Allow microdroid_manager to run kexec
/system/bin/kexec in Microdroid is now properly labeled as kexec_exec.
The binary is responsible for loading the crashkernel into memory so
that when a kernel panic occurs the crashkernel is executed to dump the
RAM.
Microdroid_manager executes the kexec binary as part of the boot
process. It does this only when the kernel is booted with a memory
reserved for the crashkernel, which is determined by checking if
`crashkernel=` is included in the cmdline. For this, it is allowed to
read /proc/cmdline.
Bug: 238404545
Test: boot microdroid
Change-Id: Id08ba9610e3849ba811367917df8dfcc1774b561
diff --git a/microdroid/system/private/kexec.te b/microdroid/system/private/kexec.te
new file mode 100644
index 0000000..c0ab735
--- /dev/null
+++ b/microdroid/system/private/kexec.te
@@ -0,0 +1,12 @@
+# kexec loads a crashdump kernel into memory using the kexec_file_load syscall.
+type kexec, domain, coredomain;
+type kexec_exec, exec_type, file_type, system_file_type;
+
+# allow kexec to write into /dev/kmsg for logging
+allow kexec kmsg_device:chr_file w_file_perms;
+
+# kexec is launched by microdroid_manager with fork/execvp.
+allow kexec microdroid_manager:fd use;
+
+# allow kexec to have SYS_BOOT
+allow kexec self:capability sys_boot;