Initialize __libc_sysinfo early on.
__libc_sysinfo is hidden, so accessing it doesn't require a relocated GOT.
It is important not to have a relocatable initializer on __libc_sysinfo,
because if it did have one, and if we initialized it before relocating the
linker, then on 32-bit x86 (which uses REL rather than RELA), the
relocation step would calculate the wrong addend and overwrite
__libc_sysinfo with garbage.
Asides:
* It'd be simpler to keep the __libc_sysinfo initializer for static
executables, but the loader pulls in libc_init_static (even though it
uses almost none of the code in that file, like __libc_init).
* The loader has called __libc_init_sysinfo three times by the time it
has relocated itself. A static executable calls it twice, while libc.so
calls it only once.
Bug: none
Test: lunch aosp_x86-userdebug ; emulator
Test: adb shell /data/nativetest/bionic-unit-tests/bionic-unit-tests
Test: adb shell /data/nativetest/bionic-unit-tests-static/bionic-unit-tests-static
Change-Id: I5944f57847db7191608f4f83dde22b49e279e6cb
diff --git a/linker/linker_main.cpp b/linker/linker_main.cpp
index fa4fd4c..331f831 100644
--- a/linker/linker_main.cpp
+++ b/linker/linker_main.cpp
@@ -510,6 +510,10 @@
extern "C" ElfW(Addr) __linker_init(void* raw_args) {
KernelArgumentBlock args(raw_args);
+#if defined(__i386__)
+ __libc_init_sysinfo(args);
+#endif
+
// AT_BASE is set to 0 in the case when linker is run by iself
// so in order to link the linker it needs to calcuate AT_BASE
// using information at hand. The trick below takes advantage
@@ -552,15 +556,6 @@
// functions at this point.
if (!linker_so.link_image(g_empty_list, g_empty_list, nullptr)) __linker_cannot_link(args.argv[0]);
-#if defined(__i386__)
- // On x86, we can't make system calls before this point.
- // We can't move this up because this needs to assign to a global.
- // Note that until we call __libc_init_main_thread below we have
- // no TLS, so you shouldn't make a system call that can fail, because
- // it will SEGV when it tries to set errno.
- __libc_init_sysinfo(args);
-#endif
-
// Initialize the main thread (including TLS, so system calls really work).
__libc_init_main_thread(args);