d/freebsd-skq
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

- Reorganize osigstack() to do the copyin first, grab the proc lock once,

Browse Source 
do all the various sigstack dances, unlock the proc lock, and finally do
  the copyout.  This more closely resembles the behavior of
  kern_sigaltstack() and closes a small race.
- Remove Giant from osigstack as it is no longer needed.
This commit is contained in:
jhb 2003-04-23 18:50:25 +00:00
parent 2958cf621b
commit 89c52cff2e
1 changed files with 17 additions and 23 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

40
sys/kern/kern_sig.c
View File

@ -1157,33 +1157,27 @@ osigstack(td, uap)
register struct osigstack_args *uap;
{
struct proc *p = td->td_proc;
struct sigstack ss;
struct sigstack nss, oss;
int error = 0;
mtx_lock(&Giant);
if (uap->oss != NULL) {
PROC_LOCK(p);
ss.ss_sp = p->p_sigstk.ss_sp;
ss.ss_onstack = sigonstack(cpu_getstack(td));
PROC_UNLOCK(p);
error = copyout(&ss, uap->oss, sizeof(struct sigstack));
if (error)
goto done2;
}
if (uap->nss != NULL) {
if ((error = copyin(uap->nss, &ss, sizeof(ss))) != 0)
goto done2;
PROC_LOCK(p);
p->p_sigstk.ss_sp = ss.ss_sp;
p->p_sigstk.ss_size = 0;
p->p_sigstk.ss_flags |= ss.ss_onstack & SS_ONSTACK;
p->p_flag |= P_ALTSTACK;
PROC_UNLOCK(p);
error = copyin(uap->nss, &nss, sizeof(nss));
if (error)
return (error);
}
done2:
mtx_unlock(&Giant);
PROC_LOCK(p);
oss.ss_sp = p->p_sigstk.ss_sp;
oss.ss_onstack = sigonstack(cpu_getstack(td));
if (uap->nss != NULL) {
p->p_sigstk.ss_sp = nss.ss_sp;
p->p_sigstk.ss_size = 0;
p->p_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK;
p->p_flag |= P_ALTSTACK;
}
PROC_UNLOCK(p);
if (uap->oss != NULL)
error = copyout(&oss, uap->oss, sizeof(oss));
return (error);
}
#endif /* COMPAT_43 || COMPAT_SUNOS */