Date: Sun, 18 Jun 2017 17:20:23 +0800 From: Jia-Ju Bai <baijiaju1990@163.com> To: erj@freebsd.org, sbruno@FreeBSD.org Cc: freebsd-drivers@freebsd.org, freebsd-net@freebsd.org, Jia-Ju Bai <baijiaju1990@163.com> Subject: [BUG 220033][PATCH] if_ixgb: Fix a possible sleep-under-mutex bug in ixge_get_buf Message-ID: <20170618092023.40369-1-baijiaju1990@163.com>
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The ixgb driver may sleep under a mutex, and the function call path is:
ixgb_init [acquire the mutex]
ixgb_init_locked
ixgb_setup_receive_structures
ixgb_allocate_receive_structures
ixgb_get_buf
bus_dmamap_load(BUS_DMA_WAITOK) --> may sleep
The possible fix of these bugs 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/ixgb/if_ixgb.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/sys/dev/ixgb/if_ixgb.c b/sys/dev/ixgb/if_ixgb.c
index 430c13c72d1..e6d02dd172e 100644
--- a/sys/dev/ixgb/if_ixgb.c
+++ b/sys/dev/ixgb/if_ixgb.c
@@ -1811,7 +1811,7 @@ ixgb_get_buf(int i, struct adapter * adapter,
*/
error = bus_dmamap_load(adapter->rxtag, rx_buffer->map,
mtod(mp, void *), mp->m_len,
- ixgb_dmamap_cb, &paddr, 0);
+ ixgb_dmamap_cb, &paddr, BUS_DMA_NOWAIT);
if (error) {
m_free(mp);
return (error);
--
2.13.0
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