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For reducing memory usage of attribute table, x86 instruction decoder puts "Group" attribute only on "no-last-prefix" attribute table (same as vex_p == 0 case). Thus, the decoder should look no-last-prefix table first, and then only if it is not a group, move on to "with-last-prefix" table (vex_p != 0). However, current implementation, inat_get_avx_attribute() looks with-last-prefix directly. So, when decoding a grouped AVX instruction, the decoder fails to find correct group because there is no "Group" attribute on the table. This ends up with the mis-decoding of instructions, as Ingo reported in http://thread.gmane.org/gmane.linux.kernel/1214103 This patch fixes it to check no-last-prefix table first even if that is an AVX instruction, and get an attribute from "with last-prefix" table only if that is not a group. Reported-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: yrl.pp-manager.tt@hitachi.com Link: http://lkml.kernel.org/r/20111205120539.15475.91428.stgit@cloud Signed-off-by: Ingo Molnar <mingo@elte.hu>
98 lines
2.7 KiB
C
98 lines
2.7 KiB
C
/*
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* x86 instruction attribute tables
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*
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* Written by Masami Hiramatsu <mhiramat@redhat.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*
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*/
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#include <asm/insn.h>
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/* Attribute tables are generated from opcode map */
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#include "inat-tables.c"
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/* Attribute search APIs */
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insn_attr_t inat_get_opcode_attribute(insn_byte_t opcode)
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{
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return inat_primary_table[opcode];
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}
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insn_attr_t inat_get_escape_attribute(insn_byte_t opcode, insn_byte_t last_pfx,
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insn_attr_t esc_attr)
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{
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const insn_attr_t *table;
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insn_attr_t lpfx_attr;
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int n, m = 0;
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n = inat_escape_id(esc_attr);
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if (last_pfx) {
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lpfx_attr = inat_get_opcode_attribute(last_pfx);
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m = inat_last_prefix_id(lpfx_attr);
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}
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table = inat_escape_tables[n][0];
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if (!table)
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return 0;
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if (inat_has_variant(table[opcode]) && m) {
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table = inat_escape_tables[n][m];
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if (!table)
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return 0;
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}
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return table[opcode];
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}
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insn_attr_t inat_get_group_attribute(insn_byte_t modrm, insn_byte_t last_pfx,
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insn_attr_t grp_attr)
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{
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const insn_attr_t *table;
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insn_attr_t lpfx_attr;
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int n, m = 0;
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n = inat_group_id(grp_attr);
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if (last_pfx) {
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lpfx_attr = inat_get_opcode_attribute(last_pfx);
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m = inat_last_prefix_id(lpfx_attr);
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}
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table = inat_group_tables[n][0];
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if (!table)
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return inat_group_common_attribute(grp_attr);
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if (inat_has_variant(table[X86_MODRM_REG(modrm)]) && m) {
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table = inat_group_tables[n][m];
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if (!table)
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return inat_group_common_attribute(grp_attr);
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}
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return table[X86_MODRM_REG(modrm)] |
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inat_group_common_attribute(grp_attr);
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}
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insn_attr_t inat_get_avx_attribute(insn_byte_t opcode, insn_byte_t vex_m,
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insn_byte_t vex_p)
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{
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const insn_attr_t *table;
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if (vex_m > X86_VEX_M_MAX || vex_p > INAT_LSTPFX_MAX)
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return 0;
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/* At first, this checks the master table */
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table = inat_avx_tables[vex_m][0];
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if (!table)
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return 0;
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if (!inat_is_group(table[opcode]) && vex_p) {
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/* If this is not a group, get attribute directly */
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table = inat_avx_tables[vex_m][vex_p];
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if (!table)
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return 0;
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}
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return table[opcode];
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}
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