net/ice/base: fix strict-aliasing with GCC

Code changes done for build issue as reported in Bug 817
error: dereferencing type-punned pointer will break strict-aliasing rules.
added union to avoid pointer dereferencing

The build issue has been reported with both gcc 4.8.5 (RHEL 7) and
gcc 5.4.0 (Ubuntu 16.04).

Bugzilla ID: 817
Fixes: 39925373a333 ("net/ice/base: add parser execution main loop")

Signed-off-by: Aman Deep Singh <aman.deep.singh@intel.com>
Tested-by: David Marchand <david.marchand@redhat.com>
Acked-by: Ferruh Yigit <ferruh.yigit@intel.com>

diff --git a/drivers/net/ice/base/ice_parser_rt.c b/drivers/net/ice/base/ice_parser_rt.c
index 7a44675..eb35ad0 100644 (file)
--- a/drivers/net/ice/base/ice_parser_rt.c
+++ b/drivers/net/ice/base/ice_parser_rt.c
@@ -187,21 +187,23 @@ static u32 _bit_rev_u32(u32 v, int len)
 
 static u32 _hv_bit_sel(struct ice_parser_rt *rt, int start, int len)
 {
-       u64 d64, msk;
-       u8 b[8];
+       u64 msk;
+       union {
+               u64 d64;
+               u8 b[8];
+       } bit_sel;
        int i;
 
        int offset = GPR_HB_IDX + start / 16;
 
-       ice_memcpy(b, &rt->gpr[offset], 8, ICE_NONDMA_TO_NONDMA);
+       ice_memcpy(bit_sel.b, &rt->gpr[offset], 8, ICE_NONDMA_TO_NONDMA);
 
        for (i = 0; i < 8; i++)
-               b[i] = _bit_rev_u8(b[i]);
+               bit_sel.b[i] = _bit_rev_u8(bit_sel.b[i]);
 
-       d64 = *(u64 *)&b[0];
        msk = (1ul << len) - 1;
 
-       return _bit_rev_u32((u32)((d64 >> (start % 16)) & msk), len);
+       return _bit_rev_u32((u32)((bit_sel.d64 >> (start % 16)) & msk), len);
 }
 
 static u32 _pk_build(struct ice_parser_rt *rt, struct ice_np_keybuilder *kb)
@@ -444,21 +446,23 @@ static void _po_update(struct ice_parser_rt *rt, struct ice_alu *alu)
 static u16 _reg_bit_sel(struct ice_parser_rt *rt, int reg_idx,
                        int start, int len)
 {
-       u32 d32, msk;
-       u8 b[4];
-       u8 v[4];
+       u32 msk;
+       union {
+               u32 d32;
+               u8 b[4];
+       } bit_sel;
 
-       ice_memcpy(b, &rt->gpr[reg_idx + start / 16], 4, ICE_NONDMA_TO_NONDMA);
+       ice_memcpy(bit_sel.b, &rt->gpr[reg_idx + start / 16], 4,
+                  ICE_NONDMA_TO_NONDMA);
 
-       v[0] = _bit_rev_u8(b[0]);
-       v[1] = _bit_rev_u8(b[1]);
-       v[2] = _bit_rev_u8(b[2]);
-       v[3] = _bit_rev_u8(b[3]);
+       bit_sel.b[0] = _bit_rev_u8(bit_sel.b[0]);
+       bit_sel.b[1] = _bit_rev_u8(bit_sel.b[1]);
+       bit_sel.b[2] = _bit_rev_u8(bit_sel.b[2]);
+       bit_sel.b[3] = _bit_rev_u8(bit_sel.b[3]);
 
-       d32 = *(u32 *)&v[0];
        msk = (1u << len) - 1;
 
-       return _bit_rev_u16((u16)((d32 >> (start % 16)) & msk), len);
+       return _bit_rev_u16((u16)((bit_sel.d32 >> (start % 16)) & msk), len);
 }
 
 static void _err_add(struct ice_parser_rt *rt, int idx, bool val)