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authorXi Wang <xi.wang@gmail.com>2012-11-16 23:40:03 +0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-01-17 20:50:44 +0400
commit3814b31a89b1fbb5c6f92c11c8371a2e4c97d2f1 (patch)
tree6d9e245958e29c1b91b6c5ff1cb970069679c7ee /drivers/scsi
parent8f735b2774f5e200a65c5fe9143fb431023a5267 (diff)
downloadlinux-3814b31a89b1fbb5c6f92c11c8371a2e4c97d2f1.tar.xz
SCSI: mvsas: fix undefined bit shift
commit beecadea1b8d67f591b13f7099559f32f3fd601d upstream. The macro bit(n) is defined as ((u32)1 << n), and thus it doesn't work with n >= 32, such as in mvs_94xx_assign_reg_set(): if (i >= 32) { mvi->sata_reg_set |= bit(i); ... } The shift ((u32)1 << n) with n >= 32 also leads to undefined behavior. The result varies depending on the architecture. This patch changes bit(n) to do a 64-bit shift. It also simplifies mv_ffc64() using __ffs64(), since invoking ffz() with ~0 is undefined. Signed-off-by: Xi Wang <xi.wang@gmail.com> Acked-by: Xiangliang Yu <yuxiangl@marvell.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/scsi')
-rw-r--r--drivers/scsi/mvsas/mv_94xx.h14
-rw-r--r--drivers/scsi/mvsas/mv_sas.h2
2 files changed, 3 insertions, 13 deletions
diff --git a/drivers/scsi/mvsas/mv_94xx.h b/drivers/scsi/mvsas/mv_94xx.h
index 8f7eb4f21140..487aa6f97412 100644
--- a/drivers/scsi/mvsas/mv_94xx.h
+++ b/drivers/scsi/mvsas/mv_94xx.h
@@ -258,21 +258,11 @@ enum sas_sata_phy_regs {
#define SPI_ADDR_VLD_94XX (1U << 1)
#define SPI_CTRL_SpiStart_94XX (1U << 0)
-#define mv_ffc(x) ffz(x)
-
static inline int
mv_ffc64(u64 v)
{
- int i;
- i = mv_ffc((u32)v);
- if (i >= 0)
- return i;
- i = mv_ffc((u32)(v>>32));
-
- if (i != 0)
- return 32 + i;
-
- return -1;
+ u64 x = ~v;
+ return x ? __ffs64(x) : -1;
}
#define r_reg_set_enable(i) \
diff --git a/drivers/scsi/mvsas/mv_sas.h b/drivers/scsi/mvsas/mv_sas.h
index c04a4f5b5972..da249553858c 100644
--- a/drivers/scsi/mvsas/mv_sas.h
+++ b/drivers/scsi/mvsas/mv_sas.h
@@ -69,7 +69,7 @@ extern struct kmem_cache *mvs_task_list_cache;
#define DEV_IS_EXPANDER(type) \
((type == EDGE_DEV) || (type == FANOUT_DEV))
-#define bit(n) ((u32)1 << n)
+#define bit(n) ((u64)1 << n)
#define for_each_phy(__lseq_mask, __mc, __lseq) \
for ((__mc) = (__lseq_mask), (__lseq) = 0; \