[PATCH bpf-next 06/11] bpf: Rename sanitize_stack_spill to nospec_result
From: Luis Gerhorst <hidden>
Date: 2025-03-13 17:42:08
Also in:
bpf, linux-kselftest, linuxppc-dev, lkml
Subsystem:
bpf [core], bpf [general] (safe dynamic programs and tools), the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Linus Torvalds
This is made to clarify that this flag will cause a nospec to be added after this insn and can therefore be relied upon to reduce speculative path analysis. Signed-off-by: Luis Gerhorst <redacted> Cc: Henriette Herzog <redacted> Cc: Maximilian Ott <redacted> Cc: Milan Stephan <redacted> --- include/linux/bpf_verifier.h | 2 +- kernel/bpf/verifier.c | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h
index d6cfc4ee6820..da586dd4703e 100644
--- a/include/linux/bpf_verifier.h
+++ b/include/linux/bpf_verifier.h@@ -563,7 +563,7 @@ struct bpf_insn_aux_data { u64 map_key_state; /* constant (32 bit) key tracking for maps */ int ctx_field_size; /* the ctx field size for load insn, maybe 0 */ u32 seen; /* this insn was processed by the verifier at env->pass_cnt */ - bool sanitize_stack_spill; /* subject to Spectre v4 sanitation */ + bool nospec_result; /* result is unsafe under speculation, nospec must follow */ bool zext_dst; /* this insn zero extends dst reg */ bool needs_zext; /* alu op needs to clear upper bits */ bool storage_get_func_atomic; /* bpf_*_storage_get() with atomic memory alloc */
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index eb65038682b0..4c1ed31d86af 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c@@ -5007,7 +5007,7 @@ static int check_stack_write_fixed_off(struct bpf_verifier_env *env, } if (sanitize) - env->insn_aux_data[insn_idx].sanitize_stack_spill = true; + env->insn_aux_data[insn_idx].nospec_result = true; } err = destroy_if_dynptr_stack_slot(env, state, spi);
@@ -20719,7 +20719,7 @@ static int convert_ctx_accesses(struct bpf_verifier_env *env) } if (type == BPF_WRITE && - env->insn_aux_data[i + delta].sanitize_stack_spill) { + env->insn_aux_data[i + delta].nospec_result) { struct bpf_insn patch[] = { *insn, BPF_ST_NOSPEC(),
--
2.48.1