may_goto instruction does not use any registers,
but in compute_insn_live_regs() it was treated as a regular
conditional jump of kind BPF_K with r0 as source register.
Thus unnecessarily marking r0 as used.
Fixes: 7dad03653567 ("bpf: simple DFA-based live registers analysis")
Signed-off-by: Eduard Zingerman <eddyz87@xxxxxxxxx>
---
kernel/bpf/verifier.c | 1 +
tools/testing/selftests/bpf/progs/compute_live_registers.c | 6 +++---
2 files changed, 4 insertions(+), 3 deletions(-)
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 4edb2db0f889..3303a3605ee8 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -23567,6 +23567,7 @@ static void compute_insn_live_regs(struct bpf_verifier_env *env,
case BPF_JMP32:
switch (code) {
case BPF_JA:
+ case BPF_JCOND:
def = 0;
use = 0;
break;
diff --git a/tools/testing/selftests/bpf/progs/compute_live_registers.c b/tools/testing/selftests/bpf/progs/compute_live_registers.c
index 14df92949e81..f3d79aecbf93 100644
--- a/tools/testing/selftests/bpf/progs/compute_live_registers.c
+++ b/tools/testing/selftests/bpf/progs/compute_live_registers.c
@@ -294,9 +294,9 @@ __naked void gotol(void)
SEC("socket")
__log_level(2)
-__msg("0: 0......... (b7) r1 = 1")
-__msg("1: 01........ (e5) may_goto pc+1")
-__msg("2: 0......... (05) goto pc-3")
+__msg("0: .......... (b7) r1 = 1")
+__msg("1: .1........ (e5) may_goto pc+1")
+__msg("2: .......... (05) goto pc-3")
__msg("3: .1........ (bf) r0 = r1")
__msg("4: 0......... (95) exit")
__naked void may_goto(void)
--
2.48.1
