Don't mmap ELF segments with zero filesz

pk/elf.c

@@ -84,8 +84,10 @@ void load_elf(const char* fn, elf_info* info)
         info->brk_min = vaddr + ph[i].p_memsz;
       int flags2 = flags | (prepad ? MAP_POPULATE : 0);
       int prot = get_prot(ph[i].p_flags);
-      if (__do_mmap(vaddr - prepad, ph[i].p_filesz + prepad, prot | PROT_WRITE, flags2, file, ph[i].p_offset - prepad) != vaddr - prepad)
-        goto fail;
+      if (ph[i].p_filesz != 0) {
+        if (__do_mmap(vaddr - prepad, ph[i].p_filesz + prepad, prot | PROT_WRITE, flags2, file, ph[i].p_offset - prepad) != vaddr - prepad)
+          goto fail;
+      }
       memset_user((void*)vaddr - prepad, 0, prepad);
       if (!(prot & PROT_WRITE))
         if (do_mprotect(vaddr - prepad, ph[i].p_filesz + prepad, prot))