*pprog = prog;
}
+static void emit_return(u8 **pprog, u8 *ip)
+{
+ u8 *prog = *pprog;
+
+ if (cpu_feature_enabled(X86_FEATURE_RETHUNK)) {
+ emit_jump(&prog, &__x86_return_thunk, ip);
+ } else {
+ EMIT1(0xC3); /* ret */
+ if (IS_ENABLED(CONFIG_SLS))
+ EMIT1(0xCC); /* int3 */
+ }
+
+ *pprog = prog;
+}
+
/*
* Generate the following code:
*
ctx->cleanup_addr = proglen;
pop_callee_regs(&prog, callee_regs_used);
EMIT1(0xC9); /* leave */
- EMIT1(0xC3); /* ret */
+ emit_return(&prog, image + addrs[i - 1] + (prog - temp));
break;
default:
if (flags & BPF_TRAMP_F_SKIP_FRAME)
/* skip our return address and return to parent */
EMIT4(0x48, 0x83, 0xC4, 8); /* add rsp, 8 */
- EMIT1(0xC3); /* ret */
+ emit_return(&prog, prog);
/* Make sure the trampoline generation logic doesn't overflow */
if (WARN_ON_ONCE(prog > (u8 *)image_end - BPF_INSN_SAFETY)) {
ret = -EFAULT;