Don't use xwrite() when patching legacy rootfs init

Fix topjohnwu#4810
> [    2.927463]  [1:           init:    1] magiskinit: Replace [/system/etc/selinux/plat_sepolicy.cil] -> [xxx]
[    2.936801]  [1:           init:    1] magiskinit: write failed with 14: Bad address

Since topjohnwu#4596, magisk fails to patch `/init`, xwrite() fails with EFAULT, break the original `/init` file and make the device unbootable. Reverting this commit for legacy rootfs devices fixes the problem. I think this is a Samsung kernel magic since currently I can't reproduce this on other devices or find something special in the log currently we have.
This commit is contained in:
残页 2021-10-29 09:00:43 +08:00 committed by John Wu
parent 89c2c21774
commit e3f6399473

View File

@ -343,11 +343,16 @@ void RootFSBase::patch_rootfs() {
}
if (patch_sepolicy("/sepolicy")) {
auto init = mmap_data::ro(access("/system/bin/init",F_OK) == 0 ? "/system/bin/init" : "/init");
if (access("/system/bin/init", F_OK) == 0) {
auto init = mmap_data::ro("/system/bin/init");
init.patch({ make_pair(SPLIT_PLAT_CIL, "xxx") });
int dest = xopen("/init", O_TRUNC | O_WRONLY | O_CLOEXEC, 0);
xwrite(dest, init.buf, init.sz);
close(dest);
} else {
auto init = mmap_data::rw("/init");
init.patch({ make_pair(SPLIT_PLAT_CIL, "xxx") });
}
}
// Handle overlays