* Daniel Colascione: > See, both pro-FP and anti-FP camps think that it's the kernel that has > to do the unwinding unless we copy whole stacks into traces.
Well, I think we should explore hardware-assisted backtraces (shadow stacks), which hopefully are going to get merged in Linux 6.2. > Why should that be? As mentioned in [1], instead of finding a way to > have the kernel unwind user programs, we can create a protocol through > which the kernel can ask usermode to unwind itself. It could work like > this: If the unwind information is incomplete, this … > 7) signal handler unwinds the calling thread however it wants (and can > sleep and take page faults if needed) … might encounter segmentation faults and terminate the process. So far, incorrect unwind information (whether it's a clobbered frame pointer, or missing DWARF information about clobbered registers) is not a problem, but it's kind of hard to validate this information from within the process itself. Maybe we'd have to add a magic memcpy first to the vDSO, which the kernel recognizes based on the code addresses, and suppresses sending the signal for it. Thanks, Florian _______________________________________________ devel mailing list -- devel@lists.fedoraproject.org To unsubscribe send an email to devel-le...@lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/devel@lists.fedoraproject.org Do not reply to spam, report it: https://pagure.io/fedora-infrastructure/new_issue
