aboutsummaryrefslogtreecommitdiff
path: root/kernel/bpf/verifier.c
diff options
context:
space:
mode:
authorIngo Molnar <[email protected]>2018-10-23 12:30:19 +0200
committerIngo Molnar <[email protected]>2018-10-23 12:30:19 +0200
commitdda93b45389f025fd3422d22cc31cc1ea6040305 (patch)
tree44a856744843e24ed1baf6ca4edb1be04809a606 /kernel/bpf/verifier.c
parent2e62024c265aa69315ed02835623740030435380 (diff)
parentb61b8bba18fe2b63d38fdaf9b83de25e2d787dfe (diff)
Merge branch 'x86/cache' into perf/core, to pick up fixes
Signed-off-by: Ingo Molnar <[email protected]>
Diffstat (limited to 'kernel/bpf/verifier.c')
-rw-r--r--kernel/bpf/verifier.c10
1 files changed, 9 insertions, 1 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index bb07e74b34a2..465952a8e465 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -2896,6 +2896,15 @@ static int adjust_scalar_min_max_vals(struct bpf_verifier_env *env,
u64 umin_val, umax_val;
u64 insn_bitness = (BPF_CLASS(insn->code) == BPF_ALU64) ? 64 : 32;
+ if (insn_bitness == 32) {
+ /* Relevant for 32-bit RSH: Information can propagate towards
+ * LSB, so it isn't sufficient to only truncate the output to
+ * 32 bits.
+ */
+ coerce_reg_to_size(dst_reg, 4);
+ coerce_reg_to_size(&src_reg, 4);
+ }
+
smin_val = src_reg.smin_value;
smax_val = src_reg.smax_value;
umin_val = src_reg.umin_value;
@@ -3131,7 +3140,6 @@ static int adjust_scalar_min_max_vals(struct bpf_verifier_env *env,
if (BPF_CLASS(insn->code) != BPF_ALU64) {
/* 32-bit ALU ops are (32,32)->32 */
coerce_reg_to_size(dst_reg, 4);
- coerce_reg_to_size(&src_reg, 4);
}
__reg_deduce_bounds(dst_reg);