linux-stable.git/tools/testing/selftests/bpf/test_loader.c, branch linux-6.10.y

selftests/bpf: correctly move 'log' upon successful match

2024-10-04T14:33:24+00:00

commit d0a29cdb6ef95d8a175e09ab2d1334271f047e60 upstream.

Suppose log="foo bar buz" and msg->substr="bar".
In such case current match processing logic would update 'log' as
follows: log += strlen(msg->substr); -> log += 3 -> log=" bar".
However, the intent behind the 'log' update is to make it point after
the successful match, e.g. to make log=" buz" in the example above.

Fixes: 4ef5d6af4935 ("selftests/bpf: no need to track next_match_pos in struct test_loader")
Signed-off-by: Eduard Zingerman 
Link: https://lore.kernel.org/r/20240820102357.3372779-3-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov 
Signed-off-by: Greg Kroah-Hartman

selftests/bpf: fix to avoid __msg tag de-duplication by clang

2024-10-04T14:32:55+00:00

[ Upstream commit f00bb757ed630affc951691ddaff206039cbb7ee ]

__msg, __regex and __xlated tags are based on
__attribute__((btf_decl_tag("..."))) annotations.

Clang de-duplicates such annotations, e.g. the following
two sequences of tags are identical in final BTF:

    /* seq A */            /* seq B */
    __tag("foo")           __tag("foo")
    __tag("bar")           __tag("bar")
    __tag("foo")

Fix this by adding a unique suffix for each tag using __COUNTER__
pre-processor macro. E.g. here is a new definition for __msg:

    #define __msg(msg) \
      __attribute__((btf_decl_tag("comment:test_expect_msg=" XSTR(__COUNTER__) "=" msg)))

Using this definition the "seq A" from example above is translated to
BTF as follows:

    [..] DECL_TAG 'comment:test_expect_msg=0=foo' type_id=X component_idx=-1
    [..] DECL_TAG 'comment:test_expect_msg=1=bar' type_id=X component_idx=-1
    [..] DECL_TAG 'comment:test_expect_msg=2=foo' type_id=X component_idx=-1

Surprisingly, this bug affects a single existing test:
verifier_spill_fill/old_stack_misc_vs_cur_ctx_ptr,
where sequence of identical messages was expected in the log.

Fixes: 537c3f66eac1 ("selftests/bpf: add generic BPF program tester-loader")
Signed-off-by: Eduard Zingerman 
Link: https://lore.kernel.org/r/20240820102357.3372779-4-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov 
Signed-off-by: Sasha Levin

selftests/bpf: __arch_* macro to limit test cases to specific archs

2024-10-04T14:32:55+00:00

[ Upstream commit ee7fe84468b1732fe65c5af3836437d54ac4c419 ]

Add annotations __arch_x86_64, __arch_arm64, __arch_riscv64
to specify on which architecture the test case should be tested.
Several __arch_* annotations could be specified at once.
When test case is not run on current arch it is marked as skipped.

For example, the following would be tested only on arm64 and riscv64:

  SEC("raw_tp")
  __arch_arm64
  __arch_riscv64
  __xlated("1: *(u64 *)(r10 - 16) = r1")
  __xlated("2: call")
  __xlated("3: r1 = *(u64 *)(r10 - 16);")
  __success
  __naked void canary_arm64_riscv64(void)
  {
  	asm volatile (
  	"r1 = 1;"
  	"*(u64 *)(r10 - 16) = r1;"
  	"call %[bpf_get_smp_processor_id];"
  	"r1 = *(u64 *)(r10 - 16);"
  	"exit;"
  	:
  	: __imm(bpf_get_smp_processor_id)
  	: __clobber_all);
  }

On x86 it would be skipped:

  #467/2   verifier_nocsr/canary_arm64_riscv64:SKIP

Acked-by: Andrii Nakryiko 
Signed-off-by: Eduard Zingerman 
Link: https://lore.kernel.org/r/20240722233844.1406874-10-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov 
Signed-off-by: Andrii Nakryiko 
Stable-dep-of: f00bb757ed63 ("selftests/bpf: fix to avoid __msg tag de-duplication by clang")
Signed-off-by: Sasha Levin

selftests/bpf: allow checking xlated programs in verifier_* tests

2024-10-04T14:32:55+00:00

[ Upstream commit 9c9f7339131030949a8ef111080427ff1a8085b5 ]

Add a macro __xlated("...") for use with test_loader tests.

When such annotations are present for the test case:
- bpf_prog_get_info_by_fd() is used to get BPF program after all
  rewrites are applied by verifier.
- the program is disassembled and patterns specified in __xlated are
  searched for in the disassembly text.

__xlated matching follows the same mechanics as __msg:
each subsequent pattern is matched from the point where
previous pattern ended.

This allows to write tests like below, where the goal is to verify the
behavior of one of the of the transformations applied by verifier:

    SEC("raw_tp")
    __xlated("1: w0 = ")
    __xlated("2: r0 = &(void __percpu *)(r0)")
    __xlated("3: r0 = *(u32 *)(r0 +0)")
    __xlated("4: exit")
    __success __naked void simple(void)
    {
            asm volatile (
            "call %[bpf_get_smp_processor_id];"
            "exit;"
            :
            : __imm(bpf_get_smp_processor_id)
            : __clobber_all);
    }

Acked-by: Andrii Nakryiko 
Signed-off-by: Eduard Zingerman 
Link: https://lore.kernel.org/r/20240722233844.1406874-9-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov 
Signed-off-by: Andrii Nakryiko 
Stable-dep-of: f00bb757ed63 ("selftests/bpf: fix to avoid __msg tag de-duplication by clang")
Signed-off-by: Sasha Levin

selftests/bpf: extract test_loader->expect_msgs as a data structure

2024-10-04T14:32:55+00:00

[ Upstream commit 64f01e935ddb26f48baec71883c27878ac4231dc ]

Non-functional change: use a separate data structure to represented
expected messages in test_loader.
This would allow to use the same functionality for expected set of
disassembled instructions in the follow-up commit.

Acked-by: Andrii Nakryiko 
Signed-off-by: Eduard Zingerman 
Link: https://lore.kernel.org/r/20240722233844.1406874-8-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov 
Signed-off-by: Andrii Nakryiko 
Stable-dep-of: f00bb757ed63 ("selftests/bpf: fix to avoid __msg tag de-duplication by clang")
Signed-off-by: Sasha Levin

selftests/bpf: no need to track next_match_pos in struct test_loader

2024-10-04T14:32:55+00:00

[ Upstream commit 4ef5d6af493558124b7a6c13cace58b938fe27d4 ]

The call stack for validate_case() function looks as follows:
- test_loader__run_subtests()
  - process_subtest()
    - run_subtest()
      - prepare_case(), which does 'tester->next_match_pos = 0';
      - validate_case(), which increments tester->next_match_pos.

Hence, each subtest is run with next_match_pos freshly set to zero.
Meaning that there is no need to persist this variable in the
struct test_loader, use local variable instead.

Acked-by: Andrii Nakryiko 
Signed-off-by: Eduard Zingerman 
Link: https://lore.kernel.org/r/20240722233844.1406874-7-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov 
Signed-off-by: Andrii Nakryiko 
Stable-dep-of: f00bb757ed63 ("selftests/bpf: fix to avoid __msg tag de-duplication by clang")
Signed-off-by: Sasha Levin

selftests/bpf: Support checks against a regular expression

2024-10-04T14:32:54+00:00

[ Upstream commit f06ae6194f278444201e0b041a00192d794f83b6 ]

Add support for __regex and __regex_unpriv macros to check the test
execution output against a regular expression. This is similar to __msg
and __msg_unpriv, however those expect do substring matching.

Signed-off-by: Cupertino Miranda 
Signed-off-by: Andrii Nakryiko 
Acked-by: Eduard Zingerman 
Link: https://lore.kernel.org/bpf/20240617141458.471620-2-cupertino.miranda@oracle.com
Stable-dep-of: f00bb757ed63 ("selftests/bpf: fix to avoid __msg tag de-duplication by clang")
Signed-off-by: Sasha Levin

selftests/bpf: Add unit tests for bpf_arena_alloc/free_pages

2024-03-11T22:43:43+00:00

Add unit tests for bpf_arena_alloc/free_pages() functionality
and bpf_arena_common.h with a set of common helpers and macros that
is used in this test and the following patches.

Also modify test_loader that didn't support running bpf_prog_type_syscall
programs.

Signed-off-by: Alexei Starovoitov 
Signed-off-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/20240308010812.89848-13-alexei.starovoitov@gmail.com

selftests/bpf: detect testing prog flags support

2024-01-23T22:40:22+00:00

Various tests specify extra testing prog_flags when loading BPF
programs, like BPF_F_TEST_RND_HI32, and more recently also
BPF_F_TEST_REG_INVARIANTS. While BPF_F_TEST_RND_HI32 is old enough to
not cause much problem on older kernels, BPF_F_TEST_REG_INVARIANTS is
very fresh and unconditionally specifying it causes selftests to fail on
even slightly outdated kernels.

This breaks libbpf CI test against 4.9 and 5.15 kernels, it can break
some local development (done outside of VM), etc.

To prevent this, and guard against similar problems in the future, do
runtime detection of supported "testing flags", and only provide those
that host kernel recognizes.

Acked-by: Song Liu 
Acked-by: Jiri Olsa 
Signed-off-by: Andrii Nakryiko 
Link: https://lore.kernel.org/r/20240109231738.575844-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov

selftests/bpf: fix test_loader check message

2024-01-23T22:40:21+00:00

Seeing:

  process_subtest:PASS:Can't alloc specs array 0 nsec

... in verbose successful test log is very confusing. Use smaller
identifier-like test tag to denote that we are asserting specs array
allocation success.

Now it's much less distracting:

  process_subtest:PASS:specs_alloc 0 nsec

Signed-off-by: Andrii Nakryiko 
Acked-by: Eduard Zingerman 
Link: https://lore.kernel.org/r/20240105000909.2818934-2-andrii@kernel.org
Signed-off-by: Alexei Starovoitov