diff options
Diffstat (limited to 'freebsd/sys/kern/sys_generic.c')
| -rw-r--r-- | freebsd/sys/kern/sys_generic.c | 89 |
1 files changed, 82 insertions, 7 deletions
diff --git a/freebsd/sys/kern/sys_generic.c b/freebsd/sys/kern/sys_generic.c index b0201d68..deda7afd 100644 --- a/freebsd/sys/kern/sys_generic.c +++ b/freebsd/sys/kern/sys_generic.c @@ -843,6 +843,54 @@ select(struct thread *td, struct select_args *uap) } #endif /* __rtems__ */ +/* + * In the unlikely case when user specified n greater then the last + * open file descriptor, check that no bits are set after the last + * valid fd. We must return EBADF if any is set. + * + * There are applications that rely on the behaviour. + * + * nd is fd_lastfile + 1. + */ +static int +select_check_badfd(fd_set *fd_in, int nd, int ndu, int abi_nfdbits) +{ + char *addr, *oaddr; + int b, i, res; + uint8_t bits; + + if (nd >= ndu || fd_in == NULL) + return (0); + + oaddr = NULL; + bits = 0; /* silence gcc */ + for (i = nd; i < ndu; i++) { + b = i / NBBY; +#if BYTE_ORDER == LITTLE_ENDIAN + addr = (char *)fd_in + b; +#else + addr = (char *)fd_in; + if (abi_nfdbits == NFDBITS) { + addr += rounddown(b, sizeof(fd_mask)) + + sizeof(fd_mask) - 1 - b % sizeof(fd_mask); + } else { + addr += rounddown(b, sizeof(uint32_t)) + + sizeof(uint32_t) - 1 - b % sizeof(uint32_t); + } +#endif + if (addr != oaddr) { + res = fubyte(addr); + if (res == -1) + return (EFAULT); + oaddr = addr; + bits = res; + } + if ((bits & (1 << (i % NBBY))) != 0) + return (EBADF); + } + return (0); +} + int kern_select(struct thread *td, int nd, fd_set *fd_in, fd_set *fd_ou, fd_set *fd_ex, struct timeval *tvp, int abi_nfdbits) @@ -857,20 +905,30 @@ kern_select(struct thread *td, int nd, fd_set *fd_in, fd_set *fd_ou, fd_mask s_selbits[howmany(2048, NFDBITS)]; fd_mask *ibits[3], *obits[3], *selbits, *sbp; struct timeval atv, rtv, ttv; - int error, timo; + int error, lf, ndu, timo; u_int nbufbytes, ncpbytes, ncpubytes, nfdbits; if (nd < 0) return (EINVAL); + ndu = nd; #ifndef __rtems__ - fdp = td->td_proc->p_fd; - if (nd > fdp->fd_lastfile + 1) - nd = fdp->fd_lastfile + 1; + lf = fdp->fd_lastfile; #else /* __rtems__ */ (void) fdp; - if (nd > rtems_libio_number_iops) - nd = rtems_libio_number_iops; + lf = rtems_libio_number_iops; #endif /* __rtems__ */ + if (nd > lf + 1) + nd = lf + 1; + + error = select_check_badfd(fd_in, nd, ndu, abi_nfdbits); + if (error != 0) + return (error); + error = select_check_badfd(fd_ou, nd, ndu, abi_nfdbits); + if (error != 0) + return (error); + error = select_check_badfd(fd_ex, nd, ndu, abi_nfdbits); + if (error != 0) + return (error); /* * Allocate just enough bits for the non-null fd_sets. Use the @@ -1204,7 +1262,7 @@ rtems_bsd_poll(td, uap) struct pollfd *bits; struct pollfd smallbits[32]; struct timeval atv, rtv, ttv; - int error = 0, timo; + int error, timo; u_int nfds; size_t ni; @@ -1549,6 +1607,23 @@ selfdfree(struct seltd *stp, struct selfd *sfp) uma_zfree(selfd_zone, sfp); } +/* Drain the waiters tied to all the selfd belonging the specified selinfo. */ +void +seldrain(sip) + struct selinfo *sip; +{ + + /* + * This feature is already provided by doselwakeup(), thus it is + * enough to go for it. + * Eventually, the context, should take care to avoid races + * between thread calling select()/poll() and file descriptor + * detaching, but, again, the races are just the same as + * selwakeup(). + */ + doselwakeup(sip, -1); +} + /* * Record a select request. */ |