Alexei Starovoitov wrote: > From: Yonghong Song <yhs@xxxxxx> > > Under register pressure the llvm may spill registers with bounds into the stack. > The verifier has to track them through spill/fill otherwise many kinds of bound > errors will be seen. The spill/fill of induction variables was already > happening. This patch extends this logic from tracking spill/fill of a constant > into any bounded register. There is no need to track spill/fill of unbounded, > since no new information will be retrieved from the stack during register fill. > > Though extra stack difference could cause state pruning to be less effective, no > adverse affects were seen from this patch on selftests and on cilium programs. > > Signed-off-by: Yonghong Song <yhs@xxxxxx> > Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxx> > Acked-by: Andrii Nakryiko <andrii@xxxxxxxxxx> > --- > kernel/bpf/verifier.c | 16 +++++++++++++++- > 1 file changed, 15 insertions(+), 1 deletion(-) LGTM and will be useful. Acked-by: John Fastabend <john.fastabend@xxxxxxxxx>
