mirror of
https://github.com/freebsd/freebsd-src
synced 2024-09-18 15:53:37 +00:00
- Push down Giant in exit() and wait().
- Push Giant down a bit in coredump() and call coredump() with the proc lock already held rather than unlocking it only to turn around and relock it. Requested by: peter
This commit is contained in:
John Baldwin
parent
8144e3b884
commit
4ae89b957c
Notes:
svn2git
2020-12-20 02:59:44 +00:00
svn path=/head/; revision=126672
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@ -97,7 +97,6 @@ void
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sys_exit(struct thread *td, struct sys_exit_args *uap)
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{
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mtx_lock(&Giant);
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exit1(td, W_EXITCODE(uap->rval, 0));
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/* NOTREACHED */
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}
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@ -121,7 +120,12 @@ exit1(struct thread *td, int rv)
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#endif
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struct plimit *plim;
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GIANT_REQUIRED;
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/*
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* Drop Giant if caller has it. Eventually we should warn about
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* being called with Giant held.
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*/
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while (mtx_owned(&Giant))
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mtx_unlock(&Giant);
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p = td->td_proc;
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if (p == initproc) {
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@ -133,6 +137,7 @@ exit1(struct thread *td, int rv)
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/*
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* MUST abort all other threads before proceeding past here.
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*/
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mtx_lock(&Giant);
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PROC_LOCK(p);
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if (p->p_flag & P_SA || p->p_numthreads > 1) {
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/*
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@ -167,6 +172,7 @@ exit1(struct thread *td, int rv)
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p->p_flag &= ~P_SA;
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thread_single_end(); /* Don't need this any more. */
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}
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mtx_unlock(&Giant);
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/*
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* With this state set:
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* Any thread entering the kernel from userspace will thread_exit()
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@ -197,17 +203,23 @@ exit1(struct thread *td, int rv)
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}
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#ifdef PGINPROF
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mtx_lock(&Giant);
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vmsizmon();
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mtx_unlock(&Giant);
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#endif
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STOPEVENT(p, S_EXIT, rv);
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PROC_LOCK(p);
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_STOPEVENT(p, S_EXIT, rv);
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wakeup(&p->p_stype); /* Wakeup anyone in procfs' PIOCWAIT */
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PROC_UNLOCK(p);
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/*
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* Check if any loadable modules need anything done at process exit.
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* e.g. SYSV IPC stuff
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* XXX what if one of these generates an error?
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*/
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mtx_lock(&Giant);
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EVENTHANDLER_INVOKE(process_exit, p);
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mtx_unlock(&Giant);
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MALLOC(p->p_ru, struct rusage *, sizeof(struct rusage),
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M_ZOMBIE, M_WAITOK);
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@ -238,6 +250,7 @@ exit1(struct thread *td, int rv)
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* Reset any sigio structures pointing to us as a result of
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* F_SETOWN with our pid.
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*/
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mtx_lock(&Giant); /* XXX: not sure if needed */
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funsetownlst(&p->p_sigiolst);
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/*
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@ -245,6 +258,7 @@ exit1(struct thread *td, int rv)
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* This may block!
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*/
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fdfree(td);
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mtx_unlock(&Giant);
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/*
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* Remove ourself from our leader's peer list and wake our leader.
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@ -259,6 +273,7 @@ exit1(struct thread *td, int rv)
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}
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mtx_unlock(&ppeers_lock);
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mtx_lock(&Giant);
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/* The next two chunks should probably be moved to vmspace_exit. */
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vm = p->p_vmspace;
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/*
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@ -345,6 +360,7 @@ exit1(struct thread *td, int rv)
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fixjobc(p, p->p_pgrp, 0);
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sx_xunlock(&proctree_lock);
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(void)acct_process(td);
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mtx_unlock(&Giant);
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#ifdef KTRACE
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/*
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* release trace file
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@ -368,7 +384,9 @@ exit1(struct thread *td, int rv)
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*/
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if ((vtmp = p->p_textvp) != NULL) {
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p->p_textvp = NULL;
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mtx_lock(&Giant);
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vrele(vtmp);
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mtx_unlock(&Giant);
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}
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/*
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@ -424,6 +442,7 @@ exit1(struct thread *td, int rv)
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* Save exit status and final rusage info, adding in child rusage
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* info and self times.
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*/
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mtx_lock(&Giant);
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PROC_LOCK(p);
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p->p_xstat = rv;
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*p->p_ru = p->p_stats->p_ru;
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@ -436,6 +455,7 @@ exit1(struct thread *td, int rv)
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* Notify interested parties of our demise.
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*/
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KNOTE(&p->p_klist, NOTE_EXIT);
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mtx_unlock(&Giant);
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/*
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* Just delete all entries in the p_klist. At this point we won't
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* report any more events, and there are nasty race conditions that
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@ -580,7 +600,6 @@ wait1(struct thread *td, struct wait_args *uap, int compat)
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}
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if (uap->options &~ (WUNTRACED|WNOHANG|WCONTINUED|WLINUXCLONE))
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return (EINVAL);
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mtx_lock(&Giant);
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loop:
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nfound = 0;
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sx_xlock(&proctree_lock);
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@ -649,7 +668,6 @@ wait1(struct thread *td, struct wait_args *uap, int compat)
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wakeup(t);
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PROC_UNLOCK(t);
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sx_xunlock(&proctree_lock);
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mtx_unlock(&Giant);
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return (0);
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}
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@ -669,6 +687,7 @@ wait1(struct thread *td, struct wait_args *uap, int compat)
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* all other writes to this proc are visible now, so
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* no more locking is needed for p.
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*/
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mtx_lock(&Giant);
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PROC_LOCK(p);
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p->p_xstat = 0; /* XXX: why? */
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PROC_UNLOCK(p);
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@ -677,6 +696,7 @@ wait1(struct thread *td, struct wait_args *uap, int compat)
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PROC_UNLOCK(q);
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FREE(p->p_ru, M_ZOMBIE);
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p->p_ru = NULL;
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mtx_unlock(&Giant);
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/*
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* Decrement the count of procs running with this uid.
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@ -696,6 +716,7 @@ wait1(struct thread *td, struct wait_args *uap, int compat)
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/*
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* do any thread-system specific cleanups
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*/
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mtx_lock(&Giant);
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thread_wait(p);
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/*
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@ -704,6 +725,7 @@ wait1(struct thread *td, struct wait_args *uap, int compat)
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* release while still running in process context.
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*/
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vm_waitproc(p);
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mtx_unlock(&Giant);
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#ifdef MAC
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mac_destroy_proc(p);
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#endif
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@ -713,7 +735,6 @@ wait1(struct thread *td, struct wait_args *uap, int compat)
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sx_xlock(&allproc_lock);
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nprocs--;
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sx_xunlock(&allproc_lock);
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mtx_unlock(&Giant);
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return (0);
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}
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mtx_lock_spin(&sched_lock);
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@ -740,7 +761,6 @@ wait1(struct thread *td, struct wait_args *uap, int compat)
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PROC_UNLOCK(p);
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error = 0;
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}
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mtx_unlock(&Giant);
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return (error);
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}
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mtx_unlock_spin(&sched_lock);
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@ -757,30 +777,25 @@ wait1(struct thread *td, struct wait_args *uap, int compat)
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} else
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error = 0;
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mtx_unlock(&Giant);
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return (error);
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}
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PROC_UNLOCK(p);
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}
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if (nfound == 0) {
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sx_xunlock(&proctree_lock);
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mtx_unlock(&Giant);
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return (ECHILD);
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}
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if (uap->options & WNOHANG) {
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sx_xunlock(&proctree_lock);
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td->td_retval[0] = 0;
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mtx_unlock(&Giant);
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return (0);
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}
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PROC_LOCK(q);
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sx_xunlock(&proctree_lock);
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error = msleep(q, &q->p_mtx, PWAIT | PCATCH, "wait", 0);
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PROC_UNLOCK(q);
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if (error) {
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mtx_unlock(&Giant);
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return (error);
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}
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if (error)
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return (error);
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goto loop;
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}
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@ -2409,10 +2409,8 @@ sigexit(td, sig)
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* (Log as LOG_INFO to appease those who don't want
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* these messages.)
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* XXX : Todo, as well as euid, write out ruid too
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* Note that coredump() drops proc lock.
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*/
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PROC_UNLOCK(p);
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if (!mtx_owned(&Giant))
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mtx_lock(&Giant);
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if (coredump(td) == 0)
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sig |= WCOREFLAG;
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if (kern_logsigexit)
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@ -2422,11 +2420,8 @@ sigexit(td, sig)
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td->td_ucred ? td->td_ucred->cr_uid : -1,
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sig &~ WCOREFLAG,
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sig & WCOREFLAG ? " (core dumped)" : "");
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} else {
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} else
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PROC_UNLOCK(p);
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if (!mtx_owned(&Giant))
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mtx_lock(&Giant);
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}
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exit1(td, W_EXITCODE(0, sig));
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/* NOTREACHED */
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}
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@ -2529,7 +2524,7 @@ coredump(struct thread *td)
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char *name; /* name of corefile */
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off_t limit;
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PROC_LOCK(p);
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PROC_LOCK_ASSERT(p, MA_OWNED);
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_STOPEVENT(p, S_CORE, 0);
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if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0) {
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@ -2550,16 +2545,21 @@ coredump(struct thread *td)
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if (limit == 0)
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return (EFBIG);
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mtx_lock(&Giant);
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restart:
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name = expand_name(p->p_comm, td->td_ucred->cr_uid, p->p_pid);
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if (name == NULL)
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if (name == NULL) {
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mtx_unlock(&Giant);
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return (EINVAL);
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}
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NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); /* XXXKSE */
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flags = O_CREAT | FWRITE | O_NOFOLLOW;
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error = vn_open(&nd, &flags, S_IRUSR | S_IWUSR, -1);
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free(name, M_TEMP);
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if (error)
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if (error) {
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mtx_unlock(&Giant);
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return (error);
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}
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NDFREE(&nd, NDF_ONLY_PNBUF);
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vp = nd.ni_vp;
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@ -2568,7 +2568,7 @@ coredump(struct thread *td)
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VOP_GETATTR(vp, &vattr, cred, td) || vattr.va_nlink != 1) {
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VOP_UNLOCK(vp, 0, td);
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error = EFAULT;
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goto out2;
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goto out;
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}
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VOP_UNLOCK(vp, 0, td);
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@ -2608,8 +2608,9 @@ coredump(struct thread *td)
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VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK);
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}
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vn_finished_write(mp);
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out2:
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out:
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error1 = vn_close(vp, FWRITE, cred, td);
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mtx_unlock(&Giant);
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if (error == 0)
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error = error1;
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return (error);
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