RFR: 8315739: Missing null check in os::vm_min_address [v2]

[David Holmes]

On Tue, 12 Sep 2023 05:20:31 GMT, Daniel Jeliński <djelinski at openjdk.org> wrote:

>> src/hotspot/os/linux/os_linux.cpp line 4258:
>> 
>>> 4256:     FILE* f = os::fopen("/proc/sys/vm/mmap_min_addr", "r");
>>> 4257:     if (f != nullptr) {
>>> 4258:       if (fscanf(f, "%zu", &value) != 1) {
>> 
>> I think you can simplify the whole thing by only making this one change:
>> 
>> if (f != nullptr && fscanf(f, "%zu", &value) != 1) {
>> 
>> the "assignment" in the null case will be handled by the existing:
>> 
>> value = MAX2(_vm_min_address_default, value);
>
> Changed, but I'm not sure if the result is more simple. I still need a proper check for `f != nullptr` before `fclose`.

Ah! I missed that.

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PR Review Comment: https://git.openjdk.org/jdk/pull/15596#discussion_r1322407247