[Backtracing][Linux] Correctly handle signals from other processes.#89461
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[Backtracing][Linux] Correctly handle signals from other processes.#89461al45tair wants to merge 1 commit into
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weissi
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| // this case what we want to do is stop the memory server and | ||
| // reinstall the signal handlers in order that we catch future | ||
| // crashes. | ||
| memserver_stop(); |
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@al45tair I don't love this because that's functionality that's only accessible from PID 1. Would it not be possible to re-raise the signal in a way that's guaranteed to kill the process even as pid 1?
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It won't ever kill the process if it's PID 1, because Linux protects PID 1 processes from being killed by crashes(!)
Trying to terminate would actually change the standard behaviour for PID 1. I did think about it, but I don't think we should do that.
It's possible to `kill -SEGV` or `kill -ILL` a Swift program; when this happens, we need to be aware and handle it slightly differently to normal, because the signal we get doesn't have the same information attached to it that it normally would. Additionally we need to make sure the behaviour is as expected. That means, for PID 1, the process should output a backtrace *and continue running*, while in the normal case the process should terminate with a status code reflecting the signal that was delivered. rdar://177740814
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It's possible to
kill -SEGVorkill -ILLa Swift program; when this happens, we need to be aware and handle it slightly differently to normal, because the signal we get doesn't have the same information attached to it that it normally would.Additionally we need to make sure the behaviour is as expected. That means, for PID 1, the process should output a backtrace and continue running, while in the normal case the process should terminate with a status code reflecting the signal that was delivered.
rdar://177740814