK

 load_btfs:PASS:could not load vmlinux BTF 0 nsec
 test_btf_type_tag_vmlinux_percpu:PASS:btf_type_tag_percpu 0 nsec
 test_btf_type_tag_vmlinux_percpu:PASS:btf_type_tag_percpu_helper 0 nsec
 #26/9 btf_tag/btf_type_tag_percpu_vmlinux_helper:OK

Signed-off-by: Hao Luo <haoluo@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20220304191657.981240-5-haoluo@google.com
2022-03-05 18:39:51 -08:00
Matteo Croce
976a38e05a selftests/bpf: Test bpf_core_types_are_compat() functionality.
Add several tests to check bpf_core_types_are_compat() functionality:
- candidate type name exists and types match
- candidate type name exists but types don't match
- nested func protos at kernel recursion limit
- nested func protos above kernel recursion limit. Such bpf prog
  is rejected during the load.

Signed-off-by: Matteo Croce <mcroce@microsoft.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220204005519.60361-3-mcroce@linux.microsoft.com
2022-02-04 11:29:01 -08:00
Yonghong Song
696c390115 selftests/bpf: add a selftest with __user tag
Added a selftest with three__user usages: a __user pointer-type argument
in bpf_testmod, a __user pointer-type struct member in bpf_testmod,
and a __user pointer-type struct member in vmlinux. In all cases,
directly accessing the user memory will result verification failure.

  $ ./test_progs -v -n 22/3
  ...
  libbpf: prog 'test_user1': BPF program load failed: Permission denied
  libbpf: prog 'test_user1': -- BEGIN PROG LOAD LOG --
  R1 type=ctx expected=fp
  0: R1=ctx(id=0,off=0,imm=0) R10=fp0
  ; int BPF_PROG(test_user1, struct bpf_testmod_btf_type_tag_1 *arg)
  0: (79) r1 = *(u64 *)(r1 +0)
  func 'bpf_testmod_test_btf_type_tag_user_1' arg0 has btf_id 136561 type STRUCT 'bpf_testmod_btf_type_tag_1'
  1: R1_w=user_ptr_bpf_testmod_btf_type_tag_1(id=0,off=0,imm=0)
  ; g = arg->a;
  1: (61) r1 = *(u32 *)(r1 +0)
  R1 invalid mem access 'user_ptr_'
  ...
  #22/3 btf_tag/btf_type_tag_user_mod1:OK

  $ ./test_progs -v -n 22/4
  ...
  libbpf: prog 'test_user2': BPF program load failed: Permission denied
  libbpf: prog 'test_user2': -- BEGIN PROG LOAD LOG --
  R1 type=ctx expected=fp
  0: R1=ctx(id=0,off=0,imm=0) R10=fp0
  ; int BPF_PROG(test_user2, struct bpf_testmod_btf_type_tag_2 *arg)
  0: (79) r1 = *(u64 *)(r1 +0)
  func 'bpf_testmod_test_btf_type_tag_user_2' arg0 has btf_id 136563 type STRUCT 'bpf_testmod_btf_type_tag_2'
  1: R1_w=ptr_bpf_testmod_btf_type_tag_2(id=0,off=0,imm=0)
  ; g = arg->p->a;
  1: (79) r1 = *(u64 *)(r1 +0)          ; R1_w=user_ptr_bpf_testmod_btf_type_tag_1(id=0,off=0,imm=0)
  ; g = arg->p->a;
  2: (61) r1 = *(u32 *)(r1 +0)
  R1 invalid mem access 'user_ptr_'
  ...
  #22/4 btf_tag/btf_type_tag_user_mod2:OK

  $ ./test_progs -v -n 22/5
  ...
  libbpf: prog 'test_sys_getsockname': BPF program load failed: Permission denied
  libbpf: prog 'test_sys_getsockname': -- BEGIN PROG LOAD LOG --
  R1 type=ctx expected=fp
  0: R1=ctx(id=0,off=0,imm=0) R10=fp0
  ; int BPF_PROG(test_sys_getsockname, int fd, struct sockaddr *usockaddr,
  0: (79) r1 = *(u64 *)(r1 +8)
  func '__sys_getsockname' arg1 has btf_id 2319 type STRUCT 'sockaddr'
  1: R1_w=user_ptr_sockaddr(id=0,off=0,imm=0)
  ; g = usockaddr->sa_family;
  1: (69) r1 = *(u16 *)(r1 +0)
  R1 invalid mem access 'user_ptr_'
  ...
  #22/5 btf_tag/btf_type_tag_user_vmlinux:OK

Signed-off-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20220127154616.659314-1-yhs@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-01-27 12:03:46 -08:00
Kumar Kartikeya Dwivedi
4656569643 selftests/bpf: Add test for race in btf_try_get_module
This adds a complete test case to ensure we never take references to
modules not in MODULE_STATE_LIVE, which can lead to UAF, and it also
ensures we never access btf->kfunc_set_tab in an inconsistent state.

The test uses userfaultfd to artificially widen the race.

When run on an unpatched kernel, it leads to the following splat:

[root@(none) bpf]# ./test_progs -t bpf_mod_race/ksym
[   55.498171] BUG: unable to handle page fault for address: fffffbfff802548b
[   55.499206] #PF: supervisor read access in kernel mode
[   55.499855] #PF: error_code(0x0000) - not-present page
[   55.500555] PGD a4fa9067 P4D a4fa9067 PUD a4fa5067 PMD 1b44067 PTE 0
[   55.501499] Oops: 0000 [#1] PREEMPT SMP KASAN NOPTI
[   55.502195] CPU: 0 PID: 83 Comm: kworker/0:2 Tainted: G           OE     5.16.0-rc4+ #151
[   55.503388] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ArchLinux 1.15.0-1 04/01/2014
[   55.504777] Workqueue: events bpf_prog_free_deferred
[   55.505563] RIP: 0010:kasan_check_range+0x184/0x1d0
[   55.509140] RSP: 0018:ffff88800560fcf0 EFLAGS: 00010282
[   55.509977] RAX: fffffbfff802548b RBX: fffffbfff802548c RCX: ffffffff9337b6ba
[   55.511096] RDX: fffffbfff802548c RSI: 0000000000000004 RDI: ffffffffc012a458
[   55.512143] RBP: fffffbfff802548b R08: 0000000000000001 R09: ffffffffc012a45b
[   55.513228] R10: fffffbfff802548b R11: 0000000000000001 R12: ffff888001b5f598
[   55.514332] R13: ffff888004f49ac8 R14: 0000000000000000 R15: ffff888092449400
[   55.515418] FS:  0000000000000000(0000) GS:ffff888092400000(0000) knlGS:0000000000000000
[   55.516705] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   55.517560] CR2: fffffbfff802548b CR3: 0000000007c10006 CR4: 0000000000770ef0
[   55.518672] PKRU: 55555554
[   55.519022] Call Trace:
[   55.519483]  <TASK>
[   55.519884]  module_put.part.0+0x2a/0x180
[   55.520642]  bpf_prog_free_deferred+0x129/0x2e0
[   55.521478]  process_one_work+0x4fa/0x9e0
[   55.522122]  ? pwq_dec_nr_in_flight+0x100/0x100
[   55.522878]  ? rwlock_bug.part.0+0x60/0x60
[   55.523551]  worker_thread+0x2eb/0x700
[   55.524176]  ? __kthread_parkme+0xd8/0xf0
[   55.524853]  ? process_one_work+0x9e0/0x9e0
[   55.525544]  kthread+0x23a/0x270
[   55.526088]  ? set_kthread_struct+0x80/0x80
[   55.526798]  ret_from_fork+0x1f/0x30
[   55.527413]  </TASK>
[   55.527813] Modules linked in: bpf_testmod(OE) [last unloaded: bpf_testmod]
[   55.530846] CR2: fffffbfff802548b
[   55.531341] ---[ end trace 1af41803c054ad6d ]---
[   55.532136] RIP: 0010:kasan_check_range+0x184/0x1d0
[   55.535887] RSP: 0018:ffff88800560fcf0 EFLAGS: 00010282
[   55.536711] RAX: fffffbfff802548b RBX: fffffbfff802548c RCX: ffffffff9337b6ba
[   55.537821] RDX: fffffbfff802548c RSI: 0000000000000004 RDI: ffffffffc012a458
[   55.538899] RBP: fffffbfff802548b R08: 0000000000000001 R09: ffffffffc012a45b
[   55.539928] R10: fffffbfff802548b R11: 0000000000000001 R12: ffff888001b5f598
[   55.541021] R13: ffff888004f49ac8 R14: 0000000000000000 R15: ffff888092449400
[   55.542108] FS:  0000000000000000(0000) GS:ffff888092400000(0000) knlGS:0000000000000000
[   55.543260]CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   55.544136] CR2: fffffbfff802548b CR3: 0000000007c10006 CR4: 0000000000770ef0
[   55.545317] PKRU: 55555554
[   55.545671] note: kworker/0:2[83] exited with preempt_count 1

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20220114163953.1455836-11-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-01-18 14:27:39 -08:00
Kumar Kartikeya Dwivedi
b202d84422 bpf: Remove check_kfunc_call callback and old kfunc BTF ID API
Completely remove the old code for check_kfunc_call to help it work
with modules, and also the callback itself.

The previous commit adds infrastructure to register all sets and put
them in vmlinux or module BTF, and concatenates all related sets
organized by the hook and the type. Once populated, these sets remain
immutable for the lifetime of the struct btf.

Also, since we don't need the 'owner' module anywhere when doing
check_kfunc_call, drop the 'btf_modp' module parameter from
find_kfunc_desc_btf.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20220114163953.1455836-4-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-01-18 14:26:41 -08:00
Alexei Starovoitov
7edc3fcbf9 selftest/bpf: Add a test that reads various addresses.
Add a function to bpf_testmod that returns invalid kernel and user addresses.
Then attach an fexit program to that function that tries to read
memory through these addresses.

This logic checks that bpf_probe_read_kernel and BPF_PROBE_MEM logic is sane.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2021-12-16 21:41:13 +01:00
Hou Tao
fa7f17d066 bpf/selftests: Add test for writable bare tracepoint
Add a writable bare tracepoint in bpf_testmod module, and
trigger its calling when reading /sys/kernel/bpf_testmod
with a specific buffer length. The reading will return
the value in writable context if the early return flag
is enabled in writable context.

Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211004094857.30868-4-hotforest@gmail.com
2021-10-08 13:22:57 -07:00
Kumar Kartikeya Dwivedi
c48e51c8b0 bpf: selftests: Add selftests for module kfunc support
This adds selftests that tests the success and failure path for modules
kfuncs (in presence of invalid kfunc calls) for both libbpf and
gen_loader. It also adds a prog_test kfunc_btf_id_list so that we can
add module BTF ID set from bpf_testmod.

This also introduces  a couple of test cases to verifier selftests for
validating whether we get an error or not depending on if invalid kfunc
call remains after elimination of unreachable instructions.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211002011757.311265-10-memxor@gmail.com
2021-10-05 17:07:42 -07:00
Song Liu
025bd7c753 selftests/bpf: Add test for bpf_get_branch_snapshot
This test uses bpf_get_branch_snapshot from a fexit program. The test uses
a target function (bpf_testmod_loop_test) and compares the record against
kallsyms. If there isn't enough record matching kallsyms, the test fails.

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20210910183352.3151445-4-songliubraving@fb.com
2021-09-13 10:53:50 -07:00
Qais Yousef
407be92206 selftests: bpf: Add a new test for bare tracepoints
Reuse module_attach infrastructure to add a new bare tracepoint to check
we can attach to it as a raw tracepoint.

Signed-off-by: Qais Yousef <qais.yousef@arm.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210119122237.2426878-3-qais.yousef@arm.com
2021-01-20 14:14:05 -08:00
Andrii Nakryiko
430d97a8a7 selftests/bpf: Test kernel module ksym externs
Add per-CPU variable to bpf_testmod.ko and use those from new selftest to
validate it works end-to-end.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Hao Luo <haoluo@google.com>
Link: https://lore.kernel.org/bpf/20210112075520.4103414-8-andrii@kernel.org
2021-01-12 17:24:30 -08:00
Andrii Nakryiko
9f7fa22589 selftests/bpf: Add bpf_testmod kernel module for testing
Add bpf_testmod module, which is conceptually out-of-tree module and provides
ways for selftests/bpf to test various kernel module-related functionality:
raw tracepoint, fentry/fexit/fmod_ret, etc. This module will be auto-loaded by
test_progs test runner and expected by some of selftests to be present and
loaded.

Pahole currently isn't able to generate BTF for static functions in kernel
modules, so make sure traced function is global.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20201203204634.1325171-7-andrii@kernel.org
2020-12-03 17:38:20 -08:00