diff options
author | ed <ed@FreeBSD.org> | 2009-04-25 10:05:55 +0000 |
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committer | ed <ed@FreeBSD.org> | 2009-04-25 10:05:55 +0000 |
commit | b8d7cb19636eb37c6cbc16a9e6d44a68265e7138 (patch) | |
tree | 3cb0dc4398f6ff8a3f7bbff483ff279c4332724b /sys/kern/tty_pts.c | |
parent | 4ffa3051a8799989b43481594165c440e60f74a6 (diff) | |
download | FreeBSD-src-b8d7cb19636eb37c6cbc16a9e6d44a68265e7138.zip FreeBSD-src-b8d7cb19636eb37c6cbc16a9e6d44a68265e7138.tar.gz |
Turn MAXPTSDEVS into a sysctl tunable.
This allows users to increase the maximum amount of pseudo-terminals
without changing any source code. Users must increase UT_LINESIZE before
attempting to increase kern.pts_maxdev.
Diffstat (limited to 'sys/kern/tty_pts.c')
-rw-r--r-- | sys/kern/tty_pts.c | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/sys/kern/tty_pts.c b/sys/kern/tty_pts.c index 74ab185..67704b8 100644 --- a/sys/kern/tty_pts.c +++ b/sys/kern/tty_pts.c @@ -50,6 +50,7 @@ __FBSDID("$FreeBSD$"); #include <sys/filedesc.h> #include <sys/filio.h> #include <sys/kernel.h> +#include <sys/limits.h> #include <sys/malloc.h> #include <sys/poll.h> #include <sys/proc.h> @@ -58,6 +59,7 @@ __FBSDID("$FreeBSD$"); #include <sys/stat.h> #include <sys/syscall.h> #include <sys/syscallsubr.h> +#include <sys/sysctl.h> #include <sys/sysent.h> #include <sys/sysproto.h> #include <sys/systm.h> @@ -66,8 +68,16 @@ __FBSDID("$FreeBSD$"); #include <machine/stdarg.h> +/* + * Our utmp(5) format is limited to 8-byte TTY line names. This means + * we can at most allocate 1000 pseudo-terminals ("pts/999"). Allow + * users to increase this number, assuming they have manually increased + * UT_LINESIZE. + */ static struct unrhdr *pts_pool; -#define MAXPTSDEVS 999 +static unsigned int pts_maxdev = 999; +SYSCTL_UINT(_kern, OID_AUTO, pts_maxdev, CTLFLAG_RW, &pts_maxdev, 0, + "Maximum amount of pts(4) pseudo-terminals"); static MALLOC_DEFINE(M_PTS, "pts", "pseudo tty device"); @@ -716,6 +726,11 @@ pts_alloc(int fflags, struct thread *td, struct file *fp) chgptscnt(uid, -1, 0); return (EAGAIN); } + if (unit > pts_maxdev) { + free_unr(pts_pool, unit); + chgptscnt(uid, -1, 0); + return (EAGAIN); + } /* Allocate TTY and softc. */ psc = malloc(sizeof(struct pts_softc), M_PTS, M_WAITOK|M_ZERO); @@ -829,7 +844,7 @@ static void pts_init(void *unused) { - pts_pool = new_unrhdr(0, MAXPTSDEVS, NULL); + pts_pool = new_unrhdr(0, INT_MAX, NULL); #if defined(PTS_COMPAT) || defined(PTS_LINUX) make_dev(&ptmx_cdevsw, 0, UID_ROOT, GID_WHEEL, 0666, "ptmx"); #endif /* PTS_COMPAT || PTS_LINUX */ |