Nice work !
Some time ago I was in a project, where we would like to get more context in syslog when e.g. SIGSEGV occurred (embedded Linux). On x86 this was working fine, and I hope a change like this for ARM will allow it to work here as well (as long as stack is still valid). I don't have access to such an ARM setup currently. Can somebody try if e.g. backtrace_symbols () will show where the offending code was called from? http://linux.die.net/man/3/backtrace_symbols Also I really like the idea to get this back into the mainstream version, so we all will benefit from it in future ;-) /Mads Fra: Matthijs van Duin [via gcc] [mailto:ml-node+s1065356n1191196...@n5.nabble.com] Sendt: 3. oktober 2015 22:42 Til: mads_bn <mad...@mail.dk> Emne: Re: ARM Linux EABI: unwinding through a segfault handler A shiny revised version of my unwind-through-signal code for ARM EABI: https://github.com/mvduin/arm-signal-unwind/ For actual unwinding it now uses sigreturn as a cleanup handler (after diddling the ucontext to make it land right onto a call to _Unwind_Resume), which means that all state should get properly restored by the kernel. Virtual unwinding still only restores core registers, but hopefully that isn't too big a problem in practice. A small test is included that confirms throwing exceptions out of SEGV, checks VFP is restored properly, and that returning normally from an async signal handler still works (my original patch accidently broke that). I'd finally like to take a moment to say this was hell to figure out.... this shit is really documented nowhere properly since it appears to be a magic blend of ARM EABI and IA64 C++ ABI (meaning neither documentation quite applies) and I had to plow through the innards of libgcc and libsupc++ to figure out how things *actually* work. Argh. Anyhow, it only took four years, but you can now throw NullPointerExceptions on ARM. Enjoy. ;-) Matthijs van Duin _____ If you reply to this email, your message will be added to the discussion below: http://gcc.1065356.n5.nabble.com/ARM-Linux-EABI-unwinding-through-a-segfault -handler-tp692287p1191196.html To unsubscribe from ARM Linux EABI: unwinding through a segfault handler, click here <http://gcc.1065356.n5.nabble.com/template/NamlServlet.jtp?macro=unsubscribe _by_code&node=692287&code=bWFkc2JuQG1haWwuZGt8NjkyMjg3fDIwNDQ1NTEzNzU=> . <http://gcc.1065356.n5.nabble.com/template/NamlServlet.jtp?macro=macro_viewe r&id=instant_html%21nabble%3Aemail.naml&base=nabble.naml.namespaces.BasicNam espace-nabble.view.web.template.NabbleNamespace-nabble.view.web.template.Nod eNamespace&breadcrumbs=notify_subscribers%21nabble%3Aemail.naml-instant_emai ls%21nabble%3Aemail.naml-send_instant_email%21nabble%3Aemail.naml> NAML -- View this message in context: http://gcc.1065356.n5.nabble.com/SV-ARM-Linux-EABI-unwinding-through-a-segfault-handler-tp1191260.html Sent from the gcc - Dev mailing list archive at Nabble.com.
