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-rw-r--r--arch/x86/net/bpf_jit_comp.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c
index a5930042139d..bcca1c9b9a02 100644
--- a/arch/x86/net/bpf_jit_comp.c
+++ b/arch/x86/net/bpf_jit_comp.c
@@ -303,8 +303,12 @@ static void emit_prologue(u8 **pprog, u32 stack_depth, bool ebpf_from_cbpf,
prog += X86_PATCH_SIZE;
if (!ebpf_from_cbpf) {
if (tail_call_reachable && !is_subprog)
+ /* When it's the entry of the whole tailcall context,
+ * zeroing rax means initialising tail_call_cnt.
+ */
EMIT2(0x31, 0xC0); /* xor eax, eax */
else
+ /* Keep the same instruction layout. */
EMIT2(0x66, 0x90); /* nop2 */
}
EMIT1(0x55); /* push rbp */