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--- a/linux-user/elfload.c 2019-06-03 13:06:40.755755923 +0200
+++ b/linux-user/elfload.c 2019-06-03 13:33:01.315709801 +0200
@@ -2303,7 +2303,20 @@
info->brk = 0;
info->elf_flags = ehdr->e_flags;
- if (!afl_entry_point) afl_entry_point = info->entry;
+ if (!afl_entry_point) {
+ char *ptr;
+ if ((ptr = getenv("AFL_ENTRYPOINT")) != NULL) {
+ afl_entry_point = strtoul(ptr, NULL, 16);
+ } else {
+ afl_entry_point = info->entry;
+ }
+#ifdef TARGET_ARM
+ /* The least significant bit indicates Thumb mode. */
+ afl_entry_point = afl_entry_point & ~(target_ulong)1;
+#endif
+ }
+ if (getenv("AFL_DEBUG") != NULL)
+ fprintf(stderr, "AFL forkserver entrypoint: %p\n", (void*)afl_entry_point);
for (i = 0; i < ehdr->e_phnum; i++) {
struct elf_phdr *eppnt = phdr + i;
@@ -2668,6 +2681,22 @@
change some of these later */
bprm->p = setup_arg_pages(bprm, info);
+ // On PowerPC64 the entry point is the _function descriptor_
+ // of the entry function. For AFL to properly initialize,
+ // afl_entry_point needs to be set to the actual first instruction
+ // as opposed executed by the target program. This as opposed to
+ // where the function's descriptor sits in memory.
+ // copied from PPC init_thread
+#if defined(TARGET_PPC64) && !defined(TARGET_ABI32)
+ if (get_ppc64_abi(infop) < 2) {
+ uint64_t val;
+ get_user_u64(val, infop->entry + 8);
+ _regs->gpr[2] = val + infop->load_bias;
+ get_user_u64(val, infop->entry);
+ infop->entry = val + infop->load_bias;
+ }
+#endif
+
scratch = g_new0(char, TARGET_PAGE_SIZE);
if (STACK_GROWS_DOWN) {
bprm->p = copy_elf_strings(1, &bprm->filename, scratch,
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