eclipse / omr

Eclipse OMR™ Cross platform components for building reliable, high performance language runtimes
http://www.eclipse.org/omr
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Don't map systemcfg on Power in checkpoint mode #7351

Open ymanton opened 1 month ago

ymanton commented 1 month ago

On Power omrtime_current_time_millis and omrtime_hires_clock can use the timebase register to very quickly get the current time. This requires mmapping the special /proc/ppc64/systemcfg file.

Some security modules (e.g. SELinux) prevent systemcfg from being mapped by user processes. If we take a checkpoint in an environment that that allows systemcfg to be mapped it will not be restorable in an environment that forbids it.

This patch disables the mapping of systemcfg in checkpoint mode, which will force the omrtime functions to fall back to conventional Linux time APIs.