Hi! David and I faced a deadlock with switch_root when fscrypt was in use. When /sbin/modprobe is encrypted using fscrypt and no other kernel component requested an AES cipher before, first access to an encrypted file will trigger the module_request() function, which will execute usermode helper /sbin/modprobe. Is /sbin/modprobe also encrypted the kernel will deadlock because executing it will again enter the module_request() path... As workaround we currently do something like "ls /new_root > /dev/null" in our initramfs to make request_module() happen before we change the root directory to /new_root. While this workaround is legit we think that this could be handled better. Is there a way to request these ciphers before first usage? Herbert? e.g. such that the filesystem can request them upon mount time. Btw: This happens even when AES modules are builtins. Thanks, //richard -- To unsubscribe from this list: send the line "unsubscribe linux-fscrypt" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
|