The driver may sleep under a mutex, and the code path is: tws_init_reqs [line 684: acquire the mutex] tws_init_reqs [line 685] bus_dmamap_create(BUS_DMA_WAITOK) [line 687] --> may sleep
The possible fix of this bug is to replace "BUS_DMA_WAITOK" in bus_dmamap_create with "BUS_DMA_NOWAIT". This bug is found by a static analysis tool written by myself, and it is checked by my review of the FreeBSD code. Signed-off-by: Jia-Ju Bai <[email protected]> --- sys/dev/tws/tws.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/sys/dev/tws/tws.c b/sys/dev/tws/tws.c index 480f6f95489..6d21a524f18 100644 --- a/sys/dev/tws/tws.c +++ b/sys/dev/tws/tws.c @@ -684,7 +684,8 @@ tws_init_reqs(struct tws_softc *sc, u_int32_t dma_mem_size) mtx_lock(&sc->q_lock); for ( i=0; i< tws_queue_depth; i++) { - if (bus_dmamap_create(sc->data_tag, 0, &sc->reqs[i].dma_map)) { + if (bus_dmamap_create(sc->data_tag, BUS_DMA_NOWAIT, + &sc->reqs[i].dma_map)) { /* log a ENOMEM failure msg here */ mtx_unlock(&sc->q_lock); return(FAILURE); -- 2.13.0 _______________________________________________ [email protected] mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-bugs To unsubscribe, send any mail to "[email protected]"
