[PATCH v4 net-next 04/13] bpf/verifier: more concise register state logs for constant var_off

From: Edward Cree
Date: Thu Aug 03 2017 - 12:12:56 EST


Signed-off-by: Edward Cree <ecree@xxxxxxxxxxxxxx>
---
kernel/bpf/verifier.c | 46 +++++++++++++++++++++++++++-------------------
1 file changed, 27 insertions(+), 19 deletions(-)

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index ca14f59..2924b01 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -234,25 +234,33 @@ static void print_verifier_state(struct bpf_verifier_state *state)
verbose(",ks=%d,vs=%d",
reg->map_ptr->key_size,
reg->map_ptr->value_size);
- if (reg->smin_value != reg->umin_value &&
- reg->smin_value != S64_MIN)
- verbose(",smin_value=%lld",
- (long long)reg->smin_value);
- if (reg->smax_value != reg->umax_value &&
- reg->smax_value != S64_MAX)
- verbose(",smax_value=%lld",
- (long long)reg->smax_value);
- if (reg->umin_value != 0)
- verbose(",umin_value=%llu",
- (unsigned long long)reg->umin_value);
- if (reg->umax_value != U64_MAX)
- verbose(",umax_value=%llu",
- (unsigned long long)reg->umax_value);
- if (!tnum_is_unknown(reg->var_off)) {
- char tn_buf[48];
-
- tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
- verbose(",var_off=%s", tn_buf);
+ if (tnum_is_const(reg->var_off)) {
+ /* Typically an immediate SCALAR_VALUE, but
+ * could be a pointer whose offset is too big
+ * for reg->off
+ */
+ verbose(",imm=%llx", reg->var_off.value);
+ } else {
+ if (reg->smin_value != reg->umin_value &&
+ reg->smin_value != S64_MIN)
+ verbose(",smin_value=%lld",
+ (long long)reg->smin_value);
+ if (reg->smax_value != reg->umax_value &&
+ reg->smax_value != S64_MAX)
+ verbose(",smax_value=%lld",
+ (long long)reg->smax_value);
+ if (reg->umin_value != 0)
+ verbose(",umin_value=%llu",
+ (unsigned long long)reg->umin_value);
+ if (reg->umax_value != U64_MAX)
+ verbose(",umax_value=%llu",
+ (unsigned long long)reg->umax_value);
+ if (!tnum_is_unknown(reg->var_off)) {
+ char tn_buf[48];
+
+ tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
+ verbose(",var_off=%s", tn_buf);
+ }
}
verbose(")");
}