Files
linux/tools/testing
Yonghong Song 9786d424a3 selftests/bpf: Fix chained_global_func_calls_success() for cpu v4
The chained_global_func_calls_success() test hardcodes the instruction
counts reported by the verifier's per-subprog stats:

  subprog {{[0-9]+}} (global_good) global insns_self 5 insns_total 5 stack
  processed 14 insns

global_good() does 'return arr[0]', where arr[] is an int array and the
return type is long. Without cpu v4 this is a zero-extending load
followed by a <<32/s>>32 sign-extension pair. With -mcpu=v4 llvm emits a
single sign-extending load instead:

  18: (18) r1 = 0xffa00000008eb000
  20: (81) r0 = *(s32 *)(r1 +0)
  21: (95) exit

so the subprog is 3 insns rather than 5, and the whole program is
12 processed insns rather than 14. test_progs-cpuv4 fails with:

  EXPECTED    REGEX: 'subprog {{[0-9]+}} (global_good) global insns_self 5 insns_total 5 stack'
  #606/1   verifier_global_subprogs/chained_global_func_calls_success:FAIL

Select the expected counts based on __BPF_CPU_VERSION__.

Fixes: c2e6c7de88 ("bpf: Show more useful info in stack depth stats")
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20260813150641.3347662-1-yonghong.song@linux.dev
2026-08-13 18:23:33 +02:00
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