Author: ed Date: Thu Oct 22 09:33:34 2015 New Revision: 289748 URL: https://svnweb.freebsd.org/changeset/base/289748
Log: Add a way to distinguish between forking and thread creation in schedtail. For CloudABI we need to initialize the registers of new threads differently based on whether the thread got created through a fork or through simple thread creation. Add a flag, TDP_FORKING, that is set by do_fork() and cleared by fork_exit(). This can be tested against in schedtail. Reviewed by: kib Differential Revision: https://reviews.freebsd.org/D3973 Modified: head/sys/kern/kern_fork.c head/sys/kern/subr_syscall.c head/sys/sys/proc.h Modified: head/sys/kern/kern_fork.c ============================================================================== --- head/sys/kern/kern_fork.c Thu Oct 22 09:07:53 2015 (r289747) +++ head/sys/kern/kern_fork.c Thu Oct 22 09:33:34 2015 (r289748) @@ -586,7 +586,7 @@ do_fork(struct thread *td, int flags, st * been preserved. */ p2->p_flag |= p1->p_flag & P_SUGID; - td2->td_pflags |= td->td_pflags & TDP_ALTSTACK; + td2->td_pflags |= (td->td_pflags & TDP_ALTSTACK) | TDP_FORKING; SESS_LOCK(p1->p_session); if (p1->p_session->s_ttyvp != NULL && p1->p_flag & P_CONTROLT) p2->p_flag |= P_CONTROLT; @@ -1023,6 +1023,7 @@ fork_exit(void (*callout)(void *, struct if (p->p_sysent->sv_schedtail != NULL) (p->p_sysent->sv_schedtail)(td); + td->td_pflags &= ~TDP_FORKING; } /* Modified: head/sys/kern/subr_syscall.c ============================================================================== --- head/sys/kern/subr_syscall.c Thu Oct 22 09:07:53 2015 (r289747) +++ head/sys/kern/subr_syscall.c Thu Oct 22 09:33:34 2015 (r289748) @@ -176,6 +176,9 @@ syscallret(struct thread *td, int error, struct proc *p, *p2; int traced; + KASSERT((td->td_pflags & TDP_FORKING) == 0, + ("fork() did not clear TDP_FORKING upon completion")); + p = td->td_proc; /* Modified: head/sys/sys/proc.h ============================================================================== --- head/sys/sys/proc.h Thu Oct 22 09:07:53 2015 (r289747) +++ head/sys/sys/proc.h Thu Oct 22 09:33:34 2015 (r289748) @@ -446,7 +446,7 @@ do { \ #define TDP_RESETSPUR 0x04000000 /* Reset spurious page fault history. */ #define TDP_NERRNO 0x08000000 /* Last errno is already in td_errno */ #define TDP_UIOHELD 0x10000000 /* Current uio has pages held in td_ma */ -#define TDP_UNUSED29 0x20000000 /* --available-- */ +#define TDP_FORKING 0x20000000 /* Thread is being created through fork() */ #define TDP_EXECVMSPC 0x40000000 /* Execve destroyed old vmspace */ /* _______________________________________________ svn-src-all@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
