Messages in this thread Patch in this message | | | From | Serge Semin <> | Subject | [PATCH v4 03/15] NTB: Fix UB/bug in ntb_mw_get_align() | Date | Wed, 6 Dec 2017 17:31:54 +0300 |
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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> Reviewed-by: Logan Gunthorpe <logang@deltatee.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 21b1826a0953..181d16601dd9 100644 --- a/include/linux/ntb.h +++ b/include/linux/ntb.h @@ -767,7 +767,7 @@ 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
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