1 files changed, 52 insertions, 0 deletions
diff --git a/build/unix/elfhack/inject.c b/build/unix/elfhack/inject.c
new file mode 100644
index 000000000..942426330
--- /dev/null
+++ b/build/unix/elfhack/inject.c
@@ -0,0 +1,52 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include <stdint.h>
+#include <elf.h>
+
+/* The Android NDK headers define those */
+#undef Elf_Ehdr
+#undef Elf_Addr
+
+#if defined(__LP64__)
+#define Elf_Ehdr Elf64_Ehdr
+#define Elf_Addr Elf64_Addr
+#else
+#define Elf_Ehdr Elf32_Ehdr
+#define Elf_Addr Elf32_Addr
+#endif
+
+extern __attribute__((visibility("hidden"))) void original_init(int argc, char **argv, char **env);
+
+extern __attribute__((visibility("hidden"))) Elf32_Rel relhack[];
+extern __attribute__((visibility("hidden"))) Elf_Ehdr elf_header;
+
+static inline __attribute__((always_inline))
+void do_relocations(void)
+{
+    Elf32_Rel *rel;
+    Elf_Addr *ptr, *start;
+    for (rel = relhack; rel->r_offset; rel++) {
+        start = (Elf_Addr *)((intptr_t)&elf_header + rel->r_offset);
+        for (ptr = start; ptr < &start[rel->r_info]; ptr++)
+            *ptr += (intptr_t)&elf_header;
+    }
+}
+
+__attribute__((section(".text._init_noinit")))
+int init_noinit(int argc, char **argv, char **env)
+{
+    do_relocations();
+    return 0;
+}
+
+__attribute__((section(".text._init")))
+int init(int argc, char **argv, char **env)
+{
+    do_relocations();
+    original_init(argc, argv, env);
+    // Ensure there is no tail-call optimization, avoiding the use of the
+    // B.W instruction in Thumb for the call above.
+    return 0;
+}