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

fork: bump process count before checking for permission to cross the limit

Browse Source 
The limit is almost never reached. Do the check only on failure to see if
we can override it.

No change in user-visible behavior.

Sponsored by:	The FreeBSD Foundation
This commit is contained in:
mjg 2019-08-17 17:56:43 +00:00
parent a514630027
commit 29304171f5
1 changed files with 10 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

23
sys/kern/kern_fork.c
View File

@ -800,9 +800,10 @@ fork1(struct thread *td, struct fork_req *fr)
struct proc *p1, *newproc;
struct thread *td2;
struct vmspace *vm2;
struct ucred *cred;
struct file *fp_procdesc;
vm_ooffset_t mem_charged;
int error, nprocs_new, ok;
int error, nprocs_new;
static int curfail;
static struct timeval lastfail;
int flags, pages;
@ -973,21 +974,17 @@ fork1(struct thread *td, struct fork_req *fr)
/*
* Increment the count of procs running with this uid. Don't allow
* a nonprivileged user to exceed their current limit.
*
* XXXRW: Can we avoid privilege here if it's not needed?
*/
error = priv_check_cred(td->td_ucred, PRIV_PROC_LIMIT);
if (error == 0)
ok = chgproccnt(td->td_ucred->cr_ruidinfo, 1, 0);
else {
ok = chgproccnt(td->td_ucred->cr_ruidinfo, 1,
lim_cur(td, RLIMIT_NPROC));
}
if (ok) {
do_fork(td, fr, newproc, td2, vm2, fp_procdesc);
return (0);
cred = td->td_ucred;
if (!chgproccnt(cred->cr_ruidinfo, 1, lim_cur(td, RLIMIT_NPROC))) {
if (priv_check_cred(cred, PRIV_PROC_LIMIT) != 0)
goto fail0;
chgproccnt(cred->cr_ruidinfo, 1, 0);
}
do_fork(td, fr, newproc, td2, vm2, fp_procdesc);
return (0);
fail0:
error = EAGAIN;
sx_xunlock(&allproc_lock);
#ifdef MAC