If AutoRemoteSyscalls fails to map a file, print the file name.

Author: khuey

src/AutoRemoteSyscalls.cc

@@ -894,9 +894,13 @@ bool AutoRemoteSyscalls::check_syscall_result(long ret, int syscallno, bool allo
       extra_msg = " opening " + t->read_c_str(t->regs().arg1());
     } else if (is_openat_syscall(syscallno, arch()) || is_openat2_syscall(syscallno, arch())) {
       extra_msg = " opening " + t->read_c_str(t->regs().arg2());
-    } else if (is_mremap_syscall(syscallno, arch()) ||
-               is_mmap_syscall(syscallno, arch())) {
+    } else if (is_mremap_syscall(syscallno, arch())) {
       AddressSpace::print_process_maps(t);
+    } else if (is_mmap_syscall(syscallno, arch())) {
+      AddressSpace::print_process_maps(t);
+      if ((t->regs().arg4() & MAP_ANONYMOUS) == 0) {
+        extra_msg = " mmapping " + t->file_name_of_fd(t->regs().arg5());
+      }
     }
     ASSERT(t, false) << "Syscall " << syscall_name(syscallno, arch())
                      << " failed with errno " << errno_name(-ret) << extra_msg