RFR: 8349554: [UBSAN] os::attempt_reserve_memory_between reported applying non-zero offset to non-null pointer produced null pointer

[SendaoYan]

On Fri, 7 Feb 2025 12:51:42 GMT, Stefan Karlsson <stefank at openjdk.org> wrote:

> > `hi_end` less than `lo_att` in some cases
> 
> Do you know if that only happens in our tests and not in normal JVM runs? 

It happens in normal JVM runs. The command is:


build/linux-x86_64-server-slowdebug/images/jdk/bin/java -Xlog:os+map=trace -Xshare:dump -XX:SharedArchiveFile=build/linux-x86_64-server-slowdebug/images/jdk/lib/server/classes_nocoops_coh.jsa -server -XX:-UseCompressedOops -XX:+UnlockExperimentalVMOptions -XX:+UseCompactObjectHeaders -Xmx128M -Xms128M -XX:+UseG1GC


The output snippet:

[0.020s][debug][os,map] reserve_between (range [0x0000000000000000-0x0000000000400000), size 0x40000000, alignment 0x1000000, randomize: 1)

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PR Comment: https://git.openjdk.org/jdk/pull/23508#issuecomment-2642870928