Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
bpf, arm64: fix stack_depth tracking in combination with tail calls
Using dynamic stack_depth tracking in arm64 JIT is currently broken in combination with tail calls. In prologue, we cache ctx->stack_size and adjust SP reg for setting up function call stack, and tearing it down again in epilogue. Problem is that when doing a tail call, the cached ctx->stack_size might not be the same. One way to fix the problem with minimal overhead is to re-adjust SP in emit_bpf_tail_call() and properly adjust it to the current program's ctx->stack_size. Tested on Cavium ThunderX ARMv8. Fixes: f1c9eed ("bpf, arm64: take advantage of stack_depth tracking") Signed-off-by: Daniel Borkmann <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]>
- Loading branch information