i386: Issue a warning to IRET without suffix for .code16gcc

The .code16gcc directive to support 16-bit mode with 32-bit address.
For IRET without a suffix, generate 16-bit IRET with a warning to
return from an interrupt handler in 16-bit mode.

	PR gas/24485
	* config/tc-i386.c (process_suffix): Issue a warning to IRET
	without a suffix for .code16gcc.
	* testsuite/gas/i386/jump16.s: Add tests for iretX.
	* testsuite/gas/i386/jump16.d: Updated.
	* testsuite/gas/i386/jump16.e: New file.
This commit is contained in:
H.J. Lu
2019-05-02 10:46:55 -07:00
parent b8c05e85ef
commit 06f74c5cb8
5 changed files with 46 additions and 7 deletions

View File

@ -1,3 +1,12 @@
2019-05-02 H.J. Lu <hongjiu.lu@intel.com>
PR gas/24485
* config/tc-i386.c (process_suffix): Issue a warning to IRET
without a suffix for .code16gcc.
* testsuite/gas/i386/jump16.s: Add tests for iretX.
* testsuite/gas/i386/jump16.d: Updated.
* testsuite/gas/i386/jump16.e: New file.
2019-05-01 Sudakshina Das <sudi.das@arm.com>
* config/tc-aarch64.c (parse_operands): Add case for

View File

@ -6242,7 +6242,19 @@ process_suffix (void)
/* exclude fldenv/frstor/fsave/fstenv */
&& i.tm.opcode_modifier.no_ssuf)
{
i.suffix = stackop_size;
if (stackop_size == LONG_MNEM_SUFFIX
&& i.tm.base_opcode == 0xcf)
{
/* stackop_size is set to LONG_MNEM_SUFFIX for the
.code16gcc directive to support 16-bit mode with
32-bit address. For IRET without a suffix, generate
16-bit IRET (opcode 0xcf) to return from an interrupt
handler. */
i.suffix = WORD_MNEM_SUFFIX;
as_warn (_("generating 16-bit `iret' for .code16gcc directive"));
}
else
i.suffix = stackop_size;
}
else if (intel_syntax
&& !i.suffix
@ -6352,13 +6364,7 @@ process_suffix (void)
if (!add_prefix (ADDR_PREFIX_OPCODE))
return 0;
}
/* stackop_size is set to LONG_MNEM_SUFFIX for the .code16gcc
directive to support 16bit mode with 32-bit address. Since
IRET (opcode 0xcf) in 16bit mode returns from an interrupt
in 16bit mode, we shouldn't add DATA_PREFIX_OPCODE here. */
else if (i.suffix != QWORD_MNEM_SUFFIX
&& (stackop_size != LONG_MNEM_SUFFIX
|| i.tm.base_opcode != 0xcf)
&& !i.tm.opcode_modifier.ignoresize
&& !i.tm.opcode_modifier.floatmf
&& !i.tm.opcode_modifier.vex

View File

@ -1,5 +1,6 @@
#name: i386 jump16
#objdump: -drw -mi8086
#warning_output: jump16.e
.*: file format .*i386.*
@ -69,4 +70,8 @@ Disassembly of section .text:
[ ]*[a-f0-9]+: ea 00 00 90 90 ljmp \$0x9090,\$0x0 f2: (R_386_)?16 xxx
[ ]*[a-f0-9]+: cf iret
[ ]*[a-f0-9]+: cf iret
[ ]*[a-f0-9]+: 66 cf iretl
[ ]*[a-f0-9]+: cf iret
[ ]*[a-f0-9]+: cf iret
[ ]*[a-f0-9]+: 66 cf iretl
#pass

View File

@ -0,0 +1,3 @@
.*: Assembler messages:
.*:77: Warning: generating 16-bit `iret' for .code16gcc directive
.*:88: Warning: generating 16-bit `iret' for .code16gcc directive

View File

@ -72,8 +72,24 @@
jmp 0x9090,xxx
jmp 0x9090:xxx
.att_syntax
.code16gcc
iret
iretw
iretl
.code16
iret
iretw
iretl
.intel_syntax noprefix
.code16gcc
iret
iretw
iretd
.code16
iret
iretw
iretd