diff mbox series

[bpf-next,06/11] bpf: Rename sanitize_stack_spill to nospec_result

Message ID 20250313174149.1113165-1-luis.gerhorst@fau.de (mailing list archive)
State New
Headers show
Series bpf: Mitigate Spectre v1 using barriers | expand

Commit Message

Luis Gerhorst March 13, 2025, 5:41 p.m. UTC 
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 <luis.gerhorst@fau.de>
Cc: Henriette Herzog <henriette.herzog@rub.de>
Cc: Maximilian Ott <ott@cs.fau.de>
Cc: Milan Stephan <milan.stephan@fau.de>
---
 include/linux/bpf_verifier.h | 2 +-
 kernel/bpf/verifier.c        | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)
diff mbox series

Patch

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(),