linux-stable.git/tools/testing/selftests/bpf/progs/stack_arg.c, branch master Linux kernel stable tree selftests/bpf: Use at least 10 args in stack argument tests 2026-06-01T00:49:21+00:00 Puranjay Mohan puranjay@kernel.org 2026-05-28T16:17:48+00:00 157317ba662a7c476320fdb334216154eaa8b856 On arm64, the first 8 arguments are passed in registers (x0-x7), so tests with 8 or fewer arguments never exercise the native stack argument path in the JIT. Increase argument counts to at least 10 across all BPF-to-BPF subprog and kfunc stack argument tests so that at least 2 arguments land on the arm64 stack. For the two-callees test, bump foo1 from 8 to 10 and foo2 from 10 to 12 args to preserve the different-stack-depth flavor of the test. The bpf_kfunc_call_stack_arg_mem kfunc is left unchanged at 7 args to avoid breaking the precision backtracking test which relies on hardcoded verifier log instruction indices. Suggested-by: Will Deacon <will@kernel.org> Signed-off-by: Puranjay Mohan <puranjay@kernel.org> Acked-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/r/20260528161750.1900674-3-puranjay@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> 
On arm64, the first 8 arguments are passed in registers (x0-x7), so
tests with 8 or fewer arguments never exercise the native stack argument
path in the JIT. Increase argument counts to at least 10 across all
BPF-to-BPF subprog and kfunc stack argument tests so that at least 2
arguments land on the arm64 stack.

For the two-callees test, bump foo1 from 8 to 10 and foo2 from 10 to 12
args to preserve the different-stack-depth flavor of the test.

The bpf_kfunc_call_stack_arg_mem kfunc is left unchanged at 7 args to
avoid breaking the precision backtracking test which relies on hardcoded
verifier log instruction indices.

Suggested-by: Will Deacon <will@kernel.org>
Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20260528161750.1900674-3-puranjay@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
selftests/bpf: Enable stack argument tests for arm64 2026-05-13T16:27:32+00:00 Puranjay Mohan puranjay@kernel.org 2026-05-13T04:52:04+00:00 90e43f1b47535cc7aceef3add1a61ba3260b7aee Now that arm64 supports stack arguments, enable the existing stack_arg, stack_arg_kfunc and verifier_stack_arg tests for __TARGET_ARCH_arm64. Signed-off-by: Puranjay Mohan <puranjay@kernel.org> Signed-off-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/r/20260513045204.2403441-1-yonghong.song@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org> 
Now that arm64 supports stack arguments, enable the existing stack_arg,
stack_arg_kfunc and verifier_stack_arg tests for __TARGET_ARCH_arm64.

Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20260513045204.2403441-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
selftests/bpf: Add tests for BPF function stack arguments 2026-05-13T16:27:32+00:00 Yonghong Song yonghong.song@linux.dev 2026-05-13T04:51:27+00:00 79e7ec00634e95e20217ba922906574041b9bbf0 Add selftests covering stack argument passing for both BPF-to-BPF subprog calls and kfunc calls with more than 5 arguments. All tests are guarded by __BPF_FEATURE_STACK_ARGUMENT and __TARGET_ARCH_x86. BPF-to-BPF subprog call tests (stack_arg.c): - Scalar stack args - Pointer stack args - Mixed pointer/scalar stack args - Nested calls - Dynptr stack arg - Two callees with different stack arg counts - Async callback Kfunc call tests (stack_arg_kfunc.c, with bpf_testmod kfuncs): - Scalar stack args - Pointer stack args - Mixed pointer/scalar stack args - Dynptr stack arg - Memory buffer + size pair - Iterator - Const string pointer - Timer pointer Acked-by: Puranjay Mohan <puranjay@kernel.org> Signed-off-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/r/20260513045127.2397187-1-yonghong.song@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org> 
Add selftests covering stack argument passing for both BPF-to-BPF
subprog calls and kfunc calls with more than 5 arguments. All tests
are guarded by __BPF_FEATURE_STACK_ARGUMENT and __TARGET_ARCH_x86.

BPF-to-BPF subprog call tests (stack_arg.c):
  - Scalar stack args
  - Pointer stack args
  - Mixed pointer/scalar stack args
  - Nested calls
  - Dynptr stack arg
  - Two callees with different stack arg counts
  - Async callback

Kfunc call tests (stack_arg_kfunc.c, with bpf_testmod kfuncs):
  - Scalar stack args
  - Pointer stack args
  - Mixed pointer/scalar stack args
  - Dynptr stack arg
  - Memory buffer + size pair
  - Iterator
  - Const string pointer
  - Timer pointer

Acked-by: Puranjay Mohan <puranjay@kernel.org>
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20260513045127.2397187-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>