Make SIGILL fatal instead of looping in its signal handler - #1926
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willbuckner wants to merge 1 commit into
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Make SIGILL fatal instead of looping in its signal handler#1926willbuckner wants to merge 1 commit into
willbuckner wants to merge 1 commit into
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Found by: michaelortmann Fixes: eggheads#1640 got_ill() logged the signal and returned. Returning from a SIGILL handler re-executes the faulting instruction, so a real illegal instruction re-raised the signal immediately, spamming the log in an endless loop, and no core dump or stack trace was ever produced. Treat SIGILL like SIGBUS/SIGSEGV: write the DEBUG file, log the crash and re-raise the signal with its default action restored so the bot dies with a core dump. Restore the default action explicitly instead of relying on SA_RESETHAND alone: at least on macOS the handler stays installed when the signal is re-raised from within the handler, which would turn the re-raise into another endless loop. This removes the (now pointless) sigill Tcl evnt bind; the bot no longer survives SIGILL.
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ok, I'll bite... Wcc? |
Author
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yes :P |
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Found by: michaelortmann
Patch by: willbuckner
Fixes: #1640
One-line summary: Make SIGILL fatal instead of looping in its signal handler
Additional description (if needed):
got_ill() logged the signal and returned. Returning from a SIGILL handler re-executes the faulting instruction, so a real illegal instruction re-raised the signal immediately, spamming the log in an endless loop, and no core dump or stack trace was ever produced.
Treat SIGILL like SIGBUS/SIGSEGV: write the DEBUG file, log the crash and re-raise the signal with its default action restored so the bot dies with a core dump.
Restore the default action explicitly instead of relying on SA_RESETHAND alone: at least on macOS the handler stays installed when the signal is re-raised from within the handler, which would turn the re-raise into another endless loop.
This removes the (now pointless) sigill Tcl evnt bind; the bot no longer survives SIGILL.
Test cases demonstrating functionality (if applicable): N/A