From: Serge Semin <fancer.lancer@gmail.com>
To: jdmason@kudzu.us, dave.jiang@intel.com, Allen.Hubbe@emc.com,
Shyam-sundar.S-k@amd.com, Xiangliang.Yu@amd.com
Cc: Sergey.Semin@t-platforms.ru, linux-ntb@googlegroups.com,
linux-kernel@vger.kernel.org,
Serge Semin <fancer.lancer@gmail.com>
Subject: [PATCH] NTB: Fix UB/bug in ntb_mw_get_align()
Date: Fri, 1 Dec 2017 00:39:41 +0300 [thread overview]
Message-ID: <20171130213941.21114-1-fancer.lancer@gmail.com> (raw)
Simple (1 << pidx) operation causes undefined behaviour when
pidx >= 32. It must be casted to u64 to match the actual return
value of ntb_link_is_up() method, so to have all the possible
peer indexes covered and to get rid of undefined behaviour.
Additionally there are special macros in "linux/bitops.h" to perform
the bit-set-shift operations, so it's recommended to have them used
for proper bit setting.
Signed-off-by: Serge Semin <fancer.lancer@gmail.com>
---
include/linux/ntb.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/linux/ntb.h b/include/linux/ntb.h
index c1646f2c6344..488e586fb76c 100644
--- a/include/linux/ntb.h
+++ b/include/linux/ntb.h
@@ -764,7 +764,7 @@ static inline int ntb_mw_get_align(struct ntb_dev *ntb, int pidx, int widx,
resource_size_t *size_align,
resource_size_t *size_max)
{
- if (!(ntb_link_is_up(ntb, NULL, NULL) & (1 << pidx)))
+ if (!(ntb_link_is_up(ntb, NULL, NULL) & BIT_ULL(pidx)))
return -ENOTCONN;
return ntb->ops->mw_get_align(ntb, pidx, widx, addr_align, size_align,
--
2.12.0
next reply other threads:[~2017-11-30 21:39 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-30 21:39 Serge Semin [this message]
2017-11-30 22:07 ` [PATCH] NTB: Fix UB/bug in ntb_mw_get_align() Logan Gunthorpe
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