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authorArnaldo Carvalho de Melo <acme@redhat.com>2018-10-18 11:13:01 -0300
committerArnaldo Carvalho de Melo <acme@redhat.com>2018-10-18 11:13:01 -0300
commitce6c9da1113ad681bff27a3e376d2017f7f8a59c (patch)
tree922ee99522f8e47e4fa5c735d4ea378dfdb79085 /kernel/bpf/verifier.c
parentperf/x86/intel: Export mem events only if there's PEBS support (diff)
parentMerge tag 'perf-urgent-for-mingo-4.19-20181017' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent (diff)
downloadwireguard-linux-ce6c9da1113ad681bff27a3e376d2017f7f8a59c.tar.xz
wireguard-linux-ce6c9da1113ad681bff27a3e376d2017f7f8a59c.zip
Merge remote-tracking branch 'tip/perf/urgent' into perf/core
To pick up fixes. Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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);