diff options
| author | Alexis Lothoré (eBPF Foundation) <alexis.lothore@bootlin.com> | 2026-05-28 16:27:14 +0300 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2026-06-04 19:47:39 +0300 |
| commit | bf29346fc39355cc57118e4e825109f66ac3542d (patch) | |
| tree | 314b54a78cf3642e8818bf0f482e6533bc724deb | |
| parent | 80b89d0226a05e8b67969de99c31b51fcd54f76a (diff) | |
| download | linux-bf29346fc39355cc57118e4e825109f66ac3542d.tar.xz | |
selftests/bpf: ignore call depth accounting for retbleed in verifier tests
When running the selftests on a retbleed-affected platform (eg:
Skylake), with call depth accounting enabled
(CONFIG_CALL_DEPTH_TRACKING=y) _and_ with retbleed=stuff, some verifier
selftests fail to validate the jited instructions. For example:
MATCHED SUBSTR: ' endbr64'
MATCHED SUBSTR: ' nopl (%rax,%rax)'
MATCHED SUBSTR: ' xorq %rax, %rax'
MATCHED SUBSTR: ' pushq %rbp'
MATCHED SUBSTR: ' movq %rsp, %rbp'
MATCHED SUBSTR: ' endbr64'
MATCHED SUBSTR: ' cmpq $0x21, %rax'
MATCHED SUBSTR: ' ja L0'
MATCHED SUBSTR: ' pushq %rax'
MATCHED SUBSTR: ' movq %rsp, %rax'
MATCHED SUBSTR: ' jmp L1'
MATCHED SUBSTR: 'L0: pushq %rax'
MATCHED SUBSTR: 'L1: pushq %rax'
MATCHED SUBSTR: ' movq -0x10(%rbp), %rax'
WRONG LINE REGEX: ' callq 0x{{.*}}'
Those affected selftests allways fail on some call instruction: this
failure is due to the JIT compiler emitting call depth accounting for
retbleed mitigation (see x86_call_depth_emit_accounting calls in
bpf_jit_comp.c), resulting in an additional instruction being inserted
in front of every call instruction, similar to this one:
sarq $0x5, %gs:-0x39882741(%rip)
Fix those selftests by allowing them to ignore this possibly present
call depth accounting instruction.
Signed-off-by: Alexis Lothoré (eBPF Foundation) <alexis.lothore@bootlin.com>
Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>
Link: https://lore.kernel.org/r/20260528-fix_tests_for_retbleed_stuff-v1-1-c2022a1f3bee@bootlin.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| -rw-r--r-- | tools/testing/selftests/bpf/progs/verifier_private_stack.c | 5 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/progs/verifier_tailcall_jit.c | 1 |
2 files changed, 6 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/verifier_private_stack.c b/tools/testing/selftests/bpf/progs/verifier_private_stack.c index 046f7445a458..bb8206e10880 100644 --- a/tools/testing/selftests/bpf/progs/verifier_private_stack.c +++ b/tools/testing/selftests/bpf/progs/verifier_private_stack.c @@ -94,6 +94,7 @@ __jited(" addq %gs:{{.*}}, %r9") __jited(" movl $0x2a, %edi") __jited(" movq %rdi, -0x200(%r9)") __jited(" pushq %r9") +__jited("...") __jited(" callq 0x{{.*}}") __jited(" popq %r9") __jited(" xorl %eax, %eax") @@ -153,11 +154,13 @@ __jited(" endbr64") __jited(" movabsq $0x{{.*}}, %r9") __jited(" addq %gs:{{.*}}, %r9") __jited(" pushq %r9") +__jited("...") __jited(" callq") __jited(" popq %r9") __jited(" movl $0x2a, %edi") __jited(" movq %rdi, -0x200(%r9)") __jited(" pushq %r9") +__jited("...") __jited(" callq") __jited(" popq %r9") __arch_arm64 @@ -199,6 +202,7 @@ __description("Private stack, exception in main prog") __success __retval(0) __arch_x86_64 __jited(" pushq %r9") +__jited("...") __jited(" callq") __jited(" popq %r9") __arch_arm64 @@ -246,6 +250,7 @@ __success __retval(0) __arch_x86_64 __jited(" movq %rdi, -0x200(%r9)") __jited(" pushq %r9") +__jited("...") __jited(" callq") __jited(" popq %r9") __arch_arm64 diff --git a/tools/testing/selftests/bpf/progs/verifier_tailcall_jit.c b/tools/testing/selftests/bpf/progs/verifier_tailcall_jit.c index 8d60c634a114..48fa34d2959f 100644 --- a/tools/testing/selftests/bpf/progs/verifier_tailcall_jit.c +++ b/tools/testing/selftests/bpf/progs/verifier_tailcall_jit.c @@ -56,6 +56,7 @@ __jited("L1: pushq %rax") /* rbp[-16] = rax */ * (cause original rax might be clobbered by this point) */ __jited(" movq -0x10(%rbp), %rax") +__jited("...") __jited(" callq 0x{{.*}}") /* call to sub() */ __jited(" xorl %eax, %eax") __jited(" leave") |