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x86emul: correct 64-bit mode repeated string insn handling with zero count
When a 32-bit address override is in effect these zero-extend all registers which would also get updated in case of non-zero repeat count. Signed-off-by: Jan Beulich <jbeulich@suse.com> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
This commit is contained in:
Jan Beulich committed
1 parent
847464b5d9
commit
79e996a89f
1 file changed
+25
-14
@@ -917,15 +917,24 @@ static inline void put_loop_count(
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regs->ecx = ad_bytes == 4 ? (uint32_t)count : count;
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}
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#define get_rep_prefix() ({ \
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#define get_rep_prefix(using_si, using_di) ({ \
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unsigned long max_reps = 1; \
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if ( rep_prefix() ) \
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max_reps = get_loop_count(&_regs, ad_bytes); \
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if ( max_reps == 0 ) \
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{ \
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/* Skip the instruction if no repetitions are required. */ \
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dst.type = OP_NONE; \
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goto writeback; \
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/* \
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* Skip the instruction if no repetitions are required, but \
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* zero extend involved registers first when using 32-bit \
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* addressing in 64-bit mode. \
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*/ \
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if ( mode_64bit() && ad_bytes == 4 ) \
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{ \
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_regs.ecx = 0; \
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if ( using_si ) _regs.esi = (uint32_t)_regs.esi; \
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if ( using_di ) _regs.edi = (uint32_t)_regs.edi; \
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} \
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goto no_writeback; \
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} \
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max_reps; \
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})
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@@ -2911,7 +2920,7 @@ x86_emulate(
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goto imul;
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case 0x6c ... 0x6d: /* ins %dx,%es:%edi */ {
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unsigned long nr_reps = get_rep_prefix();
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unsigned long nr_reps = get_rep_prefix(false, true);
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unsigned int port = (uint16_t)_regs.edx;
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dst.bytes = !(b & 1) ? 1 : (op_bytes == 8) ? 4 : op_bytes;
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dst.mem.seg = x86_seg_es;
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@@ -2941,7 +2950,7 @@ x86_emulate(
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}
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case 0x6e ... 0x6f: /* outs %esi,%dx */ {
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unsigned long nr_reps = get_rep_prefix();
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unsigned long nr_reps = get_rep_prefix(true, false);
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unsigned int port = (uint16_t)_regs.edx;
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dst.bytes = !(b & 1) ? 1 : (op_bytes == 8) ? 4 : op_bytes;
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ea.mem.off = truncate_ea_and_reps(_regs.esi, nr_reps, dst.bytes);
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@@ -3182,7 +3191,8 @@ x86_emulate(
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break;
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case 0xa4 ... 0xa5: /* movs */ {
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unsigned long nr_reps = get_rep_prefix();
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unsigned long nr_reps = get_rep_prefix(true, true);
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dst.bytes = (d & ByteOp) ? 1 : op_bytes;
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dst.mem.seg = x86_seg_es;
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dst.mem.off = truncate_ea_and_reps(_regs.edi, nr_reps, dst.bytes);
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@@ -3215,7 +3225,8 @@ x86_emulate(
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case 0xa6 ... 0xa7: /* cmps */ {
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unsigned long next_eip = _regs.eip;
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get_rep_prefix();
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get_rep_prefix(true, true);
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src.bytes = dst.bytes = (d & ByteOp) ? 1 : op_bytes;
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if ( (rc = read_ulong(ea.mem.seg, truncate_ea(_regs.esi),
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&dst.val, dst.bytes, ctxt, ops)) ||
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@@ -3236,7 +3247,8 @@ x86_emulate(
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}
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case 0xaa ... 0xab: /* stos */ {
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unsigned long nr_reps = get_rep_prefix();
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unsigned long nr_reps = get_rep_prefix(false, true);
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dst.bytes = (d & ByteOp) ? 1 : op_bytes;
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dst.mem.seg = x86_seg_es;
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dst.mem.off = truncate_ea(_regs.edi);
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@@ -3258,8 +3270,8 @@ x86_emulate(
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break;
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}
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case 0xac ... 0xad: /* lods */ {
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/* unsigned long max_reps = */get_rep_prefix();
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case 0xac ... 0xad: /* lods */
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get_rep_prefix(true, false);
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dst.type = OP_REG;
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dst.bytes = (d & ByteOp) ? 1 : op_bytes;
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dst.reg = (unsigned long *)&_regs.eax;
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@@ -3270,11 +3282,11 @@ x86_emulate(
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_regs.esi, (_regs.eflags & EFLG_DF) ? -dst.bytes : dst.bytes);
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put_rep_prefix(1);
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break;
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}
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case 0xae ... 0xaf: /* scas */ {
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unsigned long next_eip = _regs.eip;
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get_rep_prefix();
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get_rep_prefix(false, true);
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src.bytes = dst.bytes = (d & ByteOp) ? 1 : op_bytes;
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dst.val = _regs.eax;
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if ( (rc = read_ulong(x86_seg_es, truncate_ea(_regs.edi),
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@@ -5397,7 +5409,6 @@ x86_emulate(
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goto cannot_emulate;
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}
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writeback:
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switch ( dst.type )
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{
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case OP_REG:
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