sh(1): make smark a static variable instead of a local in main()
ClosedPublic
Actions

Authored by daniel_octaforge.org on Jun 3 2023, 10:44 PM.

Details

Reviewers

bapt
jilles
imp

Commits

rG2178e8c27aad: sh: make smark a static variable instead of a local in main()

Summary

We are modifying it after setjmp and then accessing it after the jump, so it cannot be a local.

Diff Detail

Repository

rG FreeBSD src repository

Lint

Lint Skipped

Unit

Tests Skipped

Event Timeline

daniel_octaforge.org requested review of this revision.Jun 3 2023, 10:44 PM

daniel_octaforge.org created this revision.

daniel_octaforge.org mentioned this in D40413: sh(1): initialize smark to zero in main().

I agree with the analysis, but the variables should still be defined inside main (with static) so they cannot be used outside. Some of the other functions in this file have their own smark locals that should not be mixed up with main's.

An alternative fix could be to change setstackmark and popstackmark to return/take the struct stackmark by value and make main's variables volatile. I'm not really sure that's better than just adding the static keyword though.