RFR: 8342607: Enhance register printing on x86_64 platforms [v7]

[Martin Doerr]

On Mon, 28 Oct 2024 14:19:29 GMT, Richard Reingruber <rrich at openjdk.org> wrote:

>> Martin Doerr has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Add check for uc->uc_mcontext.fpregs >= uc.
>
> src/hotspot/os_cpu/linux_x86/os_linux_x86.cpp line 552:
> 
>> 550:   size_t fpregs_offset = ((address)uc->uc_mcontext.fpregs >= (address)uc) ?
>> 551:                          pointer_delta(uc->uc_mcontext.fpregs, uc, 1) : 0;
>> 552:   if (fpregs_offset >= sizeof(ucontext_t) || fpregs_offset == 0) {
> 
> Why protect against the assertion in `pointer_delta` here and not also in `store_context`?
> You could do the following in both methods:
> Suggestion:
> 
>   size_t fpregs_offset = ((address)uc->uc_mcontext.fpregs >= (address)uc) ?
>                          pointer_delta(uc->uc_mcontext.fpregs, uc, 1) : sizeof(ucontext_t);
>   if (fpregs_offset >= sizeof(ucontext_t)) {

I've changed it such that we don't touch in this case.

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PR Review Comment: https://git.openjdk.org/jdk/pull/21615#discussion_r1819426998