erasure_code: check for size in gf_Xvect_mad_avx512_gfni

Length of data was not checked in implementation with AVX512+GFNI,
at the start of the gf_Xvect_mad_avx512_gfni functions, resulting
in buffer overflow if length was less than 64 bytes.

Signed-off-by: Pablo de Lara <[email protected]>

Author: pablodelara

erasure_code/gf_2vect_mad_avx512_gfni.asm

@@ -158,6 +158,8 @@ func(gf_2vect_mad_avx512_gfni)
 	mov	dest2, [dest1 + 8]	; reuse mul_array
 	mov	dest1, [dest1]
 
+        cmp     len, 64
+        jl      .len_lt_64
 .loop64:
         ENCODE_64B_2
 

erasure_code/gf_3vect_mad_avx512_gfni.asm

@@ -173,6 +173,8 @@ func(gf_3vect_mad_avx512_gfni)
 	mov	dest3, [dest1 + 2*8]		; reuse vec
 	mov	dest1, [dest1]
 
+        cmp     len, 64
+        jl      .len_lt_64
 .loop64:
         ENCODE_64B_3
 

erasure_code/gf_4vect_mad_avx512_gfni.asm

@@ -192,6 +192,8 @@ func(gf_4vect_mad_avx512_gfni)
 	mov	dest4, [dest1 + 3*8]		; reuse vec_i
 	mov	dest1, [dest1]
 
+        cmp     len, 64
+        jl      .len_lt_64
 .loop64:
         ENCODE_64B_4
 

erasure_code/gf_5vect_mad_avx512_gfni.asm

@@ -209,6 +209,8 @@ func(gf_5vect_mad_avx512_gfni)
 	mov	dest5, [dest1 + 4*8]		; reuse vec_i
 	mov	dest1, [dest1]
 
+        cmp     len, 64
+        jl      .len_lt_64
 .loop64:
         ENCODE_64B_5
 

erasure_code/gf_6vect_mad_avx512_gfni.asm

@@ -228,6 +228,8 @@ func(gf_6vect_mad_avx512_gfni)
 	mov	dest6, [dest1 + 5*8]		; reuse vec_i
 	mov	dest1, [dest1]
 
+        cmp     len, 64
+        jl      .len_lt_64
 .loop64:
         ENCODE_64B_6
 

erasure_code/gf_vect_mad_avx512_gfni.asm

@@ -144,6 +144,8 @@ func(gf_vect_mad_avx512_gfni)
 
         vbroadcastf32x2 xgft1, [vec_i + mul_array]
 
+        cmp     len, 64
+        jl      .len_lt_64
 .loop64:
         ENCODE_64B