return "", err
		}

		// Check if the data was written
		if length <= len(buffer) {
			// Exclude the null terminator
			return string(buffer[:length-1]), nil
		}

		// Make a bigger buffer if needed
		buffer = make([]byte, length)
	}
}

// Keyctl commands with special signatures.

// KeyctlGetKeyringID implements the KEYCTL_GET_KEYRING_ID command.

// canRotate reports whether the architecture supports
// rotates of integer registers with the given number of bits.
func canRotate(c *Config, bits int64) bool {
	if bits > c.PtrSize*8 {
		// Don't rewrite to rotates bigger than the machine word.
		return false
	}
	switch c.arch {
	case "386", "amd64", "arm64", "riscv64":
		return true
	case "arm", "s390x", "ppc64", "ppc64le", "wasm", "loong64":
		return bits >= 32

// However, for zero-extended values, we can cheat a bit, and calculate
// BSR(x<<1 + 1), which is guaranteed to be non-zero, and which conveniently
// places the index of the highest set bit where we want it.
// For GOAMD64>=3, BitLen can be calculated by OperandSize - LZCNT(x).
(BitLen64 <t> x) && buildcfg.GOAMD64 < 3 => (ADDQconst [1] (CMOVQEQ <t> (Select0 <t> (BSRQ x)) (MOVQconst <t> [-1]) (Select1 <types.TypeFlags> (BSRQ x))))