Date: Sun, 18 Jun 2017 17:46:01 +0800 From: Jia-Ju Bai <baijiaju1990@163.com> Cc: freebsd-drivers@freebsd.org, freebsd-scsi@freebsd.org, Jia-Ju Bai <baijiaju1990@163.com> Subject: [Bug 220095][PATCH] dpt_scsi: Fix a possible sleep-under-mutex bug in dpt_init Message-ID: <20170618094601.40636-1-baijiaju1990@163.com>
next in thread | raw e-mail | index | archive | help
The driver may sleep under a mutex, and the function call path is:
dpt_init [acquire the mutex]
dptallocsgmap
bus_dmamap_load(BUS_DMA_WAITOK) --> may sleep
The possible fix of this bug is to set the last parameter in
bus_dmamap_load to "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 <baijiaju1990@163.com>
---
sys/dev/dpt/dpt_scsi.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/sys/dev/dpt/dpt_scsi.c b/sys/dev/dpt/dpt_scsi.c
index 541b58665cf..f39ebfba2a7 100644
--- a/sys/dev/dpt/dpt_scsi.c
+++ b/sys/dev/dpt/dpt_scsi.c
@@ -300,7 +300,7 @@ dptallocsgmap(struct dpt_softc *dpt)
(void)bus_dmamap_load(dpt->sg_dmat, sg_map->sg_dmamap, sg_map->sg_vaddr,
PAGE_SIZE, dptmapmem, &sg_map->sg_physaddr,
- /*flags*/0);
+ /*flags*/BUS_DMA_NOWAIT);
SLIST_INSERT_HEAD(&dpt->sg_maps, sg_map, links);
--
2.13.0
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20170618094601.40636-1-baijiaju1990>