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| author | Kumar Kartikeya Dwivedi <memxor@gmail.com> | 2026-09-21 04:38:30 +0200 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2026-09-21 17:12:39 +0000 |
| commit | bca730ba6df6d62fa7f94011fe089e666ccb65ad (patch) | |
| tree | a62f51f5af7838a2fb62dd8a1fb647a1a0037ca8 /include/linux | |
| parent | a8bbd9ee1bbc73ae51508ca045bbb693bbdda446 (diff) | |
| download | linux-next-bca730ba6df6d62fa7f94011fe089e666ccb65ad.tar.gz linux-next-bca730ba6df6d62fa7f94011fe089e666ccb65ad.zip | |
bpf: Support multiple __uninit kfunc output arguments
A single output descriptor cannot retain the initialization ranges of two
__uninit memory arguments. Track raw-mode eligibility and the definite
output size separately for each ABI slot, so a variable-size output leaves
independent constant-size outputs intact.
Use the shared argument-checking path to record outputs for both helpers
and kfuncs. With per-slot tracking, neither needs the single-output
prototype restriction. Initialize every recorded output after checking all
arguments, skipping empty slots before looking up their register state.
Use the resolved BTF parameter when looking up __uninit for stack liveness.
A preceding by-value parameter can consume multiple ABI slots, so its slot
number cannot index the BTF parameter array.
Suggested-by: Amery Hung <ameryhung@gmail.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://patch.msgid.link/20260921023843.411943-7-memxor@gmail.com
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/bpf_verifier.h | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h index 6ff1c227d298..9ddbb20ec1e9 100644 --- a/include/linux/bpf_verifier.h +++ b/include/linux/bpf_verifier.h @@ -1547,13 +1547,13 @@ struct ref_obj_desc { }; /* - * A memory argument a call fills in. The verifier allows the stack to be uninitialized if - * the range is a known constant. Stack slots are marked as STACK_MISC by check_mem_access() - * after all arguments have been checked. + * Memory arguments a call fills in, indexed by argument slot. The verifier allows the + * stack to be uninitialized if the range is a known constant. Stack slots are marked as + * STACK_MISC by check_mem_access() after all arguments have been checked. */ struct arg_raw_mem_desc { - u8 argno; /* One-based ABI argument slot; zero means no output. */ - int size; + u16 mask; + int size[MAX_BPF_FUNC_ARGS]; }; /* Size of PTR_TO_MEM returned, taken from a constant allocation-size argument */ |