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  1. JDK
  2. JDK-8216427

ciMethodData::load_extra_data() does not always unpack the last entry

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        When unpacking the extra data section of the MDOs, the source and destination might not have the same number of entries, because there can be safepoints between cloning the extra data section of the MDO and unpacking the source entries to the destination entries.

        Therefore the unpacking loop loops through all the source entries and copies them to the destination. Except the last DataLayout::arg_info_data_tag entry, that never gets copied form the source to the destination. Therefore, if a safepoint occurred between cloning the extra data section and unpacking its entries in ciMethodData::load_extra_data(), the last entry could contain random bogus memory.

        It seems like the reason the last entry is not copied is because the copying requires a length which is calculated by taking the difference between the current entry and the next entry in the loop. But as there is no next entry when you are at the last entry, the copying is simply not performed, instead of calculating what the length of that entry would be.

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            Backport - A issue that is required to port a Bug or Feature into another product release. This issue type is generally associated with the main Bug/Feature to represent each individual release of the port. JDK-8217174 ciMethodData::load_extra_data() does not always unpack the last entry

            • P3 - Major loss of function.
            • Resolved

            Backport - A issue that is required to port a Bug or Feature into another product release. This issue type is generally associated with the main Bug/Feature to represent each individual release of the port. JDK-8217539 ciMethodData::load_extra_data() does not always unpack the last entry

            • P3 - Major loss of function.
            • Resolved

            Backport - A issue that is required to port a Bug or Feature into another product release. This issue type is generally associated with the main Bug/Feature to represent each individual release of the port. JDK-8227143 ciMethodData::load_extra_data() does not always unpack the last entry

            • P3 - Major loss of function.
            • Resolved

            Backport - A issue that is required to port a Bug or Feature into another product release. This issue type is generally associated with the main Bug/Feature to represent each individual release of the port. JDK-8227520 ciMethodData::load_extra_data() does not always unpack the last entry

            • P3 - Major loss of function.
            • Resolved
            relates to

            Bug - A problem which impairs or prevents the functions of the product. JDK-8057038 Speculative traps not robust when compilation and class unloading are concurrent

            • P4 - Minor loss of function, or other problem where easy workaround is present.
            • Resolved

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                eosterlund Erik Österlund
                eosterlund Erik Österlund
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