Page MenuHomeFreeBSD

Fix makecontext() on MIPS O32.
ClosedPublic

Authored by jhb on Feb 2 2018, 10:51 PM.
Tags
None
Referenced Files
F81971460: D14179.id38800.diff
Sun, Dec 15, 3:01 AM
F81971058: D14179.diff
Sat, Dec 14, 11:43 PM
Unknown Object (File)
Feb 15 2024, 9:52 AM
Unknown Object (File)
Dec 20 2023, 3:24 AM
Unknown Object (File)
Nov 2 2023, 10:20 AM
Unknown Object (File)
Sep 10 2023, 5:38 AM
Unknown Object (File)
Aug 16 2023, 3:40 AM
Unknown Object (File)
Jul 10 2023, 10:52 PM
Subscribers

Details

Summary

The GP register can be clobbered by the callback, so save it in S1 while
invoking the callback function.

Test Plan
  • the various makecontext tests now pass on o32 instead of core dumping when trying to call ctx_done due to a trashed GP.

Diff Detail

Repository
rS FreeBSD src repository - subversion
Lint
Lint Not Applicable
Unit
Tests Not Applicable

Event Timeline

I take full blame, and acknowledge spending too much time in code with -G0, and thus being somewhat lazy about gp's treatment.

I'd say that because there are a bunch of different ABI semantics here, the comment could be modified to be more explicit about s1 being callee-saved in o32, while gp is callee-saved in n32 and n64, or something.

Thank you! It's good as-is, or with a comment which is more explicit about register saving responsibility.

This revision is now accepted and ready to land.Feb 3 2018, 1:11 AM
This revision was automatically updated to reflect the committed changes.