On 2/15/17, Mark Millard <mar...@dsl-only.net> wrote: >> Author: andrew >> Date: Wed Feb 15 14:56:47 2017 >> New Revision: 313772 >> URL: >> https://svnweb.freebsd.org/changeset/base/313772 >> >> Log: >> Load the new sp_el0 with interrupts disabled in fork_trampoline. If an >> interrupt arrives in fork_trampoline after sp_el0 was written we may >> then >> switch to a new thread, enter userland so change this stack pointer, >> then >> return to this code with the wrong value. This fixes this case by >> moving >> the load of sp_el0 until after interrupts have been disabled. > > https://svnweb.freebsd.org/base/stable/11/sys/arm64/arm64/swtch.S?revision=302408&view=markup > > shows stable/11 has the same issue. > > Is this to be MFC'd at some point? > > > stable/10 seems to have a different code structure: > > https://svnweb.freebsd.org/base/stable/10/sys/amd64/amd64/
This is x86-64 aka amd64 in FreeBSD, in 10-STABLE only 32 bit ARM support exists, so there isn't arm64. > > does not list swtch.S . So I'm unsure about its status for > fork returning to the child process and its handling of the > stack pointer to be restored. > > === > Mark Millard > markmi at dsl-only.net > > _______________________________________________ > svn-src-head@freebsd.org mailing list > https://lists.freebsd.org/mailman/listinfo/svn-src-head > To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org" > _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
