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>
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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
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