Fix a few bionic test failures caused by hwasan global instrumentation.

The call to the load hook needs to be moved before the call to link_image()
because the latter calls ifunc resolvers which might access global
variables. This fixes a bunch of ifunc tests.

The dlfcn.segment_gap test is currently failing. One problem is that the name
of the .bss.end_of_gap section changes as a result of global instrumentation.
Add some wildcards in so that we match both names. The other problem seems
to be the same as b/139089152.

It turns out that we need to untag pointers in a few more places. Since we have
quite a few of these now it seems worth creating a function for it.

Test: bionic-unit-tests
Change-Id: I44e2b0904faacdda7cc0c5e844ffc09de01dea2d

1 files changed, 6 insertions, 4 deletions

diff --git a/linker/linker.cpp b/linker/linker.cpp
index 0361a8ab3..e41194d1a 100644
--- a/linker/linker.cpp
+++ b/linker/linker.cpp
@@ -951,7 +951,9 @@ static const ElfW(Sym)* dlsym_linear_lookup(android_namespace_t* ns,
 }
 
 soinfo* find_containing_library(const void* p) {
-  ElfW(Addr) address = reinterpret_cast<ElfW(Addr)>(p);
+  // Addresses within a library may be tagged if they point to globals. Untag
+  // them so that the bounds check succeeds.
+  ElfW(Addr) address = reinterpret_cast<ElfW(Addr)>(untag_address(p));
   for (soinfo* si = solist_get_head(); si != nullptr; si = si->next) {
     if (address < si->base || address - si->base >= si->size) {
       continue;
@@ -1901,13 +1903,13 @@ bool find_libraries(android_namespace_t* ns,
           // flag is set.
           link_extinfo = extinfo;
         }
+        if (__libc_shared_globals()->load_hook) {
+          __libc_shared_globals()->load_hook(si->load_bias, si->phdr, si->phnum);
+        }
         if (!si->link_image(global_group, local_group, link_extinfo, &relro_fd_offset) ||
             !get_cfi_shadow()->AfterLoad(si, solist_get_head())) {
           return false;
         }
-        if (__libc_shared_globals()->load_hook) {
-          __libc_shared_globals()->load_hook(si->load_bias, si->phdr, si->phnum);
-        }
       }
 
       return true;