Rework the arm64 sigtramp code to be a trampoline
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Authored by andrew on Dec 29 2021, 6:03 PM.

Details

Reviewers

kib
markj
manu

Group Reviewers

arm64

Commits

rGdb3a1eec371f: Rework the arm64 sigtramp code to be a trampoline

Summary

To help with switching to a vdso sigtramp switch to passing through the
sigcode function when entering a signal. This ensures the return address
is within the function.

Diff Detail

Repository

rG FreeBSD src repository

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Unit

Tests Not Applicable

Event Timeline

andrew created this revision.Dec 29 2021, 6:03 PM

Herald added a reviewer: manu. · View Herald TranscriptDec 29 2021, 6:03 PM

Herald added subscribers: emaste, imp. · View Herald Transcript

andrew requested review of this revision.Dec 29 2021, 6:03 PM

Harbormaster completed remote builds in B43639: Diff 100711.Dec 29 2021, 6:03 PM

kib added inline comments.Dec 29 2021, 10:36 PM

sys/arm64/arm64/exec_machdep.c
633	When does this case needed at all?

andrew added inline comments.Jan 4 2022, 1:51 PM

sys/arm64/arm64/exec_machdep.c
633	It's used in Linux emulation.

kib added inline comments.Jan 4 2022, 2:14 PM

sys/arm64/arm64/exec_machdep.c
633	Don't Linux emulation need its own sendsig() implementation? I doubt that our sigframe format is identical to the Linux one. Even, if unlikely it is, there is high probability that we diverge in future.