On Mon, 10 Oct 2022 04:43:03 GMT, David Holmes <dhol...@openjdk.org> wrote:
>> No, don't do this. The code is just wrong, and should be fixed. >> >> We have a struct sigaction. We've set the sa_flags member to a value that >> includes SA_SIGINFO. That means the 3 argument sa_sigaction handler is >> supposed to be invoked. >> >> We're storing the SR_handler (cast to a value matching the type of the >> sa_handler member of the sigaction). This is "working" purely by accident. >> Apparently on all POSIX platforms we support, the sa_handler and sa_sigaction >> occupy the same memory (being in a union, which is permitted by the spec). >> >> The signature for SR_handler should be changed from >> void SR_handler(int, siginfo_t*, ucontext_t*) >> to >> void SR_handler(int, siginfo_t*, void*) >> and adjust the code to deal with the change to the type of the 3rd parameter. >> >> Then we can just assign the sa_sigaction member to SR_handler without any >> casts. > > But this is how POSIX specifies it: `sigaction.sa_handler` is declared as > `void(*) (int)` - so that is what we have to use when storing the handler > address. But the handler itself has to be the three arg version because that > is how it will be called. Oh! Sorry I wasn't reading the `sigaction` definition properly I missed it contains two "handler" slots and we are using the wrong one! ------------- PR: https://git.openjdk.org/jdk/pull/10494
