linker: changes to init work arounds
Change three things regarding the work around to the fact that init is
special:
1) Only first stage init is special, so we change the check to include
accessing /proc/self/exe, which if is available, means that we're
not first stage init and do not need any work arounds.
2) Fix the fact that /init may be a symlink and may need readlink()
3) Suppress errors from realpath_fd() since these are expected to fail
due to /proc not being mounted.
Bug: 80395578
Test: sailfish boots without the audit generated from calling stat()
on /init and without the errors from realpath_fd()
Change-Id: I266f1486b142cb9a41ec791eba74122bdf38cf12
diff --git a/linker/linker_main.cpp b/linker/linker_main.cpp
index f7c496a..d88fc75 100644
--- a/linker/linker_main.cpp
+++ b/linker/linker_main.cpp
@@ -195,11 +195,19 @@
static ExecutableInfo get_executable_info(KernelArgumentBlock& args) {
ExecutableInfo result = {};
- if (is_init()) {
- // /proc fs is not mounted when init starts. Therefore we can't use
- // /proc/self/exe for init.
+ if (is_first_stage_init()) {
+ // /proc fs is not mounted when first stage init starts. Therefore we can't
+ // use /proc/self/exe for init.
stat("/init", &result.file_stat);
- result.path = "/init";
+
+ // /init may be a symlink, so try to read it as such.
+ char path[PATH_MAX];
+ ssize_t path_len = readlink("/init", path, sizeof(path));
+ if (path_len == -1 || path_len >= static_cast<ssize_t>(sizeof(path))) {
+ result.path = "/init";
+ } else {
+ result.path = std::string(path, path_len);
+ }
} else {
// Stat "/proc/self/exe" instead of executable_path because
// the executable could be unlinked by this point and it should