From 06f74c5cb868cfd37af3e680d29784c217700bdf Mon Sep 17 00:00:00 2001 From: "H.J. Lu" Date: Thu, 2 May 2019 10:46:55 -0700 Subject: [PATCH] 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. --- gas/ChangeLog | 9 +++++++++ gas/config/tc-i386.c | 20 +++++++++++++------- gas/testsuite/gas/i386/jump16.d | 5 +++++ gas/testsuite/gas/i386/jump16.e | 3 +++ gas/testsuite/gas/i386/jump16.s | 16 ++++++++++++++++ 5 files changed, 46 insertions(+), 7 deletions(-) create mode 100644 gas/testsuite/gas/i386/jump16.e diff --git a/gas/ChangeLog b/gas/ChangeLog index 2dd2cf38a46..8a82fdecbe6 100644 --- a/gas/ChangeLog +++ b/gas/ChangeLog @@ -1,3 +1,12 @@ +2019-05-02 H.J. Lu + + 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 * config/tc-aarch64.c (parse_operands): Add case for diff --git a/gas/config/tc-i386.c b/gas/config/tc-i386.c index 032b1d30811..7159432f133 100644 --- a/gas/config/tc-i386.c +++ b/gas/config/tc-i386.c @@ -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 diff --git a/gas/testsuite/gas/i386/jump16.d b/gas/testsuite/gas/i386/jump16.d index 7a1dc7661ee..c883eba0e85 100644 --- a/gas/testsuite/gas/i386/jump16.d +++ b/gas/testsuite/gas/i386/jump16.d @@ -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 diff --git a/gas/testsuite/gas/i386/jump16.e b/gas/testsuite/gas/i386/jump16.e new file mode 100644 index 00000000000..2ad7ea056b6 --- /dev/null +++ b/gas/testsuite/gas/i386/jump16.e @@ -0,0 +1,3 @@ +.*: Assembler messages: +.*:77: Warning: generating 16-bit `iret' for .code16gcc directive +.*:88: Warning: generating 16-bit `iret' for .code16gcc directive diff --git a/gas/testsuite/gas/i386/jump16.s b/gas/testsuite/gas/i386/jump16.s index aff56657201..fb9e830c52b 100644 --- a/gas/testsuite/gas/i386/jump16.s +++ b/gas/testsuite/gas/i386/jump16.s @@ -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 -- 2.30.2