Created attachment 10032 [details] Test case The AArch64 system registers dbgdtrrx_el0 and dbgdtrtx_el0 use the same encoding, but the former is only used for MRS instructions and the latter for MSR. Assembling the following code: .text msr dbgdtrtx_el0, x3 mrs x3, dbgdtrrx_el0 And then disassembling with objdump gives the incorrect register name for the MSR 0000000000000000 <.text>: 0: d5130503 msr dbgdtrrx_el0, x3 4: d5330503 mrs x3, dbgdtrrx_el0 The resulting binary is, of course, fine, but the disassembly output is off for the MSR.
Created attachment 10033 [details] Pre-assembled object file
The master branch has been updated by Tamar Christina <tnfchris@sourceware.org>: https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=561a72d4ddf825ffaf8e88551e9bd6707cd6c59f commit 561a72d4ddf825ffaf8e88551e9bd6707cd6c59f Author: Tamar Christina <tamar.christina@arm.com> Date: Tue May 15 16:11:42 2018 +0100 Modify AArch64 Assembly and disassembly functions to be able to fail and report why. This patch if the first patch in a series to add the ability to add constraints to system registers that an instruction must adhere to in order for the register to be usable with that instruction. These constraints can also be used to disambiguate between registers with the same encoding during disassembly. This patch adds a new flags entry in the sysreg structures and ensures it is filled in and read out during assembly/disassembly. It also adds the ability for the assemble and disassemble functions to be able to gracefully fail and re-use the existing error reporting infrastructure. The return type of these functions are changed to a boolean to denote success or failure and the error structure is passed around to them. This requires aarch64-gen changes so a lot of the changes here are just mechanical. gas/ PR binutils/21446 * config/tc-aarch64.c (parse_sys_reg): Return register flags. (parse_operands): Fill in register flags. gdb/ PR binutils/21446 * aarch64-tdep.c (aarch64_analyze_prologue, aarch64_software_single_step, aarch64_displaced_step_copy_insn): Indicate not interested in errors. include/ PR binutils/21446 * opcode/aarch64.h (aarch64_opnd_info): Change sysreg to struct. (aarch64_decode_insn): Accept error struct. opcodes/ PR binutils/21446 * aarch64-asm.h (aarch64_insert_operand, aarch64_##x): Return boolean and take error struct. * aarch64-asm.c (aarch64_ext_regno, aarch64_ins_reglane, aarch64_ins_reglist, aarch64_ins_ldst_reglist, aarch64_ins_ldst_reglist_r, aarch64_ins_ldst_elemlist, aarch64_ins_advsimd_imm_shift, aarch64_ins_imm, aarch64_ins_imm_half, aarch64_ins_advsimd_imm_modified, aarch64_ins_fpimm, aarch64_ins_imm_rotate1, aarch64_ins_imm_rotate2, aarch64_ins_fbits, aarch64_ins_aimm, aarch64_ins_limm_1, aarch64_ins_limm, aarch64_ins_inv_limm, aarch64_ins_ft, aarch64_ins_addr_simple, aarch64_ins_addr_regoff, aarch64_ins_addr_offset, aarch64_ins_addr_simm, aarch64_ins_addr_simm10, aarch64_ins_addr_uimm12, aarch64_ins_simd_addr_post, aarch64_ins_cond, aarch64_ins_sysreg, aarch64_ins_pstatefield, aarch64_ins_sysins_op, aarch64_ins_barrier, aarch64_ins_prfop, aarch64_ins_hint, aarch64_ins_reg_extended, aarch64_ins_reg_shifted, aarch64_ins_sve_addr_ri_s4xvl, aarch64_ins_sve_addr_ri_s6xvl, aarch64_ins_sve_addr_ri_s9xvl, aarch64_ins_sve_addr_ri_s4, aarch64_ins_sve_addr_ri_u6, aarch64_ins_sve_addr_rr_lsl, aarch64_ins_sve_addr_rz_xtw, aarch64_ins_sve_addr_zi_u5, aarch64_ext_sve_addr_zz, aarch64_ins_sve_addr_zz_lsl, aarch64_ins_sve_addr_zz_sxtw, aarch64_ins_sve_addr_zz_uxtw, aarch64_ins_sve_aimm, aarch64_ins_sve_asimm, aarch64_ins_sve_index, aarch64_ins_sve_limm_mov, aarch64_ins_sve_quad_index, aarch64_ins_sve_reglist, aarch64_ins_sve_scale, aarch64_ins_sve_shlimm, aarch64_ins_sve_shrimm, aarch64_ins_sve_float_half_one, aarch64_ins_sve_float_half_two, aarch64_ins_sve_float_zero_one, aarch64_opcode_encode): Likewise. * aarch64-dis.h (aarch64_extract_operand, aarch64_##x): Likewise. * aarch64-dis.c (aarch64_ext_regno, aarch64_ext_reglane, aarch64_ext_reglist, aarch64_ext_ldst_reglist, aarch64_ext_ldst_reglist_r, aarch64_ext_ldst_elemlist, aarch64_ext_advsimd_imm_shift, aarch64_ext_imm, aarch64_ext_imm_half, aarch64_ext_advsimd_imm_modified, aarch64_ext_fpimm, aarch64_ext_imm_rotate1, aarch64_ext_imm_rotate2, aarch64_ext_fbits, aarch64_ext_aimm, aarch64_ext_limm_1, aarch64_ext_limm, decode_limm, aarch64_ext_inv_limm, aarch64_ext_ft, aarch64_ext_addr_simple, aarch64_ext_addr_regoff, aarch64_ext_addr_offset, aarch64_ext_addr_simm, aarch64_ext_addr_simm10, aarch64_ext_addr_uimm12, aarch64_ext_simd_addr_post, aarch64_ext_cond, aarch64_ext_sysreg, aarch64_ext_pstatefield, aarch64_ext_sysins_op, aarch64_ext_barrier, aarch64_ext_prfop, aarch64_ext_hint, aarch64_ext_reg_extended, aarch64_ext_reg_shifted, aarch64_ext_sve_addr_ri_s4xvl, aarch64_ext_sve_addr_ri_s6xvl, aarch64_ext_sve_addr_ri_s9xvl, aarch64_ext_sve_addr_ri_s4, aarch64_ext_sve_addr_ri_u6, aarch64_ext_sve_addr_rr_lsl, aarch64_ext_sve_addr_rz_xtw, aarch64_ext_sve_addr_zi_u5, aarch64_ext_sve_addr_zz, aarch64_ext_sve_addr_zz_lsl, aarch64_ext_sve_addr_zz_sxtw, aarch64_ext_sve_addr_zz_uxtw, aarch64_ext_sve_aimm, aarch64_ext_sve_asimm, aarch64_ext_sve_index, aarch64_ext_sve_limm_mov, aarch64_ext_sve_quad_index, aarch64_ext_sve_reglist, aarch64_ext_sve_scale, aarch64_ext_sve_shlimm, aarch64_ext_sve_shrimm, aarch64_ext_sve_float_half_one, aarch64_ext_sve_float_half_two, aarch64_ext_sve_float_zero_one, aarch64_opcode_decode): Likewise. (determine_disassembling_preference, aarch64_decode_insn, print_insn_aarch64_word, print_insn_data): Take errors struct. (print_insn_aarch64): Use errors. * aarch64-asm-2.c: Regenerate. * aarch64-dis-2.c: Regenerate. * aarch64-gen.c (print_operand_inserter): Use errors and change type to boolean in aarch64_insert_operan. (print_operand_extractor): Likewise. * aarch64-opc.c (aarch64_print_operand): Use sysreg struct.
The master branch has been updated by Tamar Christina <tnfchris@sourceware.org>: https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=7d02540ab73206249779ced77a6abe0be156442e commit 7d02540ab73206249779ced77a6abe0be156442e Author: Tamar Christina <tamar.christina@arm.com> Date: Tue May 15 16:34:54 2018 +0100 Allow non-fatal errors to be emitted and for disassembly notes be placed on AArch64 This patch adds a new platform option "notes" that can be used to indicate if disassembly notes should be placed in the disassembly as comments. These notes can contain information about a failing constraint such as reading from a write-only register. The disassembly will not be blocked because of this but -M notes will emit a comment saying that the operation is not allowed. For assembly this patch adds a new non-fatal status for errors. This is essentially a warning. The reason for not creating an actual warning type is that this causes the interaction between the ordering of warnings and errors to be problematic. Currently the error buffer is almost always filled because of the way operands are matched during assembly. An earlier template may have put an error there that would only be displayed if no other template matches or generates a higher priority error. But by definition a warning is lower priority than a warning, so the error (which is incorrect if another template matched) will supersede the warning. By treating warnings as errors and only later relaxing the severity this relationship keeps working and the existing reporting infrastructure can be re-used. binutils/ PR binutils/21446 * doc/binutils.texi (-M): Document AArch64 options. * NEWS: Document notes and warnings. gas/ PR binutils/21446 * config/tc-aarch64.c (print_operands): Indicate no notes. (output_operand_error_record): Support non-fatal errors. (output_operand_error_report, warn_unpredictable_ldst, md_assemble): Likewise. include/ PR binutils/21446 * opcode/aarch64.h (aarch64_operand_error): Add non_fatal. (aarch64_print_operand): Support notes. opcodes/ PR binutils/21446 * aarch64-dis.c (no_notes: New. (parse_aarch64_dis_option): Support notes. (aarch64_decode_insn, print_operands): Likewise. (print_aarch64_disassembler_options): Document notes. * aarch64-opc.c (aarch64_print_operand): Support notes.
The master branch has been updated by Tamar Christina <tnfchris@sourceware.org>: https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=f9830ec1655e7cc2aa88c9c34a20503978d9dc88 commit f9830ec1655e7cc2aa88c9c34a20503978d9dc88 Author: Tamar Christina <tamar.christina@arm.com> Date: Tue May 15 16:37:20 2018 +0100 Implement Read/Write constraints on system registers on AArch64 This patch adds constraints for read and write only system registers with the msr and mrs instructions. The code will treat having both flags set and none set as the same. These flags add constraints that must be matched up. e.g. a system register with a READ only flag set, can only be used with mrs. If The constraint fails a warning is emitted. Examples of the warnings generated: test.s: Assembler messages: test.s:5: Warning: specified register cannot be written to at operand 1 -- `msr dbgdtrrx_el0,x3' test.s:7: Warning: specified register cannot be read from at operand 2 -- `mrs x3,dbgdtrtx_el0' test.s:8: Warning: specified register cannot be written to at operand 1 -- `msr midr_el1,x3' and disassembly notes: 0000000000000000 <main>: 0: d5130503 msr dbgdtrtx_el0, x3 4: d5130503 msr dbgdtrtx_el0, x3 8: d5330503 mrs x3, dbgdtrrx_el0 c: d5330503 mrs x3, dbgdtrrx_el0 10: d5180003 msr midr_el1, x3 ; note: writing to a read-only register. Note that because dbgdtrrx_el0 and dbgdtrtx_el0 have the same encoding, during disassembly the constraints are use to disambiguate between the two. An exact constraint match is always prefered over partial ones if available. As always the warnings can be suppressed with -w and also be made errors using warnings as errors. binutils/ PR binutils/21446 * doc/binutils.texi (-M): Document AArch64 options. gas/ PR binutils/21446 * testsuite/gas/aarch64/illegal-sysreg-2.s: Fix pmbidr_el1 test. * testsuite/gas/aarch64/illegal-sysreg-2.l: Likewise. * testsuite/gas/aarch64/illegal-sysreg-2.d: Likewise. * testsuite/gas/aarch64/sysreg-diagnostic.s: New. * testsuite/gas/aarch64/sysreg-diagnostic.l: New. * testsuite/gas/aarch64/sysreg-diagnostic.d: New. include/ PR binutils/21446 * opcode/aarch64.h (F_SYS_READ, F_SYS_WRITE): New. opcodes/ PR binutils/21446 * aarch64-asm.c (opintl.h): Include. (aarch64_ins_sysreg): Enforce read/write constraints. * aarch64-dis.c (aarch64_ext_sysreg): Likewise. * aarch64-opc.h (F_DEPRECATED, F_ARCHEXT, F_HASXT): Moved here. (F_REG_READ, F_REG_WRITE): New. * aarch64-opc.c (aarch64_print_operand): Generate notes for AARCH64_OPND_SYSREG. (F_DEPRECATED, F_ARCHEXT, F_HASXT): Move to aarch64-opc.h. (aarch64_sys_regs): Add constraints to currentel, midr_el1, ctr_el0, mpidr_el1, revidr_el1, aidr_el1, dczid_el0, id_dfr0_el1, id_pfr0_el1, id_pfr1_el1, id_afr0_el1, id_mmfr0_el1, id_mmfr1_el1, id_mmfr2_el1, id_mmfr3_el1, id_mmfr4_el1, id_isar0_el1, id_isar1_el1, id_isar2_el1, id_isar3_el1, id_isar4_el1, id_isar5_el1, mvfr0_el1, mvfr1_el1, mvfr2_el1, ccsidr_el1, id_aa64pfr0_el1, id_aa64pfr1_el1, id_aa64dfr0_el1, id_aa64dfr1_el1, id_aa64isar0_el1, id_aa64isar1_el1, id_aa64mmfr0_el1, id_aa64mmfr1_el1, id_aa64mmfr2_el1, id_aa64afr0_el1, id_aa64afr0_el1, id_aa64afr1_el1, id_aa64zfr0_el1, clidr_el1, csselr_el1, vsesr_el2, erridr_el1, erxfr_el1, rvbar_el1, rvbar_el2, rvbar_el3, isr_el1, tpidrro_el0, cntfrq_el0, cntpct_el0, cntvct_el0, mdccsr_el0, dbgdtrrx_el0, dbgdtrtx_el0, osdtrrx_el1, osdtrtx_el1, mdrar_el1, oslar_el1, oslsr_el1, dbgauthstatus_el1, pmbidr_el1, pmsidr_el1, pmswinc_el0, pmceid0_el0, pmceid1_el0. * aarch64-tbl.h (aarch64_opcode_table): Add constraints to msr (F_SYS_WRITE), mrs (F_SYS_READ).
Issue is now fixed in master.
The master branch has been updated by Tamar Christina <tnfchris@sourceware.org>: https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=2a9b2c1abe29e1063240604d2464b8de9a46011f commit 2a9b2c1abe29e1063240604d2464b8de9a46011f Author: Tamar Christina <tamar.christina@arm.com> Date: Thu Jun 7 11:53:13 2018 +0100 Fix AArch64 unintialized variable which can cause diagnostic failures. This patch fixes an uninitialized memory issue that can under certain circumstances turn an error into a warning because non_fatal was not initialised in all cases. Verified using valgrind. gas/config/tc-aarch64.c PR binutils/21446 * tc-aarch64.c (record_operand_error, record_operand_error_with_data): Initialize non_fatal.