RFR: 8353468: [ubsan] arguments.cpp:2422:23: runtime error: 2.14748e+11 is outside the range of representable values of type 'int' [v6]

[Stefan Karlsson]

On Wed, 3 Sep 2025 08:08:52 GMT, Afshin Zafari <azafari at openjdk.org> wrote:

>> In converting values of `-XMinf` and `-XMaxf` options to `int`, overflow was not checked. 
>> The values are checked against INT_MAX and clamped.
>> 
>> Tests: tiers 1-5.
>
> Afshin Zafari has updated the pull request incrementally with one additional commit since the last revision:
> 
>   message fix

I still find it weird that the error message says "percentage":

jio_fprintf(defaultStream::error_stream(),
            "Bad max heap free percentage size: %s\n",
            option->optionString);


The new code also mixes the style w.r.t. using redundant `else`s vs early returns. Could you straighten up the code so that all error checking is at the same indentation level?:


      if (*err != '\0' || *tail == '\0') {
        jio_fprintf(defaultStream::error_stream(),
                    "Bad max heap free ratio: %s\n",
                    option->optionString);
        return JNI_EINVAL;
      }
      if (dmaxf < 0.0 || dmaxf > 1.0) {
        jio_fprintf(defaultStream::error_stream(),
                    "-Xmaxf value (%s) is outside the allowed range [ 0.0 ... 1.0 ]\n",
                    option->optionString);
        return JNI_EINVAL;
      }
      if (MinHeapFreeRatio > (uintx)(dmaxf * 100)) {
        jio_fprintf(defaultStream::error_stream(),
                    "-Xmaxf value (%s) must be greater than or equal to the implicit -Xminf value (%3.2lf)\n",
                    tail, MinHeapFreeRatio / 100.0);
        return JNI_EINVAL;
      }
      if (FLAG_SET_CMDLINE(MaxHeapFreeRatio, (uintx)(dmaxf * 100)) != JVMFlag::SUCCESS) {
          return JNI_EINVAL;
      }

This could be extracted into a local constant:

(uintx)(dmaxf * 100)

I don't think there should be a 3 here:

(%3.2lf)

In another PR I saw that the usage of `%lf` instead of `%f` was questioned. Should we be using `%lf` here?

      if (FLAG_SET_CMDLINE(MaxHeapFreeRatio, (uintx)(dmaxf * 100)) != JVMFlag::SUCCESS) {
          return JNI_EINVAL;
      }

There's an incorrect indentation at the return statement.

-------------

Changes requested by stefank (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/26859#pullrequestreview-3185325686