RFR: 8371048: ImageFileReader::open fails to check return value of osSupport::map_memory

[Alan Bateman]

On Fri, 31 Oct 2025 14:00:38 GMT, Justin King <jcking at openjdk.org> wrote:

> Check whether `osSupport::map_memory` actually succeeded in all compliation modes, instead of crashing shortly after in non-debug builds. Ideally we should fall back to just reading the entire file into memory manually or use seek+read, but this is good enough for now to avoid crashing.

In an images build, the VM has to fail during startup if the jimage file cannot be opened. Maybe @jcking could paste in the output from both release and fastdebug builds. It may be that it trips an assert earlier with debug builds.

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PR Comment: https://git.openjdk.org/jdk/pull/28087#issuecomment-3527546988