RFR: JDK-8260022: [ppc] os::print_function_and_library_name shall resolve function descriptors transparently [v3]

[Martin Doerr]

On Thu, 21 Jan 2021 10:05:21 GMT, Thomas Stuefe <stuefe at openjdk.org> wrote:

>> When function descriptors are fed to os::print_function_and_library_name() to get debug output, it would be very helpful to transparently handle the case where the address is not a code pointer but a function descriptor.
>> 
>> Of the official OpenJDK platforms this affects only ppc, but also includes at least ia64 for those who maintain ports to that platform.
>> 
>> Fixing this will also fix the display of signal handlers on linux ppc which still show up without function names after JDK-8258606.
>> 
>> Before:
>> 695 Signal Handlers:
>> 696    SIGSEGV: 0x00000fff8d0f4348 in libjvm.so+34882376, sa_mask[0]=11100100010111111101111111111110, sa_flags=SA_RESTART|SA_SIGINFO
>> 697     SIGBUS: 0x00000fff8d0f4348 in libjvm.so+34882376, sa_mask[0]=11100100010111111101111111111110, sa_flags=SA_RESTART|SA_SIGINFO
>> 698     SIGFPE: 0x00000fff8d0f4348 in libjvm.so+34882376, sa_mask[0]=11100100010111111101111111111110, sa_flags=SA_RESTART|SA_SIGINFO
>> 699    SIGPIPE: 0x00000fff8d0e0158 in libjvm.so+34799960, sa_mask[0]=11100100010111111101111111111110, sa_flags=SA_RESTART|SA_SIGINFO
>> 700    SIGXFSZ: 0x00000fff8d0e0158 in libjvm.so+34799960, sa_mask[0]=11100100010111111101111111111110, sa_flags=SA_RESTART|SA_SIGINFO
>> 701     SIGILL: 0x00000fff8d0f4348 in libjvm.so+34882376, sa_mask[0]=11100100010111111101111111111110, sa_flags=SA_RESTART|SA_SIGINFO
>> 702    SIGUSR2: 0x00000fff8d0e0098 in libjvm.so+34799768, sa_mask[0]=00000000000000000000000000000000, sa_flags=SA_RESTART|SA_SIGINFO
>> 703     SIGHUP: 0x00000fff8d0e0080 in libjvm.so+34799744, sa_mask[0]=11100100010111111101111111111110, sa_flags=SA_RESTART|SA_SIGINFO
>> 704     SIGINT: 0x00000fff8d0e0080 in libjvm.so+34799744, sa_mask[0]=11100100010111111101111111111110, sa_flags=SA_RESTART|SA_SIGINFO
>> 705    SIGTERM: 0x00000fff8d0e0080 in libjvm.so+34799744, sa_mask[0]=11100100010111111101111111111110, sa_flags=SA_RESTART|SA_SIGINFO
>> 706    SIGQUIT: 0x00000fff8d0e0080 in libjvm.so+34799744, sa_mask[0]=11100100010111111101111111111110, sa_flags=SA_RESTART|SA_SIGINFO
>> 707    SIGTRAP: 0x00000fff8d0f4348 in libjvm.so+34882376, sa_mask[0]=11100100010111111101111111111110, sa_flags=SA_RESTART|SA_SIGINFO
>> 
>> Now:
>> 693 Signal Handlers:
>> 694    SIGSEGV: crash_handler in libjvm.so (FD), sa_mask[0]=11100100010111111101111111111110, sa_flags=SA_RESTART|SA_SIGINFO
>> 695     SIGBUS: crash_handler in libjvm.so (FD), sa_mask[0]=11100100010111111101111111111110, sa_flags=SA_RESTART|SA_SIGINFO
>> 696     SIGFPE: crash_handler in libjvm.so (FD), sa_mask[0]=11100100010111111101111111111110, sa_flags=SA_RESTART|SA_SIGINFO
>> 697    SIGPIPE: javaSignalHandler in libjvm.so (FD), sa_mask[0]=11100100010111111101111111111110, sa_flags=SA_RESTART|SA_SIGINFO
>> 698    SIGXFSZ: javaSignalHandler in libjvm.so (FD), sa_mask[0]=11100100010111111101111111111110, sa_flags=SA_RESTART|SA_SIGINFO
>> 699     SIGILL: crash_handler in libjvm.so (FD), sa_mask[0]=11100100010111111101111111111110, sa_flags=SA_RESTART|SA_SIGINFO
>> 700    SIGUSR2: SR_handler in libjvm.so (FD), sa_mask[0]=00000000000000000000000000000000, sa_flags=SA_RESTART|SA_SIGINFO
>> 701     SIGHUP: UserHandler in libjvm.so (FD), sa_mask[0]=11100100010111111101111111111110, sa_flags=SA_RESTART|SA_SIGINFO
>> 702     SIGINT: UserHandler in libjvm.so (FD), sa_mask[0]=11100100010111111101111111111110, sa_flags=SA_RESTART|SA_SIGINFO
>> 703    SIGTERM: UserHandler in libjvm.so (FD), sa_mask[0]=11100100010111111101111111111110, sa_flags=SA_RESTART|SA_SIGINFO
>> 704    SIGQUIT: UserHandler in libjvm.so (FD), sa_mask[0]=11100100010111111101111111111110, sa_flags=SA_RESTART|SA_SIGINFO
>> 705    SIGTRAP: crash_handler in libjvm.so (FD), sa_mask[0]=11100100010111111101111111111110, sa_flags=SA_RESTART|SA_SIGINFO
>> 
>> The patch also adds a little trailing marker `(FD)` as an indication for the developer that this had been a function descriptor.
>
> Thomas Stuefe has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Use ABI_ELFv2 instead of VM_LITTLE_ENDIAN

Thanks!

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Marked as reviewed by mdoerr (Reviewer).

PR: https://git.openjdk.java.net/jdk/pull/2157