On Mon, 2020-03-23 at 15:45 +0100, Christophe Leroy wrote:

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Le 23/03/2020 à 15:43, Christophe Leroy a écrit :

quoted

Le 23/03/2020 à 15:17, Joakim Tjernlund a écrit :

quoted

In __die(), see below, there is this call to notify_send() with
SIGSEGV hardcoded, this seems odd
to me as the variable "err" holds the true signal(in my case SIGBUS)
Should not SIGSEGV be replaced with the true signal no.?

As far as I can see, comes from
https://nam03.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.kernel.org%2Fpub%2Fscm%2Flinux%2Fkernel%2Fgit%2Ftorvalds%2Flinux.git%2Fcommit%2F%3Fid%3D66fcb1059&data=02%7C01%7CJoakim.Tjernlund%40infinera.com%7C4291ac1b501e4296869a08d7cf38cdb4%7C285643de5f5b4b03a1530ae2dc8aaf77%7C1%7C0%7C637205715189366995&sdata=Z2bFsmDlD2MKhLACQvayk9ejz0dqgMEOlBTlocAmtTg%3D&reserved=0

And
https://nam03.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.kernel.org%2Fpub%2Fscm%2Flinux%2Fkernel%2Fgit%2Ftorvalds%2Flinux.git%2Fcommit%2F%3Fid%3Dae87221d3ce49d9de1e43756da834fd0bf05a2ad&data=02%7C01%7CJoakim.Tjernlund%40infinera.com%7C4291ac1b501e4296869a08d7cf38cdb4%7C285643de5f5b4b03a1530ae2dc8aaf77%7C1%7C0%7C637205715189366995&sdata=97kyz3Ur88BhDUUYzya5t%2FFQVhXYu6qiHoW8hsEg81s%3D&reserved=0
shows it is (was?) similar on x86.

I tried to follow that chain thinking it would end up sending a signal to user space but I cannot see
that happens. Seems to be related to debugging.

In short, I cannot see any signal being delivered to user space. If so that would explain why
our user space process never dies.
Is there a signal hidden in machine_check handler for SIGBUS I cannot see?

     Jocke