[PATCH 2/2] x86/math-emu: Remove define layer for undocumented opcodes

From: Denys Vlasenko
Date: Wed Sep 16 2015 - 15:48:52 EST


No code changes.

Signed-off-by: Denys Vlasenko <dvlasenk@xxxxxxxxxx>
CC: Ingo Molnar <mingo@xxxxxxxxxx>
CC: Borislav Petkov <bp@xxxxxxxxx>
CC: "H. Peter Anvin" <hpa@xxxxxxxxx>
CC: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
CC: Kees Cook <keescook@xxxxxxxxxxxx>
CC: x86@xxxxxxxxxx
CC: linux-kernel@xxxxxxxxxxxxxxx
---
arch/x86/math-emu/fpu_entry.c | 29 +++++++++--------------------
1 file changed, 9 insertions(+), 20 deletions(-)

diff --git a/arch/x86/math-emu/fpu_entry.c b/arch/x86/math-emu/fpu_entry.c
index 77c6505..0e86006 100644
--- a/arch/x86/math-emu/fpu_entry.c
+++ b/arch/x86/math-emu/fpu_entry.c
@@ -40,34 +40,23 @@

#define __BAD__ FPU_illegal /* Illegal on an 80486, causes SIGILL */

-/* WARNING: These codes are not all documented by Intel in their 80486 manual
- and may not work on FPU clones or later Intel FPUs. */
-
-/* Changes to support the un-documented instructions provided by Linus Torvalds. */
-
-#define _d9_d8_ fstp_i /* unofficial code (19) */
-#define _dc_d0_ fcom_st /* unofficial code (14) */
-#define _dc_d8_ fcompst /* unofficial code (1c) */
-#define _dd_c8_ fxch_i /* unofficial code (0d) */
-#define _de_d0_ fcompst /* unofficial code (16) */
-#define _df_c0_ ffreep /* unofficial code (07) ffree + pop */
-#define _df_c8_ fxch_i /* unofficial code (0f) */
-#define _df_d0_ fstp_i /* unofficial code (17) */
-#define _df_d8_ fstp_i /* unofficial code (1f) */
-
/* fcmovCC and f(u)comi(p) are enabled if CPUID(1).EDX(15) "cmov" is set */

+/* WARNING: "u" entries are not documented by Intel in their 80486 manual
+ and may not work on FPU clones or later Intel FPUs.
+ Changes to support the un-documented instructions provided by Linus Torvalds. */
+
static FUNC const st_instr_table[64] = {
/* Opcode: d8 d9 da db */
/* dc dd de df */
/* c0..7 */ fadd__, fld_i_, fcmovb, fcmovnb,
-/* c0..7 */ fadd_i, ffree_, faddp_, _df_c0_,
+/* c0..7 */ fadd_i, ffree_, faddp_, ffreep,/*u*/
/* c8..f */ fmul__, fxch_i, fcmove, fcmovne,
-/* c8..f */ fmul_i, _dd_c8_, fmulp_, _df_c8_,
+/* c8..f */ fmul_i, fxch_i,/*u*/ fmulp_, fxch_i,/*u*/
/* d0..7 */ fcom_st, fp_nop, fcmovbe, fcmovnbe,
-/* d0..7 */ _dc_d0_, fst_i_, _de_d0_, _df_d0_,
-/* d8..f */ fcompst, _d9_d8_, fcmovu, fcmovnu,
-/* d8..f */ _dc_d8_, fstp_i, fcompp, _df_d8_,
+/* d0..7 */ fcom_st,/*u*/ fst_i_, fcompst,/*u*/ fstp_i,/*u*/
+/* d8..f */ fcompst, fstp_i,/*u*/ fcmovu, fcmovnu,
+/* d8..f */ fcompst,/*u*/ fstp_i, fcompp, fstp_i,/*u*/
/* e0..7 */ fsub__, FPU_etc, __BAD__, finit_,
/* e0..7 */ fsubri, fucom_, fsubrp, fstsw_,
/* e8..f */ fsubr_, fconst, fucompp, fucomi_,
--
1.8.1.4

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