Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752364AbbHWQG4 (ORCPT ); Sun, 23 Aug 2015 12:06:56 -0400 Received: from mx1.redhat.com ([209.132.183.28]:42405 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751938AbbHWQGy (ORCPT ); Sun, 23 Aug 2015 12:06:54 -0400 From: Denys Vlasenko To: Ingo Molnar Cc: Denys Vlasenko , Borislav Petkov , "H. Peter Anvin" , Andy Lutomirski , Kees Cook , x86@kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] x86/math-emu: Add support for FISTTP insns Date: Sun, 23 Aug 2015 18:06:50 +0200 Message-Id: <1440346010-8098-1-git-send-email-dvlasenk@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4918 Lines: 147 Only compile-tested. Signed-off-by: Denys Vlasenko CC: Ingo Molnar CC: Borislav Petkov CC: "H. Peter Anvin" CC: Andy Lutomirski CC: Kees Cook CC: x86@kernel.org CC: linux-kernel@vger.kernel.org --- arch/x86/math-emu/load_store.c | 63 ++++++++++++++++++++++++++++++++++-------- 1 file changed, 51 insertions(+), 12 deletions(-) diff --git a/arch/x86/math-emu/load_store.c b/arch/x86/math-emu/load_store.c index 2931ff3..95228ff 100644 --- a/arch/x86/math-emu/load_store.c +++ b/arch/x86/math-emu/load_store.c @@ -33,11 +33,12 @@ #define pop_0() { FPU_settag0(TAG_Empty); top++; } +/* index is a 5-bit value: (3-bit FPU_modrm.reg field | opcode[2,1]) */ static u_char const type_table[32] = { - _PUSH_, _PUSH_, _PUSH_, _PUSH_, - _null_, _null_, _null_, _null_, - _REG0_, _REG0_, _REG0_, _REG0_, - _REG0_, _REG0_, _REG0_, _REG0_, + _PUSH_, _PUSH_, _PUSH_, _PUSH_, /* /0: d9:fld f32, db:fild m32, dd:fld f64, df:fild m16 */ + _null_, _REG0_, _REG0_, _REG0_, /* /1: d9:undef, db,dd,df:fisttp m32/64/16 */ + _REG0_, _REG0_, _REG0_, _REG0_, /* /2: d9:fst f32, db:fist m32, dd:fst f64, df:fist m16 */ + _REG0_, _REG0_, _REG0_, _REG0_, /* /3: d9:fstp f32, db:fistp m32, dd:fstp f64, df:fistp m16 */ _NONE_, _null_, _NONE_, _PUSH_, _NONE_, _PUSH_, _null_, _PUSH_, _NONE_, _null_, _NONE_, _REG0_, @@ -45,15 +46,19 @@ static u_char const type_table[32] = { }; u_char const data_sizes_16[32] = { - 4, 4, 8, 2, 0, 0, 0, 0, - 4, 4, 8, 2, 4, 4, 8, 2, + 4, 4, 8, 2, + 0, 4, 8, 2, /* /1: d9:undef, db,dd,df:fisttp */ + 4, 4, 8, 2, + 4, 4, 8, 2, 14, 0, 94, 10, 2, 10, 0, 8, 14, 0, 94, 10, 2, 10, 2, 8 }; static u_char const data_sizes_32[32] = { - 4, 4, 8, 2, 0, 0, 0, 0, - 4, 4, 8, 2, 4, 4, 8, 2, + 4, 4, 8, 2, + 0, 4, 8, 2, /* /1: d9:undef, db,dd,df:fisttp */ + 4, 4, 8, 2, + 4, 4, 8, 2, 28, 0, 108, 10, 2, 10, 0, 8, 28, 0, 108, 10, 2, 10, 2, 8 }; @@ -65,6 +70,7 @@ int FPU_load_store(u_char type, fpu_addr_modes addr_modes, FPU_REG *st0_ptr; u_char st0_tag = TAG_Empty; /* This is just to stop a gcc warning. */ u_char loaded_tag; + int sv_cw; st0_ptr = NULL; /* Initialized just to stop compiler warnings. */ @@ -111,7 +117,8 @@ int FPU_load_store(u_char type, fpu_addr_modes addr_modes, } switch (type) { - case 000: /* fld m32real */ + /* type is a 5-bit value: (3-bit FPU_modrm.reg field | opcode[2,1]) */ + case 000: /* fld m32real (d9 /0) */ clear_C1(); loaded_tag = FPU_load_single((float __user *)data_address, &loaded_data); @@ -123,13 +130,13 @@ int FPU_load_store(u_char type, fpu_addr_modes addr_modes, } FPU_copy_to_reg0(&loaded_data, loaded_tag); break; - case 001: /* fild m32int */ + case 001: /* fild m32int (db /0) */ clear_C1(); loaded_tag = FPU_load_int32((long __user *)data_address, &loaded_data); FPU_copy_to_reg0(&loaded_data, loaded_tag); break; - case 002: /* fld m64real */ + case 002: /* fld m64real (dd /0) */ clear_C1(); loaded_tag = FPU_load_double((double __user *)data_address, @@ -142,12 +149,44 @@ int FPU_load_store(u_char type, fpu_addr_modes addr_modes, } FPU_copy_to_reg0(&loaded_data, loaded_tag); break; - case 003: /* fild m16int */ + case 003: /* fild m16int (df /0) */ clear_C1(); loaded_tag = FPU_load_int16((short __user *)data_address, &loaded_data); FPU_copy_to_reg0(&loaded_data, loaded_tag); break; + /* case 004: undefined (d9 /1) */ + /* fisttp are enabled if CPUID(1).ECX(0) "sse3" is set */ + case 005: /* fisttp m32int (db /1) */ + clear_C1(); + sv_cw = control_word; + control_word |= RC_CHOP; + if (FPU_store_int32 + (st0_ptr, st0_tag, (long __user *)data_address)) + pop_0(); /* pop only if the number was actually stored + (see the 80486 manual p16-28) */ + control_word = sv_cw; + break; + case 006: /* fisttp m64int (dd /1) */ + clear_C1(); + sv_cw = control_word; + control_word |= RC_CHOP; + if (FPU_store_int64 + (st0_ptr, st0_tag, (long long __user *)data_address)) + pop_0(); /* pop only if the number was actually stored + (see the 80486 manual p16-28) */ + control_word = sv_cw; + break; + case 007: /* fisttp m16int (df /1) */ + clear_C1(); + sv_cw = control_word; + control_word |= RC_CHOP; + if (FPU_store_int16 + (st0_ptr, st0_tag, (short __user *)data_address)) + pop_0(); /* pop only if the number was actually stored + (see the 80486 manual p16-28) */ + control_word = sv_cw; + break; case 010: /* fst m32real */ clear_C1(); FPU_store_single(st0_ptr, st0_tag, -- 1.8.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/